1917] VETERINAKY MEDICINE. 177 



extent, it would not have a deleterious influence on the process, while salt, 

 being more readily absorbed, might well interfere with this function of the 

 leucocytes. 



" Experimental work in physical chemistry and pharmacology points to mag- 

 nesium sulphate as the least absorbable of the readily soluble salts, while 

 clinical evidence — absence of pain, etc. — points in the same direction. By virtue 

 of the nonabsorption of magnesium sulphate the granulations produced are 

 more compact than when a more readily absorbable salt is employed. The 

 magnesium ion has a marliedly inhibitory action on the growth of streptococci 

 and Bacillus coli, and a slightly inhibitory effect on the growth of J3. pyocyaneus. 

 It has, however, no easily demonstrable influence in the concentrations ex- 

 amined on the growth of staphylococci, or on the diphtheroids investigated." 



Platelets and the coagulation of the blood, V. Ducceschi (Arch. Ital. Biol., 

 64 {1915), No. 3, pp. 341-353).- — In the study reported the addition of cocaine 

 (2.5 per cent solution) to frog blood immediately after being drawn prevented 

 its coagulation. It retarded tlie coagulation time about 24 hours in chicli;en 

 blood and from 1 to 2 hours in dog's blood. 



In equal amounts the cocaine prevents the agglutinating phenomenon of the 

 platelets in frog and chicken blood and also arrests the morphological modi- 

 fications which ordinarily occur. The same effect, although not so marked, is 

 observed with dog blood. In cases where coagulation results even after the 

 addition of the cocaine a marked retraction in the clot was observed. 



From the results it is concluded that the first phase of the coagulation of the 

 blood consists of an active reaction of the platelets (agglutination, adhesion 

 to the surface contacts, and morphological modifications), and a mechanical 

 and chemical stimulation caused by contact with the normal cai'diovascular sur- 

 faces and the presence of the thrombokinase, stimulations which are ordinarily 

 the cause of coagulation. This first phase of the coagulation appears to be 

 paralyzed completely or partially by cocaine, which also retards the coagulation. 



The separation of serum into coag'ulative and noncoagulative fractions, 

 A. F. Hess (Jmir. Expt. Med., 24 (1916), No. 6, pp. 701-708).— The coagulative 

 principle of blood serum was found to be closely associated with the euglobulin 

 fraction. A hemostatic containing about 2 per cent protein, which is more 

 potent than the whole serum, has been prepared by the following procedure : 

 The serum was saturated in the cold with pure crystals of sodium chlorid, 

 filtered, and a small amount of chloroform added to the precipitate, which was 

 then dialyzed for about a week. The dialyzate was taken up with Ringer's 

 solution, and 0.3 per cent tricresol added. This solution was then filtered 

 through a Berkefeld filter and bottled in 20-cc. vials. 



The preparation has been employed in various manifestations of intractable 

 hemorrhage, and has yielded most satisfactory results. When injected in- 

 travenously the euglobulin fraction is preferable, since a much smaller amount 

 of foreign protein is introduced. It is also more quickly absorbed from the sub- 

 cutaneous tissues. 



While the exact way in which the substance exerts its coagulative effect 

 on the blood was not determined " it would seem, in view of the fact that 

 euglobulin is found in the normal blood, that it should be regarded as a physio- 

 logic coagulant, and its mode of action in these tests as merely an intensifica- 

 tion of the normal clotting processes." Other globulins examined (egg and 

 edestin from hemp seed) showed no coagulative power. That the coagulative 

 effect of the euglobulin fraction was not due to a counteraction of antithrombin 

 was evident from experiments in which the material was only partly able to 

 overcome the inhibitory effect of hirudin. 



