positively an acid, but thinks that, like alumen, it may combine with acids as well as bases.

The action of bile in the process of digestion is briefly considered, without any very definite conclusions. A brief abstract is given of the conflicting views and observations of Brodie, Tiedeman, Gmelin, Berzelius, Theyer, Schlosser, Enderlin, and Schwann, and our author inclines very strongly to the view, that the bile is not merely an excrementitious fluid, but that it is a secretion essential to the animal economy, and performing some important part in the process of digestion. He throws out the following suggestion in regard to its action:

"If the bilin becomes decomposed in the intestinal canal into various constituents, through the influence of the acid chyme, then a wide field of investigation is open to us respecting the function of the biliary secretion in relatian to chylification. No explanation has yet been afforded of the discrepancy in the amount of albumen contained in the chyme absorbed by the intestinal villi, and in the chyle discharged by the absorbents, (even without passing through the mesenteric glands.) May it not happen that a constituent of the bile acts on some hitherto ill-defined protein-compound of the chyme, and converts it into the form known as uncoagulated albumen?"

OF MILK.

In addition to the general composition and relations of milk we have some particulars given in relation of the modifications which it undergoes in nurses. In regard to the influence of temperaments on the quality of the milk, we have the following observation :

"It has been long believed that the milk of fair women is inferior in its properties to the milk of brunettes. As far as I am aware, the only analyses bearing on this point are those of L'Heretier. He selected two females of equal age, and made them submit to the same diet and mode of life. The following are the results of his analyses:

He appears to have selected the analyses that presented the most marked contrast; for he observes, that if he had taken the mean of all his analyses, the difference between the amount of the solid constituents in the two cases would have been less marked, the average ratio being 120: 134.

Also:

Changes in the milk, corresponding with the age of the infant.

It seems probable that certain changes will be observed in the milk when the progress of development of the child indicates the necessity for other food. The question is one of considerable physiological interest, and in order to elucidate it I made analyses of the milk of a woman during a period of nearly six months, commencing with the second day after delivery, and repeating my observation at intervals of eight or ten days.

The results would doubtless be more decisive if the experimentalist were able to exclude all disturbing influences but in almost all cases the exercise of a strict control over the method of living and the nature of the food of the mother, is just as impossible as the exclusion of exciting moral forces.

The fourteen analyses (the colostrum being excluded) gave the following

A glance at the three columns of casein, sugar, and butter, will show, that, with few exceptions, 1st, the quantity of casein is at its minimum at the commencement; it then rises considerably, and ultimately attains a nearly fixed proportion; that, 2d, the quantity of sugar is at its maximum at the commencement, and subsequently diminishes; and that, 3d, the butter is a very variable constituent of the milk.

Also:

Other changes in the milk.

Certain substances which are not included in the ordinary constituents of the milk are sometimes detected in it, after having been taken into the system, either as food or medicine. It is not to be expected that all the substances which enter the circulating flaid and are separated by the kidneys, should be found in the milk, since the absorbents appear to exert a sort of selective power, and would thus reject those substances which occur in the blood, but which would produce an injurious effect on the tender frame of the infant, if they entered into the milk.

I have sought in vain for ferrocyanide of potassium in the milk of women who were suckling, and to whom I have given it in doses of six drachms. This salt is known to enter very readily into the circulation, and is found after a very short interval in the urine. After the lapse of two days I gave the same woman twenty-three grains of iodide of potassium, but I could detect no trace of this salt in the milk. Lastly, I attempted in vain to detect sulphate of magnesia in the milk of a woman who was suckling, and to whom I had administered it in a sufficient dose to act as a laxative.

For the particulars of these experiments I must refer to my essay 'On the Milk of Woman, in its Chemical and Physiological relations." From these observations I think that I am justified in the conclusion that energetic substances, which are foreign to normal milk, either do not enter into that secretion at all, or if they do, they undergo modifications, which render them more compatible with the organism. Although I could not detect the sulphuric acid of the sulphate of magnesia in the milk, it is very probable that the magnesia entered the milk as a lactate, while the sulphuric acid was carried off by the urine as a sulphate.

Peligot, however, has detected iodide of potassium in asses' milk; and Herberger in the milk of woman. [I have on several occasions observed the ordinary indication of iodine on the addition of xyloidin, or of starch and a drop or two of nitric acid to the urine of infants at the breast during the period of the mother taking three grains of hydriodate of potash thrice a day-a convincing proof that the salt has entered the milk.] Mercurial medicines used by women who are suckling have never been traced in the milk, [although their effects on the infant are undoubted.]”

Milk is observed to undergo some change when allowed to stand sometime after being drawn. Some of these changes are familiar to all, but others are less common and are curious.

"The milk is sometimes observed to become blue on its surface after standing for 24 to 48 hours, and the tint gradually diffuses itself through the whole fluid: the milk has also been observed to turn yellow in a similar manner. Fuchs* has carefully investigated this phenomenon, and has detected in milk of this nature a peculiar infusorium, to which he has applied the name vibrio cyanogenus; it is not of a blue colour itself, but it appears to have the power of gradually changing the milk to this tint. When removed from the milk, and placed in an infusion of marsh-mallows, these animalcules increase in size, and communicate a faint blue tinge to the fluid; in this way they may be preserved for a long time. Closely allied to this animalcule is the vibrio xanthogenus; they are sometimes found together in milk, and Fuchs had also an opportunity of observing them in milk which had become yellow, a much more rare change than the former."

Our author devotes a large portion of this part of the work to the urine and urinary deposits, but a full notice of the subject would carry us beyond the limits of our review department, and we will limit our remarks to one or two interesting particulars.

It will be remembered, that a few years ago, Nauche announced the discovery of a peculiar substance, which he termed kystein, in the urine of pregnant women. The presence of this substance he regarded as an infallible sign of pregnancy, and he has been followed in his belief by a large proportion of the writers on this subject. It was, however, supposed, that kystein was only some modified form of albumen. Dr. Kane, however, convinced himself that its occurrence was independent of the presence of albumen, and showed that it occurred in the urine during lactation as well as during pregnancy.

"During the first weeks of pregnancy, Kane only rarely observed it; it was most commonly noticed during the seventh, eighth, and ninth months, and up to the period of delivery. In eighty-five cases of pregnancy it was absent eleven times, and was present in thirty-two out of ninety-four cases examined during lactation.

I have examined the urine during the second, third, fourth, fifth, and sixth months of pregnancy, but have not invariably detected kystein. In the cases in which it was formed, as in the second, fifth, and sixth months of pregnancy, the urine on emission was clear, yellow, faintly acid, and not affected either by nitric or acetic acid, or by heat. Usually, in about twenty-four hours, the whole urine became slightly turbid, the acid reaction disappeared, a white viscid sediment was deposited, and soon afterwards the surface of the fluid became covered with a pellicle at first extremely delicate, but after from twelve to twenty-four hours becoming tough, thick, opaque, and with a glistening appearance in consequence of the light reflected from numerous minute crystals of ammoniaco-magnesian phosphate with which it was studded. On examining this pellicle in its early state under the microscope, it appeared (when magnified 300 times) to consist of an amorphous matter composed of minute, opaque points, such as are presented by sediments of phosphate of lime or urate of ammonia, except that in the latter the individual particles are usually darker, more clearly defined, and larger than in kystein. The whole field of vision was likewise bestrewed with numerous vibriones in active motion, and crystals of ammoniaco-magnesian phosphate. When the pellicle became thicker, precisely similar phenomena were observed, but the vibriones were supplanted

*Beiträge zur näheren Kenntniss der gesunden and fehlerhaften Milch der Hausthiere. Magazin für die gesammte Thier heilkunde, Jahrg. 7. St. 2.

by a considerable number of monads; on the addition of acetic acid the crystals disappeared, while the amorphous matter remained unaffected. On digesting the pellicle in acetic acid, and adding ferrocyanide of potassium to the filtered solution, a comparatively slight turbidity ensued, but on macerating the pellicle in a dilute solution of potash, acidulating the filtered solution with acetic acid, heating, and adding ferrocyanide of potassium after a second filtration, a more decided turbidity was observed. From these experiments I concluded that a protein-compound was present. The white sediment that occurred after the urine had stood for some days, possessed a disagreeable, pungent, caseous odour: under the microscope it presented the same appearance as the pellicle. After repeatedly washing a portion of the sediment with water, and then heating it with alcohol and a little sulphuric acid, it developed a disagreeable, fruit-like odour, reminding me of butyric ether. [We shall presently show that the accuracy of this observation has been thoroughly established by Lehmann.] It results from the above observations, that kystein is not a new and distinct substance, but a proteincompound, whose formation is undoubtedly and closely connected with the lacteal secretion. From the observations of Kane and myself, it seems to follow that pregnancy may exist without the occurrence of kystein in the urine; if, however, there is a probability or possibility of pregnancy, and kystein is found in the urine, then the probability is reduced almost to a certainty. We are unable to draw any positive inferences respecting the stage of pregnancy from the appearance of the kystein.

A deposit of caseous matter and earthy phosphates was frequently observed by Golding Bird in the advanced stages of pregnancy. The sediment is probably similar to Nauche's kystein.

Every urine left to itself forms a pellicle, more or less resembling that of kystein. If formed soon after the urine is discharged, it consists of earthy phosphates, which, from the urine being alkaline, are, for the most part precipitated, but likewise form a delicate film on the surface. When this is the case, the pellicle is very thin and readily sinks to the bottom. Under the microscope crystals of ammoniaco-magnesian phosphate, and an amorphous matter very similar to kystein, but consisting of phosphate of lime, are observed this likewise differs from kystein in being soluble in free acids. A pellicle of fat on the surface of urine may sometimes be mistaken for kystein: films of this nature are very thin and usually iridescent, and the microscope reveals the presence of numerous fat-globules.

:

The membrane formed on the surface of urine six or eight days after emission, usually consists of a species of mould; under the microscope there may be seen innumerable filaments matted together, and interspersed with sporules.

I once observed a pellicle on the surface of a man's urine three days after emission, which both in chemical and microscopical characters presented the closest analogy to kystein.*

1

[Lehmann frequently examined the urine of a pregnant woman from the second to the seventh month. It was of a dirty yellow colour, and more inclined to froth than usual; it generally became turbid in from two to six hours; but the morning urine, after standing for thirty-six or forty-eight hours, was always covered with a grayish-white film, which often, in two or three days, sank and mixed with the sediment that formed when the turbidity appeared, but sometimes was a longer period before it broke up. By means of ether he could always remove from this film a considerable quantity of viscid fat, which formed a soap with potash, and then, on the addition of sulphuric acid, developed

[A similar appearance has been observed by Prout in the urine of a delicate child, fed chiefly on milk. (On Stomach and Renal Diseases, 4th edition, p. 555, note.]

+ Lehrbuch der physiologischen Chemie, vol. I, p. 252.

a well marked odour of butyric acid. On treating a large quantity of this urine with sulphuric acid, and distilling, he obtained, after treating the distiliate with baryta water, brilliant crystals of butyrate of baryta. The substance taken up by ether, when gently evaporated with nitric acid and exposed to the vapour of ammonia, was not in the least reddened; with concentrated hydrochloric acid, on the other hand, it assumed a blue tint; dissolved in potash, boiled, and treated with hydrochloric acid, it developed sulphuretted hydrogen; it dissolved tolerably freely in acetic acid, from which it was precipitated by ferrocyanide of potassium. These reactions left no doubt of its being a protein-compound. The portion of the film insoluble in potash consisted chiefly of phosphate of magnesia, [ammoniaco-magnesian phosphate?] with a little phosphate of lime. Hence Lehmann concludes that the kystein of Nauche is not a new and distinct substance, but a mixture of butyraceous fat, phosphate of magnesia, and a protein-compound very similar to casein. He likewise mentions that, in examining the urine of a woman who was not suckling, and was kept on very low and sparing diet, on the third, fourth, sixth, and ninth days after delivery, he found a large quantity of butyric acid taken up by ether from the solid residue; and on dissolving the ethereal extract in water, adding sulphuric acid, and distilling, he obtained a further quantity. The urine in this case was always rather turbid, of a dirty yellow colour, very acid, and contained a very small amount of uric acid.

Möller relates two cases in which the urine of women who were not pregnant was covered with a film exactly resembling kystein; in one case there was considerable hypertrophy of the uterus; in the other no affection of the generative organs could be detected. The film of kystein consists, according to his observation, of fat, earthy phosphates, and a caseous matter, which differs, however, from the casein of milk in being held in solution by a free acid. When the urine becomes neutral or alkaline, the caseous matter ceases to be held in solution, and separates as kystein. Every thing checking the decomposition of the urine hinders the formation of the pellicle, and if the recent secretion is treated with a free acid (mineral or organic), no separation of kystein takes place even if ammonia be added to saturation, or decomposition allowed to proceed to any

extent.

In a case of decided pregnancy, no kystein was formed during the period of a severe cold, attended with a copious deposition of urates; but when the urine became natural, the kystein reappeared. He twice detected cholesterin in kystein.

Kleybolter has examined the urine in ten cases of pregnancy, and invariably found kystein on the fifth day. The morning secretion was used, and after being slightly covered to protect it from dust, was allowed to stand at an ordinary temperature, for ten days. The following appearances were observed in the tenth week of pregnancy: urine peculiarly yellow, with a greenish tint. 2d day, mucous sediment; 3d day, no change; 4th day, turbidity ascending from the bottom; 5th day, white points and leaflets on the surface, turbidity ascend ng from all parts of the bottom, and the sediment almost gone; 6th day, kystein distinctly observed on the surface, like lumps of fat on the surface of cold broth; 7th day, no change. From the 8th to the 10th day, the kystein disappears, the turbidit again descends, and the sediment noticed on the 2d day is reproduced. The nine remaining cases are in most respects similar to the above.

A few observations on kystein have been recently published by Audouard,‡ but contain nothing of importance, except that in six specimens of urine

Casper's Wochenschrift, Jan. 11-18, 1815.

+ Casper's Wochenschrift, April 26, 1845, * Journal de Chemie Méd, May, 1845.