The diseases of the stomach / by Dr. C. A. Ewald ; Authorized Translation from the 2d German ed. with special additions by the author by Morris Manges.

  • Carl Anton Ewald
Date:
1892
Catalogue details

Licence: Public Domain Mark

Credit: The diseases of the stomach / by Dr. C. A. Ewald ; Authorized Translation from the 2d German ed. with special additions by the author by Morris Manges. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

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    The two important varieties of dextrin are erythrodextrin and acliroodextrin. Maltose is to a certain extent an intermediate body between starcli and dextrin on tlie one band, and grape sugar on tbe other. Starch is recognized by the familiar deep-blue color struck with iodine or a mixture of iodine and potassium iodide—i, e., Lugol's solution : lodi O'l [gr. jss.] Potass, iodidi 0'2 [gr. iij] Aq. destillat 200-0 [f I vj 3 vj] This reaction becomes less marked in proportion to the amount of starch converted into dextrin and sugar. A solution of ery- throdextrin, as its name indicates, no longer gives a blue color, but purple; solutions of acliroodextrin, maltose, or dextrose assume no other color than the yellow of the iodine solution. The latter substances have a closer relation to iodine than dextrin, and the latter again more than starch ; hence, in a mixture of these bodies, the first drops of iodine solution added cause either no color at all or only a transitory one, and it is only after adding more iodine that the purple of erythrodextrin or the blue tinge of starch is observed. As was shown by von Mering in laboratory experiments, and by myself on human beings, in the transformation of starch into sugar by ptyalin, the smaller portion only is converted into dex- trose, the greater into maltose. The latter passes on into the intes- tines, where it is changed into dextrose (Brown and Heron). The practical result of these conditions is the following : If the amylaceous transformation proceeds normally in the mouth and stomach, after a time, within an hour at least, so much starch has been changed into achroodextrin, maltose, or dextrose that the ad- dition of small quantities of Lugol's solution to the filtered stomach- contents no longer produces any changes of color. The occurrence of a purple (erythrodextrin) or a blue color (starch) shows that the sugar transformation has been incomplete. This may be due either to a deficiency of ptyalin or to a too rapidly increasing acidity or an original hyperacidity of the stomach. If, then, we should be unable to titrate the gastric contents— 5
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