1906.] The Chemistry of Globulin. 147 



ductivity is but little changed. So in this case a quarter of the base reacts in 

 quite a different way from the remaining three-quarters. The same considera- 

 tions apply to the case of NH 4 OH. The first term 290 is close to the 311 

 which the standard datum of Kohlrausch would give if half the NH 4 existed 

 as basic ions taking the place of the H ions of globulinic acid. The other 

 half of the NH 4 OH combines additively like the second half of the NaOH. 

 In the alkali globulins we must distinguish between the basic half of the 

 alkali and the additive. To the additive half exactly the same considerations 

 apply as to the additive HC1 globulinate, and the degree of dissociation of the 

 additive alkali hydrate can be determined as in the case of HC1 globulin. 

 Hardy found that to neutralise globulin to phenolphthalein with NaOH the 

 amount of alkali required is twice that needed to dissolve the globulin. Here 

 we have additional evidence that the alkalies act in two ways. Hardy finds 

 that 1 gramme of globulin is dissolved by 10~ 4 gramme equivalents of alkali, 

 and by 2 x 10~ 4 of acid. Now only half the alkali displaces acidic H, hence 

 the acidic H atoms are only one-quarter the number of places where HC1 can 

 add itself to the globulin molecule. Mellanby's measurements on horse 

 globulin do not agree with Hardy's distinction between the number of 

 equivalents of acid and alkali needed to dissolve globulin. He finds a 

 gramme of globulin dissolved by about 10 -4 gramme equivalents of HC1 and 

 about the same number of NaOH. Globulins of different origin and history 

 appear to differ to an extent that limits us at present to a discussion only of 

 orders of magnitude in this connection. 



Concerning the molecular conductivity of neutral salt solutions saturated 

 with globulin, Hardy made some measurements. NaCl of concentration 0*16 N 

 had its conductivity depressed 24 per cent., of 0*11 N by 2*3 per cent., and 

 of 0*09 N by 2*1 per cent. While of MgS0 4 0*3 N the lowering of conductivity 

 was only 1*4 per cent. 



Hardy does not give the strength of the globulin suspension with which he 

 saturated his salt solutions, but states that a gramme of globulin was dissolved 

 by from 10" 2 gramme equivalents up to 2 x 10~ 2 . About 100 times as many 

 equivalents of NaCl are required to keep globulin in solution as of NaOH, but 

 as the globulin reduces the conductivity of ISTaCl about 2 per cent., we may 

 take 2 per cent, of the salt to be combined with globulin, so two equivalents of 

 NaCl actually unite with globulin for one of NaOH. Thus it appears that 

 NaCl in its action on globulin is liker to HC1 than to NaOH. The con- 

 ductivity measurements fully confirm the conclusions arrived at from 

 the solvent powers of neutral salts, namely, that the compounds formed 

 are very unstable and require a large excess of salt to maintain their 

 existence. 



