Selected monographs.

Date:: 1888

Catalogue details

Licence: Public Domain Mark

Credit: Selected monographs. Source: Wellcome Collection.

53/440 (page 37)

iissure represents tlie space occupied by the minimal amount ■of transudation present at tliat moment, and a consideration of these facts will make it appear quite natural that the infini- tesimally minute trace of albumen contained in this minimal .transudation, should remain invisible even after coagulation. To obtain some approximate idea as to how far the minute traces of albumen with which we are dealing are within the limits of vision, supposing that they can be thus included, it is sufficient to take a simple estimate based on the well- known dimensions of a Malpighian corpuscle, and the thoroughly admissible supposition that the corpuscle is per- fectly globular in form. The diameter of such a corpuscle, and therefore of the Bowman-Miiller capsule, is on an average •25 mm., its capacity is therefore (s'^'V) '00818 cbmm. If we assume that this space is not, as is really the case, quite completely occupied by the glomerular vessels, but only to three-fourths of its extent, so that a complete fourth of the <;ontents is taken up by the transudation, our supposition will have exceeded the most exaggerated demands. There is then at a given moment '00204 cbmm. of transudation in a capsule, or, expressed in weight—for it is somewhat heavier than water—'00206 milligrammes. This transudation, as we have explained in a previous page, must be poorer in albumen than ihe poorest normal transudation, than, for example, the cerebro-spinal fluid. But if we here also advance the most exaggerated assumption, and estimate that the quantity of albumen contained in the fluid of the capsule is equal to that in the cerebro-spinal fluid at its highest amount (see p. 24), that is, 3 per 1000, we should have '00000618 milligrm. of albumen in '00206 milligrm. of transudation. That is the result of a calculation based upon figures exaggerated beyond all belief in order to obtain as large an amount of albumen as possible; and the most extravagant fancy would find a difficulty in supposing that this quantity, even when com- pressed into a spot, would be visible under the microscope, to say nothing of its being more or less diffused in the capsule, and therefore necessarily only partially exhibited on a trans- verse section. As a matter of course the circumstances are different .under abnormal conditions, when more albumen transudes,