332 PHYSICAL PROPERTIES 



the difference amounted to only 0.006 degrees, the experimental 

 error of the cryoscopic method being about 0.005 degrees. In 

 connection with experiments such as these it should be recollected, 

 however, that heating induces many modifications in protein- 

 containing solutions which might conceivably affect the osmotic 

 pressure (freezing-point) in a variety of diverse ways (92) . Liide- 

 king found that even 40 per cent of gelatin in solution did not 

 perceptibly alter the boiling-point (67) and Krafft and Wiglow 

 (55) confirmed his results. Bugarszky and Liebermann (17) 

 estimated the depression of the freezing-point due to dissolved 

 egg-albumin, albumose and pepsin, and their ash, separately, and 

 deducted the latter from the former. They estimated in this 

 manner the molecular (or, in reality mean molecular and ionic) 

 weight of egg-albumin to be 6400, that of albumose to be 2400 and 

 that of pepsin to be 760. They also found that if egg-albumin, 

 albumose or pepsin be added to solutions of acids or alkalies, the 

 cryoscopic depression of the resultant solution is less than the sum 

 of the depressions due to the acid or alkali and the proteins dis- 

 solved separately; while if the egg-albumin, albumose or pepsin 

 were dissolved in salt solutions the cryoscopic depression of the 

 mixture was found to be (within the limits of experimental error) 

 identical with the sum of the cryoscopic depressions due to the 

 protein and the salt dissolved separately. The significance of 

 these latter results has already been commented upon in Chap. IV. 

 Bugarszky and Tangl (18) carried out an extended series of 

 investigations aiming at the determination of the cryoscopic 

 depression due to the non-electrolytes of the blood, among which 

 they included the proteins. They determined the chlorine con- 

 tent of the blood and, from that, deduced the equivalent molec- 

 ular concentration of the sodium chloride in the blood and its 

 conductivity; they then measured the conductivity of the blood 

 and subtracting from it that due to sodium chloride, considered 

 the remainder as due to sodium carbonate and estimated there- 

 from the molecular concentration of the sodium carbonate. They 

 then subtracted the cryoscopic depression due to the sodium 

 chloride and sodium carbonate contents thus estimated, from the 

 observed cryoscopic depression of the blood; the difference they 

 ascribed to the non-electrolytes and proteins. In this way they 

 estimated the concentration of non-electrolytes in horse's blood 

 to be about 0.056 mol. per litre. The accuracy of this determina- 



