168 OUtuary Notices of Fellows deceased. 



observations and analyses of air, under circumstances of extreme- 

 difficulty and personal discomfort. His experiences are recounted in 

 his book on "The Principal Southern and Swiss Health Resorts," 

 which was published in 1883, and which contains much valuable 

 information concerning the climatology of the principal places in 

 question. During the last twenty years of his life Marcet gave up 

 practice altogether and devoted his energies during the winter and 

 spring entirely to scientific research, spending the summer and autumn 

 partly in travelling, but mainly residing at his family property, 

 Malagny, near Versoix, on the Lake of Geneva. Both here and at 

 Yvoire, on the Savoy side of the lake, where he resided when 

 in Switzerland, before his father's death, he spent his leisure 

 time yachting and mountaineering. For his winter work, he set 

 up a laboratory in London, at first in his own house, but from 

 1883 onwards in one of the rooms belonging to the Physiological 

 Department of University College, which was placed at his disposal. 

 Here, with the aid of skilled assistants, he carried on his researches 

 upon the gases of respiration, for which his ingenuity devised 

 a number of new and beautifully-constructed pieces of apparatus^ 

 amongst which may be specially mentioned an approved form 

 of spirometer, with a bell accurately balanced at every plane of 

 immersion, and a new form of eudiometer for determining the per- 

 centage of oxygen in expired air. Here also he caused to be 

 constructed a large copper chamber enclosed within a jacket of 

 non-conducting material, which he employed as an ice-calorimeter 

 for the human subject, the air inside the chamber being both 

 kept in motion and of a constant temperature by being driven by 

 electric fans over the ice, the melting of which was to serve as a 

 measure of the amount of heat produced during the stay of the 

 subject of experiment within the chamber. This apparatus, which 

 appears to represent the first attempt at human calorimetry by the aid 

 of the ice-method, was ultimately presented by Marcet to Professor 

 Schafer, and is now set up in the Physiological Laboratory of the 

 University of Edinburgh. The results of Marcet's later observations,, 

 both upon the respiratory exchanges and upon the conditions of heat- 

 formation in the human body, were for the most part communicated to 

 the Royal Society and published in the "Proceedings" or "Trans- 

 actions," usually in the joint names of himself and his assistant for no 

 one could be more punctilious than Marcet in acknowledging the work 

 of others, even if immediately inspired and directed by himself. Many 

 of his results were collected and published with much additional matter 

 in his " Contribution to the History of Respiration of Man," which 

 appeared in 1897, and was an extension of the Croonian Lecturer 

 which he delivered before the Royal College of Physicians in 1895. 



