THE 



LONDON AND EDINBURGH 

 PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[THIRD SERIES.] 



JUNE 1839. 



LX. Experiments upon the Products of Respiration at dif- 

 ferent Periods of the Day. By Charles T. Coathupe, 

 Esq* 



T^HE apparatus employed in the following experiments for 

 -*■ ascertaining the amount of carbonic acid gas respired, 

 differs in its construction from any that has hitherto been 

 used for a similar purpose ; but (although original in its con- 

 struction,) it may claim advantages, both as regards simplicity 

 and utility, which will most probably be admitted by those 

 who are conversant v/ith gaseous manipulations. 



It consists of a cylindrical glass tube 24i inches long, and 

 0*55 inch in diameter, terminated at each extremity by a brass 

 cap, into which a stop-cock may be screwed. The glass tube 

 is accurately divided into 1 75 equal parts, by e(|ual measures 

 of mercury, and the divisions are numbered on opposite sides 

 of the tube in such a manner, that let either end be upper- 

 most, the graduations may be instantly read. Every experi- 

 ment may thus be tested by a double reading, by simply in- 

 verting the tube, and waiting a few seconds until the liquid 

 employed for any examination has drained to its ultimate 

 level. 



The total capacity of the tube is about 5*33 cubic inches, 

 and each division is separated by a space exceeding |^th of an 

 inch. 



The reagent used was a clear saturated solution of quick- 

 lime in distilled water, with which a preliminary experiment 

 was made for the purpose of ascertaining the extent of atmo- 



• Communicated by the Autlior. 

 Phil. Mas. S. 3. Vol. H. No. 91. June 1839. 2 D 



