1918-19.] Reaction Velocity of Sodium Nitrite on Blood. 155 
effect of millinormal caustic soda on the reaction of twentieth normal 
sodium nitrite on blood is also seen in fig. 7. In this particular series of 
experiments, which were made on washed blood corpuscles that had been 
Fig. 5.— Effect of concentration of sodium hydroxide indicated against the curves on 
the reaction between dL sodium nitrite and 2 per cent, blood solution. 
200 r 
Ordinates, extinction coefficients ; Abscissce, time in seconds. 
stored in the laboratory for six days, twentieth normal sodium nitrite com- 
pleted the change on the blood in fifteen seconds, and the course of the 
Fig. 6. — Effect of concentration of sodium nitrite indicated against 
the curves on a solution of 0 5 percent, washed blood corpuscles 
in millinormal sodium hydroxide. 
Ordinates , extinction coefficients ; Abscissce, time in minutes. 
reaction could not consequently be followed. Even in the presence of two- 
thousandth normal caustic soda the reaction was completed in half a 
minute. The addition of millinormal sodium hydroxide caused an induc- 
tion period of half a minute and a reactionary period of one and a half 
