322 TRANSUDATIONS. 



a quantitative determination of this constituent; but from the 

 microscopic examination of the ether-extract even of normal tran- 

 sudations, we may arrive at the certain conclusion that the amount 

 of cholesterin in the fluid either exceeds, or at all events very nearly 

 reaches that of the true fats. The capillaries generally have the 

 power under certain, not yet accurately determined, conditions of 

 allowing the transudation of cholesterin in larger quantity than 

 other substances ; for it is not only in the above mentioned cases 

 of dropsy that we find accumulations of cholesterin ; the choroid 

 plexus of the brain, which secretes a fluid that is very poor in fibrin, 

 is not unfrequently found to be covered with an entire crust of 

 minute plates of this lipoid ; and how many analyses are there of 

 the transudations into the peritoneum and pleura, in which the 

 quantity of cholesterin has been noted as strikingly great ! Indeed 

 we might almost believe that the walls of the vessels possess a 

 peculiar attractive power for the cholesterin, when we reflect on 

 the atheromatous process which is so common in the arteries, if 

 these accumulations of cholesterin cannot be more simply (even if 

 not completely) explained by the circumstance that water, albumi- 

 nous substances, and salts, are more readily absorbed from the 

 transuded fluid by the lymphatics, or some other means, than the 

 cholesterin, or that by a process of partial absorption its solvent is 

 taken up and removed, and that it is thus compelled to separate in 

 a solid crystalline form in the cavity in which the transudation 

 occurred. 



In a hydrocele-fluid, which formed a tolerably consistent pulp, 

 I found 3-041^ of pure cholesterin (amounting to 38'202 of the 

 solid residue), and in another fluid of the same nature 1*569}}; 

 Simon,* in a similar case, found 0'84 -jj- of cholesterin, with a little 

 olein and margarin. 



Serolin, which forms hexagonal or rhombic tablets, whose 

 crystallometric determination has been given in the first volume, 

 and which may be so readily distinguished from cholesterin and 

 crystallisable fatty acids by its peculiar shape, always occurs with 

 the cholesterin in the transudations, but seldom in any considerable 

 quantity. 



Since Pettenkofer^s discovery of his admirable test for the 

 detection of the resinous adds of the bile, many chemists who have 

 investigated morbid transudations have met with these substances 

 in dropsical fluids: and it was only to be expected that these 

 substances, if they occurred in the blood, should also simul- 



* Medic. Chem. Bd. 2, S. 582 [or English translation, vol. 2, p. 495.] 



