492 ABSOKPTKXN". 



parative observations, the same membrane was used, being 

 soaked for a number of hours in distilled water before each 

 experiment. The tube was graduated in millimeters, and in 

 each observation, the degrees of elevation or depression were 

 noted hourly for five hours. "When the principal current was 

 from the exterior to the interior, the liquid in the endos- 

 mometer was said to be positively osmotic, and the number 

 of degrees of elevation in the tube after immersion for five 

 hours was taken as its osmotic equivalent. When, on the 

 other hand, there was an excess in the diffusion of the li- 

 quid, it was said to be negatively osmotic, and the number 

 of degrees of depression in the tube after immersion for five 

 hours was taken as its negative osmotic equivalent. 



"With this apparatus, Graham determined the osmotic 

 equivalents of a number of different solutions, the strength 

 of each being one per cent. In the following table are given 

 a few of these results : 



Osmose of one per cent. Solutions in Membranes. 1 



Oxalic acid 148 



Hydrochloric acid (O'l per cent.) 92 



Bichloride of tin 46 



Chloride of sodium + 2 



Chloride of potassium + 18 



Chloride of calcium + 20 



Sulphate of magnesia. + 14 



Protochloride of iron + 435 



Chloride of mercury +121 



Mercuric nitrate + 476 



Chloride of aluminium + 540 



Carbonate of potash + 439 



Experiments on the endosmotic power of different liquids 

 have been very numerous, and some of them, particularly 

 those referring to the endosmotic power of albumen, possess 

 considerable physiological interest. The great endosmotic 

 power of albumen, or the force with which albumen attracts 



1 GRAHAM, Op. cit. Philosophical Transactions, London, 1854, p. 225, and 

 Elements of Inorganic Chemistry, Philadelphia, 1858, p. 750. 



