1913.] 



Phenomena of" Clot " Formations. 



479 



lowers the surface tension of water the narrower the limits of con- 

 centration within which clot formation is impossible. The inhibition of 

 intravascular clotting after peptone injection is probably a similar phenomenon. 



2. This inhibition of clotting is probably due to the adsorption of simple 

 molecules by the more complex colloidal substances, which are thereby 

 inhibited from aggregation to form a clot. The results suggested that in 

 other cases, such as that of milk, the materials necessary for clot forma- 

 tion pre-exist, but that aggregation is prevented by the adsorption of 

 simpler molecules from the system. The conception was formed that a 

 ferment, for which the colloidal substances could act as a substrate, could 

 clear the surface of such substances of adsorbed bodies and thus allow 

 aggregation (clot) formation to take place. If such an action of ferments 

 takes place it might be possible to explain the function of the intracellular 

 ferments. If they act in the manner suggested, an aggregation equilibrium 

 in the system — colloids (proteins, etc.), simpler adsorbable substances 

 (extractives, etc.), ferment — would be maintained and would be probably 

 necessary for the maintenance of the normal functions of the cell. There 

 would, in this respect, exist a contrast between the " solid " tissues and the 

 fluids of the body. 



3. In attempting to apply this hypothesis to explain the clotting of milk, 

 efforts were made to obtain a " natural " caseinogen. It is already known 

 that caseinogen forms with alkalis solutions of very acid salts, and con- 

 siderable differences were found in the individual preparations with regard 

 to the amount of caseinogen dissolved by alkalis. The solubility in half- 

 saturated lime water was employed as the criterion for differentiating the 

 various preparations. It was found that if caseinogen is prepared in such 

 a way that it is allowed to remain for as short a time as possible with 

 acetic acid used for its precipitation (1 in 1000), a product is obtained which 

 gives an opaque milky fluid containing nearly 8 per cent, of caseinogen. If 

 such a preparation is heated with water at 37°, or allowed to stand with the 

 acetic acid (1 in 1000) at room temperature, it gives rise to a product, the 

 solubility of which in lime water is only about \ of that of natural caseiuogen. 

 This has been designated " metacaseinocfen," the solution of which in half- 

 saturated lime water is opalescent and not opaque. Metacaseinogen can be 

 reconverted into caseinogen by solution in sodium hydroxide and precipita- 

 tion with acetic acid, provided that the precautions are taken that the 

 precipitate does not remain too long in contact with the acid. The solvent 

 capacity of sodium hydroxide approximates to that of an equimolar (not 

 equinormal) solution of calcium hydroxide. 



4. The action of calcium chloride solutions on a saturated solution of 



