A N ESSAY O N CULINARY POISONS. CONTAINING CAUTIONS RELATIVE TO THE USE of LAUREL-LEAVES, HEMLOCK, MUSHROOMS, COPPER-VESSELS, EARTHEN JARS, fcc. with Obfervations on the Adulteration of Bread and Flour, And the Nature and Properties of Water, Unde fames homini vetitorum tanta ciborum ? Audetis vefci, genus 6 mortale ? quod, oro, .Ne faclte ; ct monitis animos advertite nollris. Ovid. Met, xv. 13$, Printed for G. Kearsly, at No. 46, near Serjeants LONDON. Inn, Fleet-Street, MjDCC^LXXja. CONTENTS. page Of the Lauro-Cerafus, or common Laurel, - 9 Hemlock - - 12 Mufhrooms - - 13 Copper veflels * - 15 The folution or fait of lead - 21 Brown earthen ware, &c. - ib. Of the adulteration of bread and flour 25 Of Water. -r - 28 Rain water - - 31 Snow water - - 33 Spring water - - 35 Stagnant water 36 Pump water - - ib. Thames and New-River water 39 Methods, by which water may be ob- tained in its greatefl: purity - 40 PREFACE. MANKIND are fubjed: to innu- merable difeafes, from which other animals are exempted. But from whence do thefe difeafes arife ? From the feeds of mortality in the human frame ? From luxury and in- temperance ? Or from an indifcreet life of vegetable and mineral poi- fons in the preparation of our food ? —From the laft of thefe fources we certainly derive many troubleiome, and fometimes fatal diforders : fo that, on many occafons, we may exclaim with the Tons of the pro- phets*, “ There is death in the pot!” * a Kings iv, 40. The defign of this publication is to guard people againft thefe difafi ters; and, if poflible, to prevem: fome of the calamities of human life. If it fliould anfwer this ufeful purpofe, the author’s ambition will be fully gratified. O N CULINARY POISONS. t. The LAURO-CERASUS, or Common LAUREL. THE water diftilled from the leaves of this tree has been frequently mixed with bran- dy, and other fpirituous liquors, in order to give them the flavour of ratifia; and the leaves are often ufed in cookery, to communicate the fame kind of tafte to cream, cuftards, pud- dings, and fome forts of fweetmeats. But, in the year 1728, an account of two women dying fud- denly in Dublin, after drinking fome of the com- mon diftilled laurel water, gave rife to feveral ex- periments, made upon dogs, with the diftilled water, and with the infufion of the leaves of the IO lauro-cerafus, communicated by Dr. Madden, phyfician at Dublin, to the Royal Society in Eng- land, and afterwards repeated fin the year J731) and confirmed by Dr. Mortimer, F. R. S. by which it appeared, that both the water and the mfufion brought on convulfions, palfy, and death, when taken by the mouth, or anus *, Dr. Mead f fpeaks of the foregoing accident and experiments in thefe terms : tc A fmall quantity of this water killed two women, who drank it, very Suddenly. Hereupon a learned phylician, fur- prized at the event, (this plant having never been thought to be any wife noxious.) made feveral ex- periments with it upon dogs, which were after- wards, fome of them, repeated here, with the fame fatal fuccefs.” Dr. Mortimer affirms, “ that laurel-water is equally mortal with the bite of the rattle-fnake, and more quick in its operations than any mineral poifon.” • See Philofophical Tranfa&ions, No. 418, and 430, t Mead on Pollens, Effay r. Dr. James fays: “ laurel-water is the moft de- leterious poifon perhaps known, killing almoft inftantaneoufly J.” The laurus of the ancients, or the hay, is, on the contrary, of a falutary nature, and of ufe in fe- veral diforders. It may be faid, that the laurel in cuftards, and other articles of cookery, is ufed in very fmall quantities, and has never been attended with any pernicious effefl. But, I afle, who can pretend to aflert, that it has not occafioned feme latent diforder, or fome complaints, which have been aferibed to other caufes ? What perfon of fenfe or prudence would truft to the diferetion of an ig- norant cook, in the ufe of a dangerous ingredient in his puddings or cuftards ? Or, who, but a madman, would choofe to feafon his victuals with poifon ? The remedy is from ten to forty drops of fal ammoniac, in a glafs of water, repeated as the fymptoms may require. % James’s Difpcnfatory, book iii. c. i. p. zzS %. Small HEMLOCK, or FOOLS PARSLEY, Description. The firft leaves are divided into numerous fmalj parts, which are of a pale green, oval, pointed, and deeply indented. The italic is ilender, round, upright, ftriated, and about a yard high. The flowers are white, growing at the tops of the branches in little umbells. It is an annual plant* common in orchards and kitchen gardens, and flowers in June and July. This plant has been often miilaken for parfley: and from thence it has received the name of Fools Varjley. Though it feems not to be of fo virulent a na- ture as the larger hemlock, yet Boerhaave places it among the vegetable poifons, in his Inftitutes; and, in his Hiftory of Plants, produces an in- ftance of its pernicious effefls J. It is there- % Inftitutes, § 1138, Hift. of Plants, p. 93. fore necefiary to guard againft it in collefting herbs for fallads, and other purpofes. 3. MUSHROOMS. Mulhrooms have been long ufed in fauces, in ketchup, and other forms of cookery. They were highly efteemed by the Romans, as they are at prefent, by the French, Italians, and other na- tions. Pliny exclaims againft the luxury of his coun- trymen in this article; and wonders, what extra- ordinary plcafure there can be, in eating fuch dan- gerous food*, The ancient writers on the Materia Medica feem to agree, that mulhrooms are in ge- neral unwholefome j and the moderns, Lemery, Allen, Geoffrey, Boerhaave, Linnaeus, and others, concur in the fame opinion. There are nume- rous inftances upon record of their fatal effedls. * Quae voluptas tanta emdpitis cibi ? Plin. Nat. Hift, xxii, 23. Almoft all of them, as the laft-mcntioned author affirms, c< are fraught with poifon f.” The common efculent kinds, if eaten too freely, frequently bring on heart-burns, ficknefies, vo- mitings, diarrhoeas, dyfenteries, and other danger- ous fymptoms. It is therefore to be wiffied, that they were baniffied from the table. But, if the palate muft be indulged in theft treacherous gra- tifications, or, as Seneca £ calls them, this << vo- luptuous poifon”, it is necefifary, that they, who are employed in coliefling them, Ihould be ex- tremely cautious, left they fnould collefl fuch aS are abfolutely pernicious ; which, confidering- to whole care this is generally committed, may, and undoubtedly has, frequently happened §. f Fungi plerique veneno turgent. Liana;! Amaen* Acad. vol. i. | Quid tu illos bolctos, voluptarium venenum, nihil occulti operis judicas facere, etiamfi, praifentanei non fu- rant ? Sen. Ep. 95. § Sec Gentleman’s Magazine, December, 175$ ; and Sup- plement, September, 1757. The eatable mufhrooms at firft appear of a roundilh form, like a button ; the upper part and the ftalk are very white j the under part is of a livid flefh-colour ; but the flelhy part, when bro- ken, is very white. When thefe are fuffered to remain undifturbed, they will grow to a large fize> and expand themfelves almoft: to a flatnefs, and the red part underneath will change to a dark colour. COPPER VESSELS, Copper, when it is handled, yields an offenfivc fmell, and if touched with the tongue, a lharp pungent tafte, and even excites a naufea. Yer- degris is nothing but a folution of this metal by vegetable acids. And it is well known, that a veryfmall quantity of this folution will produce chokes, vomitings, intolerable third:, univerfal convulfions, and other dangerous fymptoms* If thefe effeds, and the prodigious divilibility of this metal be conlidered, there can be no doubt of* its being a violent and fubtile poifon, We are daily expofed to this poifon by the prefent ufe of copper veffels for dreffing our food. The very air of the kitchen, abounding with oleaginous and faline particles, penetrates and dilpofes them to diflblution, before they are ufed. Water, by Handing fome time in a copper veffel, is impreg- nated with verdegris, as may be demonftrated by throwing into it a fmail quantity of any volatile alkali, which will immediately tinge it with a paler or deeper blue, in proportion to the ruft contained in the water. Vinegar, apple-fauce, greens, oil, greafe, butter, and almoft every other kind of food, will extrad the verdegris in a greater degree. It is true, people imagine, that the ill effeds of copper are prevented by its being tinned : but the tin, which adheres to the is fo extremely thin, that it is foon penetrated by the verdegris, which infinuates itfelf through the pores of that metal, and appears green upon the furface. M. Amy, of the Academy of Sciences at Paris, obfcrves, that tc verdegris is one of the moft vio- lent poifons in natureyet, fays he, “ rather than quit an old cuftom, the greater part of man- kind are content to fwallow fome of this poifon every day”. Amy’s Treat, upon Citterns, printed at Paris, 1750. M. Thiery, in a thefts, which is added to this tra especially in London. It appears from the analyfis performed by Dr, Hebcrden t, that Several pump waters in Lon- don, which he had examined, and probably molt f See Medical Tranfaft. vo!, i. of them, contain powder of lime-ftone, and the mineral acids of vitriol, nitre, and fea-falt, united in various proportions. Thefe waters are like- wife tainted with an oilinefs, which gives them a remarkably yellowifh caft, when compared with pure diftilied water. It is reafonable to think, that waters impregnated with fuch active fub- ftances, in a quantity fufticient to render them difagreeable to the tafte, cannot always be drunk with impunity. They have accordingly been fuf- pected of occafioning pains in the ftomach and bowels, glandular tumors and coftivenefs, v/here the fimple lime-ftone prevails ; and diarrhoeas, where much of it is united with the folution of a- cids; and it is probable, that a continued ufe of fuch water may be the caufe of many other dif- orders, efpecialiy to the infirm, and to children. From whence it follows, that a change of place may often be of as much ufe to weak perfons, from the change of water, as of air. Some obfeure notion of the unwhoiefomenefs of pump water, induces many perfons to boil it, and let it ftand to grow cold ; by which it will indeed be made to part from moft of its un- neutralized lime-ftone and felenite ; but at the fame time it will become more ftrongly impreg- nated with the faline matter, and therefore it will be worfe. If a fmall quantity of fait of tartar were added to the water, it would readily precipitate both the loofe lime ftone, andlikewife that which is united to the acids. Ten or fifteen grains would gene- rally be enough for a pint; but the exad propor- tion would readily be found, by continuing to add to it, by little and little, till it ceafed to oc- cafion white clouds. This is an eafy way, not only of freeing the water from its lime-ftone, but alfo of changing the faline part into nitre and fal fylvii, both of which we know, by long experi- ence, to be innocent. But the beft way of avoiding the bad effects of pump water would be, not to make a confcant ufe of it ; and in a place fo well fupplied with river water as London, there is very little necef- fity to drink of the fprings, which in fo large a city, befides their natural contents, muft collecl many additional impurities from cellars, burying- grounds, common-fewers, and many other offen- iive places, with which they undoubtedly often communicate ; fo that it is indeed a wonder, that we find this water at all tolerable *. THAMES and NEW-RIVER WATER. V River waters partake of the properties of their fprings, and the channels, through which they run ; yet, in a wonderful manner, they foon free themfelves from their impurities. The motion of the current f, the abforption of the foil, the fun and rain, have each of them a confidcrable fhare in this efled. The Thames water, efpecially in the neigh- bourhood of London, is mixed with many impure ingredients. It is faid to become offenfive in fe- ven or eight days, or fometimes fooner, if it be kept in unfeafoned cafks. In this ftate it gene- rates a quantity of foul inflammable air, as may be feen by holding the flame of a candle to the bung-hole of a calk when it is firfl; opened. But * See Medical Tranfadl. vol. i. f The moll: rapid rivers contain, cseteris paribus, the pure# water. by this fermentation it foon purges itfelf; and by opening the bung, it will often become fweet in twenty-four hours, and fooner, if it be poured from one veffel to another, or ventilated *. Methods, by which Water may be OBTAINED IN ITS GREATEST PuRITY. As it appears, that almoft all the water ufed in cookery is tainted with impure ingredients ; rain water, with a great variety of volatile bodies, fuligi- nous particles, exhalations, invifible feeds, and in- fers ; river, pond, and well water, with a mixture of foil and mud, decayed vegetables, and the fpawn of vermin, it will be very proper to purify it, before it is ufed for drinking, or any culinary purpofe. This may be done by various contrivances. i. The water of the Thames, and that of the New River, are very often muddy, or take ilrongly of weeds and leaves. Dr. Heberden ac- knowledges, that the latter fault cannot eafily be * Philof. Tranf. No. 127, 268. Boerh. Elem. of Chem. vol. 1. p. 333. Rotlieram’s Philof. Inquiry. 4* remedied ; but, he obferves, they would foon be freed from their muddinefs, if kept fome time in an open jar ; and he is of opinion, that if the wa- ter given to very young children, were thus puri- fied, it might prevent fome of their bowel-difor- ders, and fo contribute a little to leflcn that a- mazing mortality among the children, which arc nurfed in London, 2. Rain water, when grown putrid, as Boerhaavc allures us, may be eafily rendered wholefome a- gain, and may be drunk without being offenfive, by only boiling it a few moments: for by this expedient, the animals that are in it will bede- ftroyed, and, with the reft of the impurities, will fubfide to the bottom. If then, fays he, you make it moderately acid, by adding to it a fmali quantity of acid that is very ftrong, it will be fit for ufe. This is found to be of excellent fervice under the Equator, and between the Tropics, where the waters putrify in a horrible manner, and breed a multitude of infefls, and yet muft be drunk. For the fame reafon, a fmali quantity of fpirit of vitriol, mixed with water, will prevent its growing putrid, and breeding any animals, and, at the fame time, preferve It wholefome and good *. 3. A common way of purifying water is by fil- tration. Water, which is filterated through por- ous flones, is extremely clear and limpid j but fome writers have afferted, that it acquires a pe- trifying quality in its padage, which, at length, may produce dlfagreeable effedds jl. However this may be, thefe ftoncs are too dear for common ufe. Dr. Rotheram afferts, that one of the readied; and belt methods of filtering water, is, to let it run through a bed of clean fand. This is, he fays, preferable to the filtering-done, as it per- forms its work much fooner; and the grains of fand are of fo many different figures, that they arc pretty fure to flop the progrefs of any bodies of fenfible bulk, in paffing through them §. * Boerh. Chetn. vol. 1. p. 348. 4 M. Amy on Cifterns; but fee above, p. 31. § If you view ten thoufand grains of fand through a ml- crofcope, you will fcarcely find two of the fame fizg and lhape. Rotheram’s Philofophical Inquiry, p. 4S. cc A friend of mine, fays the Dodor, in this town [Newcaftle] has a ciftern for colleding rainwater, fo conftruded, that it both allows the water to fubfide, and the upper part of it to run through a bed offand, which is raifed by a parti- tion above the bottom of the ciftern; by which means the water becomes perfedly clear and bright, and is preferred by molt who have tailed it, to any other water in this town”. 4. Some have objeded, but probably without reafon, to this mode of filtration, on a prefump- tion, that the fand has the fame effed on the wa- ter as the filtering ftone : for it is faid, that the fand is infenfibly diflblved by the water ; fo that in four or five years it will have loft a fifth part of its weight. M. Amy therefore recommends the filtration of water through a fpunge, more or lefs comprefled. And this, he allures us, will render it, not only more clear, but more whole- fome, than either a ftone or fand. 5. As the pureft of all water is obtained by diftillation. Dr. Heberden recommends this me- thod, as particularly ufeful where fuel is cheap ? and the water is bad j as it is in Ibme of our fo- reign fcttlemenrs. The firft running of diftilied water has a difa- greeable mu fly tafte: on this account, if the ftiil hold twenty gallons, it will be neceffary to throw away the firft gallon. The reft, through free from this muftinefs, will have a dilagreeable em- pyreumatic or burnt tafte. This tafte goes off by keeping about a month, by ventillation, in a few minutes, or by boiling the water in an open vef- fel. Diftilied water mull be kept in perfedtly clean glafs or ftone bottles, with glafs ftoppers, or metal covers; and then, having in it no prin- ciple of corruption, it is incapable of being fpoiled, and will keep juft the fame for ever. But the leaft particle of any animal or vegetable fubftance, will fpoil a great quantity ; and there- fore the ftili and bottles ftiould be kept wholly for this ufc. This proeefs, though certainly attended with many good effects, requires too much time and attention for common nfe; and therefore, in ge- neral, it may be fufficient to adopt the mode 45 of Alteration, recommended by Dr. Rotheram, or that which is propofed by M. Amy. The obfervations, which I have here laid before the reader, are not new. They have been com- municated to the public by others. But they are difperfed through many different publications, I have therefore thrown them into a fmail compafs. And I flatter myfelf, that, in this commodious form, they may be acceptable to the public i as many of the foregoing ar- ticles are of infinite importance to the health, and confequently to the happinefs of mankind. FINIS,