NUTRITION LABORATORY. 297 



Clinical respiration chamber. — Any type of respiration apparatus 

 requiring the use of nose-breathing or mouth-breathing apphances pre- 

 sents certain difficulties in deahng with pathological cases; a respiration 

 chamber, which may be used in hospitals for studying the respiratory 

 exchange in pathological cases, has therefore long been needed. Such 

 a chamber, based upon our experience with chambers to be used with 

 small animals, has been devised, constructed, and tested during the 

 year with the assistance of Miss E. H. Tompkins. Of the two cham- 

 bers which have been built, one has been installed in the diabetic ward 

 of the New England Deaconess Hospital for the researches on diabetics; 

 the other chamber has been retained in the Nutrition Laboratory for 

 our regular researches in metabolism. A most critical study of these 

 chambers, including tests of every variety, has demonstrated the com- 

 fort of the patients in this apparatus and the accuracy of the results 

 under all experimental conditions. 



Infant respiration apparatus. — As a result of our experience with the 

 respiration apparatus for infants, it has been possible to construct a 

 new model which will be employed the coming year for studying the 

 metabolism of infants from one month to two years of age. This, as 

 well as the clinical respiration chambers, is used in connection with the 

 universal respiration apparatus. 



Respiration apparatus for small animals. — A complete respiration 

 apparatus for studying the metabolism of small animals, both warm- 

 blooded and cold-blooded, has been constructed and is installed in a 

 building of the New York Zoological Society, where an extensive research 

 on the metabolism of the lower animals is being carried out. This appa- 

 ratus consists of a small chamber used w^ith the universal respiration 

 apparatus and is of the latest design. 



Universal respiration apparatus. — The general use of the universal res- 

 piration apparatus, particularly in connection with respiration chambers 

 of varying size, has resulted in the building of two additional apparatus. 



Apparatus for the psychological laboratory. — Numerous changes have 

 been made in the psychological laboratory, including particularly the 

 entire reconstruction of the camera for use in photographic registration, 

 for electro-cardiograms, and similar records. A new micrometer head- 

 rest has been constructed for ocular work in general, and a gap commu- 

 tator for studying the wave-forms of induced currents. 



Minor apparatus. — Other products of the Laboratory shop are a 

 photographic apparatus for the reproduction of books, plates, dia- 

 grams, etc., a large spirometer which permits the graphic registration 

 of the number and character of the respu'ations of a subject when 

 walking on the treadmill, and numerous minor alterations in the 

 accessory apparatus used in the walking experiments. In connection 

 \vith a series of observations on the metabolism of geese during fasting, 

 several metabolism cages for geese were built. 



