820 M. Dutrochet's New Researches 



fluids which have contrary qualities, that is to say, which are 

 active fluids. 



I have found that the fluids of putrified animals are inactive. 

 When put into the endosmometer surrounded by pure water, 

 they desoend in the tube notwithstanding their superiority of 

 density to water. It may be established as a general fact, 

 that all active fluids miscible in water, whether organic fluids 

 or chemical fluids, act like fluids denser than pure water, 

 when they are separated from the latter by a permeable mem- 

 brane, that is, they are all agents producing endosmose. It is 

 never towards the side occupied by the water that the strongest 

 of the two currents is directed, and which constitute by their 

 union the endosmose and exosmose. Thus every active fluid 

 placed in affinity with pure water is not an agent producing 

 exosmose. Whenever, then, we observe a fluid descend in the 

 tube of the endosmometer when the bladder is plunged in 

 pure water, we may conclude that this interior fluid is inactive. 

 Its falling in the tube is the simple result of its filtration de- 

 scending by the effect of its weight. Here I ought to mention 

 an error into which I had fallen. Observing the manner in 

 which sulphuric acid comports itself, I was led to think that 

 the acids were the agents producing exosmose ; but it is not 

 so. Vinegar, nitric acid, hydrochloric acid, placed in the en- 

 dosmometer surrounded by water, produce endosmose, hydro- 

 chloric acid, in particular, a very powerful endosmose. 



We come now to observe, that, in relation to the property 

 of producing endosmose and exosmose, there are active and 

 inactive fluids. This fact, which is of the greatest importance, 

 had escaped me in my first researches. 



I have shown in my book that endosmose is produced by 

 putting the pure water inside as well as outside of the endos- 

 mometer closed with an organic membrane, but making the 

 interior water correspond with the negative pole of the voltaic 

 pile, and the external w r ater with the positive pole. It became 

 necessary to determine if, by substituting any porous mineral 

 plate whatever in this experiment for the organic membrane, 

 the same result would be obtained. I have given an account 

 in my book of experiments made with this view, which prove 

 that we obtain no elevation of the water above its level, by 

 means of the electricity of the pile, when the organic mem- 



