Ill 



Besides p and K also another constant, or to put it 

 more exactly, two constants, viz. two of the powers in 

 the above equation, must be determined by means of 

 the material. Yet in this case only simple integers can 

 be used, so that the choice is not difficult, a hasty glance 

 on the figure giving the most probable values. It must 

 still be noticed, that the powers 1 and 2 represent as 

 simple a case, as could be expected, and this makes it 

 more probable that the equation represents a natural 

 process. 



For the purpose of illustrating still more thoroughly 

 the great resemblance between the neutralisation of toxin 

 through antitoxin and of a base through an acid, we have 

 examined a closely allied phenomenon, where a base 

 ammonia, also acting as a lysin, is neutralised by an acid 

 the boracic acid. This case could be examined with quite 

 the same method which was used with the combina- 

 tion of toxin with antitoxin. Here we know beforehand 

 p, as the amount of boracic acid, equivalent to a 

 certain amount of ammonia or, to put it more exactly, 

 very few values of p were left to choose between. We 

 might suppose either that one molecule of ammonia NH 3 

 combined with one molecule boracic acid H 3 O 3 B to 

 NH 4 H 2 3 B, or that two molecules H 3 N combined with 

 4 molecules boracic acid to the salt (NH 4 ) 2 B 4 o 7 (+ 12 

 H 2 0), analogous to borax. Also other possibilities might 

 be supposed, viz. that two or three molecules of ammo- 

 nia combined with one molecule boracic acid. The 

 experiments showed the first supposition - - the sim- 

 pler one - - to be right. Solutions were made, which 

 to 1 molecule of ammonia contained 0, l / G , l / 3 , 2 / 3 , 3 / 3 , 

 4 /s, 5 /s an( l 2 molecules of boracic acid. Of these mixtu- 

 res various doses were added to 10 cc. blood emulsion 

 (2,5% in saltwater) and put at 37 C. for 1 hour, quite 



