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masses, and sometimes to dissolve them. 2. The starchy and saccharine principles are converted wholly or in part into lactic acid, and in that form are absorbed in the stomach. 3. The fatty matters are insoluble, and pass into the intestines, where they are taken up by the lacteals, and form the greater part of the chyle. The experiments which were performed to confirm these opinions before the reporters to the Institute did not succeed well; but if they had done so it would still be hard to explain how the albumen and fibrin can be formed in the chyle from fatty matter alone. Still that some of the starch of food may be transformed and absorbed in the stomach is confirmed by the experiments of Dr. Percy. These make it probable, 1, that sugar is formed in the stomach by the digestion of starch or wheat flour, though neither these experiments, nor any others yet performed can afford demonstrative evidence of it; 2, that the dextrin into which the starch is first transformed may be at once absorbed, so as to reduce the quantity of sugar which is formed; and 3, that the sugar which is formed must be quickly further changed or absorbed. The latter is the more probable conclusion, and best accounts for the very small quantity of sugar which is ever found after feeding on starch. Lastly, Dr. Percy suggests, that in the cases in which Dr. McGregor found sugar in the stomachs of those diabetic patients who for several days had had only animal food, it might be formed by the oxydation of the fat which is constantly being absorbed from the body during emaciation.

Composition of the bile. Dr. Kemp,† by careful elementary analysis of the bile of the ox, has corroborated Demarçay's opinion that it is essentially a true chemical compound of an electro-negative body with soda. But he holds that this body is neither the choleic acid of Demarçay, since it is not precipitated from the soda by acetic acid, nor the bilin of Berzelius, because it is not precipitated from the soda by carbonic acid. He has therefore given it the name of bilic acid. It has a peculiar bitter-sweet taste, and in mass resembles a fine resin. It is soluble in every proportion in water. In a subsequent paper he has shown that a much greater difference than is usually imagined is effected in the bile while in the gallbladder. Bile from the hepatic ducts of an ox was destitute of the bitter taste of cystic bile; its smell also was different. It chiefly consisted of two different electro-negative bodies, separable by alcohol, and each combined with soda.

AESORPTION.

M. Lacauchies describes the intestinal villi as possessing during life a power of alternately retracting and elongating themselves by a kind of vermicular motion, which he believes to be influential in the propulsion of chyle. And his account, so far as these movements are concerned, is confirmed by MM. Gruby and Delafond,|| who have observed them in the recently-slain horse, dog, and rabbit. They add that besides the movements of retraction and elongation, the villi are capable of moving laterally in all directions, and that their epitheliumcells bear ciliæ.

Some experiments by Dr. Behr¶ may serve, perhaps, to explain somewhat of that which was supposed to depend on an elective power of absorption possessed by the lymphatics, and certainly have added much to the probability that the force by which the lymph is carried along the lymphatics is that of the contraction of their walls.** It has been long known that the lymphatics will not convey certain

"Case of Diabetes," Medical Gazette, April 7, and following numbers, 1843. + London Medical Gazette, Dec. 16, 1842, and March 3, 1843.

Medical Gazette, May 5, 1843.

Paper read at the Académie des Sciences, May 15, 1843, see Comptes Rendus and contemporary journals.

Paper read and reported as above, June 5, 1843. MM. Graby and Delafond assign to the epithelium-cells of the villi nearly the same offices as are, with much more probability, assigned by Mr. Goodsir to the transitory cells developed within the villi.

Henle and Pfeufer's Zeitschrift, für ration. Medicin. Heft i, 1842, and Schmidt's Jahrbucher, Heft iii, 1843.

• See last Report.

substances, especially narcotic poisons, while they do carry others. If, for example, the animal's abdominal aorta be tied so as to stop the circulation in its posterior extremities, and ferrocyanate of potass be inserted in a wound in one of them, it is absorbed and carried into the blood by the lymphatics, and is found again in the urine. But if, under the same circumstances, a narcotic poison is put in the wound the animal is not killed by it; and it was supposed that the lymphatics in this exercised some kind of choice. The results of Dr. Behr's experiments are these: 1. Acetate of strychnine was introduced into a wound in an animal's leg, while the circulation was uninterrupted, and death, with convulsions, &c., occurred in five minutes. 2. Ferrocyanate of potass was introduced into a similar wound, and ten minutes after acetate of strychnine into another wound: in four minutes the animal died of the poison, and the ferrocyanate was found in the urine. 3. The same substances were introduced together into a wound in the leg: the animal died poisoned, and even sooner than before, and the salt was found in the urine. 4. The abdominal aorta was tied below the renal arteries, and when the hind limbs were paralysed the acetate of strychnine was put into a wound in one leg and the ferrocyanate of potass into a wound in the other. After two hours and half there were no signs of poisoning but on killing the animal the salt was found in the urine. 5. The abdominal aorta was tied as in No. 4, and the acetate of strychnine and ferrocyanate of potass were introduced into the same wound. The animal showed no signs of poisoning, and the salt could not be found in the urine. This last experiment was several times repeated, and, with unimportant variations, with a constantly similar result. It would follow, therefore, that when the circulation in the blood-vessels is stopped, the lymphatics can absorb and convey to the blood ferrocyanate of potass, but not acetate of strychnine; and that when the two substances are applied to them together it can absorb or carry neither. Hence it is supposed that the force by which the lymphatics convey fluids is that of the contraction of their walls, and that they are paralysed by the direct contact of narcotics, as other involuntary muscles are.

Mr. George Robinson has related some experiments in evidence that the absorption of blood-vessels depends on a force generated by and proportioned to the velocity of the blood which is moving in them. He compares it to that force with which water or any other fluid traversing a main tube will draw fluid through a side branch, even against the weight of a considerable column. He has often repeated this well-known experiment, and has added proof that the same force will act in the same way through one or more membranes. Having filled a wineglass with coloured fluid, and having connected its contents, (by means of a bent tube twelve inches long and of an inch in diameter, and having one of its ends covered with membrane,) with the interior of a pipe half an inch in diameter, be found that within five minutes after the stream had begun to flow rapidly through the last-mentioned pipe, the whole of the air present in the smaller tube was absorbed, and its place supplied by the coloured fluid, which had risen from the glass. In another experiment the fluid from the glass was raised through a shorter tube to the membrane, and was made to flow in a slow but constant stream towards the fluid, passing through the larger pipe.

TRANSFORMATIONS OF NUTRITIOUS SUBSTANCES.

Among the numerous papers written on the transformations which the food undergoes in its passage in the body, the most interesting and almost the only ones which afford any definite conclusion are those relating to the formation of fatty matters from the saccharine and starchy principles. It seemed to be proved by Huber's experiments on bees that wax could be formed by them out of pure sugar or honey; for when their food contained nothing but one of these they formed their combs as usual. M. Dumas, who had opposed Liebig's deductions from these facts, suspected that the wax might be formed from the fat which the bees bad in their own bodies before they commenced their purely saccharine diet. He therefore,

Lancet, May 27, 1843.

with M. Milne Edwards, repeated the experiment, and in a successful trial obtained the following results: 1988 bees were inclosed in a hive, and from an analysis of the bodies of 117 from the same stock it was estimated that the bodies of the 1988 contained 3.218 grammes of fatty matter. The honey on which they fed contained of waxy matter. The experiment was continued thirty-one days, and the bees consumed 834-889 gr. of honey, and produced 11-515 gr. of wax, or at the rate of 0.0064 for each bee. After the experiment 105 bees were analysed, and yielded 0-442 gr. of fatty matter, or at the rate of 00042 gr. each. Thus the fatty matter preexisting in each bee was 0.0018 gr., and the quantity furnished to each in its food was 0.0038: but each produced in thirty-one day's 0-0064 gr., and each at the end contained 0-0042, giving a total of fatty matter 0.0106, and an excess, which must have been formed by transformation of the food, equal to 0 00742 gr. per bee.

The old view of the production of the oleaginous constituents of the bodies of herbivora by the transformation of the saccharine and amylaceous principles of their food is thus confirmed; and the evidence is the better for its being honestly published by one who had been the chief opponent of the view. Connected with it is a fact recently observed by MM Pelouze and Gelis,† that under certain circumstances, butyric acid is formed during the fermentation of sugar. By the action of the acid thus obtained upon glycerin they formed also butyrin, another of the constituents of butter. Still, however, the results of the experiments on which Dumas' former opinion was founded are important, as proving that the several articles of food of the herbivora contain a much larger proportion of fatty matter than had been imagined. In maize and other grains, for example, he has found from 7 to 9 per cent., and in grass, hay, &c. considerable proportions, which in all probability contribute to the formation of the fat, though they are not its only

source.

Assimilation. In the last Report some remarkable observations were referred to, proving the analogies between the forms assumed by certain inorganic precipitates such as those of the carbonates of lime and iron, and the forms of the nuclei and cells of organic tissues. Now, Dr. Hermann Jordan § of Saarbrück, has called attention to the phenomena of the reparation of damaged crystals, as bearing analogy to the repair of injured organized bodies. The facts which he establishes are these: 1. Any portion of crystal-whatever surfaces, angles, or edges may have been removed from it-may, under proper circumstances, repair itself into a complete individual; that is, restore itself to the same form which it would have had if no injury had been done to it. 2. At the same time with the reproduction of the truncated part, a growth of the whole crystal takes place: but the effort of the formative act is especially directed to replace the lost part. 3. The effort at reparation stands in a direct relation to the extent of the loss, and decreases in proportion as the loss is replaced. 4. He points out the mode in which the process of reparation takes place, and concludes that his examinations "have demonstrated the tendency of individuals to maintain their integrity and to replace material losses by the formation of more matter, according to the type of their original form, as a phenomenon to be observed as well in inorganic as in organic nature --as a phenomenon which belongs to the individual as such, whether it have a membered body or the simple structure of a crystal."

ORGANS OF ANIMAL LIFE.

Chemical composition of bone. The following are the results of the most recent and careful analyses of human bone, by Marchand and Lehmann. In both cases • Paper read at the Académie des Sciences, Paris, Sept. 18, in the Comptes Rendus, and contemporary journals. Before the publication of these experiments many controversial papers of much interest had appeared, many of which may be found in the Annales de Chimie et de Physique, and the Annalen der Chimie und Pharmacie, January, April, &c. 1843, as well as in the contemporary numbers of the Gazette Médicale, the Medical Times, the Annals of Chymistry, &c.

+ Paper read and repo:ted as above, Juin 12, 1843.

See p. 12.

Müller's Archiv, Heft i, 1842.

the bones were deprived of fat and periosteum: in each the average of six examinations is given; Marchand's were made on thigh-bones, Lehmann's† on the long bones of the arm and leg.

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The following are average relative proportions of organic and earthy matter, collected by Lehmann from his own and the analyses of two other observers.

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All found that the earthy matter increases with age.

In a memoir on ancient and fossil bones, M. Gerarding states that the degrees of alteration which buried bones undergo depend almost entirely on the degrees in which the soils are exposed to air and moisture. They always lose more or less of their animal matter; and sometimes, when they lie in a soil traversed by streams of water, it is completely removed: the ammonia proceeding from the part first decomposed saponifies the rest and makes it soluble. In human bones long buried and in fossil bones there is always more subphosphate of lime than in recent bones; in human bones long buried the proportion of carbonate of lime is generally diminished, in fossil bones it is increased. In fossil bones also there is always some fluate of lime; in human bones, under whatever circumstances, there is none: it seems to be introduced into fossil bones by infiltration from without, and its presence may be depended on as a sign that a bone is really fossilized.

Structure of bone. Dr. Fleischmann|| has described the minute structure of vegetable ivory, from the fruit of the manicaria saccifera, (Gärtner,) a species of palm growing near the coast of Guiana, as being closely analogous to that of bone, at least in regard to the corpuscles which it presents. It possesses also, he says, somewhat of the chemical properties of bone. Thin sections exhibit the most beautiful structures, like the bone-corpuscles, except that they are more regular, and lie within regularly-formed cells, of which they appear to be the nuclei. Branches like the calcigerous canals proceed from each corpuscle, but do not give off smaller branches nor extend beyond the wall of the cell; each branch ends within the cell-wall in a bluntly-closed extremity. He believes that there is the same arrangement in true bone; that each corpuscle has, like a nucleus, a distinct cell-wall around it, such as he has figured in a section of bone from a child; that the canals of the corpuscles are unbranched, and that they end within the cell-walls, having only an appearance of anastomosis with the canals in adjacent cells.¶

• Journal der Prakt. Chemie, Bd. xxvii, p. 83.

Schmidt's Jahrbucher, 1843, No. vi; see also the Chemist, 1843, Nos. 1, 2, and 3. See the next paragraph from M. Gerardin, whose analyses confirm those of Mr. G. O. Rees, in denying the presence of fluate of lime in human or any but fossilized bones. Report from the Académie des Sciences, Gazette Médicale, Oct. 15, 1842. Müller's Archiv, 1843, Heft iii, p. 202.

In these two last opinions he is certainly wrong; the first is in accordance with the

The chapter on 'Bone,' in the Physiological Anatomy' of Todd and Bowman, contains by far the best plates yet published of the minute osseous structure. The ultimate structure also is there described, from preparations made by Mr. Tomes, to be granular. The ultimate granules vary in size from 1-6000 to 1-14000 of an inch; they are oval or oblong, and cohere firmly, possibly by the medium of some second substance. In some instances Mr. Tomes has met with a very minute network, which seems adapted to receive them in its interstices; but this, he considers, requires confirmation.

Process of ossification. In the same work is a description of the process of ossification, which is, in several points, new and interesting, (p. 117.) In the vicinity of the point of ossification the nucleated cartilage-cells (which usually are scattered irregularly) arrange themselves in linear series, which run down, as it were, to the ossifying surface. At first the series are small and not regular, but nearer to the ossifying part they form rows of twenty or thirty. The cells in these rows are closely compressed, and their nuclei seem flattened. The lowest rows dip into and rest in deep narrow cups of bone, formed by the osseous transformation of the intercellular substance between the rows, and as ossification advances these cups are converted into closed areolæ or cancelli, with extremely thin lamelliform walls. Immediately upon the ossifying surface nuclei, which before were closely compacted, separate considerably from one another by the increase of material within the cells: they also often enlarge and become more transparent. Deeper in the new bone the lamella which inclose the cancelli, and which were formed by the ossification of the intercellular substance, are found thicker and more like perfect bone: they include in their substance elongated oval spaces, which, except that they are roughly granular, exactly resemble the ordinary bone-corpuscles, and which are evidently the nuclei of the cells of the temporary cartilages. The curvilinear outline of the now ossified cells of these nuclei can often be discerned. Within the cancelli only a few cells can be detected, these cavities (of the cancelli) being chiefly occupied by a quantity of new substance, consisting of granules, and resembling a formative blastema or basis. It thus appears that after the ossification of the intercellular substance, (by which are formed the lamella which are the walls of the cancelli,) the rows of cartilage all arrange themselves on the inner surface of these newly-formed cancelli, and are ossified, with the exception of their nuclei, which remain granular, and subsequently form the corpuscles of bone; and that a new substance or blastema appears within the cancelli, from which, probably, vessels are developed, and the further steps in the growth of the bone proceed.

NERVOUS SYSTEM.

Minute structure. Remak* says that on the axes of each of the larger primitive tubes of the abdominal nervous cord of the River Cray Fish(astacus fluviatilis), there is, in the recent state, a winding bundle of extremely delicate fibres, occupying one third or one fourth of the whole diameter of the tube. The fibres of this central fasciculus are smooth, parallel, without branches or anastomoses, and less than 1-5000 of an inch thick. They may be seen distinctly when the tubuli are injured: some of them often protrude from the broken extremity. They are found, however, only in tubules from 1-60 to 1-30 of a line in diameter; smaller tubules than these either appear translucent or contain a fine granular substance, and none but the smaller tubules, such as these, are found in the nerves and nervous trunks near the abdominal cord. The spaces between the central fasciculi and the walls of the larger tubules are filled by a clear, colourless fluid. The relation of the central fasciculus in the large tubules of the nervouscord to the central substance of ordinary nerves (the primitive band of Remak,) is uncertain.

Repair and union of nerves. Dr. Bidder,† of Dorpat, has made several experiments to determine whether nervous filaments of originally different functions can be made to unite. He experimented on the lingual and hypoglossal nerves manner in which Henle supposes the corpuscles and their canals to be developed by a deposition within cells, having in each a central cavity (the corpuscle) and interstitial passages or pores (the canals). See his Allgemeine Anatomie, p. 182.

• Müller's Archiv, 1843, Heft iii, p. 197.

Ib. 1842, Heft i and ii.

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