96 



Mr. J. S. Macdonald. Studies in the 



indistinguishable morphologically from T. rhodesiense should be disseminated 

 amongst horses by coitus is of considerable interest. We are at present 

 conducting experiments with a view to ascertaining whether these three 

 strains, all of them obtained from horses suffering from " mal de coit," are still 

 capable, after numerous passages through laboratory animals extending over 

 many years, of being transmitted in equines by coitus. For the present, we 

 propose for this rhodesiense-like trypan osome the name T. equi. 



DESCRIPTION OF PLATE. 

 Drawn with Abbe camera lucida, using 2 mm. ape-chromatic objective and No. 12 

 compensating ocular (Zeiss). Magnification 2000 diameters. 



Figs. 1- 6. — Strain A (Berlin Strain). 

 Figs. 7-10.— Strain B (Frankfurt Strain). 

 Figs. 11-14. — Strain C (East Prussian Strain). 



Studies in the Heat-production Associated with Muscular 

 , Work. (Preliminary Communication : Section A. — Methods ; 

 Section B. — Results.) 



By J. S. Macdonald, University of Sheffield. 



(Communicated by Prof. C. S. Sherrington, F.E.S. Eeceived June 14, — Read 



June 26, 1913.) 



Section A. — Method. 



The calorimeter with which the included data have been obtained was 

 built upon the plan described by Benedict,* omitting, however, such parts as 

 were essential rather to a study of the respiratory gases than to measure- 

 ments of heat-production. The general principles of its construction are 

 well known, exceedingly ingenious, were developed by Atwater and Benedict, 

 and are briefly as follows : The body of the calorimeter is of sheet copper 

 built upon an external wooden framework, on which again is built externally 

 an outer zinc box enclosing, but nowhere in contact with, the calorimeter box 

 proper. Between the two metal boxes, sets of thermocouples arranged in 

 groups are utilised to discover any differences of temperature likely to lead 

 to a radiation of heat from one box to the other across the intervening air 

 space partially occupied by the wooden framework. In the walls of a still 



* ' A Respiration Calorimeter, etc.,' published by the Carnegie Institution of 

 "Washington, 1905. 



