1904] Properties of Solutions of Chloroform in Water, etc. 387 



can be preserved in contact with chloroform for years without pre- 

 cipitation at room temperatures, and finds this in agreement with 

 Formanek's results, who found, in presence of an alkaline reaction, no 

 precipitation of serum by chloroform even at a temperature of 

 50 — 55° C. Formanek does not state whether his alkaline reaction 

 is the natural alkaline reaction of the serum. Salkowski also found a 

 precipitating action of chloroform upon solutions of albumose and 

 casein. 



Our experiments were conducted with haemoglobin and serum 

 obtained from pig's blood. The serum used was obtained from clotted 

 blood and was thoroughly centrif ugalised before use. The haemoglobin 

 was in all cases obtained by centrifugalising the blood corpuscles three 

 times with normal saline, and then laking with distilled water and 

 making up to the same volume as that of the blood taken. 



In the case of serum we found that the fluid acquired, with less 

 than 1 per cent, of chloroform (and greater quantities up to satura- 

 tion), a peculiar opalescent and fluorescent appearance, but remained 

 quite transparent to transmitted light. On the addition of over 

 2 per cent, of chloroform, there is a tendency to precipitation even in 

 the cold, and at the end of 24 — 48 hours there is a slight precipitate 

 present, but the effect is much hastened on placing the mixture in an 

 incubator at 40° 0., so that it oecomes impossible to determine the 

 maximum solubility of chloroform in serum at body temperature. 

 Both in obtaining precipitation in the, cold and more rapidly at 40° C. 

 in presence of the natural alkaline reaction of the fluid, our results are 

 at variance with those of Formanek and Salkowski. The results were 

 obtained several times in succession. 



The marked opalescence in the serum was obtained in preparation 

 of solutions of known concentration in chloroform for purposes of 

 measurement of their vapour pressures, and led us to doubt at first 

 whether we were not dealing with a fine emulsion of chloroform in the 

 serum. Since this point was of vital importance to our experiments 

 on vapour-pressure, we investigated it as completely as possible. 



In the first place, examination with the microscope of the opalescent 

 fluid showed no visible globules of chloroform, even with the highest 

 powers. 



To make certain of the matter, a current of air from an aspirator 

 was bubbled first through chloroform contained in a Woulffs bottle, 

 afterwards through a similar bottle containing water, and then, at the 

 same temperature, was sent through a third Woulffs bottle containing 

 serum. By this procedure the serum never came in contact with fluid 

 chloroform, nor with air more highly charged with chloroform vapour 

 than corresponded to the saturation of the air in contact with it or 

 passed through it. 



There could, hence, be no condensation of chloroform and no means 



