54 THE GENERAL CHARACTERS OF THE PROTEINS 



sodium globulin compound was hydrolysed by water under the con- 

 ditions of the experiments. 



Measurements were also made of the conductivities of the differ- 

 ent salts in gradually increasing concentrations. It was found that 

 in the case of the hydrochloride the molecular conductivity increases 

 much more for increase of volume than does the conductivity in the 

 case of the sodium hydroxide compound. This is due to the fact 

 that the acid functions of globulin are far more marked than its basic 

 functions, for from the equation 



M y = (l - *)/i y + *M H C1 or NaOH' 



where M y is the total conductivity, x the fraction of the salt 

 hydrolysed, /ju y the conductivity of the non-hydrolysed salt, and 

 MHCI or NaOH the conductivity of the salt or acid, when /* H ci or NaOH is 

 greater than p y (as is the case with the globulin salts), the more x 

 increases with dilution the greater M y must become. In the case 

 of the sodium hydroxide compound of globulin the increase of con- 

 ductivity with dilution is not markedly greater than it is in the case of 

 the inorganic salts mono- and disodium-hydrogen phosphates ; there is 

 little evidence of hydrolysis. In the case of the hydrochloride the 

 conductivity determinations indicate marked hydrolysis. 



Determinations were also made of the ratios of the conductivities 

 of solutions of various acids and salts, both alone and after satura- 

 tion with globulin. In the case of very weak acids, such as boracic 

 acid, when a large amount of hydrolysis would be expected from the 

 equation 



M y = (i-*) /s/ + * Madd , 



M y would be nearly equal to //, acid . This is as a matter of fact 

 the case, for " salt = 0*9. In the case of hydrochloric acid, 



/* boracic acid 



where the amount of hydrolysis is comparatively small, the value 

 is 0*24. In the case of ammonia, the free base conducts but 

 little ; in fact, distinctly less than the salt formed by the combination 

 of globulin and ammonia, and the value - - is 2*3. 



/^ammonia 



All these facts lead to the conclusion that globulin forms with 

 alkalis salts which readily undergo ionisation and are good con- 

 ductors, but which, in contradistinction to the acid salts, are hydro- 

 lysed but little with water. 



These salts of serum-globulin have certain characteristic properties 

 which are not shared with ordinary salts. It has already been men- 

 tioned that the solubility of globulin in -acids was determined by 

 adding acids to a suspension until a definite grade of solution was 

 reached, which in most cases was that of minimal opalescence (a 

 process described by Hardy as that of matching). Conversely, if 

 such a solution be dialysed against distilled water, acid passes out, 

 and the globulin solution becomes more and more opaque, without 

 the separation at any time of a solid phase. Such an action Hardy 

 ascribes to hydrolysis and the formation of basic salts, which would 

 take place according to the equation 



*GHAc + ^HOH = (GHOHGHAc) +>-HAc, 



where G represents globulin and Ac acid. 



