2l6 REPORTS ON INVESTIGATIONS AND PROJECTS. 



umes of carbon dioxide produced and oxygen consumed with a man working 

 at the limit of human endurance. The apparatus was finally so adjusted 

 that it was possible to measure accurately the consumption of oxygen and 

 the carbon-dioxide production during work of such severity as to result in 

 the production of nearly 3 liters of carbon dioxide per minute. By means of a 

 Zuntz mouthpiece and a tension equalizer, consisting of a rubber diaphragm, 

 the large respiration volume common in muscular work could be provided 

 for easily without distressing the subject. 



MISCELLANEOUS EQUIPMENT. 



A large spirometer for the special study of ventilation with the different 

 types of valves and for determining lung-volume has been devised by Mr. 

 Carpenter and recently constructed. 



Owing to the increase in the number of researches on the metabolism of 

 animals, it has been necessary to add to the equipment of the laboratory three 

 metabolism cages for small animals, the design being that of Prof. Hans 

 Meyer, of Vienna. 



The bicycle ergometer, which has proved of great value in studying the 

 metabolism of man during excessive muscular work, has been extensively 

 used this winter in Dr. Cathcart's research. It has also been carefully cali- 

 brated, and with the cooperation of Prof. W. G. Cady, of Wesleyan Uni- 

 versity, Middletown, Connecticut, the distortion of the magnetic field by the 

 rapidly rotating copper disk was measured. The apparatus has now several 

 well-determined constants which increase its value greatly. 



In preparation for the psychological measurements which will be made 

 later in connection with the metabolism experiments, a full equipment of 

 apparatus has been ordered, including the apparatus devised by Prof. Ray- 

 mond Dodge, of Wesleyan University, several string galvanometers, and 

 photographic registration apparatus. 



The equipment of the chemical laboratory has been added to the past year 

 by the installation of a large-sized electrically driven centrifuge. 



The chemical laboratory has also been equipped with a complete set of the 

 apparatus required for the methods of urine analysis recently devised by 

 Prof. Otto Folin, of the Harvard Medical School. These methods promise 

 to revolutionize the technique of urine analysis and are of great value in 

 many other biochemical problems. Through the kindness of Professor Folin, 

 Mr. H. L,. Higgins, of the laboratory staff, has been trained in the use of the 

 methods, and they have been employed in this laboratory for several months. 



FIREPROOF PROTECTION OF RECORDS. 



The multiplication of valuable records made it necessary to secure some 

 simple means of fireproof protection. Although the building is as a whole 

 fireproof, a local conflagration is always possible, and the safe originally 

 installed has long since been outgrown. All of the experimental records, 



