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Prof. B. Moore and Mr. H. E. Roaf. [Apr. 12, 



by which an emulsion of chloroform, finer even than could be seen 

 with a microscope, could be formed. 



Very soon, however, after the chloroform vapour began to pass 

 through, a distinct difference in appearance was observable between 

 the serum and a control placed alongside, and after a time the serum 

 charged with chloroform in this manner was as opalescent as the 

 specimens made in the usual way by shaking with weighed quantities 

 of chloroform, and gave similar results with regard to vapour 

 pressure. 



These results show that the marked opalescence is not due to an 

 emulsion of chloroform, and further that it is not due to precipitation 

 of proteid in the ordinary sense of the word, for no precipitate can be 

 seen with the microscope in the opalescent fluid. 



Further, experiments on the vapour pressure show that the value 

 of this is a long way from the maximum value, which it must obviously 

 possess if an emulsion was present. 



A similar opalescence is obtained on adding to serum other organic 

 liquids which possess anaesthetic properties, thus we have obtained 

 it on saturation of serum with ether,* benzol and xylol, but have not 

 followed the matter up as we have done with chloroform. 



In the case of haemoglobin solutions, we have not been able to 

 observe an opalescence, similar to tnat seen in the case of serum, up 

 to the strength at which precipitation begins. In order to study where 

 precipitation commences it is necessary to keep the haemoglobin and 

 chloroform constantly stirred, or otherwise before the chloroform has 

 dissolved the lower layer of haemoglobin solution in contact with the 

 liquid chloroform becomes precipitated. When precautions are taken 

 to prevent this occurring, precipitation is found to take place when 

 about 2 per cent, of chloroform has been added, that, is long before 

 saturation is reached (vide infra). This precipitation prevents both 

 the determination of the solubility of chloroform in haemoglobin solu- 

 tions, and the observation of the vapour pressure with high con- 

 centrations. With concentrations of 1 per cent, or under no 

 precipitation whatever was found to occur. Contrary to Salkowski 

 and Formanek, we found that no raising of the temperature was 

 required to cause precipitation of the haemoglobin ; in fact, with strong 

 solutions, the precipitation occurs within a few hours, even in the ice 

 chamber. With time the precipitation is complete, and the precipitate 

 is insoluble in water or saline, but in dilute sodium carbonate it is 

 easily soluble, and we have found that the solution then shows the 

 spectrum of alkaline haematin and not that of oxy -haemoglobin as was 

 found by Formanek. 



* The opalescence with ether is not nearly so well marked, but increases on 

 standing, and the solution in time becomes extremely viscid. 



