B ACT ERIOLY SINS AND H&MOLYSINS 103 



both fresh and dried. He found that a powerful 

 haemolytic serum dissolved powdered blood com- 

 pletely, the latter being suspended in 0.9% salt 

 solution. Dried blood to which saline is added 

 brings the haemoglobin of the injured corpuscles 

 into solution, the uninjured corpuscles do not, how- 

 ever, dissolve even after twenty-four hours at 37 C. 

 If the dried blood is extracted in normal rabbit 

 serum, more haemoglobin goes into solution than 

 with saline, when the proportion added is 1:2, 

 whereas the normal serum acts like saline when 

 added in the proportion of 1:4. When two samples 

 of the same dry blood are brought into suspension 

 in normal and artificial hsemolytic serum, respect- 

 ively, a little phenol or toluol being added, the anti- 

 serum brings about complete haemolysis after twenty- 

 four hours, besides leading to the formation of a 

 precipitum, due to the action of precipitins formed 

 in the blood-treated animal in consequence of the 

 serum which was injected together with the cor- 

 puscles. When washed corpuscles alone are 

 injected precipitins are not formed. In view of 

 the specificity of the reactions observed with 

 human blood, Deutsch considers that the method 

 can be put to use in a practical way. There 

 can, however, be no question but that the pre- 

 cipitins offer many advantages over the haemoly- 

 sins for such purposes. 



For other biological blood tests see the Wasser- 



