46 Society for Experimental Biology and Medicine. 



bodies, while the extract lysins are active by themselves. The 

 action of complement diminishes with age and is destroyed by a 

 temperature of about 56 0 C, whereas the extract lysins do not de- 

 teriorate with age or on boiling. So the general conception of to- 

 day is that they are entirely distinct classes of bodies. Up to the 

 present, no account of the parts which may be played by the 

 other serum components has been taken into consideration. A 

 comparison made under different conditions is devoid of value, and 

 observations on this point seem desirable. I have therefore sub- 

 jected both complement and the " extract lysins " to a comparative 

 study under the same conditions. I have also identified the chem- 

 ical nature of various " extract lysins," and pure chemical prepara- 

 tions have been subjected to a similar comparative study. My 

 method of obtaining lytic substances from the blood or other 

 organs was carried out as follows : 



To one volume of blood or thick emulsion of any organ, three 

 volumes of 95 per cent, alcohol are added. The mixture is left 

 for about a week at 45 or 50 0 C. Then the filtrate is evaporated 

 to dryness. The dried mass is extracted with hot alcohol. The 

 alcoholic extract is dried. The dried mass is extracted with 

 ether. The ether insoluble fraction is usually highly lytic, while 

 the other fractions are inactive. The last, ether insoluble, hot 

 alcohol soluble fraction is, of course, free from salts, proteins, 

 neutral fats, fatty acids, cholesterin and its esters, lecithin and 

 other phosphorized fats. It is soluble in water or 0.9 per cent, 

 saline solution with slight opalescent appearance, and is neutral 

 to litmus. Chemically, this fraction represents various soaps. 

 The addition of acetate of lead and subsequent ethereal extraction 

 removes its original lytic substance. Any strong acid produces 

 a milky appearance due to the splitting of the soapy substance, 

 and its hemolytic activity is reduced. Osmic acid gradually 

 turns the solution dark. The solution yields a thick precipitate 

 with phosphotungstic acid and with bromine. Millon's test is 

 negative. This fraction, therefore, consists of various soluble 

 soaps derived from the blood and organs. 



My experiments with various soap fractions of the blood and 

 organs show that such fractions possess considerable lytic activity 

 when employed in 0.9 per cent, saline solution. The corpuscles 



