Ill 



Methods of investigation. 



As we have already stated, the test tube method per- 

 mits us, in a comparatively short time, to carry out a 

 great number of experiments. 



The red blood corpuscles, which served for our ex- 

 periments, were emulsionated with an aqueus solution of 

 equal osmotic pressure. As a rule we used horseblood, 

 which was centrifugalised; after the serum was taken 

 away, the corpuscles were shaken up with isotonic 

 solution and again centrifugalised in order to remove 

 the rest of the serum. Of these red corpuscles, which 

 had been so washed out, 25 cc. were added to 1000 cc. 

 of a 0,85 % solution of sodium chloride. Under some 

 conditions this sodium chloride would have had a che- 

 mical action upon the bodies to be experimented on. 

 In such experiments a 7,79 % solution of cane sugar 

 took the place of the 0,85 % NaCe solution. In other 

 cases we varied the quantity of the blood. 



10 cc. of this blood emulsion already thoroughly sha- 

 ken were measured into a tesl tube, to which by means 

 of a pipette, a certain amount of the solution to be ex- 

 amined was added. If the experiment has been succes- 

 full a certain amount of red blood corpuscles will be 

 dissolved. The added sol u I ion always therefore must 

 contain some hremolytic body, telanolysin or alkali, be- 

 sides other substances which might possibly have an 

 effect upon the haemolytic process without themselves 

 having a hiemolytic action. For the greater part of the 

 experiments a temperature of 37 C. was used. Then 

 all the test tubes after a thorough shaking were at 

 once put into a water-incubator of the said temperature 

 for 1 hour. They were then taken out and put into an 

 ice safe for about 20 hours. At such a temperature 

 (about 7 C.) the haemolysis progresses very slowly, and 



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