and the foetal circulation cease, that moment do the thorax and diaphragm commence operation; and if the placental function ceases for but a few minutes, before the mouth or nostrils get into atmospheric air, the child is irretrievably gone. That thorax and that diaphragm, having once begun, must continue their motion till death. The first sign of death is the disappearance of respiration; and the first sign of recovery from asphyxia is a renewal of respiration. It is not until God breathes into the nostrils the breath of life that man becomes a living creature; and no sooner does the breath cease, than man becomes a mere lump of organized clay.

Upon this view of respiration and nutrition, and upon the reciprocity of their functions, or rather upon the subordination of nutrition to respiration, I have formed a new theory of diseases, and more . rational and successful methods of cure. To enter upon this subject would be encroaching in kind, as well as quantity, on your Journal.. That purgation is a cure for melancholia and mania, I in the mean time take this opportunity of announcing; both to secure to myself the discovery, and the sooner to remove the most afflicting and the most horrible of all the sufferings of humanity. The rationale and cases shall be brought forward in detail elsewhere. I expect shortly to see many who had recommended or administered a few doses of physic to these diseases start forth as claimants of this discovery. I remain, very respectfully, Sir,

Your most obedient servant,

JOHN CROSS.

ARTICLE V.

Experiments showing that in Hepatitis the Urine contains no Urea. By Mr. C. B. Rose.

SIR,

(To Dr. Thomson.)

Eye, April 6, 1815.

PERMIT me, through the medium of your Annals, to transmit to its chemical and medical readers the knowledge of the absence of urea from urine not being confined to the urine of diabetes only; for, while examining the urine of a girl labouring under a chronic inflammation of the liver, I could discover no trace of urea : indeed, its absence was as complete as in cases of diabetes mellitus ; and I have ascertained this to be the case by a repetition of my experiments on the urine in several cases of acute as well as chronic inflammations of the liver. The urine operated upon in acute hepatitis was rather high coloured; in the chronic disease, it was pale; its odour not so urinous; its specific gravity less than that of healthy urine; and consequently left a smaller quantity of extract when evaporated.

Whether the above state of the urine is dependant on the

dyspeptic stomach from hepatitis only, or on every case of dyspepsia, I have not yet satisfied myself; but I intend pursuing the subject with that view.

Unavoidably drawn by this discovery to turn my thoughts on the nature of secretion and digestion, I have dared to indulge in speculative ideas. That there subsists a great connexion between the stomach and the kidneys, not merely sympathetic, and that the state of the urine depends very much upon the state of the digestive organs, has long been observed; but that there existed this decided concatenation between the liver, stomach, and kidneys, was not, I think, before known. As this concatenation is demonstrated by the above circumstance, is it not probable that the kidneys have a similar consent of action with all the chylopoetic viscera? And is it too sweeping a conclusion to draw, from our present knowledge of secretion and digestion, if we say that it is probable in diabetes mellitus the saccharine quality of the urine is dependent on the morbid action of the stomach, and the absence of urea from the urine on a deranged state of the hepatic function? Or to suggest the probability that some one or other of the proximate elements of the urine is lost, or a new one added, by a morbid action of one of the chylopoetic organs? For instance, what change in the urine may a schirrhous pancreas produce? These inferences must not be tolerated until more data are produced; nor should I have hazarded either of them, had I not some reason to believe, from the examination of the urine of two dyspeptic patients, that the want of urea is observed in cases of hepatitis only.

Might not the want of urea in the urine of persons attacked with hydrocephalus, be a diagnostic mark between hydrocephalus idiopa thicus, and hydrocephalus from altered function of the liver?

It is, I trust, the general opinion of the physiologists of the present day that the kidneys are not merely separating but secreting organs and the absence of urea in hepatitis I consider as an additional fact in support of the latter opinion; for if that state of the stomach consequent on a morbid action of the hepatitic system is productive of a want of urea in the urine; and if urea has never been found in the blood (which it never has); must we not infer that its elements are the products of digestion; that they, in a peculiar state of combination, are presented to the crypta of the kidneys, where it is presumed the secretory power resides, and there recombined. I have communicated this fact, and my reflections on it, to you, in its unexplored state, merely with the view to excite an inquiry into, and an examination of the subject, by persons far more equal to the task than myself.

You may insert the following also, if you think it worth notice. Perhaps to those of your medical readers who are but little versed in chemical analysis, and not furnished with any chemical apparatus, and yet would be desirous of examining the urine in hepatitis, not only with the intent to prosecute the above inquiry, but also to assist in establishing the diagnosis of that disease, a brief relation of the

method I have followed in my experiments, and a description of the apparatus I have invented to operate with, may not be unacceptable.

Dr. Henry, in the first number of the Annals of Philosophy, after having related some experiments on the urine discharged in diabetes mellitus, in which he employed the nitric acid with the extract as a test of urea, says, "There is one property, however, of this substance, originally pointed out by Foureroy and Vauquelin, which enables us to detect urea, even when present in such minute quantities as to escape discovery by nitric acid. Amidst the great variety of animal products, this appears to be the only one which is decomposed, when in a state of solution, by the temperature of boiling water. At this low degree of heat its elements, held together by a balance of affinities which is easily disturbed, arrange themselves in a new order; ammonia and carbonic acid are generated; and carbonate of ammonia is composed, equivalent in weight to about two-thirds that of the urea. It is in the fluid, therefore, condensed during the evaporation of diabetic urine, that we are to look for traces of the existence of urea; and in this fluid I have invariably found a sufficient quantity of carbonate of ammonia to restore the colour of reddened litmus paper, and to precipitate muriate of lime." In my search for urea I have generally chosen this method by distilling the urine, and applying the tests to the condensed fluid, in preference to the more tedious process of evaporation for the extract, &c. In Dr. Henry's paper, (Annals of Phi losophy, No. 1.) and in his Elements of Experimental Chemistry, may be found information sufficient to enable any one to accomplish the examination of urine for the above purpose with the necessary precision.

Having collected the condensed fluid, I put some of it into a wine-glass, to which I add some solutio muriatis calcis; if a precipitate subside, I drop some acidum muriaticum into the liquid, which, from its greater specific gravity, passes to the bottom of the glass, comes in contact with the precipitate, and a brisk effervescence follows, the decisive test of the existence of urea in the urine.

Not being provided with retorts, &c. the following apparatus is what I have constructed to effect the distillation of the urine, and it answers the purpose extremely well. My retort is a Florence oilflask; to which, by means of a perforated cork, I adapt a barometer tube, which has a small part at the end next the flask, bent to rather an acute angle, and at the other end a portion sufficiently long that it may reach nearly to the bottom of the receiver, bent to nearly a right angle, so that when the opposite ends are placed in their respectives places the tube lies in an inclined plane. By means of a leather collar fastened to the top of a jar, I fix in it a wide mouthed bottle for a receiver. The lower end of the tube passes into this, through a perforated cork, and a small short tube is passed into the receiver to admit of the exit of air. This cork should be

luted into the bottle; perhaps putty is the best lute. The jar is filled with cold water as a refrigerator; but the principal agent in condensing the vapour is a glass syphon (and so efficient is it, that the condensed vapour falls guttatim into the receiver). It is placed so as to convey cold water on to the tube which connects the retort with the receiver, and this, trickling along it, is received by a large bason, in which the jar and bottle stand. The tube may be luted to the flask and bottle with a stiff dough of flour and water. If the lute is not carefully, and in sufficient quantity, applied around the tube where it passes into the cork of the receiver, the water from the syphon will wash it away, and into the receiver, making the liquid cloudy, and oblige you to repeat the process. The longer the tube is to convey the vapour, and the larger its calibre, the better it is for your purpose. The calibre of the syphon may be between a twelfth and a sixteenth of an inch in diameter. These tubes may be bent in any form, with the assistance of a lamp and blow-pipe, or a blacksmith's fire. Fearful that my description of the still which I have been in the habit of using is not sufficiently clear to enable any body to construct one by it, I have subjoined a rough sketch of it as it appears when in use. The readiness with which its materials may be had, the ease with which it may be constructed, and the convenience of such a simple apparatus to the juvenile experimentalist, are things which I hope will in some measure repay you for giving the above tedious description, and the following sketch, a place, which might have been occupied by something of more importance.

I remain, Sir, yours most respectfully,

C. B. ROSE.

a, the Florence oil-flask; b, the bottle, as the receiver; c, the jar in which the bottle is fixed; d, the barometer tube to convey the vapour; e, the jug of cold water; f, the glass syphon; g, the bason in which the jar stands.

ARTICLE VI.

Reply to Mr. Phillips's Animadversions. By Mr. Hume.
(To Dr. Thomson.)

SIR,

WHEN your correspondent, Mr. Phillips, shall have finished his consultation with Klaproth's Essays he will find me ready to proceed in my reply. Mr. Phillips has practised the art of garbling most dexterously in his last letter to you, it is therefore incumbent on him, in order to satisfy your readers at least, that he turn once more to the Analytical Essays, and read and explain many passages which are more immediately connected with the subject.

If Mr. Phillips be unwilling to perform the task, or ashamed to admit the truth, I shall mention a few of the items to which I refer, as proofs that Mr. Klaproth never applied nitrate of silver as a test for arsenic, and that he never, on any occasion, combined it with the oxide of arsenic, where alone it is so eminently useful; for I never heard of a single instance where the acid of arsenic had been exhibited as a poison from sinister motives. But I shall not take up your time and space further than to offer the following references to Mr. Klaproth's work.

Vol. i. p. 566. "Both the solutions of the arsenical oxide in water showed exactly the same appearances which are exhibited by any other aqueous solution of arsenic." Here is an example, where Mr. Phillips must acknowledge there can be no quibbling about the author's acquaintance with the superior efficacy of silver, for none was used. Mr. Klaproth then proceeds. "By combination with lime-water, they (the two solutions) yielded arseniate of lime: with sulphuret of ammonia, yellow sulphuret of arsenic (orpiment) : and the green pigment of Scheele, with ammoniacal oxide of copper."

If the English translation here be correct, I may remark, that arseniate of lime and the green pigment of Scheele are incompatible products from a solution of white oxide of arsenic in water; an arseniate of lime must require the acid of arsenic, and Scheele's precipitate certainly is composed with copper and the white oxide or arsenious acid.*

In every case where great exactness was required to detect and appreciate the quantity of arsenic, I do not perceive that Klaproth ever applied silver as a test. Thus, p. 140, vol. i. no silver test was used, although at p. 142, "a weak arsenical smell was perceived." He speaks of " a slight trace of arsenic ;" and some of it combined with the copper, and some with the iron." Page 158. "The muriate of silver emitted some arsenical vapours." Page 160. "It is then evident that this ore consists of silver, iron, arsenic, and antimony." In the same place he notices" arseniated iron." Page 526. "A grey-yellow sublimate" and "a faint odour of

The English translation is inaccurate. The words used by Klaproth are arsenikalische kalkerde.-T.