58 
Arthus also found that the injection of horse serum into rabbits 
caused no symptoms, whether the horse serum was injected subcu- 
taneously or intravenously, but when he injected the serum every 
six days subcutaneously he obtained, after the fourth injection, 
edema and local reaction which continued to gangrene. 
A rabbit which von Pirquet and Schick had previously treated 
with 8 injections was then given 2 c. c. of horse serum into the ear 
vein. The rabbit reacted to this in a minute and, after characteristic 
symptoms similar to those we see in guinea pigs, died in about four 
minutes. 
Arthus obtained similar results with repeated injections of steril- 
ized milk. 
