502 PROCEEDINGS OF SECTION D. 



non-amphoteric base, or of a basic ampholate with a non-amphoteric 

 acid are termed ampho-salts. An ampho-!<alt formed by the substitution 

 of a base for hydrogen in an acid ampholate can disssociate into ions in 

 either of two ways ; either it can dissociate into the ion which has 

 replaced the hydrogen of the ampholate and an anion, or it can 

 dissociate into a cation and a hydroxyl, for example, NaXOH can 

 can dissociate either as a Na+ + XOH- or as NaX+ +0H-, in the 

 second instance the ampho-salt acts as a base and is termed a basic 

 ampho-salt. Similarly the ampho-salt formed by the substitution of an 

 acid radicle for the hydroxyl of an ampholate can act either as a salt or 

 as an acid, and, when acting as an acid, is termed an acid ampho-salt. 

 The combination of an acid ampho-salt with a basic ampho-salt, such, for 

 example, as NaXCl, which can no longer split off hydrogen or hydroxyl 

 ions, is termed a " di-salt." 



The term " association salt " is restricted to the neutral substances 

 formed by the combination to two or more ampholates of lower orders,, 

 such as, for example, XX, formed by the combination of two HXOH 

 molecules with the elimination of water. Neutral substances may also 

 be formed in ampholytes by a modification of internal structure, but on 

 these I need not dw^ell here. 



This investigation threw light in many ways upon the facts which 

 I have outlined to you ; for instance, the fact that in many cases 

 Guldberg and Waage's law cannot be applied directly to two reacting 

 proteins is explicable on the basis of the following considerations : — Let 

 A be the mass of the acid ampholates in one of the proteins and B that 

 of the basic ampholates ; similarly let A' and B' be the acid and basic 

 ampholates of the other protein, then the mass of the one protein, as 

 estimated by weighing, is equal or proportional to A+B, while that of 

 the other is equal or proportional to A' -f- B'. According to Guldberg 

 and Waage's law, the active mass of the product is proportional to the 

 product of the active masses of the reacting substances. Now, in this 

 case the product of the measured active masses of the two proteins is 

 (A + B) (A' + B') = AA' + AB' +BA + BB', but in the actual 

 reaction A only reacts with B' and B with A', not A with A' and B with 

 B', so that the mass of the product will be proportional to AB' + BA', 

 and not the product of the measured active masses of the two proteins, 

 unless A is equal to B or A' to B'. That is, as can be shown from other 

 considerations upon which I cannot dwell here, Guldberg and Waage's 

 law can only apply to the reaction between two proteins, if one of the 

 pi'oteins is isoelectric and remains so throughout the reaction — that is, does 

 not drift under an electric field, or, ii in one of the proteins the acid 

 function is negligible, and in the other the basic function. 



This point of view also clears up some of the relations of the 

 swelling and solubility of proteins to the concentration and number 

 and valency of the non-amphoteric ions in the medium ; but for 

 these and other applications of the theory I must refer to my original 

 paper. 



I have also recently shown that this point of view renders clearer 

 many phenomena in the hydrolysis of proteins by trypsin (78), but 

 for an account of these I must also refer to my original paper on the 

 subject. 



