332 Addis 



clear abd definite and such as always to indicate the same degree of 

 coagulation. 



2. A method is described which conforms to these conditions. 



3. Other methods which have been employed are reviewed, and, 

 where necessary, the result of work undertaken to test their accuracy 

 is given. 



4. The general conclusion of this testing is that no one of these methods 

 fulfils all the conditions mentioned above, and that in particular all fail 

 to comply with the essential condition that in comparative observations 

 exactly the same temperature must be maintained throughout. 



5. The effect of variations of temperature is described, and it is shown 

 that at about the normal temperature of the body the coagulation time is 

 shortest, becoming gradually longer at temperatures above 40"" C. and 

 below 36^' C. 



6. The coagulation time is constant for the same individual at difFejcent 

 times of the day, and even on different days. The daily variations which have 

 been described do not exist, but are due to fallacies in connection with the 

 methods which have been employed. 



7. The conclusion that calcium and citric acid, when administered by 

 the mouth, have no effect on the coagulation time, is referred to. 



I wish to express my thanks to Professor Schafer and to Dr Cramer 

 for advice and criticism during the progress of these investigations. 



The expenses entailed have been defrayed by a grant from the Moray 

 Fuud of the University of P^dinburgh. 



REFERENCES. 



(1) Bbodie and Russell, Journal of Physiology, 1897, xxi. p. 403. 



(2) BoGG, Deutsches Arch. f. klin. Med., Leipzig, 1904, Ixxix., S. 539; 

 International Clinics, vol. i., 18th series, p. 31. 



(3) LoEB, New York Medical News, April 1, 1 905. 



(4) Fleming, Practitioner, vol. Ixxx.^ No. 5, 1908, p. 614. 



(5) Hbktoen, Journal of Infectious Diseases, vol. iv.. No. 3, p. 297. 



(6) Pbarce and Winne, Amer. Journ. Med. Science, 1904, vol. cxxviii. p. 669. 



(7) Pearce, Journ. Med. Research, 1904 (12), p. 316; Journ. Exper. Medicine,. 

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(8) Hueter, Deutsche Zeitschr. f. Cliirurgie, 1873-1874, vol. iv., S. 105, 330. 



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(10) BoxMEYBR, Journ. Med. Research, 1903 (9), p. 146. 



(11) Kraus u. Ludwig, Wiener klin. Wochenschr., 1902, Bd. xv., S. 120, 382. 



(12) VoLK u. LipschOtz, Wiener klin. Wochenschr., 1903, Bd. xvi., S. 1894. 



