130 



T 



n he Chemistry of Globulin. 

 By William Sutherland, M.A. Melbourne. 



(Communicated by Dr. C. J. Martin, F.E.S. Received July 26, — Read 



December 6, 1906.) 



The object of the present paper is first to establish simple formulas for the 

 more important of the experimental results obtained by Hardy* and 

 Mellanby,f then to interpret these in their bearing upon the chemistry of 

 globulin in connection with a theory of colloids, and finally to find the 

 molecular mass (weight) of globulin. The work will be taken according to 

 the following table of contents. 



1. Formula for the solution of globulin in solutions of neutral salts, and 

 the laws associated with this formula. 



2. Solution of globulin in acids and alkalies. 



3. Formulas for the precipitation of globulin by salts and by acids. 



4. A theory of the colloidal state. 



5. The electric conductivity of globulin solutions. 



6. The molecular mass (weight) of globulin. 



1. Formula for the Solution of Globulin in Solutions of Neutral Salts, and the- 

 Zaivs Associated with this Formula. 



Mellanby sets forth his results in graphs, from which he makes some broad 

 deductions, to be discussed later in this section. His most striking result,, 

 obtained also by Hardy, is that the fraction (or percentage) of a globulin 

 suspension which is dissolved by a salt solution of given strength is nearly 

 independent of the original strength of the suspension. In other words, the 

 amount of globulin dissolved by a given salt solution is proportional to the 

 amount of globulin presented for solution in the form of a suspension. This 

 fact is of fundamental importance for the colloidal globulin of the suspension. 

 For example, a 0'3-per-cent. NaCl solution dissolves from a 3-04-per-cent. 

 suspension of globulin in 100 c.c. 1*12 grammes, from 1*68 per cent. 0'64, 

 from 1-06 per cent. 0'39, and from 0'7l per cent. 0"30. 



Let G be the original strength of a globulin suspension when it is 

 instantaneously distributed through a solution of a salt of concentration c, 

 G and c being given in grammes per cubic centimetre. Let g be the 

 grammes of globulin per cubic centimetre dissolved from the suspension 

 when saturation is reached, and let C be the concentration of the salt 



* 'Journal of Physiology,' 1905, vol. 33, p. 251. 

 t Loc. cit., p. 338. 



