134 



RAYMOND PEARL 



Fig. 3 Showing one of the inhalation tanks used in the administration of 

 poisons in this experiment. For description and dimensions see text. 



the air. It has been found by experiment that a single bird 

 will remain in one of the large tanks above described, tightly 

 closed so that no air from the outside can get in, for at least 

 12 hours without showing any signs whatever of discomfort, and 

 probably would stay much longer than that. Trial has shown 

 that even as many as five large birds may be put in one of the 



