Report on the progress of human anatomy and physiology in the year 1844-5 / [Sir James Paget].

  • James Paget
Date:
1846
Catalogue details

Licence: Public Domain Mark

Credit: Report on the progress of human anatomy and physiology in the year 1844-5 / [Sir James Paget]. Source: Wellcome Collection.

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    that sugar exists in the blood of the same animals in the proportion of from 2’57 to 8 05 grains in 1000 grains of the serum. In a subsequent memoir* MM. Bouchardat and Sandras state that the prin¬ ciple which, as above-mentioned, appears to act like diastase in the transforma¬ tions of starch is secreted chiefly by the pancreas. They find the pancreatic fluid of birds transparent, viscid, slightly alkaline, and capable of liquefying starch-paste, and of transforming it into dextrine and grape-sugar. Portions of pancreas cleared of blood and large vessels possess the same power in a very high degree ; and no other organ besides the pancreas, and in a slighter degree the salivary glands, possesses such a power. + It is, moreover, wholly destroyed both in the pancreatic fluid and in the pancreas itself by such in¬ fluences as destroy the like property in diastase, such as a temperature of 212°, tannin, mineral acids, metallic salts, &c. The same influence which these authors ascribe to the pancreatic secretion is ascribed by M.MialheJ to the saliva,from which he gives directions for obtaining the digestive principle, animal or salivary diastase,—by filtering it and then treating it with five or six times its weight of absolute alcohol. The diastase being inso¬ luble in alcohol is thus precipitated in white flocculi. He describes the aqueous solution of this substance as insipid and neutral, not precipitable by subace¬ tate of lead, and when left to itself undergoing a transformation into butyric or some similar acid. With raw starch this salivary diastase requires several days for the production of dextrine and sugar of starch ; but with starch- powder the change is quickly effected ; and with starch-paste it is very speedily completed if aided by a temperature of about 1G0°.§ The experiments of M. Lassaigne || confirm those of MM. Bouchardat and Sandras as to the properties of the pancreas and its fluid ; and, at least in great measure,1U those of M. Mialhe on the properties of the saliva. He shows that at the natural temperature of the body saliva has no effect on whole starch, and that mastication does not change the form in which it naturally exists in cereal grains ; that horse’s saliva does not act on starch even when its grains are broken ; birt that human saliva, though it does not affect raw and whole starch at a temperature of 100°, can even at a temperature of from 64° to 68° convert powdered starch partly into dextrine and partly into sugar of starch , the envelopes of the granules preserving at the same time their property of becoming violet when touched with iodine. Influence of the Bile in digestion. Dr. Platnei ** has made experiments to find how the bile contributes to digestion. He has confirmed, what Simon and others showed, that the faeces contain none of the bile except its colour¬ ing matter [and some of its fat?]; and what Purkinje showed, that bile will put a stop to or prevent the artificial digestion of coagulated albumen. On mixing pure artificial digestive fluid, neutralized by carbonate of soda] with bile, no change took place ; but on adding hydrochloric acid to the mixture it became very turbid. The same happened when bile was mixed with digestive fluid not neutralized ; but hydrochloric acid added to bile alone produced no precipitate. The precipitate consisted of bilic acid united with some organic body, perhaps pepsin, explaining probably the fact quoted above from Purkinje. When bile was added to a solution of albumen in acetic acid, a precipitate * Archives Gtn. de Medecine, Mai ]845 ; Report from the Acad, des Sciences, 14 Avril. + See in connexion with this subject a paper by M. Bouchardat, “ Sur la fermentation saccharine ou glucosique,” in the Annales de Chimie et de Physique, Mai 1845, t. 89, p. 61. % Ibid., 5 Avril 1845 ; Report for the 31st of March. $ According to Dr. R. D. Thompson (1. c.) the transformation of starch into dextrine is effected to some extent by boiling it for half an hour in pure distilled water. || Arch. Gdn. de Medecine, Mai 1845, from the Report of the Acad, des Sciences, 7 Avril. 1 Ibid. Juillet 1845, from the Report of the Acad, des Sciences, 2 Juin. In the earlier paper his results were opposed to those of M. Mialhe. ** Muller’s Archiv, 1845, Heft iv. He has since published a special work, “ Ueber die Natur und den Nutzen der Galle,” Heidelberg, 1845; but I have not yet received it. Another work relating to the physiology of the bileis H. Meckel, De genesi Adipis; Halis. 1845, 8vo, which will be noticed hereafter.