330 TRANSUDATIONS. 



with such extraordinary rapidity in the intestine, that we must 

 altogether abstain from analysing them, if we wait till we can 

 obtain them in their perfectly pure, native state. Ammonia must, 

 however, be found, and indeed has been found by Schmidt in all 

 transudations arising from blood containing ammonia or much 

 urea (see p t 264), and hence it is not uncommonly met with in drop- 

 sical exudations in alburninuria. 



Finally, we may very readily convince ourselves that the tran- 

 sudations, like the animal fluids generally, contain free gases, by 

 employing a simple gas-apparatus in communication with the air- 

 pump. Amongst the mixture of gases that are evolved from the 

 transudation, carbonic acid is found to preponderate, although the 

 presence of oxygen and nitrogen may be recognised with certainty. 

 From determinations which can certainly only be regarded as ap- 

 proximate ones, I obtained from fresh transudations discharged by 

 paracentesis, on an average, a less quantity of gas generally, but 

 always relatively more carbonic acid than from the fresh blood- 

 serum of persons for whom venesection had been prescribed solely 

 in consequence of plethora. 



The apparatus which I employed for this somewhat superficial 

 investigation was constructed in the following manner : Two flasks 

 are united to one another by glass tubes and corks ; in the lower 

 one we place the fluid to be examined, and in the upper one, which 

 is two-necked, we place pure almond or olive oil ; from the lateral 

 tube there proceeds a glass tube filled with oil to the bottom of a third 

 flask ; this last flask, whose bottom is covered with oil, is brought 

 in connexion with the air-pump. On now making a vacuum, the 

 bubbles of gas which are developed from the blood rise into the 

 upper flask (which stands reversed upon the lower one), and drive 

 the oil through the communicating tube into the third flask ; 

 if now we allow air again to enter the last flask, the oil is only in 

 part forced back into the upper flask ; the bulk of the gases 

 contained in it is diminished to the volume corresponding to the 

 external atmospheric pressure. Since any resorption by the 

 aqueous fluid in the lower flask is prevented by the oil, we may at 

 all events form some idea of the quantity of gases which such 

 fluids contain. 



It is unnecessary to give a special description of the different 

 methods which may be devised for the qualitative and quantitative 

 analysis of the transudations, since the same rules hold here 

 which we have fully noticed when treating of the "analysis of the 

 blood" and of the individual animal substances, in their respective 



