ceeded to make a number of experiments, with the hopes of obtaining the muriatic acid free from moiffure. Phofphorus was burnt in oxymuriatic acid, a white fubftance collected in the top of the retort, and a fluid as limpid as water trickled down the fides of the neck. Minute experiments proved that no gafeous muriatic acid had been evolved in this operation. The fublimate, when expofed to air, emitted fumes of muriatic acid. When brought in contact with water, it left diffolved in it phofphoric and muriatic acid, and evolved muriatic acid gas. It was a non-conductor of electricity, did not burn when heated, but fublimed at the temperature of boiling water, leaving no refiduum. Mr. D. regards it as a combination of phofphoric and muriatic acid in their dry states. The fluid was of a pale greenish yellow tint, very limpid; exposed to the air it rapidly difappeared, emitting denfe white fumes, in fmell refembling muriatic acid. It reddened litmus paper in its common ftate, but had no effect on well dried litmus paper. It was a non-conductor of electricity. It heated when mixed with water, and evolved muriatic acid gas. Mr. Davy confiders it as a compound of phosphorous acid, and muriatic acid, both free from water. Having failed in obtaining uncombined muriatic acid, in this way, Mr. D. performed a fimilar procefs with fulphur, but was unable to cause it to flame in oxymuriatic gas. When heated in it, it produced an orange coloured liquid, emitted yellow fumes, which condensed into a greenish yellow fluid. By repeatedly paffing oxymuriatic acid through this fluid, and diftilling it feveral times in the gas, it became of a bright olive colour, and in this ftate it feemed to Mr. D. to be a compound of dry fulphuric and muriatic acid, holding in folution a very little fulphur. When heated in contact with fulphur, it rapidly diffolved it, and became of a bright red colour, no permanent aeriform fluid was evolved, and no inuriatic gas appeared, unless moisture was introduced. When these compounds are expofed to potaffium, a violent detonation takes place, which Mr. Davy feems to think an evidence that the muriatic acid then fuffers decompofition, He intimates that he is ftill profecuting the inquiry, and promifes to communicate the refult of his labours to the fociety. (To be concluded in our next.) ART ART. V. A Practical Treatife on Tinea Capitis Contagiofa, and its Cure. c. c. by W. Cooke, Surgeon, Brentford. Pp. 259. IN London. 1810. Nufhering his book into the world under the protection of that celebrated morbid anatomift Dr. Baillie, Mr. Cooke flatters himself that the public (from esteem for Dr. B.'s" talents and integrity") will be "induced to receive his work more favourably," than if expofed without fuch patronage, "with all its imperfections on its head." This is a fnare very commonly used to entrap the unwary reader, · whom, however, we cannot too earneftly guard against fuffering himself to be blinded by the fplendor of any name which may appear at the head of a dedication. He should rather think for himself, and meafure the merit of an author by the fcale of his own judgment. On a curfory view of this book, we were certainly inclined to be fevere with the author on account of the multiplicity of his references and quotations, a practice fo prevalent among modern authors, that we cannot forbear faying with Hamlet, "'tis villainous, and fhows a pitiful ambition in the that ufes it.” But let not Mr. Cooke be offended at this phrafe, for he of all others fhould remember as Sylvefter Daggerwood cells Fuftian, that 'tis only a quotation.' Upon a more attentive perufal however, though we fill cannot avoid thinking that this volume favours not a little of book-making, yet we find fome very ingenious, and practically valuable obfervations, which do credit to the author, and may render the work upon the whole far from being ufelefs: it difplays alfo a degree of profeffional zeal and attention, which though we muft lament its unfortunate combination with the Scribendi Cacoëthes is at leaft very gratifying. The first part of the book is occupied by an enquiry into the nature, origin, diftinguishing character, and treatment of the difeafe called fcald head, which is here ftyled Tinea Capitis Contagiofa; and is explained to be a fpecific, and the only contagious difeafe of the fcalp; having an origin fui generis, and not in the feat of any other difeafe of the fcalp. Mr. Cooke tells us, that" from a careful examination of the manner in which the hairs arife from the inner fide of the cutis," he has "long thought that the arteries of the cellular membrane, give off, in their diftribution, fmall branches to the fecreting, and involving capfules of the roots of the hairs," and it is in thefe fecreting capsules of the bulbous roots of the hairs that he fixes this difeafe. All cther 66 a other fpurious, and anomalous kinds of tinea, Mr. Cooke thinks are of a totally different origin and nature, and are feated in the cutis, which he fuppofes to have a set of veffels different from, and independent of those of the roots of the hairs. This idea is more ingenious than it is either practically useful, or demonftrably correct. It is true careful examination" is mentioned, but not a word transpires refpecting the mode of fuch examination. Nothing is faid of injecting the part, nor of any other means of coming at the truth of his thoughts. The author deduces his theory merely from the phenomena of other difeafes; he obferves, that in inflammatory affections of the fcalp, in fmall pox, fpurious tinea, &c. the hairs are not involved in the dif ease, that they" remain firmly attached to their origin ;" and thence argues, that the veffels fupplying the fecreting capfules of the bulbs of the hairs are independent of thofe which form the cuticular covering. He draws the fame deductions on the other hand from the fact of the hairs always falling off in tinea capitis contagiofa, a circumstance which he confiders as the mark by which this disease may be known from all others. Such reasoning as this, however ingenious, while unfupported by demonftration, neither can, nor ought to convince a philofopher of the prefent age. The following Mr. Cooke offers as his definition of tinea capitis contagiofa. "A flightly raifed fcurfy patch, fuddenly attacking the fcalp, accompanied with itching, and a feparation of the hairs. It generally commences in the form of a ring, in the centre of which the hairs at firft remain till the difeafe gradually fpreads, when baldness fucceeds, with occafional ulceration of parts of the fcalp denuding the pericranium." That there is one cutaneous affection of the head more inveterate, and, from the acrimony and irritating quality of the fecretion attending it, more contagious than the reff, which is the true fcald head, is, we conceive, generally allowed; and we may alfo allow that many minor affections of the fcalp are frequently confounded with it: but we do not give into the author's notion of the peculiar and specific nature of fcald head; of its differing in tote from all other cutaneous affections; for we are inclined to think that many minor cafes, by neglect, may degenerate into the inveterate fpecies, and claim a fair title to the name of tinea capitis contagiofa. In his treatment of the difeafe Mr. Cook mentions the oil fkin cap as having been a favourite remedy, and indeed it it meets with his approbation, for he is inclined to think that it acts not only by preventing evaporation," (as Mr. Fox ftates) but that it acts alfo "as a perpetual vapour bath, encouraging exhalation from the veffels of the cutis." The following remedies are what Mr. Cooke's experience has taught him chiefly to eftimate. As a liniment "R. Hydrarg: nitrico-oxydi (bene levig: 3ij. Cerat. cetacei. 3ij. m. intime et ft. liniment. Oblinatur pars affecta omni nocte per tres vel quartas vices." He uses alfo common flour of muflard, in the form of a pafte, with equal advantage; he is induced likewife to think that arfenic, and the antimonium tartarifatum, as well as hellebore, bryony, fabin, and other ftimulating vegetables will anfwer the fame purpofe. P. 82. The fymptom on which Mr. Cooke principally relies, as indicative of a cure being completed, is, "an inflammation round the ring or patch." He then withdraws the flimulus, and washes the parts with warm foap and water. We recommend from our own experience, in addition to the above, the cali fulphuratum, both as a lotion, and as an internal medicine. It will be feen that Mr. Cooke omits to notice murcurials in his lift of remedies, he however does not difcard them, but confiders them as poffelling no virtues fuperior to the vegetable preparations mentioned. At page 206, which may be confidered the fecond part of the work, Mr. Cooke gives us his " arrangement of cutaneous difeafes which," from his own experience, he flatters himself will be found practically beneficial." He previously, however, endeavours to point out fome line of diftinction between fympathetic and idiopathic affections of the fkin; the forms being very judicioufly diftinguished from the latter as requiring no topical, or fpecific remedies. This line of diftinétion, however, is not fo evident in practice as our author lays it down to be in theory; though his efforts may nevertheless prove not altogether useless. For a general view of thofe various cutaneous affections refulting from "conflitutional and contagious fevers, morbid ftructure, or difordered action of internal parts," we must refer the reader to the work itself, but the following is the outline of the above-mentioned arrange ment. "1. Thofe cutaneous difeafes which arife from local and contagious affections of the fkin, as tinea capitis contagiofa, and fcabies. 2. Thofe 2. Thofe that are primarily local, and not contagious, and which are supposed to arise from a peculiar and difordered action of the veffels of the fkin, viz. The various fpecies of farco. matous, and encyfted tumours, fungi hematodes, nævi materni, warts, corns, the cutaneous ulcer, and that which has been confidered cancerous, or more properly phagedenic. 66 3. Thofe that accompany and are characteristic of fome conftitutional and contagious disease, viz. variola, rubeola, vaccina, scarlatina, varicella and fyphilis. 4. Those that depend upon morbid ftructure, difordered action of feme internal organ, or furface, upon an acrimonious ftate of the blood, or upon an increased or diminished strength in the vis vita, which have been generally known under the terms lepra, elephantiafis, alphos, pforiafis, fcorbutus, eryfipelas, urticaria, miliaria, gutta rofea, crufta lactea, porrigo, herpes, petechiæ, carbunculus, &c. &c. to which may be added the state of the fkin in gout, acute rheumatism, and jaundice. 5. Thofe that are induced by external and fimple stimuli, fuch as incifed, lacerated, and contufed wounds, burns, fcalds, chilblains, and the bites and ftings of various infects, and animal. culæ. 6. Those that are excited by external and fpecific ftimili, viz. The bite of the mad dog, and rattle-fnake." P. 138. . Mr. Cooke doubts not that he has omitted various names that at different time have been annexed to particular cutaneous appearances, but these omiffions have arifen "folely from the defire of curtailing and fimplifying the cutaneous nomenclature," The reader will perceive that the fyftem here laid down, has its faults, and what fyftem has not? We will not, however, quarrel with our author's arrangement, but proceed to fome of his obfervations on the particular difeafes comprifed in it, firft obferving, however, that plica poloniea, not being certainly known, appears on that account to have been omitted by Mr. Cooke. In the 2nd order the reader will find that dreadful disease noticed, which has not, till of late years, been understood, fungus hematodes, but which has been molt accurately described by Mr. Hey, of Leeds, by Mr. Wardrop and others. Mr. Cooke gives us fome cafes to fhow the great fuccefs he met with in the cure of this fingular disease" by the application of the ligature, and arfenic, a mode of treatment which to us is perfectly novel. We have witneffed many cafes of fungus hematodes, but do not remember one, in which, however, cleanly and carefully the diffection was made in extirpating the tumour, it did not again return, and we believe that like cancer (Mr. Home, indeed calls it cancer affecting |