METHODS OF INVESTIGATION. 



Humboldt and ProvenpO,* Prout,t and others, that attention had 

 fot h therto been directed to this subject, but when physiologists en- 

 d vour d to elucidate the mechanism of respiration from all points 

 of view the chemistry of the process obtained some of the attention 

 wVicli merited, and the most exact and admirable mvestigations 

 we e at once prosecuted by the aid of the most recent appliances of 

 rdence The beautiful experiments of Magnus (see vol. u, p. 

 190-192) on the amount of gases in the blood, may be said in some 

 degree to have constituted the turning point in these inquiries, since 

 it Is only by the establishment of this factor that we can enter upon 

 satisfactory investigation of the interchange of gases in the lungs. 

 Kta2 of which the greater number are very 

 admirable, have been instituted both on man and animals with a 

 lw of determining the relation between the inspired and expired 

 Ir ScharlingJ Dumas, Andral and Gavarret,|| Valentin and 

 Brunner fvie ordt,** Malcolm,tt and Hannover^ directed their 

 fnveSalnsfor the most part to the excretion of ^"J 

 in man under different physical, physiological, and ** 

 relations. Many of the difficulties which are inseparable from 

 nvestigations on man, or which influence the accuracy of the 

 method of investigation were happily obviated in the series of exact 

 Tnd hthly successful investigations of Valentin, Marchand 

 au y it,Hl| Letellier, Ph. Zimmermann,*** von Erlach ttt 

 eltt myself, and especially Regnault and Reiset. 

 principali y y indebted to the labours of these chemists for 



* Mem. de la Soc. d'Arcueil. T. 2. 



t Thomson's Annals of Philosophy. Vol. 2, p. 328. 



J Ann. d. Ch. u. Pharm. Bd. 45, S. 214. 



3 



aes At ICa^uUe, 



1 



' f. pr. Ch. Bd. 33, S. 120, and Bd. 37, S. 1. 



. de Chim. et de Phys. T. 11, 



p. 32 ako ed.erches chimiques de la respiration 

 classes. Paris, 1849. 



des 



