Juke 2. 1910] 



NA TURE 



411 



A NUTRITION LABORATORY. 



A TWATER'S development of apparatus for the exact 

 •^ measurement of the heat given off by the human 

 body under varied conditions of food-supply and activity is 

 well known. Prof. F. G. Benedict, who cooperated with 

 Atwater, has continued similar observations as director of 

 the Nutrition Laboratory in Boston, which is devoted 

 exclusively to work of this type, and is well endowed by 

 the Carnegie Institute for that purpose. The calorimeter 

 equipment of this new laboratory, as described by Benedict 

 and Carpenter in a recent publication,^ affords remarkable 

 evidence of the value that may be secured by giving a 

 mature investigator a free hand in the organisation of 

 means for furthering standard research of the tjpe in 

 which he is most interested. 

 Two " respiration calorimeters," shown in the accom- 



75 litres of air are driven per minute over periods of hours 

 without leakage of material or of heat. The heat issuing 

 from the subject is carried out of the chamber along one 

 definite channel by a stream of water traversing a 

 •• radiator system " within the chamber, and is accurately 

 measured by weighing the escaping water and observing 

 its temperature increment. The ingenuity displajed in 

 modifying known thermometric methods in the interests of 

 these observations, and in obtaining continuous records of 

 temperature differences, is in itself remarkable. 



In the accompanying illustration are shown some of 

 the internal fittings of the large constant temperature 

 room in which the calorimeters are housed, the "' oven- 

 like " structure on the right being the " bed-calorimeter " 

 into which a recumbent patient is inserted upon a stretcher. 

 In the background is the "chair calorimeter," into which 

 the subject enters by the roof, and in the foreground are 



General View of the Caiorinieter ko3m in tr.e Nutniion Laborato y m Eoston. 



panying photograph, have been constructed, and are in 

 use for observations upon subjects of different physiques 

 and different conditions of health continued over periods 

 of several hours. Others are being constructed for more 

 prolonged observations, occupying days, under varied con- 

 ditions of rest and work. In their construction a rare 

 amount of successful attention to minute detail has secured 

 perfect instruments showing at every point substantial 

 improvements upon the original pattern. As tested by 

 the combustion of known quantities of ethyl alcohol within 

 these chambers, the errors in estimating the am.ount of 

 oxygen consumed, the carbonic acid and water vapour 

 given off, and the output of heat, have been reduced to 

 less than 0-5 per cent. The tests were made with the 

 apparatus arranged as for an actual experiment, and the 

 difficulties surmounted may be gathered from the fact that, 

 through the " closed circuit " formed by the calorimeter 

 chamber and a series of water and carbonic acid absorbers, 



I " Respiration Calorimeters for Studying the Respiratory Exchaoge and 

 Energy Transformations of Man." By F. G. Benedict and T. M. Carpenter. 

 Pp. viii + TC2. (Washington : Carnesie Institution, 1910.) 



placed the absorber systems and large balances used in 

 measuring their increments of weight. 



SEWAGE DISIXFECTIOS.' 



T N view of the prominence at present given to the ques- 

 ■*■ tion of the disinfection of sewage and sewage effluents, 

 the publication of the results of Prof. Phelps's latest in- 

 vestigations on the subject is undoubtedly of great interest 

 to those engaged in public-health work. 



It is stated in the introduction that the investigations 

 on which the report is based were conducted by the author 

 at the Sanitar)- Research Laboratory and Sewage Experi- 

 mental Station at Boston, Mass., and in collaboration with 

 the author by Mr. Francis E. Daniels at the sewage disposal 

 works at Red Bank, N.J., and by Mr. Ezra B. Whitman at 



1 "The Disinfection of Sewage and Sewage Filter Effluents, with a 

 Chapter on the Putrescibility and Stability of Se-wage Efflueots." By E.B. 

 Phelps. Pp. 9t ; 39 tables, i plate. (Washington : Government Printing 

 Office, 1909.) 



NO. 2 II 8, VOL. Xo] 



