On certain Properties of Solutions of Chloroform, etc. 87 



Since the publication of our paper we have extended our observations to 

 certain tissues in the fresh condition, to emulsions in saline of the ethereal 

 extracts of the tissues of equal concentration to the tissues in " lipoid " or 

 ethereal extractives, and to estimations of the relative solubilities in water 

 and serum of a number of other anaesthetics, and observation of the effects of 

 such other anaesthetics upon the proteids of the serum. 



The additional experiments show that the proteids of the tissues combine 

 with chloroform in a similar fashion to the proteids of the serum, and also 

 that other anaesthetics possess higher solubilities in serum than in water, and 

 that the effects in the case of each anaesthetic upon the proteids of the serum, 

 as the anaesthetic is increased in concentration, are similar to those already 

 recorded in the case of chloroform, although the points of commencement of 

 opalescence and precipitation vary quantitatively in the different cases. 



Experiments have also been made upon the relative variations in depression 

 of the freezing point caused by additions of chloroform to water, saline, and 

 serum respectively, as also of the variations in electrical conductivity 

 produced in saline and serum respectively by additions of chloroform. 



The various series of experiments can best be described under the headings 

 indicated above. 



A. — Experiments on the Relationship between Vapour-pressure and Concentration 

 of Chloroform in certain Tissues in the Fresh Condition. 



The experiments were made in the " differential densimeter " described in 

 our previous paper, and following the procedures and precautions there dis- 

 cussed, and it is accordingly only necessary here to state how the tissues 

 were prepared for introduction into the densimeter. The tissue concerned 

 was cleared as far as possible from blood ; in the case of the heart muscle and 

 liver by perfusion of saline through the organ, and in the case of the brain 

 by dissecting out the larger vessels and washing with saline solution. 

 Adherent connective tissue and fat were removed as completely as possible 

 and the tissue was then passed through a machine sold for comminution of 

 tissues for subcutaneous injection. The mass so obtained is too thick in 

 consistency for introduction into the densimeter and was made thinner by 

 addition of an equal volume of normal saline. The tissues were so prepared 

 in as fresh a condition as possible, and the various dilutions of chloroform 

 were made as described in our previous paper. The emulsion of tissue and 

 saline is so opaque that it is impossible to estimate the solubility of chloro- 

 form therein by direct observation as we had previously done in the case of 

 serum, but the observations on vapour-pressure given below, show that in the 



H 2 



