Diseases of the kidneys and of the spleen, hemorrhagic diseases / by H. Senator and M. Litten ; edited, with additions by James B. Herrick ; authorized translation from the German, under the editorial supervison of Alfred Stengel.

  • Hermann Senator
Date:
1905
Catalogue details

Licence: Public Domain Mark

Credit: Diseases of the kidneys and of the spleen, hemorrhagic diseases / by H. Senator and M. Litten ; edited, with additions by James B. Herrick ; authorized translation from the German, under the editorial supervison of Alfred Stengel. Source: Wellcome Collection.

Provider: This material has been provided by the Francis A. Countway Library of Medicine, through the Medical Heritage Library. The original may be consulted at the Francis A. Countway Library of Medicine, Harvard Medical School.

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    in its results, for the majority of cases of acute nephritis recover, any- way. In general it may be said that the profession looks askance—and rightly—at the indiscriminate operation upon every patient who has albumin and casts in the urine; and while in individual cases the oper- ation may perhaps be justified, an operation upon every case of nephritis is certainly to be condemned. More logical reasoning will have to be employed and more reliable statistics brought forth before it can be granted that a cure has been wrought of a disease of the character of a chronic interstitial nephritis.—Ed.] [THE VALUE OF THE METHODS OF DETERMINING THE FUNCTION OF THE KIDNEY. Several times in the course of the discussion on nephritis mention has been made of the methods by which the function of the kidney is examined—cryoscopy, methylene-blue, etc. This will be as fitting a place as any to say a brief word concerning the value of these methods. Details as to technic, etc., can be sought in the original articles and monographs upon these topics. Cryoscopy,—By this is meant the determination of the freezing- point. The principle upon which it is based is that the greater the molecular concentration of a solution, the lower is its freezing-point— in other words, the freezing-point depends upon the number of molecules in solution. The degree to which the freezing-point is lowered varies with the dissolving substance; thus, a substance dissolved in water would lower the freezing-point to a different degree from what it would if dissolved in alcohol. If a molecular weight in grams of a sub- stance could be dissolved in 1 gm. of solvent, the depression of the freezing-point is a constant (K), varying with the solvent. This value is fictitious, as it is practically impossible to dissolve in 1 gm. of solvent this weight of most substances. But by using larger amounts of solvent—e. g., 1000 gm., or smaller amounts of solute, the value is determined. For water, K^ 1870. The depression of the freezing- point below that of the solvent—for water 0°C.—is represented by J. The greater the amount of substance in solution, the greater the depres- sion ; the greater the amount of solvent, the less the depression; the greater the molecular weight of the dissolved substance, the less the depression. So if S represent the weight of the dissolved substance (the solute), K the constant, L the weight of the solvent, and M the molecular weight of the dissolved substance, the formula for J should show a variation directly as the constant and the weight of dissolved substance, and inversely as the molecular weight and the weight of solvent, , SXK or or for water, J = LxM' SX 1870 LXM '
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