486 Prof. D. F. Harris and Dr. H. J. M. Creighton. [May 10, 



the latter method only was a positive result obtained, T. vivax appearing in 

 the goat 13 days after the first inoculation of blood. The two monkeys used 

 in these experiments remained negative to daily examinations for 30 days. 



With regard to the appearance of trypanosomes in the goat it must be stated 

 that the animal was sent to Sese direct from Entebbe. I was, therefore, only 

 able to make a few preliminary blood examinations before using it for 

 experiment. In the face of former results with T. vivax and the fact that the 

 goat was to all appearance quite healthy, there is every reason to conclude 

 that the trypanosomes came from the situtunga. 



Studies on the Reductase of Liver and Kidney. — Part I. 

 By David Fraser Harris, M.D., D.Sc, F.R.S.E., Professor of Physiology and 

 Histology, and Henry Jermain Maude Creighton, M.A., M.Sc, Dr.Sc, 

 Lecturer on Physical Chemistry, Dalhousic University, Halifax, N.S. 



(Communicated by Prof. A. J. Brown, F.R.S. Received May 10, — Read June 27, 

 1912.) 



I. Introduction. 



The notion has been steadily gaining ground that the reducing powers of 

 animal tissues are due to enzymic action. In March, 1910, one of us* adduced 

 evidence that this so-called " reductase " was active in the press-juice of liver 

 and kidney of sheep, ox, horse, and frog. Soluble Prussian blue, methylene 

 blue, and sodium indigo-disulphonate are all reduced more or less perfectly to 

 leuco-compounds by press juice, whereas by a boiled control they are not. 



It seemed very desirable to conduct several lines of investigation arising out 

 of the main contention that the tissues were capable of carrying out reduction- 

 processes because they contained an endo-enzyme, viz., How rapidly does the 

 press juice deteriorate in reducing activity; how does it behave in respect of 

 such comparatively stable but reducible substances as NaN0 3 ; in what 

 way, exactly, does its activity vary with temperature ; in what way, 

 if any, is the catalase of the liver related to the reductase ? It seemed, in 

 particular, highly desirable that a method capable of following the reduction 

 changes quantitatively should be devised in order to enable us to follow the 

 velocity of any given reaction being studied. 



* Harris, D. Fraser, 'Bio-Chem. Joum.,' 1910, vol. 5, p. 143. 



