It can not be my task here to refute these assertions; drochloric acid of 2.5 per cent and left standing for microscopically casein flakes have absolutely nothing some hours, being repeatedly stirred and shaken. Af. characteristic about them, the positive results of the ter filtering the residue was washed with water, until Millons' reaction proves nothing and the fact that they the filtrate failed to give chlorine reaction, then dried contain 5 per cent nitrogen (Heubner) proves at best and extracted successively with alcohol and ether. The that they are a mixture of proteid bodies with nitrogen dried mass together with the filter was mixed with free substances. Biedert, Tschernoff, Uffelmann and nitrate of ammonium and carbonate of sodium and others even analyzed the fæces as a whole and believed heated until a white melting resulted which, with the to have been able to demonstrate the presence of a addition of some nitric acid, was dissoved in water. To larger or smaller amount of casein in them. Their the solution a surplus of ammonium molybdate was methods are not unobjectionable, it would lead me too far to show up their mistakes in detail, they are of a purely chemico-technical nature. In order to furnish a contribution to the solving of this very essential problem I sketched out the following idea: Casein as well as the residues of its digestion are chemical bodies exceedingly rich in phosphorus. If it would, therefore, be possible to determine the amount of organically combined phosphorus, which appears in the fæces, we would be allowed to make certain inferences as to its origin and as to the bodies, with which it is linked. The organically bound phosphorus of the fæces can be part of the casein and of its cleavage. products, it can be a part of the nuclein of the fæces and of the lecithin. The lecithin is easily removed by thorough extraction with ether. It is, however, im. possible to separate the nuclein phosphorus from the casein phosphorus. There is, nevertheless, a way, in which a very exact estimation of the nuclein phos phorus may be achieved, although I must state right here that for external reasons perfectly complete determinations of the metabolism (Stoffwechselversuche) had to be abandoned. The meconium consists only of the digestive juices, desquamated epithelium, some leucocytes, etc., a determination of its organic phosphorus, therefore, was bound to give a very fair idea of the nuclein phosphorus; the results thus obtained were corroborated by analyses of the fæces of breast-fed infants of varying age. In every case I determined the relation of nitrogen to the organic phosphorus (N: P), and it is clear, that the admixture of even small pro portions of casein or of its derivatives must show itself plainly in a decrease of this quotient. I employed the method to get rid of the inorganic phosphates by digesting the fæces with diluted HCl (2 to 3 per cent), although I was aware of the fact, that necessarily a certain amount of the organic phosphorus, too, was dissolved in this way. I shall show, as for that, later that this amount can be computed very ex actly, and that with a certain, definite correction, the results can be made quantitatively reliable, though this was not my intention altogether. Following the rules. laid down by HOPPE SEYLER1o in his admirable hand book the analysis ran thus: The fæces were well mixed and than dried, first on the water-bath and afterwards in a hot air chamber at 110°C. Part of them was utilized for the nitrogen determinations after Kjeldahl's method; another portion was thoroughly mixed and triturated with a hy added, and after some time the precipitate filtered off. In dilute ammonia the latter was dissolved and the solu tion precipitated by magnesium sulphate with some ammonia and ammonium chloride. This precipitate, after being washed with some diluted ammonia, was dried and ignited in a porcellain crucible of known weight. Thus pyrophosphate of magnesium was ob tained, from which the amount of phosphorus could be easily calculated. ANALYSES OF MECONIUM. No. I-Dr. B. W. Moore's case: Nitrogen determination: I-0.542 g. 0.0295 N. or 5.60 per cent. = = 6.42 g. dry meconium 100 g. dry meconium contain 0.0162 g. P. No. II-Dr. Crossen's case No. 1: Baby Carlton, January 7, 1899. dry, 14.8 g. Nitrogen determination: I-0.647 g. = 0.042 N. or 6.43 per cent. 5.39 g. N. 6.64 g. I-6.25 g.= 0.0041 Mg2 P2 O, or 0.0012 P. Average amount of P. in 100 g. dry meconium = No. III-Dr. Crossen's case No. 2: Baby Bulicsky, January 6, 1899. dry, 5.6 g. Nitrogen determination: = = 0.019 g. I-0.456 g. = 0.021 N. or 4.61 per cent. II-0.420 g. = 0.021 N. or 5.00 per cent. Average amount of N. in 100 g. dry meconium = 4.81 g. If we calculate the average of these six analyses, we arrive at a relation of N: P325: 1. As to the deviations, which the single figures show from one an other, they are easily understood. I only want to men tion the fact that I examined all of the samples of meconium microscopically not discovering in a single case any traces of lanugohairs, which are said to be present now and then and which of course would tend to increase the percentage of nitrogen, without adding to the amount of phosphorus. It is easily seen, that the addition of even a small amount of substances, rich in phosphorus, needs must considerably alter the quotient found, and by a little figuring we find that if only 5 per cent of the casein taken by an infant during 24 hours would be discharged with the fæces the proportion of N P would have to come down to about 35 : 1 (N: P in casein being about 18 5:1). I now proceed to give the results of the analyses of the fæces of breast-fed infants: 100 g. dried fæces contain 0.0172 g. P. N. P359: I. No. XII-Dr. Crossen's Case 8: Baby White; 22 days old; January 16, 1899. dry, 6.25 g. Nitrogen determination : I—0.316 g. = 0.0196 N. or 6.20 per cent. II-0.420 g. = 0.0258 N. or 6.15 per cent. dried fæces contain 6.18 g. N. Phosphorus determination : 100 g. 4.230 g. = 0.0025 Mg2 P2 Or or 0.0008 P. The quotients obtained in these experiments are suc cessively 229, 233, 513, 279, 358, 318 and 314. They give an average of 321, almost the same as found as the average of the meconium quotient. The individual variations are not excessive, if we except No. IX. with a proportion of 513: 1, in which a slight diarrhœa existed, most likely producing a surplus secretion from the mucous membranes. Our results coincide very well with the digestive experiments, in which it was found, too, that breast casein was perfectly dissolved. Certainly, we can conclude from our figures, that the casein of breast milk is completely absorbed by the gastro intestinal mucous membrane. Let us now direct our attention to the fæces of infants fed on cow's milk. : 0.0385 N. or 7.39 per cent. II-0.515 g. = 0.0382 N. or 7.42 per cent. 100 g. dried fæces contain 7.41 g. N. 100 g. dried fæces contain 0.3346 P. No. XX-Bethesda baby No. 5: Weight, moist, 41.2 g. dry, 16.4 g. Nitrogen determination : I-0.468 g.= 0.0262 N. or 5.60 per cent. 0.0291 N. or 5.71 per cent. 100 g. dried fæces contain 5.65 g. N. Phosphorus determination: 10.23 g. 0.0945 Mg2 P2 Or or 0.0264 P. 100 g. dried fæces contain 0.258 P. N: P21.9: I. XXI-Baby Cole; 11/2 months old; 2 days, 1700 cc. pure milk: Weight, moist, 45 g. dry, 16.2 g. Nitrogen determination: I—0.472 g. = 0.0321 N. or 6.80 per cent. 100 g. dried fæces contain 6.79 g. N. 11.56 g. = 0.0819 Mg2 P2 OT 100 g. dried fæces contain 0.1986 P. casein with 0.714 g. P. In the 29.6 g of dry fæces the total phosphorus excreted was 0.1107 g. If we make the necessary corrections for the nuclein phosphorus and for the loss incurred by our method we find that 16 per cent of the organic phosphorus of the food was excreted unassimilated. The average value of N:P in these eight cases is 21:1, percentage of the total organic phosphorus of the food that means these babies fed on cow's milk excrete about is excreted with the fæces, can only be answered ap15.1 times as much organic phosphorus as breast fed in-proximately. In Case XIV the baby took during three fants. There is absolutely no reason to suppose that a days 2800 cc. of pure milk, meaning about 84 g. of much greater percentage of this phosphorus belongs to the nucleins of the digestive secretions; we are forced to conclude that the greatest part of it is contained in the residues of the gastro intestinal digestion. To guard myself against any objections I will mention that I know fully well, that the digestion of cow's milk taxes the mucous membranes to a much higher degree than that of breast milk, as is clearly shown by the larger amount of fæces; but this difference can in no way account for the figures obtained. A part of the organic casein-phosphorus is excreted unassimilated with the faces in babies fed on cow's milk. The question then arises: Is the phosphorus contain ing substance of the fæces casein or rather paracasein, or is it its cleavage-product, the pseudonuclein. Before I deal with it, I must briefly refer to a correction, that our figures need. I already said, that the extraction of the fæces with 2.5 per cent HCl removed together with the anorganic phosphates a small part of the inorganic phosphorus compounds too. To estimate this loss I digested 25 g. of casein (dry) with pepsin-hydrochloric acid, thus obtaining about 1.5 g. of pseudonuclein, which contains about 2.50 per cent of phosphorus. Two por tions of this substance I treated in the same way as the fæces with 2.5 per cent HCl and found that about 12 percent of the phosphorus was thus dissolved and lost for the analytic determination of the bulk of the phos phorus. We are therefore compelled to add to the amounts of phosphorus found about one seventh, and in the same way (since the relation of N:P in pseudonuclein is 5:1) to the nitrogen found five-sevenths of the weight of the phosphorus. In this way the quotients become still smaller; I shall forbear entering into these corrections in detail, they do not influence the final re sult. In Case XXI the baby took 1400 cc. of pure milk dur. ing two days, i. e., 52 g. of casein or 0.441 P. In 16.2 g. of dry fæces 0.03217 g. of phosphorus were discharged. Calculated in the same way as before this would mean a loss of 15 per cent. You will understand, that these two calculations do not lay any claim on absolute exactness, but they are sufficient to admit of forming an adequate opinion about the relations concerned. It was certainly a great stride towards progress, when Biedert and after him Escherich introduced the principle, to limit the amount of fluid food in artificial feed. ing to the average amount taken by breast-fed children. That the recipes given by them are, from our present state of knowledge, wrong, is immaterial. Especially would I like to call attention to the great percentage of lactalbumin in breast milk, which in the most essential way interferes with all attempts at producing by dilu. tion of cow's milk a fluid equally serviceable. We hardly know of any more close and accurate adaptation than the one between the composition of the milk and the wants of the young animal, and, surely, in trying to artificially replace the natural food we have to take into consideration every one of its constituents. One of the latter, that hitherto has received very little attention is the organic phosphorus, of which certainly the rapidly growing infant needs a considerable amount. It has been impossible so far, to demonstrate that the organ. ism is capable of assimilating inorganic phosphorus Is it possible, that we have to deal with undigested compounds; so the amount of organic phosphorus due casein? The figures for meconium and breast milk fæces to an infant ought by no means to be curtailed. There show, that the nuclein phosphorus forms only about 7 are three combinations in which this element is pro. per cent of the organic phosphorus of cow's milk fæces. vided for in the milk: It is contained in the casein, in The proportion of N:P in casein is 18.4:1, in paracasein the nucleon, and in the lecithin. Figuring with an averit is said to be 16.4:1. The average value, that our re- age of 4 per cent of casein in one liter of breast-milk sults with all possible corrections would represent, we have 7.5 g. of casein or (Wroblewski) 0 052 g. P., would be N:P=17.6:1 in cow's milk fæces, so that with 1.24 g. of nucleon or 0.08 g. P., 1.78 g. of lecithin or 0.02 the possible errors it could represent nearly the rela g. P., altogether 0.202 g. of organic phosphorus. In tions known for casein. We have, however, in this cow's milk these relations are as follows: One liter (3 calculation, omitted to consider that at least 60 per cent per cent casein) contains 0 256 g. P. of casein, 0.037 of of the total nitrogen of the fæces belongs to the diges-nucleon (0.37) and 0 040 of lecithin (1.00), together 0.330 tive juices and to katabolic products. Correcting our g. of organic phosphorus. If, therefore, for young in figures according to this point we then find a quotient varying in the eight cases examined from 5.1 to 8.6, figures which most satisfactorily show, that the phos phorus-containing nitrogenous body of the cow's milk fæces is no casein, is no paracasein, but must needs be their cleavage product, pseudonuclein. fants we dilute the milk with two parts of water, the child receives only about 0.11 g., which amount is still lessened 15 per cent by the excretion of pseudonuclein. A rational dilution, so as to approach the 0.75 per cent amount of casein of breast-milk, would bring the phosphorus down even to /100 g. There is one more point, Another question, that springs up, the question, what which makes this fact of still greater importance. Ac cording to BUNGE" the pseudonuclein is the only iron. Knoepfelmacher. His researches have so far been pub. bearing constituent of the milk. The 15 per cent of it, which are discharged unassimilated by an average infant, therefore means a noticeable loss of iron too. It can not be my task here to go into the possibilities of reme. dying this want. May I be allowed only to point out, that perhaps rational admixture of the yolk and of the white of eggs to properly diluted milk would be a means of imitating more closely the natural proportions and quantities of breast-milk. lished only in a paper published in the Wiener klinische Wochenschrift, 1898, No. 17, in an aphoristic way. The average figures at which he arrives agree very well with those found by me, although on the whole it seems that in his experiments the amount of not assimilated organic phosphorus was found to be somewhat smaller than according to my analyses. A more complete comparison will only be possible after the publication in extenso of Knoepfelmacher's researches. LITERATURE 'Mittheil. a. d. Klin. d. Schweiz, 1894. II. Reihe, Heft IV. "Zeitschr. für Physiolog. Chemie, 1882, p. 7. Jahrb. für Kinderheilkunde, 1888, p. 344. 'Pflüger's Archiv., 1882 (see here the other literature). 10 Handbuch der chemischen Analyse, VI. Aufi. There is one objection to this whole ratiocination that you might hold up against it. Experience seems to teach us, that babies thrive very well on cow's milk of a much higher concentration than the one which would correspond to the composition of breast milk, and that in this way the deficiency of organic phosphorus is made up too. Certainly this is the case, and we could very well be satisfied with it. But whether, what to our limited vision appears as a normal development, should not rather be intrinsically invested with an unnoticed tendency towards a deviation below or above the norm, remains to be questioned. I, for one, am in clined to assume the former alternative, believing that here, too, degeneration is bred. Perhaps I could not better illustrate this view than by a reference to the latest beautiful article of HEUBNER," although I know Post-Natal Transfusion and Its Importthat my conclusions are quite opposite to those cherished ance for the Fetus.-Koestlin (Zeitschr. f. Ge by this author himself. Heubner subjected a number of burth u. Gyn; Amer. Jour. Med. Sci.) reviews this infants to very careful and exact investigations as to subject and gives the results of his own experience. He the whole of their metabolism. The result was that in first endeavored to ascertain how much blood from the breast-fed and cow's milk-fed babies the assimilation of mother passed to the fetus after its birth and before nitrogen was exactly the same, that means that of the the separation of the cord. To determine this he nitrogen introduced with the food the same amount was weighed the infants directly after their birth and beconverted into body-proteids. The whole rest was ex- fore the cord was tied, and then after the cord was creted, with the difference that in the cow's milk-babies separated. He also endeavored to ascertain how much the nitrogen discharged was as much in excess above blood passed from the cord as soon as it was cut. His the other group, as was the amount of proteid food in- observations were conducted upon the infants of thirty troduced above the amount in breast-milk. Heubner primiparæ and thirty multipare. As regards the aspir concludes, that the old prejudice about the indigesti-ation of blood by the infant from the placenta, he did bility of cow's casein out to be dismissed in view of the not find that such was the case. In common with other fact that both groups of babies thrive well and satisfac- observers, however, he found evidences that the infant torily. But what does really this discharge of a sur gains decidedly in weight during the short time which plus of nitrogen mean? Certainly nothing else, but an elapses between birth and separation from the mother. unnecessarily increased amount of work and energy He found that the infants of primiparæ gain less than (sometimes four times higher than normal) expended for those of multipare. The greater the weight of the in nothing. Accordingly, the production of carbondioxide fant the greater also its gain. was 24 per cent higher in the cow's milk-babies, than in those fed with breast milk. Similar relations obtained for the loss of heat by evaporation. I do not see, that with these tangible facts before us, our mind can be at ease; it needs only a slight derangement on the part of the baby's resistance and vitality to find us at the mercy of empiricism. The question of artificial feeding is not solved, yet, by a long way, although we may confidently hope, that we will live to see this goal reached. It will be one of the greatest blessings to mankind. As regards the exact way in which the blood passes from the mother to the infant, he ascribed it to contractions of the uterus during the latter part of labor, which forced the blood from the maternal into the fetal portion of the placenta. The blood-pressure in the fetal vessels becomes much increased as birth proceeds. Uterine contractions occurring after labor are of comparative slight importance. He obtained little results from weighing infants during the first ten days after labor. His experiments confirm the belief that it is best for the infant to allow some moments to elapse after birth before tying the P. S.-After my paper was finished and had been read my attention was called to a notice in Gould's Year Book for 1898, referring to experiments made by cord. |