CHEMICAL EQUILIBRIA 115 



we should investigate the neutralization of ammonia 

 regarded as a lysin, i.e. measured by its haemolytic 

 activity, by means of boracic acid, and of sodium 

 hydrate by hydrochloric acid. 



The result of the experiments was in perfect 

 accordance with what I expected. The simplest 

 case is the neutralization of one equivalent of 

 sodium hydrate by hydrochloric acid. The salt 

 formed is absolutely innocuous. Say that we have 

 o-i normal solutions of NaOH and HC1 ; if we add 

 o-i cc. of the alkali to 10 cc. of a 2-5 per cent 

 emulsion of red blood-corpuscles, this dose gives a 

 certain degree of haemolysis (after 2 hours at 37 C.). 

 Now we mix 0-5 cc. HC1 with i cc. NaOH and 

 investigate which quantity of this mixture gives the 

 same degree of haemolysis. Evidently in 1-5 cc. of 

 the mixture there is as much free sodium hydrate 

 as in 0-5 cc. of the original solution. We must 

 therefore now take 0-3 cc. of the mixture for ob- 

 taining the said effect, and so forth. The diagram 

 (Fig. 31) representing this behaviour is a straight 

 line, which cuts the .r-axis at i corresponding to 

 addition of a quantity of acid equivalent to the 

 quantity of base used. In reality the line of 

 neutralization cuts the ^r-axis a little before, because 

 the corpuscles sustain a certain minimal quantity 

 of free alkali before any haemolysis is observed. 

 If we add more acid we observe a similar small 

 region of acidity which does not attack the corpuscles, 

 and then haemolysis occurs again and the haemolytic 

 power of the solution is proportional to the excess 



