THE CONQUEST OF DISEASE 



tact with anything but the normal lining of 

 the blood vessels. The perfection of this 

 operation has been accomplished after years 

 of patient experimentation. In the older oper- 

 ations of transfusion it was found that the 

 blood of one species of animal if introduced 

 into the circulation of another species often 

 caused destruction of the red blood cells, and 

 had to be abandoned. Blood from which the 

 fibrin and red cells had been removed was 

 then employed with some success and much 

 difficulty. It was to overcome these objections 

 that Goltz, Kronecker, Sander, and Ott ex- 

 perimented with the salt solution already 

 mentioned. But the perfection of procedures 

 remained for Crile, whose technic permits the 

 blood of a healthy father to be given to his 

 son without permanent harm to the former. 

 Not only in case of the acute anemia of hemor- 

 rhage is this operation of use, but also in many 

 other conditions in which healthy blood can be 

 of service in replacing that which contains 

 poisonous materials. This operation, now in 

 use but a few years, has already resulted in 

 the saving of a number of human lives 

 exceeding the number of dogs used in its 

 discovery. 



34 



