Selected monographs.

Date:: 1888

Catalogue details

Licence: Public Domain Mark

Credit: Selected monographs. Source: Wellcome Collection.

45/440 (page 29)

greater than that of the albumen. In other words, the greater the pressure under which filtration takes place, the greater the quantity of the filtrate in general, and the smaller its percentage of albumen ; but for all this, for equal periods the total amount of the filtered albumen is greater when the pressure is high than when it is low. It follows, therefore, as regards the glomerular vessels, that they must yield a transudation richer in water, but poorer in albumen than any other set of capillaries in the whole body. The investigations which have been carried on in Ludwig's laboratory with reference to the phenomena of the formation -and flow of the lymph, which are not influenced merely by changes of pressure, have caused us to regard as inadmissible the application of the laws of filtration, as they are found to ripply in the case of animal membranes outside the body, to the processes of transudation which take place within the body. But although the connection between the formation of lymph and transudation from the capillaries is a very close one, yet the lymph which escapes from an opening in a lymphatic trunk cannot be regarded as a simple transudation, and just as little reason would there be in supposing that the conditions of the current in such a vessel were the same with those of transudations from the capillaries, so that our ideas with regard to the one could be simply transferred to the ■other. The fluid which escapes from a lymphatic vessel differs essentially and in many respects from transudations due to ■congestion of capillaries. Morphologically, the distinguishing oharacteristio of lymph is the abundance of colourless cells which it contains ; chemically, lymph and transuda- tions are very dissimilar indeed. It is a well-known fact that lymph coagulates on exposure to air, whereas the real transudations never exhibit this phenomenon, unless they are mixed with blood, or lymph, or products of inflammation. The transudations, without exception, contain ■either no potash whatever, or at most only very slight traces, as little, indeed, as the serum of the blood, when this is obtained perfectly free from corpuscles; the lymph, on the other hand, invariably contains potash in considerable amount, for the analyses of Hensen and Dahnhardt show a .proportion of more than three per cent, after incineration (33).