[Reprint prom Medical and Surgical Reporter op 7 and 14, 188 
THE INCANDESCENT ELECTRIC LIGHT 
FOK THE 
Examination of the Throat, Nose, Eye, and Ear; 
AN ELECTRIC OPHTHALMOSCOPE. 
By LOUIS J. LAUTENBACH, M. D., 
OF PHILADELPHIA. 
My experience with various kinds of lights has 
been derived from the examination of the throat, 
nose, eye, and ear ; as applied to other portions 
of the human body, I will not pretend to speak. 
In the present paper, I desire to call attention to 
the advantages of the incandescent electric lamp 
in the exploration of the parts before mentioned, 
but particularly in examination of the eye- 
ground. 
Since the employment of the reflecting mirror, 
the illumination of the various parts of the human 
body, by means of artificial light, has been con- 
tinually under discussion. As sources of light, 
the wax-candle, the oil-lamp, the gas-burner, the 
lime and electric light, have each been used. 
These lights have been modified in numerous 
ways to obtain the maximum brilliancy, the least 
yellowness, and to concentrate the light. The 
first was obtained by consuming a larger amount 
of material by means of an increase in the sur- 
face of the burners, and by increasing the thor- 
oughness of combustion. As a result, we have 
the Argand burner, the Siemens’ lamp, the stu- 
dent lamp, and other round and broad burners. 
To overcome the yellowness of the rays, slips of 
blue-glass have been interposed between the source 
of light and the reflecting mirror. To concentrate* 
the light, convex lenses have been employed, 
being placed so as to intercept the light falling on 
the reflecting mirror ; as illustrations, we have the 
Mackenzie concentrator and the Tobold lamp. 
The lamps devised, in which it has been sought 
to incorporate one or more of these advantages, 
have been quite numerous; one is particularly 
struck by the number which have been designed 
for ear examinations. The Argand burner, the 
student lamp, the Tobold lamp, with, perhaps, 
one or two others, are about all which have been 
saved from the general wreck ; of course, the lime 
and electric lamps are not here considered, both 
being but in their infancy; the Siemens’ light is 
also passed by, because, so far as I know, the 
manufacturers have no intention of making them 
sufficiently small to allow of their introduction 
into private houses. 
It is well known that there are two kinds 
of electric light—the arc light and the incan- 
descent light. The arc light is occasioned by 
the combustion usually of carbon at the positive 
pole and the carrying to the negative pole of 
nnconsumed, but intensely-heated particles of 
carbon. The light is of great intensity, and is, 
in consequence, of a violet-white color; it is, 
however, unsteady, having a strong propensity 
to vary in brilliancy, even sometimes to the point 
of absolute extinction. The most important ob- 
jection, however, is the intense heat occasioned ; 
it is mainly because of this fact that it is unsuit- 
able for medical examinations ; the intensity and 
unsteadiness being, however, also factors in pre- 
cluding its use. 
Believing that it will be impossible, for the 
present at least, to use the arc-light successfully 
for the examinations of special organs, I will not 
bestow more attentiou upon it, and will, there- 
fore, use the terms electric light and incandescent 
light synonymously. 
In the incandescent lamp there is no combus- 
tion, the carbon filament, within as absolute a 
vacuum as is possible at the present day, becomes 
iucandescent by reason of the resistance it offers 
to the passage of a current of electricity. 2 
HISTORY OF THE INCANDESCENT LIGHT AS APPLIED 
TO THE SPECIAL ORGANS UNDER DISCUSSION. 
So far as I have been able to discover, Bruck,* 
a dentist of Breslau, was the first to construct 
and use an incandescent lamp for the examina- 
tion of human structures. His instrument was 
known as the diaphanoscope, ft consisted of a 
coil of platinum wire placed in a glass tube sur- 
rounded by a column of water. This was followed 
by Gustave Trouve’sf polyscope, which was ex- 
hibited at Baden-Baden in 1879. This consisted 
of an unprotected platinum wire placed in front 
of a concave mirror. The objection to its use was 
its heat, which sometimes was sufficiently great 
to fuse the platinum. This was followed by Dr. 
Nitze’st instruments for the examination of the 
urethra, larynx, etc. Shortly after this, Dr. A. 
Wellington Adams || published an account of an 
electric laryngoscope, which consisted of the ordi- 
nary laryngeal mirror, on the handle of which 
was a concave mirror, in front of which was placed 
a spiral tube containing a platinum wire in a car- 
bonic acid vacuum. This wire was rendered in- 
candescent by means of a Rulimkortf coil. He 
used this instrument for the larynx and posterior 
nares. He promised that the description of an 
electric otoscope, which he proposed exhibiting 
before the Colorado State Medical Society, May 19, 
1880, would appear in the September number of 
The Colorado State Medical Journal and Rocky Moun- 
tain Medical Review, but I have rot been able to 
find any reference to this article. 
About this time, Josef Leiter§ constructed in- 
struments for the examination of the various or- 
gans. He made use of the light derived from an 
incandescent platinum wire; this was usually 
placed behind a window or ledge, to prevent 
contact with the structures under examination. 
The instrument was cooled by the circulation of 
water. It, however, was necessarily bulky, and 
was either too warm, or else the light was so dim 
that nothing could be seen. 
A year or two later, Carl Seiler began to use 
the reflected rays of the Edison incandescent light, 
which he must have considered of value, as he 
writes: “I have no doubt that in the near future, 
when electric lighting will have been adopted 
universally, as gas is now, electric-lamps for the 
laryngoscope will supplant all other sources of 
light, with the exception of sunlight.” 
On the 16th of April, 1883, the instrument of 
Dr. Paul Helot and Gr. Trouve was presented to 
the French Academy.* The description was pub- 
lished shortly thereafter.! The instrument was 
known as the frontal electric photophore. It con- 
sisted of a metal cylinder attached to the ordinary 
head-band. Within the cylinder is a small in- 
candescent lamp ; back of the lamp is a concave 
reflector ; anterior to it is a strong convex lens to 
concentrate the light. This instrument has been 
successfully employed by Dr. E. C. Baber t for the 
examination of the throat, nose, and ear. About 
this time, Simanovoski || published a description 
of an electric laryngoscope, but as yet I have not 
been able to obtain a description of the instrument. 
Dr. Carl Seiler § exhibited his electric laryngo- 
scope before the Pennsylvania State Medical So- 
ciety, May 16, 1884. It consists of the ordinary 
concave head mirror, with a bar attached to its 
lower tsdge. The incandescent lamp is placed on 
this bar ; between the lamp and the mirror is 
placed a strong convex lens, while between the 
lamp and the patient there is a mica shield. Dr. 
S. S. Cohen advises the use of the incandescent 
light in connection with the Mackenzie condenser. 
Dr. Laurence Turnbull** exhibited tbe laryngo- 
scope of Dr. Starrff before the Philadelphia 
County Medical Society, October 22, 1884. It 
consists of an incandescent lamp, placed in a hol- 
low cylinder of rubber, to the end of which cyl- 
inder the laryngeal mirror is attached. It is the 
object of this instrument to illuminate the parts 
under examination by means of direct rays of 
light. A very important measure incorporated in 
this instrument is a method of regulating the 
current, and thus regulating the illumination. 
* Chambers’ Jour., vol. 58, 1881, p. 314. 
f Popular Science Monthly, vol. xvii., 1880, p. 110; also 
Annals of Anatomy and Surgery, vol. vii., 1883, p. 128. 
J Annals of Anatomy and Surgery, vol. vii., p. 127. 
| Archives of Laryngology, 1880, vol. i., p. 368; also, New 
York Medical Gazette, 1880, p. 324. 
gBeschreibung einer instrumente und apparatezurdirek- 
ten Beleuchtung menschlicher Korperhohlen durch elek- 
trisches Gliihlicht, Wien 1880; also, Annals of Anatomy 
and Surgery, vol. vii., 1883, p. 129. 
If Diseases of the Throat and Nose, 2d edition, Philadel- 
phia, 1883, p. 22. 
* Proceedings of the French Academy, Paris, 1883, vol. i., 
p. 1164. 
+ La Nature, Paris, 1883, vol. i., p. 416. 
| British Medical Journal, 1883, vol, ii., p. 916. 
|| Ejened. Klin. Gaz., St. Petersburg, vol. iii., 1883, p. 473. 
§ Transactions Medical Society of Pennsylvania, vol. xvi., 
1884, p. 349. 
IT Medical News, Philadelphia, vol. xlv., 1884, p. 81. 
** Proceedings Philadelphia County Medical Society, vol. 
vii., p. 56; also, Polyclinic, Philadelphia, vol. ii., 1884, p. 77. 
ft Electrical Review, London, vol. xv., 1884, p. 424; also, 
Scientific American, October, 1884. 3 
The objection to all instruments employing an 
incandescent platinum wire is that to obtain suffi- 
cient light the heat generated is so great as to 
fuse the wire. In Bruck’s instrument its size de- 
barred its employment except for oral examin- 
ation : Nitze’s instruments were too large for 
practical use; in Leiter’s instruments, the two 
essential water-pipes made them too bulky' in 
Adams’ laryngoscope the light was apparently too 
poor. Trouv6’s frontal pliotophore is a very ser- 
viceable instrument. Dr. Seiler’s instrument is 
practically hut the pliotophore placed in front of 
the head mirror ; its disadvantage is its weight. 
The disadvantages of the Starr instrument are 
the slight heat occasioned and the fact that the 
eye is not thoroughly protected from the light. 
Up to the present time, the incandescent light 
has apparently not been employed for the exami- 
nation of the eye. Dr. Seiler,* speaking of his 
electric laryngoscope, writes that “it may he 
used for the examination of the eye.” but does 
does not appear to have so employed it. I have 
been using the electric light for this purpose for a 
period of more than five months. 
AN ELECTRIC OPHTHALMOSCOPE. 
As will he indicated later on, I have employed 
the incandescent lamp in the ordinary situation of 
the gas stand, also within a Tobold condenser, as 
well as attached directly to the ophthalmoscope, 
employing the light with plane and concave mir- 
rors, the latter of from three to fifteen inches 
focal distance. The method which has been of 
the most service where small lights only could be 
employed, was that adopted in the instrument 
here figured. Fig. 1 is £ natural size, Fig. 2 be- 
ing the exact size of the lamp. 
It consists of an ordinary Hunter’s Loring 
swinging mirror ophthalmoscope, to which is sol- 
dered the slot I, fitting into this slot is the arm 
D, which carries upon it a hard rubber cylinder, 
E, which can be slid down closer to the mirror if 
desirable ; this rubber cylinder carries upon its 
upper extremity the incandescent lamp A, over 
which is fitted the asbestos (non-conductor of 
heat) cap II, between which and the posterior sur- 
face of the lamp is the reflector. Fitting into the 
rubber base, E, is a wire carrying the biconvex 
lens B of | inch focus. The lens can be ap- 
proached to the light at will. It should, how- 
ever, be placed at about half an inch from the 
filament. On the bar D is a cross-bar C, the ends 
of which strike against the projections of the 
swinging mirror J. This bar is of such length on 
either side as to place the lamp at an angle of 
with the general plane of the mirror : by this 
device, the swinging mirror is placed in position 
for one or the other eye, by adjusting the lamp 
for the same eye. The wires are carried from 
the hard-rubber piece either down to an opening 
L, entering a hollow fixed handle, or to a ring 
which slides easily about the lower end of the 
handle: this latter device allows of the ready de- 
tachment of the handle. Two asbestos caps are 
employed : in one the light makes its exit through 
a small round opening ; in the other, which is 
only used occasionally, the opening is a vertical 
slit. The convex lens concentrates the light and 
renders it almost parallel. I have employed the 
plane reflecting surface in connection with this 
lamp, but have not found it as satisfactory. A 
concave reflector with a focal distance of three 
inches, I used without benefit. If the amount of 
light obtained in the eye is more than the ob- 
server desires, it is only necessary to revolve the 
lens B out of the field of light. 
****** ** 
This light will prove of advantage in the ex- 
amination of the dark complected; whenever 
there is a small pupil ; of myopics—in all of- 
these cases giving us better illumination than we 
can obtain by other means. It will be of service 
in atrophic nerve cases, but its advantages are 
particularly marked in slight retinal inflamma- 
tions, and for the study of the retinal circulation. 
Because of its intensity, it will allow us to make 
more thorough ophthalmoscopic examinations in 
cases of corneal, lens and vitreous opacities. 
•Transactions Pennsylvania State Medical Society, vol. 
xvi., 1884, p. 351. 4 
It may not be uninteresting, nor is it without 
the scope of this paper, to consider the various 
forms of incandescent lamps, and the means of 
generating the electricity suitable thereto. A 
very good opportunity of observing the different 
varieties of lamps was afforded at our Electrical 
Exhibition a few months ago. Of the numerous 
incandescent lamps exhibited, it will be neces- 
sary to call attention to but a few. In the Bodein 
lamp, exhibited by Messrs. Queen & Co., the in- 
candescent filament is in the form of a straight 
bar placed at right angles to the platinum poles. 
The intensity of current required is low. In the 
Weston lamp, the filament is a series of undula- 
tory curves ; in the Bernstein lamp it consists of 
a hollow cylinder of carbonized woven silk, 
shaped like a U, with long arms, requiring, to 
produce whiteness of light, a very high tension 
current; in the Edison lamp, it consists of a fine 
carbonized long armed U, requiring, also, a high 
tension ; in the Swan lamp, it consists of an elon 
gated U, with a round loop situated within the 
curve. This loop is not present in their lights less 
than 40 volts ; in the Baudet lamp the filament is 
quite broad in cross section, and is U-shaped ; it 
requires considerable quantity of current of low 
intensity. 
In my work, I have used the Swan and Edison 
lights, as well as the small lamps of Dr. Starr 
(obtained at S. S. White’s dental establishment). 
The Swan light used by me was a nine-volt lamp 
of slightly more than two-candle power ; the fila- 
ment a slight curve 6 mm. in length. The Edi- 
son light, which was placed at my disposal 
through the kindness of a friend, was a 16 c. p. 
95-volt lamp, the arms of the U-shaped fila- 
ment being 7 cm. in length, and separated 2 cm. 
from one another. The Starr lamps were both of 
them of about c.p., the one being a 3.8-volt 
lamp, the other slightly less ; the filaments were 
slightly curved, one 4 mm., the other 2.5 mm. in 
length. The employment of the electric-light 
without the use of any lenses, will often prove 
satisfactory, the objection to its use in this way 
being that with the smaller lamps employed 
the illumination is poor, and the image of the in 
candescent filament is quite small. A very im- 
portant question which must be here considered 
is the production of the electricity to work the 
lamp. How are you going to obtain it ? from a 
chemical battery, a dynamo, or from either one 
in connection with a storage battery? Hoping 
that our electric-light companies might be able to 
furnish it, I inquired at the offices of the Maxim 
and of the Brush Cos. At the Maxim’s office I 
found them willing to supply the" entire plant, 
consisting of the lamps, with a dynamo machine 
to supply them ; it would, with the necessary 
engine, cost several hundred dollars. They were 
not able to supply lights jfrom their office, but 
hoped that they would be able to do so some time 
in the future At the office of the Brush Com- 
pany, who own the American rights of the Swan 
light, I found that they would put in the lights 
with the dynamo, but that they were engaged in 
the perfection of storage batteries, which were to 
be supplied from their arc-light wires. They 
thought the problem of supplying the incandes- 
cent light was in a fair way of solution; that pro- 
gress was being made from day to day. This 
company is at the pieseut time supplying the 
basement of John Wanamaker’s Thirteenth Street 
store with some seventy 8 c.p. Swan lamps by 
means of the current from a secondary battery, 
charged from their arc wires. The examination 
of the lamp on December 6tli, 1884, showed it to be 
a Swan loop lamp, the straight arms of the U be- 
ing 2.5 cm. long and 2 cm. from one another, the 
loop being, therefore, 2 cm. in diameter. The 
light was of a decidedly yellow color, the inten- 
sity of the current being too low to attain the de- 
sired whiteness, the light, however, being steady 
and quiet; the light given forth December 10th 
was a nearer approach to whiteness. 
Not desiring to purchase a plant, I endeavored 
to employ the chemical battery, and ill a measure 
succeeded. The Grenet battery, because of its 
high intensity, appeared desirable, but unfortu- 
nately the elements'soon polarize and its efficiency 
rapidly diminishes. The battery requires consid- 
erable attention ; the zincs must be removed from 
the liquid after using, they must be kept clean 
and freshly amalgamated, the liquid must be fre- 
quently renewed. 
The Bunsen battery has also been used for 
electric lights. It is a battery which in its prac- 
tical workings is of comparatively low intensity, 
and is very dirty, too much |so’ to have in one’s 
office. At the Electrical Exhibition it was used 
to furnish the current for three small microscope 
lamps of about 1 volt each. Two~gallon Bunsen 
cells were employed, the liquid being renewed 
but once during the course of the Exhibition, the 
lamps being used one or more hours every day 
for some 35 days. The light, because of the low 
intensity of the battery, was decidedly yellow. 
The Leclanche battery is an open circuit bat- 
tery, also of low intensity.,; t Its employment is 
attended with,indifferent success. 
The Fuller battery, as modified by Dr. Starr, is 5 
also an open circuit battery, but unlike the Bun- 
sen and Leclanch£, is of high intensity, each cell 
having an electro motive force of almost 2 volts. 
This battery has been used for intervals through- 
out the day for more than three months, without 
requiring renewal of the plates nor recharging. 
The bisulphate of mercury battery has been 
employed, but runs down too rapidly. 
For the c. p. 9 volt Swan lamp, I employed 
6 to 12 half-pint Grenet cells, coupled for intens- 
ity, giving me, therefore, when the battery was 
fresh and in perfect order, an intensity of about 
20 volts. I found that this battery would answer 
fairly well, using it from 30 to 45 minutes per day, 
actual working time, for about a week. If after 
this it was used without renewal of the fluid, it 
could not be depended upon, the lamp perhaps 
burning well for a moment, and then becoming 
dull red. 
The c. p. Swan, when supplied by three 
half-gallon Fuller cells, gave a fairly good light, 
apparently steady after the battery had been 
used for more than three months. Had I been 
able to employ four of these cells, I do not doubt 
but that the whiteness of the light would have 
approached, and perhaps equaled that obtained 
from twelve fresh half-pint (frenets. 
For the c. p. 3.8 volt Starr lamp, I made use 
of four Grenet cells, half-pint each, and found 
the light thus obtained of a beautiful whiteness. 
When, however, the battery had been employed 
for about thirty minutes daily, after six or seven 
days the light became yellow and not to be relied 
upon, the battery requiring fresh fluid. 
Tbe 16 c. p. 95 volt Edison light used by me, 
was supplied from a dynamo machine, and gave 
a most beautiful light. 
Objections which have been urged against the 
employment of the electric light in examinations 
of the human organs are : first, the great heat ; 
secondly, the intensity of the light ; third, the 
sharp shadows occasioned ; fourth, the presence 
of the sharp image of the incandescent filament 
wherever the light is thrown ; fifth, its unrelia- 
bility ; sixth, its expense. 
Taking up these objections seriatim, we will 
discuss first tbe question of the excess of heat. 
The incandescent electric light is peculiarly free 
from appreciable heat, provided the lamp lias 
been well made, the vacuum being good. This is 
because there is no combustion. There is nought 
but an incandescent filament of carbon suspended 
in a vacuum. There is in fact so little heat ere 
ated by the well-made lamp that it was only with 
difficulty that the rhinoscopic mirror could be 
heated sufficiently by the 16 c. p. 95 volt Edison, 
to prevent the deposition of moisture. 
The second objection mentioned was the intens- 
ity or the brilliancy of the light. As yet, this 
has caused me no inconvenience. On one occasion 
I used the 16 c. p. 95 v. Edison steadily for an 
hour, giving forth a most brilliant bluish-white 
light, using it for the examination of a friend’s 
eyes at least half that time, with a peculiar ab- 
sence either of momentary blindness, or the least 
irritability occurring either in my friend’s or my 
own eyes. This examination was made between 
10 and 11 p. m., after a full day’s work, and was 
followed the next morning by a feeling of utmost 
comfort in both cases. Since this was written, I 
at night examined the left eye of a friend with 
the c. p. Starr light continuously for more than 
an hour, not only with no inconvenience to either 
of us, but with a feeling of the utmost ease, 
comfort and rest being present the following 
morning. However, in examinations with an 
intense white light, one must be careful not to 
gaze directly at the filament before making the 
examination, as in that case it will be difficult, 
because of the inferior intensity of the reflected 
light, to study structures carefully. This is 
easily prevented by interposing a shade between 
the light and your own eye, being careful not to 
obstruct the rays falling on the reflecting mirror. 
The sharp shadows, instead of being a disad- 
vantage, are in many cases very serviceable. In 
order to understand the reason of this, we must 
consider the nature of the light we are dealing 
with. In the electric lamp, we can get the light 
from a full red to extreme whiteness, the color 
depending mainly on the intensity of the current. 
By using a current of sufficient tension to produce 
a brilliant white light, we obtain not only the 
light from the incandescent filament, but we also 
have a less intense violet-white light occupying 
the entire globe of the lamp. If we look at an 
incandescent light, this luminous sphere may be 
so intense as to prevent us from seeing the fila- 
ment. When the electric light is reflected upon 
the membrana tympani, or upon the retina, or 
upon the structures of the posterior jnares, we 
notice the image of the filament very distinctly ; 
this is surrounded by the illumination derived 
from the vacuum (if it may be so called) sur- 
rounding the filament. This general illumina- 
tion may be used as readily as gas-light; the spe- 
cial illumination being used for the throwing of 
shadows, thus studying elevations and depres- 
sions, and for the more particular study of tbe 
structures. By throwing the bright image at 6 
various angles, we can not only overcome the 
shadow at any particular portion, but we can also 
study the more carefully any variations from the 
general curvature of the parts. By means of the 
shadow the curvature of the turbinated bones 
can be studied much more satisfactorily. The 
shadow is also of considerable advantage in ear 
work, by giving us a more correct idea of any 
irregularities or variations in the curvature. 
The fourth objection mentioned was the con- 
stant presence of the bright image of the incan- 
descent filament, whether the light was used 
alone or in connection with a Mackenzie or a To- 
bold ; whether beside a rhinoscopic or laryngeal 
mirror was employed. This fact has struck me 
as a peculiar advantage; it can be utilized, and 
will, I think, do us good se'rvice. As before men- 
tioned, the bright image is surrounded by a less 
intense, but more general illumination. In this 
general illumination the lines of the image stand 
forth sharp and clear. This bright line enables 
us not only to study special structures, such as 
the macula lutea, the porus opticus, and the 
blood-vessels of the eye more thoroughly; but 
also if the image of the light be for part of its ex- 
tent a straight line, it enables us to appreciate 
and estimate the degree of curvature of surfaces. 
Any elevation or depression present within the 
eyeball deflects the line of light; in posterior 
staphyloma there is a marked change in the di- 
rection of this line; the depth of the porus opti- 
cus is revealed by the angular deviation of the 
line; a slight elevation of the nerve is easily dis- 
covered by the same means. By means of this 
line, the degree of retraction of the membrana 
tympani and its curvature can be studied; in 
rhinoscopic examinations, the line is valuable for 
the same reason. In laryngeal examinations I 
have not found it of any service. 
The unreliability of the light is, I think, at 
present a valid objection. It is, however, not the 
lamp which is at fault, but the batteries. All 
chemical batteries are troublesome to have about, 
many of them give off acid fumes, and besides 
require considerable attention, running down 
rapidly; but by the employment of double fluid 
batteries, which are fairly constant, the light can 
be made to be much more reliable. 
At present, electric lights are expensive, not 
because of the original cost of the lamp itself, 
but because chemical batteries are expensive. 
There is, however, some hope of relief. At the 
present time, our electric light companies are 
keeping up steam all day for the running of their 
dynamo-electric machines at night; the cost is 
but little less than it would be were they to run 
them all day. There is no reason why the cur- 
rent should not be produced during the day, and 
be stored-up to be employed as necessary. There 
would he thus be a direct saving effected. Physi- 
cians could he supplied in this way at a moderate 
expense, and would then have a reliable current. 
Considering, now, the advantages of the elec- 
tric light, we have, first and foremost, its ap- 
proach to daylight—its whiteness. In all other 
artificial lights, with the exception of the calcium 
light, the yellow rays preponderate. Yellow rays 
are a decided disadvantage. So apparent was 
this to Wm. It. Wilde* that in his treatise on 
ear disease he writes, “Shades of vascularity 
produced by inflammation or congestion, speckled 
opacities, minute points of morbid‘deposit, and 
slight ulcerated abrasions, want of polish, and 
loss of transparency, etc, cannot be detected” by 
the artificial light. In the white light of the in- 
candescent filament there are no yellow rays, and 
the illumination resembles very strongly a good 
day-light. Of course, if the current traversing 
the filament be not of sufficient intensity, we may 
have yellow light. A second advantage is its 
brilliancy or intensity. This brilliancy is so in- 
tense as to allow us the more readily to recognize 
slight changes ; this is marked in ear examina- 
tions. By means of this light the rhinosoopic 
image becomes very much more dislinct, and the 
membrana tympani shows slight changes not 
otherwise discernable. 
There are two advantages possessed by this light 
which are often considered objectionable. I refer 
to the fact of the light casting strong shadows, 
and the presence of the image of the filament in 
the part illuminated. Having above set forth 
why I consider them as aids in examination, it is 
not necessary to say more. 
The vitiation of the air by gas is a material ob- 
jection, which is particularly noticeable in the 
dark-rooms of our eye dispensaries. The electric 
light would render the dark-room more bearable, 
and the headaches, so frequently occasioned, 
would be much less common. 
For the larynx and posterior nares, Dr. Starr’s 
or Dr. Seiler’s laryngoscope, or Trouve’s photo- 
phore, or the lights placed in a Mackenzie or To- 
bold condenser, can be employed. 
The illumination of the ear is best attained by 
means of a small lamp placed close to the specu- 
lum, the lamp enclosed in a shield or cap, with a 
small round opening; if a large lamp be at hand, 
* Diseases of the Ear, 1853, p. 69. 7 
the employment of the head mirror to reflect the 
direct rays into the ear is not to be despised. 
For the eye, the direct rays obtained from a 
large Edison or Swan lamp reflected into the eye 
prove of great service. These large lights are not 
always obtainable, and then the electric ophthal- 
moscope, before described, will be found to be of 
use. 
In purchasing a light, those ranging from to 
3 c.p. of not more than 10 volts, should be selected 
from. Lamps of larger size cannot at present be 
employed without the use of a very large and ex- 
pensive battery. Filaments of the Bodein, Bau- 
det, Edison, and Swan patterns should be em- 
ployed. 
To run lamps of the size indicated, requires 
from 2 to 16 half-pint Grenet cells, or 4 half-gallon 
Fuller cells. If the battery is to be employed for 
the light alone, the Fuller cells should be bought. 
For general use, a Baudet 9 volt lamp run by 4 
half-gallon Fuller cells, is, perhaps, the most sat- 
isfactory that can be purchased at present. 
When we all can have storage batteries charged 
by our electric light companies, we will be able to 
employ lamps of greater length of filament and of 
greater resistance, and will then become the more 
conscious of the advantages of the electric light 
over all the other lights for medical examinations; 
and they will then be as common as the Argand 
burner is to day. 
I can do no less than acknowledge my indebted- 
ness to Dr. Wm. H. Burk, for assistance kindly 
rendered during the course of this paper. 
Simanovoski (Ejened Klin. Gaz. St. Peter’s, vol. iii, 1883, p. 473,) describes the Trouve electrical 
pliotopliore, mentioning however that he had not even seen it. 
De Wecker (De l’emploi de la luminere electrique en chirugie oculaire, Rev. Clin. d’Ocul., Oct. 
1883) has employed the photophore electrique in the operation for cataract. 
Messrs. Queen & Co., expect to be able to furnish the electrical ophthalmoscope described, in the 
course of a few weeks, by which time it probably can be obtained from opticians generally. 
ADDENDA.