INTRODUCTION. 3 



The second type of apparatus is known as the "closed circuit." 

 The subject is placed in a chamber through which a current of air is 

 passed. The air leaving the chamber is purified by the removal of the 

 carbon dioxide (and in some instances water) , replenished with oxygen, 

 and returned to the chamber. This type of apparatus was that origi- 

 nated by Regnault and Reiset. * It has been further developed by Hoppe- 

 Seyler and Stroganow, 2 and in principle is the basis of the apparatus 

 to be described later in this report. This method permits of the deter- 

 mination of carbon dioxide, water, and oxygen. 



A third form of respiration apparatus is that known as the "open 

 circuit." The subject is placed in a closed chamber through which a 

 current of air is drawn, the incoming and outgoing air being analyzed. 

 This type of apparatus was first brought into successful use by Petten- 

 kofer, 3 and was afterward elaborated for use with man by Sonden and 

 Tigers tedt, 4 and by Atwater, Woods, and Benedict. 5 



It is interesting to note that Jaquet, 6 by using a modification of the 

 apparatus of Fetter son for exact gas analysis, has undertaken the deter- 

 mination of oxygen consumed by man in an " open-circuit " apparatus. 



The fourth type of apparatus is used primarily for short experiments. 

 By means of appliances attached to the mouth or nose the subject is 

 supplied with normal air of known composition and the products of 

 respiration are collected for analysis. With this apparatus it is possible 

 to determine the oxygen absorbed and the carbon dioxide exhaled. 

 This type has been perfected to a high degree by Zuntz 7 and by Chauveau 

 and Tissot. 8 



The development of calorimetric apparatus for use with animals and 

 with man has been far less extensive than that of respiration apparatus. 

 A summary of the methods and results of experiments on the income 

 and outgo of heat of the animal body, which includes the work done up 

 to about 1882, was published by Rosenthal. 9 A description and discus- 

 sion of more recent types of calorimeters is given by Laulanie, 10 and also 

 by Sigales. 11 One of the earliest forms suitable for use with man and 

 the larger animals was devised by Scharling 12 in 1849. The subject 



1 Ann. de Chim. et Physique (1849), 3, xxvi. 



'Archiv. f. d. ges. Physiol. (1876), 12, p. 18. 



3 Ann. der Chem. u. Pharm. (1862-3), Supp. 2, p. 17. 



4 Skand. Archiv. f. Physiol. (1895), 6, p. I. 



5 U. S. Dept. of Agr., Office of Experiment Stations Bull. 44. 



6 Verhandlungen der naturforschenden Gesellschaft in Basel, 15 (1904), part 2, 

 p. 252. 



7 Berl. klin. Wchnschr. (1887), p. 429. 



8 Comptes rendus (1899), 129, p. 249. 



9 Hermann's Handbuch der Physiologic, 4, part 2, pp. 289-456. 

 10 Clements de Physiologic, pp. 556-565. 

 "Traite" de Physique Biologique, 1, pp. 816-843. 

 12 Journ. f. prakt. Chem. (1849), 48, p. 435. 



