472 



is concentrated to 5 cc. and than 5 cc. of a sohition is added, 

 which contains 0,2 n. NajCO, and 0,2 n. NaOH (in water). After 

 five minutes the mixture is tlioroiigliiy shaken witli 5 cc. of petrol 

 etlier; in tiiis way neutral fats and choie.stei-in are eliminated 

 completely and |ihospliatids for the greater pari. The remaining 

 alcoholic extract is acidulated with 0.5 cc. of HCI cone, and shaken 

 with 2 \5 cc. of petrol ether; afterwards 1 cc. of benzol is added 

 to the alcoholic extract, and this is once more shaken with 5 cc. of 

 petrol ether. The three petrol ether fractions thus obtained contain 

 practically all normal haemolytics. 



If this extract is dried and the residue emulgated in nentral 

 isotonic phosphate mixtnie, then the amount of fatty acids obtained 

 from 1 cc. of blood and emulgated in 1 cc. of phosphate solntion 

 may be diluted to 764 ^""^ ''' ■"'^i" capable to haemolyse 'J °/, of 

 blood corpuscles completely in half an hour at 37°. 



CONCLUSION. 



It is possible by moans of lipoid extraction to isolate from normal 

 blood substances wich are strongly haemolytic. These substances 

 solely consist of highei' fatty acids. A sim[)ie method is indicated 

 for their quantitalixe extraction. 



II. IVie form in lohich stronghj haemolytic fntty acids are 

 contained in normal blood. 



In the pi'evious communication it was stated, that a lather large 

 quantity of intensively haemolytic higher fatty acids can be isolated 

 from normal blood. It will be obvious that in normal blood this 

 action mnst be completel}' on or nearly completely prevented ; the 

 mechanism of this inactivation is not definitely known. In this 

 relation the formation of a protein-fatt)' acid compound was generally 

 supposed, but we did not know if these combinations could exist 

 in the blood plasma and if their haemolytic character has disappeared 

 in this way. The knowledge of this inactivation must be important 

 for (he analj'sis of normal and pathological haemolysis, because 

 insutTiciency of the inactivation-mechanism must be dangerous to 

 the corpuscles. 



In order to investigate in which way the fatty acids are bound 

 in the blood, we have made use of the high degree of capillary 

 activity of these compounds; and this in the first place because this 



