77/ /■; progress of science. 



185 



the Eumphry Museum lias been 

 erected at a cost of about $170,000, 

 mostly supplied by the benefactors 

 fund, and a further wing for pathology 

 and physiological chemistry is planned 

 at a cost of about $65,000. The 

 Humphry Museum is treated ornament- 

 ally, both inside and out. The fact 

 that the main lecture-room is lighted 

 entirely by artificial light, might lead 

 us to suppose that utility had been 

 sacrificed to architecture, but it is said 

 that the building is well adapted to 

 the uses of the medical school. The 

 library is planned on a new principle, 

 the stacks being blocked solidly on the 

 sides, each case being movable and 

 pulled out when wanted. This scheme 

 seems to be ingenious ; the space is 

 nearly trebled and books are kept free 

 from dust. It is doubtless a disad- 

 vantage to shut the books from view, 

 but when the case is pulled out the 

 books are more accessible than in ordi- 

 nary stacks. 



The buildings here mentioned are 

 erected on land acquired by the uni- 

 versity from Downing College, and 

 three of them form part of an irreg- 

 ular quadrangle. It is hoped that a 

 school of agriculture and an archeolog- 

 ical museum will be added to the group 

 within a reasonable period. 



DEVELOPMENTS IN THE RESPIR- 

 ATION CALORIMETER. 



Two important developments have 

 lately been made in this apparatus, 



which render it a more efficient means 

 of determining tin' use which is made 

 of food nutrients in the body, and ex- 

 tend its use tn experiments with large 

 animals. As is well known, the ap- 

 paratus as developed by Atwater and 

 Rosa enabled the accurate determina- 

 tion of the carbon, nitrogen and 

 water excreted by the subject within 

 the respiration chamber, and the heat 

 given off by him under different condi- 

 tions of food and exercise. During the 

 past year an alteration has been made 

 in flie apparatus by which the oxygen 

 consumption is also determined, giving 

 increased accuracy and furnisbing 

 data for estimating the gain or loss 

 in protein and fat, as well as a new 

 method of estimating the respiratory 

 quotient. The arrangement for de- 

 termining the oxygen is new and very 

 ingenious. In adapting the apparatus 

 to it, it has been changed from what is 

 known as an ' open-circuit ' to a 

 ' closed-circuit ' apparatus, i. e., the 

 same air is used over and over again, 

 the products of combustion in the body 

 of the subject (carbon dioxide and 

 water) being constantly removed by 

 passing the air current through sul- 

 phuric acid and soda lime, and fresh 

 oxygen supplied to take the place of 

 that consumed in the respiration. The 

 oxygen content of the air current is 

 kept practically constant and normal. 

 The accuracy of the modified calori- 

 meter for measuring heat has been 

 tested by a number of electrical check 



Model of the Armsby-Feies Respiration Calorimeter. 



