Ill 



then in the presence of 0.01 n borate of ammonia 0,00417 

 n Tree ammonia is needed, and in the presence of 0.005 

 n borate of ammonia 0.00264 n ammonia is needed to 

 produce the same degree of haemolysis. All the cases 

 are chosen in such a way, that they produce a simi- 

 lar degree of haemolysis, in consequence the calcula- 

 tions of the amount of free ammonia are undertaken in 

 the above manner. 



In the following table /? indicates the amount of bo- 

 racic acid (in equivalents) present in the solution for 

 each equivalent of ammonia. The ammonia used for 

 the mixtures was 0.1 n, the solution of boric acid 0.2 

 n and they were mixed in different proportions without 

 water being added, x obs. indicates the amount of the 

 mixture in question, which added to 10 cc. of blood 

 produced the haemolysis intended. In the next column 

 a calculated value, x calc., is given. Under the heading 

 a the amount of ammonia (free or combined), present 

 in every test tube is indicated in 0.01 normal solution 

 as unit. Under b the corresponding amount of boracic 

 acid added is indicated. Under c obs. is found the 

 amount of free ammonia, which in the present case is 



The toxicity of mixtures of NH 3 and H 3 O 3 H. 



65 



