132 Obituary Notices of Fellows deceased. 



to his M.D. degree in 1878, and in that year his paper, " On the 

 Influences which Modify the Work of the Heart," was published in 

 Foster's Journal of Physiology a paper based chiefly on the research 

 done in Berlin. 



In the course of the next year Roy went as assistant to the 

 Physiological Institute of the Strassburg University, under Prof. 

 Goltz. There he was allowed to devote his time almost wholly to 

 research. Thence came " Observations on the Form of the Pulse- 

 Wave as Studied in the Carotid of the Rabbit" a paper showing 

 more clearly than any of his previous the advent of an investigator 

 of originality and great experimental skill. An instrument was 

 devised for the research the sphygmotonometer a kind of 

 plethysmograph, adapted to record the changing volume of the free 

 but unopened blood-vessel. Original tracings obtained in this 

 research hang now in not a few laboratories both at home and 

 abroad. It was at Strassburg that Roy devised his instruments for 

 measuring the extensibility and elasticity of the walls of blood- 

 vessels. This latter subject was dealt with by him in a paper 

 -appearing in Foster's Journal in 1879. His instrument had points of 

 resemblance with the Holmgren-Blix myographion, but preceded it, 

 and was invented altogether independently of it. In the same year 

 was published, also in Foster's Journal, his work with Dr. Graham 

 Brown of Edinburgh, on capillary blood pressure. The research 

 furnished more trustworthy measurements than any pre-existing of 

 the kind. They provided data, until then almost wanting, regarding 

 one of the most important factors in the circulation. The method 

 employed was extremely ingenious, and for its object has never been 

 surpassed in accuracy. 



Roy now moved from the Physiological to the Pathological Laboratory 

 at Strassburg ; both buildings were then close together in the old 

 Ecole de Me'decine, near the Spital Thor. He, however, found 

 v. Recklinghausen's laboratory occupied so exclusively in the 

 anatomical aspect of disease that he soon migrated to Leipzig, 

 attracted thither by the teaching of Cohnheim. There, in personal 

 contact with Cohnheim, his attention was directed to problems 

 regarding the renal circulation. He invented the instrument by 

 which his name is best known the renal oncometer for the study 

 of variations of the blood-flow through the kidney. The instrument 

 is now familiar to every physiologist and pathologist. With it Roy 

 and Cohnheim prosecuted a research which remains a classic to 

 students of the circulation. The acquaintance of the two workers 

 rapidly ripened into close friendship. The late Prof. Kiihne, in his 

 memorial sketch of Cohnheim (1885) prefixed to the Gesammelte 

 Abhandlungen, wrote : " These exact and laborious researches, through 



