putting his plan to the test of practice, he was so fortunate as to find that it removed some nervous, and a few acute and chronic rheumatic affections.

This plan of treatment was of no avail in any case where the disease was dependent on or connected with organic lesions, or attended with fever, or swelling of the part, or with general weakness; on the contrary, in all these cases the metallic plates augmented the disorder.—Edinburgh Med, and Surg. Journ. from Arc. Gen. de Med., March, 1841.

On the Regeneration and Union of Nerves. By MM. GUNTHER and SCHON. RABBITS were the animals on which the following observations were made, and about fifty of these were operated on, by sometimes only cutting across the ischiatic nerves, at other times by removing a portion varying from two to four lines in length. These physiologists describe the elementary fibres of the nerves as transparent cylinders with double tunics, filled with a fluid resembling liquid albumen. After maceration in water, or after death, this fluid coagulates and produces the turbid granular aspect which, till now, has been considered its natural appearance. When the two extremities of a nerve which has been cut across become united, the nerve propagates impression through the uniting medium. This is done by means of true primary fibres having been formed through the uniting medium, and the following is the mode in which MM. Gunther and Schon have observed this to take place. After division of the nerve the two ends retract somewhat, the diameter of the neurilema becomes diminished, and the medullary substance is pushed out in a globular form; exudation of plastic lymph then occurs and fills the wound, and the cut extremities of the nerve become swollen, the upper extremity more than the lower. This tumefaction of the nerve itself is owing to the presence of plastic lymph effused into the cellular tissue and also between the neurilema and primitive fibres.

The matter which unites the two ends of the nerve, is at first amorphous, but by degrees primitive fibres shoot through the mass, and become visible at the earliest on the eighth week after division. These new fibres are in every respect similar to the original fibres; but the granular exudation and the cellular tissue which surround and envelope them render them difficult of examination. These fibres are not parallel, but exhibit a confused arrangement.

With the regeneration of the fibres of the nerve returns the sensibility and mobility of the limb or organs to which the nerve was distributed.

But in general the function of the part is not so free as before the division; the animals not being able to use the limb whose nerve had been divided, so freely as the other. The influence of the will over the limb was also observed to be diminished. MM. Gunter and Schon account for this on the supposition, which is borne out by their experiments, that the number of fibres which are regenerated are not equal to those which originally existed; besides it appeared to them that the regenerated fibres occasionally united the ends of different primitive fibres, so that sensation was not always referred to its proper place. They consider that the regeneration or growth of the uniting fibre commenced at the superior extremity of the divided nerve, but concede that it is possible that it may also take place from the lower extremity.—Ibid.

The Structure of the Human Placenta.-BY JOHN Dalrymple, Esq., Assistant Surgeon to the London Ophthalmic Infirmary.

THE following are the results of Mr. D's researches and examinations, as given in a recent number of the London Medical Gazette.

1. That the placenta was made up of the innumerable subdivisions of the umbilical vessels, terminating in beautiful coils and convoluted capillaries, which formed tufts or bouquets of vessels clothed by a prolongation of the endo-chorion derived from the foetal surface of the organ.

2. That no where did a division of an umbilical artery terminate otherwise than in a branch of the umbilical vein; and each branch, as well as tuft of vessels, was covered by a prolongation of the before-named membrane.

3. Thus each tuft was, in fact, a real villus: the endochorion being covered internally with an epithelium-like tissue, having nucleated cells and corpuscles. 4. The uterine surface of the placenta is covered by the decidua, which does not appear to enter further into the structure of the organ than between the lobules; and the depth to which it thus penetrates varies with the depth of the fissures.

5. That fibrous bands stretch from the fœtal to the placental surface of the organ, giving firmness and support to the vessels.

6. That there are no defined cells in the placenta, but that the nutrient fluids of the mother are poured into the interstices of the tufts, which are not bound or connected together by a common cellular tissue.

7. That on the decidual surface of the placenta are thinly scattered, here and there, blunt conical papillæ, about a line and a half in length, made up of innumerable coiled and contorted capillaries. Query-Are these the analogous of the fœtal cotyledons of the ruminant?

From these observations, which were given in a minute detail, the author has attempted to simplify the functions of the human placenta.

He observes, that in the incubated egg, in consequence of the non-connexion between the embryo and parent, that a nutrient and a respiratory organ is indispensable, and hence the more complicated system of vessels. That in the oviparous vertebrata, the vitellary sac and the omphalo-mesenteric vessels represent the placenta of mammalia, which is the absorbent organ of the fœtus. But while in the one case the nutrient materials of the mother, already aërated by her lungs, are conveyed by the uterine arteries for absorption and nutrition of the embryo, in the other the materials of the blood are absorbed by the folds of the vitelline sac, and conveyed through the circulation of the young bird, requiring, however, contact with oxygen for a second circulation: hence a new membrane, or one that is persistent up to the time of independent respiration, viz. the allantois: and hence also the more complicated system of its vessels. The allantois, as a respiratory membrane, exists only as a rudimentary organ in mammalia, and the function of the placenta being solely that of nutrition by already oxygenized materials, the cord contains only a simple system of incurrent and excurrent vessels.

Lond. Med. Gaz.

Kiestein as an Evidence of Pregnancy.

IN No. 11 of the Guy's Hospital Reports there is a valuable paper upon this subject, by Dr. Bird, in which he enumerates many cases to prove the existence of this principle in the urine of pregnant women. The object of this paper is not only in furtherance of its value as such a test, but to point out certain precautions to be observed in the experiments, in order to prevent fallacy.

The urine should be procured at a time when the woman is as free from disease as possible; and we believe that passed early in the morning, after rest, gives the least variable indications. This should be exposed in a tall narrow glass, to a continuous temperature of about 70° of F.; if a much lower temperature than this is used, say about 40°. We have known the urine to stand for more than a fortnight without undergoing any change, although it be replete with kiestein or its principles, at a temperature of 70°. However, if the woman be pregnant, we shall observe, in two or three days, the first indication of its presence by the urine becoming turbid. In a day or two more a thin pellicle forms on its surface, and this gradually acquires consistence up to a fortnight from the outset of the experiment. But long before this time you will have noticed its characteristic odor; certainly not like cheese, to which Dr. Bird compares it, but precisely analogous to the smell of raw beef beginning to putrify; it is emphatically a putrid smell. We have kept the urine more than a month after this, but it never loses either its pellicles or peculiar odor.

Besides the error likely to arise from the adoption of too low a temperature, where the kiestein would not be separated, we would warn the early experimenter not to fall into the opposite error of confounding the pellicle which forms upon all urine on standing, especially that which contains the lithates in excess; the more so as the general as well as microscopic appearance of this pellicle is often precisely like that of kiestein. The appearance we are now alluding to, however, is never accompanied with the putrid animal odor; but, on the contrary, gives out a copious smell of ammonia, and when disturbed, falls immediately to the bottom of the liquid. These are the two especial distinctions.

On the value of this test we shall be very brief:—Of the 30 cases examined by Dr. Bird, 27 gave the required indications of the presence of kiestein; the other three were at the time suffering under febrile excitement. Dr. Bird could not detect it in the urine of unimpregnated women, or after parturition, and during suckling.

In the American Medical Library, as quoted by the British and Foreign Medical Review for October last, is a report of the experiments of Drs. McPherters and Perry, the resident physicians at Philadelphia Hospital. These gentlemen found it in the urine of 24 out of 27 pregnant women. Of the three negative cases, two were not in health when experimented on; further, they could not detect it in the urine of 27 unimpregnated women.

In our experiments, which have been made at all dates, between the second and ninth month of utero gestation, there was unquestionable evidence of kiestein in 48 out of 50 cases. We are unable to account for its absence in the two ex

ceptions, for we took care at all times to have the urine from women as free from disorder as possible.

In 17 non-pregnant women there was no indication of its presence. In examining the urine of 10 women during the time of suckling, we found it in all immediately after delivery, but that the evidence of its existence fell off at a period between the second and six months.

A question now naturally arises as to the cause of the presence of this principle, and what is its composition? It appears easily accounted for on the known sympathy that exists between the uterus and breasts; the latter of which, taking cognizance of the gravid condition of the uterus, prepares itself betimes for the proper performance of that function which by and by is to become its necessary duty. Certain principles analogous to those of milk, being imperfectly secreted, may, in this nascent condition, become reabsorbed; because, as Dr. Bird suggests, they do not find a ready outlet, and getting into the blood are excreted thence by the kidneys; and this habit of reabsorption may go on for some little time after the birth of the child.

The composition of kiestein is not so easily made out: examined by the microscope it consists at first of a multitude of globules, varying in size from the 1-32000 to the 1-8000 of an inch; after a time these break up, or coalesce and form flakes, and then crystals of triple phosphate generally become pretty abundant in it. This shows that greasy appearance of the pellicle is not due, as Dr. Bird supposes, to the triple phosphate, for this is after formation; nor are these globules composed of fat, for they are perfectly insoluble in ether. We have not been able to detect them in the urine until it becomes turbid, so that they appear to be formed in the urine after expulsion. They are soluble in alkalies and in boiling acetic acid, and give all the reactions characteristic of coagulated albumen or fibrin: to these, then, they are most analogous; but nothing but an ultimate analysis can determine their identity or not. The globules do not differ in appearance from those contained in milk, but their complete insolubility in ether shows that they do differ.—London Medical Gazette.

MATERIA MEDICA AND PHARMACY.

On the Medicinal Properties of Fish-liver Oil.

THE fish, from the livers of which the oil that has at different times been much recommended in a variety of diseases is obtained, are the cod and one or two species of the ray-―oleum jecoris asclli vell rajæ. We learn from M. Tiedemann, a merchant of Bremen who has long dealt in the article, that there are four kinds of cod-oil in commerce. The livers are packed in a cask, end upwards, and exposed for a length of time to the heat of the sun. When the upper layers are removed, the clearest oil is obtained; this is found to become stronger and darker towards the lower part of the cask. The darkest and thickest is used in the manufacture of chamois leather. MM. Gouzée and Gmelin state in their memoir, (Bulletin Med. Belge, Janvier 1838), that the clearest oil should be used for internal administration; but MM. Trousseau and Pidoux, in their treatise on Ma

teria Medica, recommend not only the second degree, which has a fishy taste and causes an acrid sensation in the back of the throat when swallowed, but also the third degree, obtained by boiling the residue, and which is of a brown color, has a most disagreeable empyreumatic smell, and is still more acrid. The opinion of these gentlemen has been confirmed by the experience of most physicians in Germany and Belgium-that the thick acrid oil is much more efficacious than that which is transparent and milder.

Within the last five years, chemical analysis has detected the presence of a small proportion of iodine in fish-liver oil; but it is very doubtful that its medicinal virtues depend upon this principle. However this may be, it is certainly true that the browner the oil is, the more iodine is usually present in it.

.....

That fish oil has been long known as a remedial agent, is proved by the narrative in the Apocryphal book of the Bible of Tobias and the Angel: Tobias is ordered to take the heart, liver, and gall of the fish that he has caught on the banks of the Tigris, and use them in a prescribed manner. Pliny too, in his Natural History, expressly states; "lichenes et lepras tollit adeps vituli marini, murœnarum cinis cum mellis obolis ternis, jecur pastinacæ (raiæ) in oleo decoctum. Quidam delphini jecur in fictili torrent, donec pinguetudo similis oleo fluat, ac perungunt." The inhabitants in many parts of England, Holland, and Germany have been from time immemorial in the habit of employing cod-liver oil in the treatment of chronic rheumatism, rachitis, &c.; but it was not until Michaelis about the middle of the last century, and subsequently Dr. Percival (1790) and Dr. Darbey (London Medical Gazette, vol. 3, p. 392), drew the public attention to its effects, that it has been at all generally known to medical men. There are numerous reports of its efficacy in the German Journals, references to all of which are given by Dr. Delcour in the number of the Archives de la Med. Belge, for last June.

The physiological effect of fish-liver oil appears to be that of a general stimulant of the whole body. It is apt to produce nausea and even vomiting at first; but after a short time it ceases to do so, and often the appetite very sensibly improves under its use. The urinary secretion is generally increased in quantity, and often a copious deposit of lateritious sediment takes place. The skin and also the uterus are stimulated by its use; hence its utility in several cutaneous diseases and in amenorrhoea. From its established efficacy in scrofulous and other cachectic states which indicate an unhealthy state of the nutritive process, it has been regarded by many as a general roborant, more especially of the alimentary canal and of the lacteal and vascular systems. In most cases where the blood is poor and thin, the best authorities assure us that a long continued use of fish-liver oil exercises a very salutary influence. If this be the case, we can readily understand how it may act in the cure of scrofula, rickets, chronic rheumatism, inveterate affections of the skin, many diseases of the bones, glands, &c. We have already said that in our opinion the therapeutic properties of cod-oil cannot be justly attributed to the small portion of iodine which exists in it. We are quite aware that in many parts of Holland it is given for a length of time to children of a scrofulous family, to prevent the development of the constitutional affection, so common in that country.