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kinase-plasma does not readily clot when treated with thrombo- 

 kinase. Moreover, Wooldridge some years ago pointed out 

 that kinase-plasma could be easily coagulated by the addition of 

 peptone-plasma. The plasmata obtained by injection are there- 

 fore dissimilar in many respects ; in peptone-plasma an anti- 

 thrombin predominates, in kinase-plasma an anti-kinase. 



9. Substances which directly Hinder Coagulation both 

 inside and outside the body 



Substances such as hirudin, which is the active principle 

 secreted by the salivary glands of the medicinal leech, a similar 

 body obtained from the heads of other blood-sucking worms, 

 such as ankylostoma caninum, as well as the virus of many 

 thanatophidia, together with anti-bodies, such as those described 

 by Pugliese 1 and extracted by him from the blood and almost 

 every organ of the body except the brain, directly check the 

 coagulation of blood both inside and outside the organism. 



The anti-body or bodies are, according to Pugliese, chiefly 

 obtained from the liver, kidneys, and muscles. They are not 

 destroyed by heat, but are diffusible. His results may be easily 

 seen in the following table : 



Plasma 



It would seem therefore as if both anti-kinase and anti-thrombin 

 were capable of being yielded by nearly all the tissues of the 

 body. The inner coat of arteries, which might have been expected 

 to form anti-bodies during life, have, however, been shown by 

 Loeb 2 to yield no anti-bodies of any kind. 



The term " hirudin " was introduced by Jakoby and Franz. 

 This substance appears as yellowish scales soluble in water 

 with a slight turbidity, and the activity of the solution is not 

 destroyed by boiling. Its activity is such that a definite amount, 

 o*oi gr., will maintain 7*5 cc. of blood fluid outside the body. 

 The researches of Fuld and Spiro show that hirudin can 

 undoubtedly neutralise thrombin both within and outside the 



1 Quoted from Centralbl. f. Physiologie, 1906. 



2 Virch. Archiv. clxxvi. 1904, and Hofincistcr 's Beitrcige, v. 1904. 



