Chemical news and Journal of physical science: Chemical news and Journal of physical science

Crookes, William

Chemical news and Journal of physical science (Volume 42, 1880 (July - December))

Bibliografische Daten

Zeitschrift

Persistenter Identifier:: 1695194465359

Titel:: Chemical news and Journal of physical science

Erscheinungsort:: London

Erscheinungsverlauf:: 18XX

Strukturtyp:: Zeitschrift

Sammlung:: Zeitschriften

Lizenz:: https://creativecommons.org/publicdomain/mark/1.0/deed.de

Persistenter Identifier:: 1695194465359

Titel:: Chemical news and Journal of physical science

Erscheinungsort:: London

Erscheinungsverlauf:: 18XX

Strukturtyp:: Zeitschrift

Sammlung:: Zeitschriften

Lizenz:: https://creativecommons.org/publicdomain/mark/1.0/deed.de

Band

Persistenter Identifier:: 1695194465359_42_1880

DOI:

Titel:: Chemical news and Journal of physical science

Herausgeber:: Crookes, William

Jahrgang/Band:: Volume 42, 1880 (July - December)

Erscheinungsjahr:: 1880

Sprache:: englisch

Strukturtyp:: Band

Standort:: Universitätsbibliothek Stuttgart

Signatur:: XIX/98.8-41/42,1880

Lizenz:: https://creativecommons.org/publicdomain/mark/1.0/deed.de

Sammlung:: Zeitschriften

Persistenter Identifier:: 1695194465359_42_1880

DOI:

Titel:: Chemical news and Journal of physical science

Herausgeber:: Crookes, William

Jahrgang/Band:: Volume 42, 1880 (July - December)

Erscheinungsjahr:: 1880

Sprache:: englisch

Strukturtyp:: Band

Standort:: Universitätsbibliothek Stuttgart

Signatur:: XIX/98.8-41/42,1880

Lizenz:: https://creativecommons.org/publicdomain/mark/1.0/deed.de

Sammlung:: Zeitschriften

Ausgabe

Titel:: No. 1080 (August 6, 1880)

Strukturtyp:: Ausgabe

Titel:: No. 1080 (August 6, 1880)

Strukturtyp:: Ausgabe

CHEMICAL ewe) Aug. 6, 1880. Hydrolytic Ferments of the Pancreas. . 63 we are about to describe will afford ample proof of the correctness of that portion of the above statement of Musculus and De Méring referring to the action of pancreatic extrac. Our experiments were made either with the aqueous infusion of the gland, or with the actual tissue itself in a finely divided state, The first method is by far the most convenient, and is the one which we generally adopted when- studying the action of the pancreas, but it will be seen that certain tissues can produce under some circumstances hydrolytic effects which their aqueous infusions are incapable of exercising. + Cr With a clear aqueous infusion ’of the gland, the course of experiment did ‘not diffef materially from that which we employed when investigating the action of malt-diastase upon starch (loc. cit). As a rule the infusion had no power of reducing cupric oxide, hence it was not neces. sary to apply any correction to the quantity of cupric oxide reduced by the transformation produ@s. In cases where the transformation was effected by the actual tissue itself, this was previously dried very rapidly in a current of air at 35°C., a process which could easily be carried out without decomposition taking place. The dried tissue was used with a given volume of the experimental liquid containing a known quantity of the carbo. hydrate. The volume of the liquid was kept constant during the experiment, and the small increase in solid matter due to hydration was taken into consideration, Far more accurate results are obtained by this method than by attempting to estimate the corre&ion for the total solids by digesting a given weight of the tissuein a given volume of water. In the latter case the solvent action of the water upon the tissue always differed somewhat from the solvent a&ion of the solution of the carbohydrate employed. When a clear infusion of pancreas, obtained by acing for several hours upon one part of the finely divided pancreas of the pig with five parts of cold water, is added to starch-paste at 40° C., complete limpidity is produced with extreme rapidity, and in from ten to fifteen minutes iodine ceases to produce any reaction for soluble starch or erythrodextrin. Careful observations at different periods of the rea&ion showed unmistakeably that the transformation in its first stages does not differ in the least from transformations of starch-paste made at 60 C. with aqueous malt-extra®, which has not been previously heated to a higher temperature. When the specific rotatory power of the transformation produds has reached [a]js-86, 162°, the cupric-oxide reducing power is found to be x 49—50. When about 3 cub. centims. of the pan. creatic infusion have been used for every grain of starch, the time occupied in fully bringing about this change is from forty to fifty minutes. The liquid now contains maltose, and an achroodextrin having all the properties of our achroodextvin Z. The maltose was proved to be identical with that obtained by the ation of malt-extrad by isolating it in its characteristic crystalline form, and by determining its specific rotatory and cupric-oxide reducing powers, The composition of the matter in solution at thig point is Maltose oo +o wo oh a0. ue LL Dextrin ov v0 vv we er en... oe THE CHEMICAL NEWS Vor. XLII. No. 1080. SOME OBSERVATIONS UPON THE HYDROLYTIC FERMENTS OF THE PANCREAS AND SMALL INTESTINE.* By HORACE T. BROWN, F.I.C, F.C.S,, and JOHN HERON, F.C.S. WE were requested a few months ago by Dr, W. Roberts to verify a statement, recently made by Musculus and De Méring, that maltose is a produ& of the a&ion of an aqueous extract of pancreas upon starch-paste. During the prosecution of the inquiry, and whilst following ug certain lines of experiment which suggested themselves from time to time, we have, besides fully confirming the results of the above-mentioned observers, ascertained certain faéts which we believe are of some physiological importance in elucidating the still very obscure processes of animal digestion and nutrition. I. Hydrolytic Action of the Pancreas. The first observation upon the amylolytic action of the pancreatic secretion appears to have been made by Bourchardat and Sandrast in the year 1845. The general functions of the gland were more fully studied in 1856 by Claude Bernard,f and a few years later by Cohnheim (Virchow’s Archiv., 28, 241, 1863). Danilewski§ in 1862, and Hiifner (Journal f. Praké. Chem. [2], 5, 1872, 396), ten years later, isolated a soluble amylolytic ferment from the pancreas, the former observer by acidifying the aqueous infusion with phosphoric acid and precipitating with lime ; the latter by the glycerin method first described by Wittich. Hiifner found that the isolated body, which was still doubtless impure, contained 14'g5 per cent. of nitrogen, but a less quantity of carbon and a greater quantity of oxygen than an ordinary albuminoid. Until recently it has always been taken for granted that the fermentable sugar produced by the a&ion of pancreas upon starch-paste is dextrose. Nasse, however, in 1878 (Pfiger's Archiv. f. Physiologie, 14, 473), attempted to show that the fermentable and "cupric-oxide reducing body, obtained by the action of saliva upon starch, is a specific sugar which he calls ptyalose, and that the a&ion of pancreatic juice appears to result in the produion of the same body. Nasse did not isolate this hypothetical sugar, nor even approximately determing its specific rotatory power, but relied mainly upon its non-redu&ion of Barfoed's solution, and its doubling in reducing power on boiling with dilute acid, as evidence of its non-identity with dextrose, In the early part of last year Musculus and De Méring published an important memoir (Bull. Soc. Chim., 31, 105), upon the action of diastase, saliva, and pancreatic secretion upon starch and glycogen. They concluded from their experiments that the fer. mentable sugar produced in all these rea&ions is a mix. ture of maltose and dextrose. We have shown in a recent communication to the Chemical Society (Fourn. Chem. Soc., 1879, 1, 648; Liebig’s Ann., 199, 245), that dextrose can certainly not be included amongst the products of the ation of malt diastase upon starch. The experiments * A Paper read before the Royal Society, May 13, 1880. , ‘Des Fon¢tions du Pancréas, et de son Influénce dans la Digestion des Féculents,” Compt. Rend., 20, T0835. I “ Mémoire sur le Pancréas,” 1856," “Lesons de Physiologic Expérimentale,” Paris, 1856. § “Ueber specifisch wirkende Korper des Natiirlichen und Kunstlichen Pancreatischen Saftes,” Virchow’s Archiv, 1852, 25, 279 80'8 19'2 Pr . I00°0 which is that required by our No. 8 equation. 10C1,H20010 + 8H,0 = 8CraHz,01; C24H004 Soluble Starch. Maltose. Achroodextrin ¢, On continuing to digest the liquid at 40° C., the values of [«]j and « undergo a little alteration, which is, howaver, very slow when compared with the previously rapid degradation of the starch-molecule, The following is an example of such ar experiment :—

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