ON 
CYANOSIS; 
OR, 
MORBUS CiERULEUS. 
BY MORETON STILLE, M.D.* 
Cyanosis, or Morbus Caeruleus, by either of which terms the disease we 
propose to treat of is sufficiently well designated, had not attracted, until of 
late years, much notice from medical writers. It is indeed true, that cases 
of the disease are to be found scattered through the periodical works of the 
last century, and that, as faithful portraits of its more striking features, they 
are unexceptionable; but we have to regret their imperfect description, in 
many instances, of structural alterations, and often the entire want of any 
account of these conditions. Had the value of these signs been always duly 
appreciated, the knowledge of the true pathology of the disease would not, 
perhaps, have been so long obscured, and the ingenuity expended in the 
support of fanciful hypotheses would have been more usefully employed in 
legitimate inferences from well ascertained facts. Several treatises on cyano- 
sis, and chiefly from the pens of the French and German writers, are now 
extant, and have been regarded as containing all that was known of its patho- 
logy. The doctrines advocated in them have received a general and tacit 
assent, but we think that they will be found to be the offspring of a too nar- 
row observation, and to embody speculative notions rather than sound prin- 
ciples. 
The first approach to a more correct mode of investigation was made by 
M. Gintrac, of Bordeaux, who, in 1814, wrote an inaugural thesis upon 
this subject. Ten years after its publication it was again issued, in a more 
complete form, M. G. having, in the mean time, much extended his re- 
searches, and somewhat modified his opinions. His essay contains the 
history of 53 cases of cyanosis, collected by him from various works, some 
of which were rare, and difficult of access. M. Louis, in 1823, published a 
* This paper was presented as an Inaugural Thesis to the Medical Faculty of the 
University of Pennsylvania, in January, 1844, and is now published in compliance with 
their unanimous request. 2 
Stille on Cyanosis. 
short treatise upon “The Free Communication between the Right and Left 
Cavities of the Heart,” and founded his views of the pathology of the dis- 
ease upon a consideration of eighteen cases. 
From these cases, and from others which we have ourselves collated, it is 
now proposed, as preliminary to the examination of some controverted points, 
to give a brief general description of cyanosis, and its more important struc- 
tural alterations, and while confining ourselves within the limits of well- 
attested facts, to avoid, for the moment, any assertion as to the relative 
frequency or value of either symptoms or lesions. 
The sense in which we shall use the word cyanosis, is that of a blue dis- 
coloration of the skin and mucous membranes referable to some organic 
lesion of the heart or its great vessels. To define the disease more strictly 
would be a transgression of the present limits of our pathological know- 
ledge, and however desirable the establishment of a positive and well sup- 
ported cause of the disease may be, we shall be able, in the course of this 
article, to show into what serious errors and inconsistencies an over-hasty and 
too restricted a definition has led. 
Cyanosis is met with chiefly in the earlier periods of life, occurring con- 
genitally, or showing itself a few years after birth. When not congenital, 
its approach may be gradual, and the first indications of a disturbed circula- 
tion so slight as scarcely to attract notice; or, on the other hand, its invasion 
may be sudden, and complete discoloration be at once established. If, as 
is sometimes the case, cyanosis has first made its appearance in mature 
years, the attack is often referred by the patient to some antecedent injury, 
as a severe blow or fall. The extent and intensity of the discoloration vary 
in different cases, and at different periods in the life of the same individual. 
When it is but partial, it is most marked in the lining membrane of the 
mouth, upon the lips, cheeks, extremities of the fingers, and in those parts 
generally where the skin is delicate, and the capillary vessels numerous. 
The colour varies in its shades, from a mere livid tint to the most complete 
blackness, and is more marked in all violent efforts, and under the influence 
of strong moral impressions. If paroxysms occur, the discoloration will 
be deepest during their continuance, while in the remissions it may be but 
slight, or even entirely absent. The discoloured parts are also, at the same 
time, more or less cedematous. The external temperature of the body may 
be perfectly natural, or, on the other hand, so much lowered as to render the 
situation of the patient very distressing.. In these latter cases the body seems 
incapable of receiving warmth, and the patient is chilled even in the hottest 
days of summer. The functions of digestion and secretion do not seem to 
be altered in any marked degree, but those of circulation and respiration 
exhibit the greatest deviations from the healthy standard. While the patient 
is in a state of repose, his breathing may be calm and regular. In some 
cases, however, the dyspnoea is habitual, but in all it is either induced or 
aggravated by any cause tending to excite the circulation. For this reason Stille on Cyanosis. 
3 
persons affected with cyanosis, are either averse from, or incapable of exer- 
tion, and in them a vivid moral emotion will often bring on great oppression. 
Some are thrown by these causes into the most alarming paroxysms; the 
countenance becomes suddenly anxious and distressed, the surface livid, the 
respiration hurried and gasping, and the movements of the heart tumultuous 
and irregular. A state of syncope follows, in which the patient may lie for 
several hours. In some cases the paroxysms occur without any obvious 
exciting cause, and it is in one of them that the fatal issue takes place. The 
following lesions, defects, and alterations of structure of the heart and its 
great vessels, have been found in persons who have, during life, been affected 
with cyanosis. 
1st. Dilatation and hypertrophy of the right cavities of the heart. 
2d. Contracted state of the left cavities. 
3d. A heart consisting of but one cavity. 
4th. A heart with two cavities, an auricle and a ventricle. 
5th. A heart with two auricles and one ventricle. 
6th. Persistence of the foramen ovale, or a cribriform condition of the 
auricular septum. 
7th. Deficiency of the ventricular septum at its base, or an entire absence 
of it. 
8th. Dilatation of the aorta. 
9th. A rudimentary condition of the pulmonary artery, contraction of it, 
adhesion of its valves, deficiency of one or more of them, cartilaginous or 
other growths at its orifice, or complete closure of it by membranous septa. 
10th. Persistence of the ductus arteriosus. 
11th. Contraction of the right auriculo-ventricular opening. 
12th. Transposition of the aorta and pulmonary artery. 
13th. The aorta and pulmonary artery arising from one ventricle. 
14th. The aorta and pulmonary artery arising from a common trunk. 
15th. The aorta giving off branches to the head and upper extremities, 
and the pulmonary artery forming the aorta descendens. 
16th. The aorta giving off two pulmonary branches. 
Some of these anatomical dispositions are often coincident, and in another 
place we shall endeavour to indicate their more frequent and important com- 
binations; at present, however, it will be sufficient to note the great variety 
of pathological conditions that have been found in cases of the disease under 
consideration. The concurrent lesions of other organs, although well de- 
serving of attention after the establishment of a well-founded theory of 
cyanosis, can be of little use in the investigation we are entering upon ; for 
they are, for the most part, either secondary effects of the disturbance of the 
respiratory or circulatory functions, or mere accidental complications. The 
elements essential to the production of the disease manifestly reside in the 
heart and great vessels; to these, therefore, must our attention be mainly 
directed if we wish to discover its laws of causation. 4 
Stille on Cyanosis. 
The phenomena of cyanosis have been, by different writers, referred to 
one or other of the following causes. 
1st. Obstruction to the return of the venous blood to the lungs. 
2d. Presence of the venous blood in the general arterial system. 
The first of these modes of explanation has been adopted by Louis, Berard, 
Bertin, and Ferrus among others, and has been regarded as an occasional 
cause by some of the advocates of the other view of the pathology of the 
disease. The class which takes this middle course is, perhaps, more nume- 
rous than either of those which maintain an exclusive doctrine, and whatever 
may be said of the consistency of thus admitting in turn one or other of two 
conflicting theories as may suit convenience, it certainly is a safe refuge from 
absolute error; for whichever may eventually be found to be incorrect, this 
class can never be wholly in the wrong. Among those who maintain the doc- 
trine of the mixture of arterial and venous blood as the cause of cyanosis, may 
be mentioned, Morgagni, Senac, Corvisart, Caillot, Labat, Bouillaud, and 
particularly Gintrac, to whose industrious researches we have been much 
indebted in the present investigation. It may be mentioned here, that 
while the presence of venous blood in the general arterial system was con- 
sidered by these writers the essential cause of cyanosis, they did not limit 
the mode of its production to any one anatomical condition of the heart; 
many, however, espousing their views, have thoughtlessly narrowed down 
the means of communication allowing the admixture of the blood to that 
one which is the most frequently met with, viz., an opening in the auricular 
septum, so that at present, and particularly in our own country, cyanosis 
and an open foramen ovale, are very generally regarded as inseparable. This 
untenable modification of the more general statement would hardly demand 
notice, were it not for its great prevalence, and the confidence with which 
remedial measures are sometimes based upon it. 
Notwithstanding, however, all that has been written upon the subject, the 
pathology of cyanosis cannot yet be considered as resting upon stable grounds. 
The affection is one of rare occurrence, presenting a great variety in the 
character of its phenomena and post-mortem appearances. Manifestly, 
therefore, the history of one or two isolated cases can never entitle the 
observer to establish a general law of the disease. Nor, again, can the 
collation of a large number of recorded cases be of any value if deduc- 
tions be made, not from the cases themselves, but from the opinions of 
those who have observed them. These last may be, and very often are, 
founded upon imperfect examinations; prejudice, ignorance, and many other 
causes, may render the conclusions obtained valueless, and one who, from such 
materials, should expect accurate results, could hardly fail of disappointment. 
It is also evident, that although in the majority of instances some one 
symptom or lesion may have been found constant in its occurrence, yet its 
mere frequency is apart entirely from the importance it may claim in the 
history of the disease. For example—the striking discoloration of the skin Stille on Cyanosis. 
5 
from which cyanosis takes its name, is entirely absent in some cases in 
which the structural alterations, regarded by some as the essential cause for 
its production, exist; and yet if the comparative frequency of their occur- 
ence were alone to be received as a sufficient test of the value of their rela- 
tion to this symptom as cause and effect, we should be led into the error of 
admitting that to be essential to the production of the discoloration, which 
facts had proved was not so. It would not be difficult, indeed, to trace to its 
true cause the proneness to fall into this logical error; it requires but feeble 
persuasion to convince us of what we are already disposed to believe, and no 
one can be safe from the mistake of admitting a plausible explanation as a 
true one, if he be in search of arguments to sustain some preconceived and 
favourite theory. To consider dispassionately, and with equal care, all the 
facts presented to our observation is an indispensable requisite in any investi 
gation, and the most certain way of practically insuring it, is the adoption 
of some method of examination, by which the erroneous influence of even 
an unconscious leaning to any particular doctrine may be precluded. The 
plan pursued in the present essay will be found to present this advantage 
among others. All the attainable cases on record in the periodical works, 
and in the treatises on cyanosis have been collated, condensed, and subse- 
quently arranged in a tabular form, the prominent points of interest in each 
being, at the same time, placed under their appropriate heads. In this 
manner upwards of 80 cases have been examined, the results of which we 
shall be enabled to present in the following pages. 
The two theories of the pathology of cyanosis having been stated above 
let us now examine to what extent they are consonant with the facts thus 
obtained—and 
1st. Of the presence of venous blood in the general arterial system. 
The conditions necessary for this result, are, abnormal communications 
between the right and left cavities of the heart, or such a disposition of the 
principal vascular trunks as will allow their contents to intermingle. When- 
ever the black is brought into contact with the red blood, the colour result- 
ing from the contamination is intermediate, or of a purple hue. If then, as the 
advocates of this doctrine maintain, there can be no discoloration of the 
skin, without this admixture of arterial and venous blood, we should always 
find, in cases where discoloration existed, some one of the communications 
abovenamed, for it is evident, that this explanation being an exclusive one, 
must, if true at all, be true of all cases. 
In five cases, however, (the authorities for which are cited below,*) neither 
the foramen ovale nor the ventricular septum was open, nor did there exist 
any other passage by which the arterial and venous blood could com- 
mingle. Yet in all of these, there was the discoloration of the skin which 
* Archives Gen. de Medecine, vol. viii. p. 594. Bouillaud, Malad. du Cceur, Obs. 77, p. 
155. Edinburgh Med. and Surg. Journal, vol. liii. p. 552. Ibid. 1830, Lond. Med. and 
Phys. Journ., vol. xiv. p. 471. 6 
Stille on Cyanosis. 
is characteristic of cyanosis; in two it was partial in extent, in three com- 
plete. The other phenomena of the disease were likewise present. In a 
future part of this paper, these cases will be again taken up; the facts perti- 
nent in this place, are those already stated, and they prove, ls£, That cya- 
nosis may exist without admixture of the blood. 
Again, the communications permitting this admixture, being of very fre- 
quent occurrence in cyanosis, it is rarely that cases are to be found, illustrat- 
ing like the preceding, the want of relation between the disease, and its 
alleged pathological cause; as these communications vary, however, in their 
seat, and in the degree in which they will allow the access of the venous to 
the arterial blood, there should be a difference in the depth and extent of the 
cyanosis corresponding to the degree in which the blood is mingled. But 
numerous cases of the continued patescence of the foramen ovale are on re- 
cord, in which, nevertheless, no symptoms of cyanosis had been manifested. 
Cases, also, of partial deficiency of the ventricular septum, without any 
accompanying discoloration of the skin, are of not infrequent occurrence. 
Setting aside these points altogether, as being open to some doubt in regard 
to the amount of blood vitiated, it will conduce more to a correct understand- 
ing of the actual relations of the discoloration with the mixture of the blood, 
if we examine those cases only in which the latter was not merely possible, 
but inevitable. In such, of course, the discoloration should bear a certain 
proportion in extent and intensity, to the degree in which the arterial was 
adulterated with the venous blood. 
The four following cases are examples of this kind; we have annexed to 
each the amount of the discoloration as stated by those who observed them. 
1. Ventricular septum open, aorta arising from the right ventricle,—no 
cyanosis except an occasional lividity of the lips.* 
2. No pulmonary artery. Aorta arose from both ventricles, and gave off 
large bronchial branches. Face only cyanosed. Age 16 years.t 
3. Heart with two cavities ; the aorta and pulmonary artery arose from 
a common trunk. The lips livid upon the day of his birth, and that of his 
death. Age 7 days.J 
4. Heart with two cavities. Aorta gave off two pulmonary branches. 
Cyanosis slight and remitting. Age 3 days.§ 
In all of these cases, there was of necessity a thorough admixture of the 
blood, and a contamination thereby of the whole circulating fluid, altering its 
colour at the same time that it vitiated its character. So complete, indeed, 
was this vitiation, that it is difficult to understand how it was compatible with 
life. If a mere perforation of the auricular or ventricular septum were ade- 
quate, as is affirmed by some to the production of a general and marked 
discoloration of the skin, and the other phenomena of cyanosis, certainly 
we should have been warranted in anticipating at least an equal result in 
* Lond. Med. and Phys. Journ., N. Ser. vol. vi. p. 548. 
t Gintrac, Recherches sur la Cyanose, p. 44. 
§ Farre, Pathol. Essay on Malform. of Heart, p. 2. 
t Ibid. Stille on Cyanosis. 
7 
these instances. For if the effect bear any proportion to its alleged cause, the 
individuals in whom the lesions just named were found, should have offered 
the symptoms of cyanosis in the extreme. But, so far from this, it will be 
seen that in those cases affording the means for the most complete mixture of 
the blood there was the least discoloration. These four cases prove, 
2d. That there is no proportion between cyanosis, and the degree in 
which the blood is mixed. 
So great, indeed, is this disproportion, that these cases would render it 
highly probable that it may sometimes amount to an entire want of connec- 
tion, but this is conclusively demonstrated by the two following cases. 
1st. Foramen ovale open; pulmonary artery arose from both ventricles, 
gave off pulmonary branches, and formed the aorta descendens. The aorta 
gave off the arteries of the head and upper extremities, and joined the pul- 
monary artery by the ductus arteriosus ; no cyanosis. Age 8 months.* 
2d. Heart with two cavities; aorta and pulmonary arising from the ven- 
tricle; no cyanosis. Age 11 days.f 
We are now entitled to proceed one step further, and to state the converse 
of the first proposition—viz: 
3d. That complete admixture of the blood may take place ivitliout cya- 
nosis. 
M. Gintrac, who is, as we have before said, the most strenuous supporter 
of the doctrine of the mixture of the blood as the cause of cyanosis, encoun- 
tered the difficulty presented by the cases just cited. Having met with several 
instances of the origin of the aorta over the ventricular septum, or in other 
words, from both ventricles, and in which cyanosis did not occur till several 
years after birth, he asks—“ How shall we account for this late appearance 
of cyanosis ?” “ Must not the venous blood in these cases mingle with the 
arterial? Does there exist, in the early periods of life, any obstacle to this 
mixture? I think not. I am inclined to believe that, in new-born children, 
the two kinds of blood differ less, than at a more advanced age. The first 
inspirations produce in the organism a general stimulation; immediately 
the skin appears of a brilliant colour, the heart and vessels are strongly ex- 
cited, the circulation of the blood is rapid, and from this activity, this velo- 
city in the course of the fluid, result on the one hand, less considerable losses 
of the vivifying principles in the general capillary system, and on the other, 
a more prompt reparation in the capillary system of the lungs.” 
These sentiments have been quoted in M. G.’s own words, as it was feared 
that, if abbreviated, they might not be conveyed with sufficient precision. 
We would be reluctant to receive an hypothesis so gratuitous as this, as a 
satisfactory explanation of a well-established fact. That an increased velo- 
city in the current of the blood is a reason why it should part with less of 
its vivifying principles, is a novel proposition in physiology, and one which, 
* Farre, Pathol. Ess. p. 15. t Am. Journ. of Med. Sciences, Oct. 1843, p. 447. 8 
Stille on Cyanosis. 
we believe, will not stand the test of the most cursory examination. Is the 
nutrition of the young and growing being less active than the same process 
in the adult, and does not this function depend upon the surrender of what 
are vaguely termed “ the vivifying principles ?” What, in fact, is the object 
of the “prompt reparation” of the blood in the lungs if not to restore to it 
anew those “ vivifying principles” which, in its route through the body, it 
has just yielded up ? Adopting this hypothesis as a sufficient explanation of 
the absence of cyanosis in new-born children, where there was an unequi- 
vocal mixture of the two kinds of blood, it then became necessary for M. 
Gintrac to show how it was that cyanosis was ever congenital. He says 
that the action of the air on the lungs was, “ in these cases, incomplete, im- 
perfect, almost null. In most of them, in fact, the pulmonary artery was 
contracted, or even obliterated at its origin.” 
One of the effects of the contraction or closure of the pulmonary artery, 
supposing no compensation for the same to exist, and to which M. G. refers, 
would be, that a less amount of blood would reach the lungs. And the idea, 
which doubtless is here implied, is, that, therefore, the whole of the circu- 
lating fluid must be of a venous character, and give, in consequence, its 
colour to the skin. But, although the blood arrive at the lungs in a dimi- 
nished quantity, there is no reason why the haematosis of this should not be 
complete; and the only influence that such a condition could exert upon the 
the character of the circulation, would be that it would diminish the mass of 
the arterial blood. M. Gintrac’s views of congenital cyanosis involve then, 
not only an abandonment of his theory of the mixture of the blood, (which 
is, indeed, acknowledged by him to be insufficient,) but also of that of defi- 
cient haematosis, which is substituted in its place. 
Having now seen the discrepancy existing between the occurrence of 
cyanosis, and the pathological conditions to which it has been referred, we 
shall here only subjoin one fact, which the cases we have collected have 
enabled us to determine, and which is, at the same time, confirmatory of the 
three positions already attained. If there be preternatural communications 
in the heart, or its great vessels, and the mixture of the blood has ever taken 
place, it must continue to do so. Moreover, the degree in which the arterial 
blood is deteriorated, will remain relatively the same; for although the heart 
may, under the influence of many causes, propel its contents with greater 
vigour, yet as this increased energy is shared alike by both sides, the dis- 
coloration can be no greater, as the amount of blood mingled is relatively 
the same as in a state of repose. Hence, it follows that there ought never 
to be any variation in the same individual of either the extent or intensity of 
the discoloration. It should be permanent. Such is, indeed, in many 
instances the case, a circumstance which, in another place, will be ascribed 
to what we consider its true cause. But in all cases in which the blood is 
mingled, the discoloration should be unvarying in its shade and extent, if 
upon that condition alone it depends. We have noted 77 cases in which Stille on Cyanosis. 
9 
there were means for the mixture of the blood to take place. Of this num- 
ber there were 29 in which the colour was constant in its extent or shade, or 
in which these particulars were not a subject of observation. In the remaining 
48 there was a variation either in the depth, extent, and progress of the dis- 
coloration. In some the lips alone, in others these, the cheeks, the chin, 
and the extremities of the fingers and toes were cyanosed, and again in 
others the whole body was implicated; a light brown, a violet or livid hue, 
or the utmost blackness, were to be seen at different periods in the same 
individual, and these shades, passing into each other insensibly, while they, 
in some, did not permit the skin to return to its natural colour, in others 
allowed the remission to be complete and the skin natural, until the super- 
vention of certain exciting causes reproduced the morbid appearance. The 
designation of the mode in which these causes act is reserved for another 
place; but from the evidence of these facts we are warranted in concluding, 
that as the mixture of arterial and venous blood is a cause acting with uni- 
formity at all periods, it follows, 
4th, That the variation in the extent, depth, and duration of the disco- 
loration is inexplicable by the doctrine of the mixture of the blood. 
It is presumed, that sufficient data have now been obtained to place the 
fact beyond cavil, that cyanosis cannot be referred to a mixture of arterial 
and venous blood as its cause. In estimating the value of these objections 
to the popular theory, let it be remembered that they claim no farther validity 
than that which belongs to the facts upon which they are based; the justice 
of the inferences we have made it is in the power of any one to verify. The 
rejection of this theory, however, does not impose upon us the necessity of 
adopting in its place any other with merely plausible pretensions; for as this 
has been abandoned only after full proof of its incorrectness, so can any 
other be entitled to reception only by resting its claim upon satisfactory 
grounds. Nor, indeed, could our inability to offer any adequate explanation 
of cyanosis, invalidate in the least the objections we have urged against the 
doctrine of the mixture of the blood, for the arguments by which this, or 
any other theory which shall account for its phenomena on distinct princi- 
ples, is upheld, are independent; an insufficient refutation, therefore, on the 
one hand, or inadequate confirmation on the other, cannot necessarily imply 
the correctness of the opposing doctrine. Nevertheless, all will admit, that 
where two theories, both of which cannot be true at the same time, are 
proposed to account for certain morbid phenomena, if one of them can be 
proved, from careful examination, to be unsupported by the evidence of well- 
observed facts, there results in favour of the other a higher presumption, 
which may be the more easily elevated into demonstration, inasmuch as it is 
then sustained, not only by positive, but by negative proof. It has been 
mentioned before that there is but one other method of explaining the pheno- 
mena of cyanosis, viz:—that which ascribes it to a congestion of the general 
venous system, resulting from some obstruction in the right side of the heart, 10 
Stille on Cyanosis. 
or in the pulmonary artery, impeding the return of its blood to the lungs. It 
is now proposed to examine the basis upon which this doctrine rests, in order 
to determine whether or not it be entitled to our belief. We shall pursue 
the same mode of investigation in the examination of this theory as in that 
of the other; therefore, if true, the structural lesion which it assumes must 
fulfil the three following indications. 
1st. That it shall account satisfactorily for the discoloration of the skin 
and the dyspncea. 
2d. That it shall be found in every case of cyanosis, or if not, there shall 
exist in its place some cause acting upon similar principles. 
3d. That it shall never be found without the concurrence of cyanosis, or 
if it is, that a satisfactory explanation of the exception shall be given. 
1st. Does the contraction, obstruction, or imperforation of the pulmonary 
artery account satisfactorily for the discoloration of the skin and the dysp- 
ncea? The fact is a familiar one, that any cause impeding the return of the 
venous blood to the heart will produce a congestion in the veins exterior to 
the locality of the obstacle, which, according to the time the impediment 
remains, will manifest itself by giving a bluish or blackish tinge to the part. 
The appearance of the arm when, in the operation of bleeding, the ligature 
has been too tightly applied, is an example of partial cyanosis. If, how- 
ever, the impediment be seated nearer the central organ of the circulation, in 
the air passages, as in croup, or in the lungs, as in pulmonary congestion, 
the cyanosis is then general, affecting first, however, the veins of the head 
and face, because of their proximity to the cause of the obstruction. Is it 
not, then, a reasonable inference, that, if the pulmonary artery, which is the 
grand outlet for the venous blood returning from every part of the body, be 
either obstructed at its orifice or narrowed in its calibre, the whole venous 
system must be consequently congested ? Moreover, where these obstruc- 
tions of the pulmonary artery exist, the capillary vessels must be constantly 
more or less distended, and it is highly probable that this state of dilatation 
must destroy, in some degree, their tonicity, and favour still more the stasis 
of venous blood in them. For this reason we should expect to find the dis- 
coloration chiefly manifest in the most vascular parts, and in those also 
which, being remote from the centre of the circulation, have the current in 
them proportionably sluggish. This, indeed, is consistent with general 
observation, and we find, accordingly, that the mucous membranes, the lips, 
the cheeks, and the ends of the fingers and toes, are the first to manifest the 
congestion. The pressure of venous blood upon the right side of the heart, 
resulting from an obstruction in the pulmonary artery, distends the cavities 
of that side, and from this distension, and the resistance to the due perform- 
ance of their functions in consequence of the obstacle to the exit of the blood, 
they become often permanently dilated and hypertrophied. Of 53 cases of 
cyanosis in which the pulmonary artery was either contracted, obstructed or 
impervious, the condition of the right cavities was the subject of observation Stille on Cyanosis. 
11 
in 36. The right auricle was dilated in 15 cases, and dilated and hyper- 
trophied in 7. The right ventricle was dilated in 10, hypertrophied in 13, 
and dilated and hypertrophied in 12. The state of the left cavities of the 
heart was observed in 33 cases of the same series. The left auricle was 
contracted in 9, dilated with thinning in 1, and natural in 3. The left 
ventricle was contracted in 12, dilated in 3, thinned in 3, and natural in 3. 
We would state here, that we are not willing to rely upon these results, and 
especially on those which regard the condition of the left cavities of the 
heart, as exact, it being highly probable that in hasty or imperfect examina- 
tions, slight differences may have been exaggerated, or really valuable indi- 
cations overlooked; yet the peculiar character of the deviation from the 
healthy standard, as exhibited in a diminution of the size of the left side, 
and a dilatation and hypertrophy of the right, is too remarkable to be passed 
by, and the dependence of the latter upon the obstruction to the passage of 
the blood through the pulmonary artery too probable to be admitted with 
much reserve. When considering the question whether or not the mixture 
of the blood was the essential cause of cyanosis, it was shown, from cretain 
cases then quoted, that there was such a disproportion between the pheno- 
mena of the discoloration, and the cause assigned for their production, that 
it was impossible to view them in the relation of cause and effect, and it was 
also shown, that the great variation in the extent and in the shade of the dis- 
coloration, was inexplicable by a cause acting with uniformity at all periods. 
Upon examining those cases in which the pulmonary artery was either con- 
tracted, obstructed, or impervious, with a view to ascertain how far the 
character of the discoloration was influenced by these conditions, we find, 
that of 53 cases of cyanosis, in which the former was observed, the latter 
was mentioned in 36. In all of these 36 cases there was a variation in its 
extent and intensity. Such a result is easily explained by the anatomical 
conditions. For it is well known that the colour is deepened and increased 
in extent under the influence of emotional causes, or of slight bodily excite- 
ment ; and as the ordinary result of these is an increased activity of the circu- 
lation, and of the flow of blood through the pulmonary artery, an obstruction 
of this vessel would, of necessity, cause a turgescence of the whole venous 
system, corresponding in degree to the grade of the excitement, and pro- 
ducing a like variation in the discoloration of the skin. 
Dyspnoea is a striking feature of cyanosis, and frequently recurs in parox- 
ysms under the influence of mental or bodily excitement. If the blood be 
sent to the lungs in a quantity less than is required for the discharge of the 
function of haematosis, an attempt is made to compensate for this deficiency 
by an increased frequency of action; but if the movements of the heart be 
suddenly augmented in energy, there is, of necessity, a greater amount of 
blood thrown upon its right cavities, and the lungs expand, at the same time, 
more rapidly to receive it. The pulmonary artery, however, being obstructed, 
and the right cavities distended with the accumulated blood, its escape, except 12 
Stille on Cyanosis. 
in small quantities, is prevented, and the action of the lungs, thus rendered 
ineffectual, becomes like that of the heart, laboured and irregular, until at 
last syncope supervenes, and gives a short repose to those organs whose 
continued action was only adding, each moment, to the obstacle they were 
endeavouring to surmount. The state of the respiration was the subject of 
observation in 39 of the cases we have collected. In 3 of these the condi- 
tion of the pulmonary artery was not observed, but in the remaining 36, in 
all of which the artery was either narrowed or obstructed, the dyspnma was 
habitual, and speedily increased by movement or by moral impressions. 
2d. Is the contraction or partial or complete obstruction of the pulmonary 
artery to be found in every case of cyanosis, and if not, is there in those 
cases where it is wanting, an efficient cause of a similar character? 
There is one difficulty which presents itself on the very threshold of this 
inquiry. It may be thus simply stated. The common lesion of the pulmo- 
nary artery in cyanosis seems to have been unknown to a great number of 
observers, while that of the foramen ovale was known to all. The latter 
was then sought for in all cases of cyanosis, while the former may, in many, 
have been neglected. The popular opinion in regard to the efficiency of the 
open foramen in producing the disease was, no doubt, an additional reason 
why the state of the pulmonary artery was not observed in every case. We 
would not, perhaps, be warranted in taking it for granted, that, in all those 
cases in which all the pulmonary artery was not observed, the lesions above- 
mentioned might, upon examination, have been found, although we would 
have good reason to infer this to have been the fact from the large number of 
cases, similar in all respects, in which the pulmonary artery was either con- 
tracted or obstructed. To avoid, however, introducing into estimates, which 
we wish to render as accurate as possible, an element, whose value we can- 
not ascertain, those cases only in which the pulmonary artery was observed, 
will form the basis upon which we shall proceed. 
The pulmonary artery was observed in 62 cases. In 53 of these, it was 
either contracted, obstructed, or impervious. The remaining 9 cases pre- 
senting the phenomena of cyanosis without any one of these anatomical condi- 
tions existing, fall under the category of those cases, which, in accordance 
with a previous statement, must be examined in order to determine whether 
they act upon the same principle. Of these cases it is stated that the pulmo- 
nary artery was in—1 natural; 1 dilated; 1 aneurismal; 1 communicated with 
the aorta; 1 arose from the left ventricle ; 2 given off by the aorta; 1 given 
off in two pulmonary branches by the aorta ; 1 absent, but bronchial arteries 
large. 
1st. In the first of these cases, the patient was a young man, who died at 
the age of 18 of an “insidious fever.” During the last ten years of his 
life, he had been the subject of observation. His history, previous to that 
period, is entirely omitted, and thus one important fact, viz., the date of the 
attack, is left entirely to conjecture. The violet colour of the skin and lips Stille on Cyanosis. 
13 
diminished or augmented every moment, according to his impressions, his 
attitude and movements, and the difficulty of his digestion or respiration. 
Upon 'post-mortem examination, evidences of sanguine congestion were 
found everywhere. The heart was large, and all its cavities filled with a 
semi-fluid black blood; the walls of the left ventricle were less than three 
lines in thickness, while those of the right ventricle were six lines thick, and 
the columnne carnese so much developed, as almost completely to obstruct the 
cavity of the ventricle. The auricular septum offered an opening of three 
lines in diameter. The effect of this almost complete obliteration of the 
cavity of the pulmonary ventricle can hardly be misunderstood. The 
amount of blood received by it could have been but very small, and there 
being provided no adequate compensation for the resistance thus opposed to 
the discharge of venous blood into its cavity, the whole of that resistance 
must have been felt throughout the entire venous system. The right ventricle 
being thus obstructed, any cause exciting the circulation, and throwing an 
increased quantity of blood upon it, must have cast it into violent, irregular 
and fruitless action, and consequently brought on the whole train of distress- 
ing symptoms which the patient experienced. The structural lesion of the 
right ventricle was, in fact, operative almost precisely in the same manner as 
would have been an obstruction to the passage of blood through the pulmo- 
nary artery. It is a matter of regret that the early history of this case has 
not been recorded, as, from the progression of the symptoms, some light 
might, perhaps, have been thrown upon the rare occurrence of hypertrophy 
of the right ventricle unconnected with other lesions of the heart.* 
2d. A postilion, aged 57 years, received some violent blows upon the 
epigastrium, and during the three following weeks had dyspnoea, fainting 
fits and great pain in the part where the injury had been inflicted. These 
symptoms had subsided in a great degree when he received a new con- 
tusion in the same place. From that time he had palpitations, irregular 
pulse, suffocation on the least movement, oedema, ascites, &c. His face was 
livid or violace. How long he survived this last injury is not mentioned. 
The heart was “voluminous,” the right ventricle very much dilated and 
hypertrophied, and its columnar cctrnese as great as those usually found in the 
left ventricle. The right auriculo-ventricular opening was dilated, and the 
tricuspid valve proportionately enlarged. The cavity of the right ventricle 
was “enormous,” its walls very thick, and the fleshy columns much deve- 
loped. “The left auricle was dilated and thinned, the left auriculo-ven- 
tricular opening very much contracted, and the mitral valve thickened and 
rugose.” The cavity of the left ventricle was so small as scarcely to receive 
a walnut, its walls being at the same time slightly thicker than natural. In 
the fossa ovalis there was an opening of an inch in diameter, its border thin, 
loose, and tendinous. The , aorta was, at its origin, very much contracted 
* Gintrac, Rech. sur la Cyanose, p. 98. 14 
Stille on Cyanosis. 
and the pulmonary artery dilated as far as its bifurcation, and its valves pro- 
portionately enlarged. It may be said that this cannot be quoted as a case of 
cyanosis, inasmuch as, previous to the reception of the injury above men- 
tioned, the patient was in good health. But it is certainly sufficiently cha- 
racteristic in the discoloration of the skin, and in the attendant symptoms, 
and so like in these to all the cases of acknowledged cyanosis in which the 
progress of the disease was gradual, that it may be ranked among them with- 
out the risk of violating any principle of arrangement. The symptoms 
recorded of this case are precisely those of all congestions of the venous 
system, where the cause of the obstruction is near the centre of the circula- 
tion. In this instance, the primary cause of the congestion may, we think, 
be found in the left side of the heart; the aorta being, as already stated, very 
much contracted, the left ventricle greatly lessened in capacity, and present- 
ing, in the thickened and contracted state of the auriculo-ventricular opening, 
an important obstacle to the discharge of the aerated blood. The right side 
of the heart, as will be seen from the.remarkable development of its muscular 
apparatus, was acting with unnatural energy, and thus the whole pulmonary 
circulation must have been consequently congested. This engorgement 
reacting, at the same time, upon the general venous system, this system was, 
in its turn, subjected to the influence of the remote cause in the left side of the 
heart, retarding the blood in its course, and preventing its free ingress into 
the lungs.* 
3d. The case coming next in order is that in which the pulmonary artery 
was “ aneurismal.” The mode in which this condition would act in inducing 
venous congestion, is too evident to require illustration. The subject of it, 
aged 41 years, “was remarkable for the lividity of his complexion, the 
fulness of the vessels of the conjunctiva, and the thickness of his lips, 
which were, at the same time, nearly black. The respiration was so much 
disturbed that he could not pronounce two consecutive words, and he died in 
a state of suffocation.”! 
4th. In this case the pulmonary artery was prolonged directly into the 
aorta, and its branches were given off from its posterior aspect. The 
heart full of black blood, and the foramen ovale open. The child who 
was the subject of this report lived but twelve hours. Its colour, which 
soon after birth was seen to be black, became gradually less dark, until 
it assumed a bluish tinge; the difficulty of its respiration increasing, how- 
ever, each moment, the skin became again perfectly black, and soon after- 
wards the child expired. The preservation, in this instance, of one of the 
characteristics of the foetal circulation in the continuance of the ductus arte- 
riosus, or (as stated in the report) the prolongation of the pulmonary artery 
into the aorta, and the failure to establish those new routes which the first 
act of inspiration should create, furnish us with a striking illustration of the 
* Bouillaud, Malad. du Cceur, p. 562. 
t Gintrac, p. 64. Stille on Cyanosis. 
15 
separate dependencies of uterine and extra-uterine existence. The placenta, 
it has often been remarked, holds the same relation to the foetus as the lungs 
to the breathing child. But the function performed in the one case by the 
placenta, in the other by the lungs, is, in each, essential to the maintenance 
of vitality. If, then, after the circulation through the placenta has been cut 
off, the blood does not find access to its new respiratory organ, or if it be 
sent there only in part, life is entirely extinguished, or but imperfectly sus- 
tained. The blood, dammed up from its natural reservoirs, surcharges the 
general venous system, and the phenomena of asphyxia, persistent in this 
case on account of the remediless nature of the malformation, become fully 
established. The gradual decline in the depth of the discoloration, and its 
sudden recurrence in all its intensity, denote the struggle that nature was 
ineffectually making to fulfil her ordinary law.* 
5th. In this case it is said that the pulmonary artery arose from the left 
ventricle. There existed, in fact, but one ventricle, the right being “rudi- 
mentary.” The two auricles also constituted but one, as they formed “ one 
large cavity without the least separation.” The left auriculo-ventricular 
opening “ was very much contracted, and its valve formed a cylindrical canal 
capable of receiving the index finger.” The corresponding opening of the 
right side was “a little orifice of three lines in diameter, with a valve made 
of a fold of the lining membrane of the heart.” The pulmonary artery was 
destitute of valves. A concurrence of such remarkable defects and alterations 
of structure of these could, of course, not have existed without a very serious 
interference with the general health. And the manner in which such dis- 
turbance was effected, cannot, we think, be a matter of doubt. By the 
morbid alteration of the valvular apparatus of the ostia venosa, both the 
systemic and pulmonary blood, in their returning currents, encountered an 
obstacle to their entrance into the ventricle. The result of this must have 
been a congestion of both systems, the signs of which, during life, were—a 
violet colour of the skin deepened by efforts in crying, difficult respiration, 
tumultuous and irregular movements of the heart, and anasarca of the abdo- 
minal parietes and the lower extremities. This child lived for three months 
and 23 days.f 
6th and 7th. These two cases are introduced here on account of their 
being instances of the anomalous origin of the pulmonary artery, it being 
given off in both by the aorta. But they are examples also of slight con- 
traction of that vessel, it being in one of an inch less in circumference 
than the aorta, and in the other its branches, as well as the pulmonary veins, 
were only one-half their usual size. The pathological influence of this 
contraction of the pulmonary artery could not have been other than that 
which would have been induced, had it arisen as usual from the right ven- 
tricle. The heart, in both these instances, consisted of only two cavities, an 
* Gintrac, p. 150. 
t Ibid., p. 173. 16 
Stille on Cyanosis. 
auricle and a ventricle. Cited before in this essay, the first of these cases 
was adduced to show the great disproportion that existed between the degree 
in which the blood was mingled, and that of the discoloration, which 
amounted merely to a lividity of the lips, apparent on the day of the birth 
of the child, and the seventh day afterward, when it died.* In the other 
case the discoloration seems to have been more diffused, the difference 
being referable to the greater diminution in the calibre of the pulmonary 
vessels.f 
8th. This case has also been cited before for the same purpose as the first of 
the two preceding, (page 30). The pulmonary branches received their blood 
only after it had first passed through the aorta. This vessel held, therefore, the 
same relation to them as a pulmonary artery, and would have fulfilled the same 
office for them, in a degree compatible, perhaps, with a more extended term 
of existence than that which the patient attained, had it not been so con- 
tracted at its origin as materially to interfere with its own proper functions, 
as well as to keep back a proper supply of blood from the lungs. The dis- 
coloration was, as stated before, slight and remitting. 
9th. The last of the cases which we proposed to examine, is that in 
which it is stated that the pulmonary artery was absent, but its place sup- 
plied by bronchial arteries. The meagreness of the details furnished in the 
report of this case, and the ambiguity of some of them, may possibly lead us 
into erroneous deductions. We cannot, however, believe that the arteries 
here referred to under the name of bronchial, were those usually given off 
by the descending aorta; for this supposition is not required by a rational 
construction of the language used, nor is at all compatible with the fact of 
the individual who is the subject of the report having reached the age of 
16 years, as there stated. We presume that the word bronchial was em- 
ployed to denote the size and not the place of origin of the arteries spoken 
of, and that they might, with greater propriety, be termed pulmonary, and 
be considered as having been given off at the arch of the aorta. If this 
view be correct the case is similar to the one immediately preceding, in 
which the aorta is said to have given off two pulmonary branches, and the 
partial discoloration of the skin is equally explicable by the anatomical con- 
dition.:): As the aorta arose from both ventricles, and therefore transmitted 
blood of a mixed character, this case has been before cited with reference to 
that fact, (page 30.) 
In order to avoid fatiguing repetition, it has been our endeavour, in the 
notice of these cases, to be as brief as was consistent with a correct apprecia- 
tion of their individual peculiarities. It is hardly necessary to revert in the 
present place to the necessity that called for their examination. It will be 
remembered that, having in a previous part of this article examined, by 
means of the cases we had collected, the doctrine which ascribed cyanosis to 
* Gintrac, p. 44. t Ibid., p. 56. 
t Lond. Med. and Phys. Journ., vol. vi. p, 548. Stille on Cyanosis. 
17 
a mixture of the venous with the arterial blood, it was considered that there 
was adequate proof of its invalidity; in looking, therefore, for some lesion 
which should be an invariable coincident of cyanosis, and at the same time, 
an efficient cause of its production, it was found that the contraction of the 
pulmonary artery was so constant in its occurrence that the few cases in 
which it was not found might, perhaps, upon examination, be discovered to 
act upon similar principles in the causation of the ordinary phenomena of 
the disease. The nine cases which we have just examined, were the only 
ones in which the pulmonary artery was not contracted, obstructed, or 
impervious. But in nearly all of them much more important alterations of 
structure than a mere contraction of the pulmonary artery were found to 
exist, and it was then necessary to examine whether the conditions pre- 
sented by them were such as were capable of producing venous congestion, 
or, in other words, of operating on the same principle as did the contraction 
of the pulmonary artery. 
It will now be seen, that so far from affording any ground for an objection 
to the doctrine that the essential characteristics of cyanosis are constituted by 
general venous congestion, they do on the contrary confirm it, and prove that 
there is no one lesion which is entitled to be considered as the anatomical 
character of cyanosis, but that it depends simply upon any cause which, 
acting at the centre of the circulation, will produce a stasis of venous blood 
in the capillary system. Cases of cyanosis, therefore, may be met with in 
which no one of the anatomical dispositions above enumerated shall be 
found; or, again, the lesion upon which the disease may really depend, shall 
be so recondite as to elude observation; but as it is evident that the variety 
of malformations and alterations of structure may be almost without limit, 
and that many more than those we have been able to gather may be pro- 
ductive of congestion, such instances will, probably, only bring additional 
proof of the correctness of the conclusions that previous facts have afforded. 
We are now prepared to state that the second requirement that was proposed 
as necessary for the establishment of any theory of cyanosis, is fulfilled by 
the facts that have been adduced, viz. 
2d. That the alleged cause shall be found in every case of cyanosis, or if 
not, there shall exist in its place some cause acting upon similar principles. 
It will be seen that the next requirement, viz : 
3d. That the cdleged cause shall never be found without the concurrence 
of cyanosis, is met by the same facts which were brought forward under the 
preceding head. We have found, in fact, no one case of contraction, obstruc- 
tion or imperforation of the pulmonary artery in which there was not cyanosis. 
If contraction of the pulmonary artery be now taken as the type of all 
the lesions that may produce a cyanosis, we are entitled to state, 
1st. That it is present in every case of cyanosis. 
2d. That it never exists without the concurrence of cyanosis; and 18 
Stille on Cyanosis. 
3d. That it is an adequate explanation of the most important phenomena 
of the disease. 
The question has been agitated, and mostly in a speculative manner, whe- 
ther or not the contraction and obstruction of the pulmonary artery were 
congenital lesions. As it has been previously stated that in all the cases of 
cyanosis which we had collected, this lesion was uniformly found (9 cases 
excepted, in which for the most part, there was a malformation of the heart), 
it is hardly necessary to add, that in all those which were congenital, either 
contraction or partial or complete obstruction must have existed from birth. 
In order, however, that direct evidence on this point may not be wanting, 
the following statement is subjoined. 
In 28 cases of congenital cyanosis the pulmonary artery was contracted, 
obstructed, or impervious. 
It was found to be impervious at its orifice, or contracted and obstructed, 
in those who died at the following ages: 
Impervious in 1 at 7 days. Contracted or obstructed in 1 at 6 years. 
1 at 13 days. 3 at 8 “ 
1 at 23 days 1 at 9 “ 
1 at 5 weeks. 2 at 10 “ 
1 at 6 weeks. 2 at 11 “ 
1 at 8 months. 1 at 14 “ 
1 at 11 months. 2 at 16 “ 
1 at 15 months. 1 at 17 “ 
1 at 1 year. 1 at 18 “ 
Contracted or obstructed in 1 at 5 months. 1 at 29 “ 
1 at 5 years. 1 at 57 “ 
A few facts in regard to the relative proportion of the two sexes which 
were the subjects of cyanosis, the number of cases in which it was conge- 
nital, and the duration of life, may here be added. 
Of 72 cases of cyanosis in which the sex was mentioned, 41 were male, 
31 female; of 71 cases in which the date of the attack was observed, it was 
congenital in 40, and occurred in the remaining 31 non-congenital cases at 
various periods after birth. 
The following table will show the duration of the disease in all the con- 
genital cases. 
7 patients died within 23 days after birth. 
3 “ “ between 23 days and 10 weeks. 
7 “ “ “ 10 weeks and 1 year. 
10 “ “ “ 1 year and 10 years. 
10 “ “ “ 10 years and 20 years. 
1 patient “ at 29 years. 
1 “ “ “ 35 “ 
1 “ “ “ 57 “ 
It having been the sole object of the present inquiry, to ascertain the laws 
of the causation of cyanosis, and at the same time, to do this in a manner Stille on Cyanosis. 
which, while it precluded speculative discussion, should place the results 
obtained upon a basis furnished by statistical evidence, it does not come 
within its proper scope to notice those other phenomena of the disease, 
which, although usually embraced in its description, are yet not to be 
deemed its essential constituents. Direct and decisive proof has been through- 
out insisted upon, and such the points alluded to are not capable of receiving. 
The writer will be amply repaid for the labour expended in the collection 
and preparation of the cases requisite for the foregoing investigation, if the 
results derived from them shall in any degree contribute to the furtherance of 
exact and useful medical knowledge.