21/ 



Fi: VKK. 



libi-raU'tl ( '^ < ""rlit in wi-ij^litd M«lu-liiiie IuIks, or Licbi{j['s liullis. auiI tlir nmouiit 

 of COj a.M i 1)) tin- dirtt'i-tiue in wciglit. 



The metliud of IVtU-ukoftr for the iibsoriitioii niul estimation of {,'ascous carbon 

 dioxide is far stuu-rior to the aliovc procedure, and was, tiierefore, tiic one adopted 

 ill thr iiiveslij^atioii. 



It is as follows: Normal sohilioiis of barium hydrate and oxalic arid art- first 

 j»repared. The solution of the hitter is so arranged tiiat one litre will contain 

 2.8036 grms. crystallized oxalic acid. The latter should not show any signs of 

 weathering or be moist ; should Ix- dried several hours over II.SOj before use. The 

 water employed in the experiments is iVectl from earl»()n dioxide by boiling. The 

 concentration of the barium liydrate is so arranged tliat 1 cub. em. of it will corrtv 

 spond to ;i cub. cms. of oxalic acid; but, when oidy small quantises of CO, are 

 to be absorbed, the concentration of both liquids is about the sanu-, /. r., 1 rub. cm. 

 of na(ll()), = I cub. cm. of ColLO,- 



.\fti'r having prepared these solutions of known strength, and by experiment 

 satislied yourself as to the relation they bear to each other, introduce a measured 

 volume of Ba(110)j into one or more long glass tubes, ■which are placed in an 

 inclined position, and permit the carbon dioxide to stream through tiic liquid. 

 AVhen the absorption is complete, and the experiment finished, the lifpiid 15:i(H0), 

 is titrated and the qjiantity of CO. ascertained from the difiVrence in the first and 

 scrdiid titrations. 



In tile hist series of experiments of this chapter the amount of heat dissipated 

 and carbon dioxide produced hourly liaviiig been obtained in tiie uninjured animal, 

 the spinal cord was divided and tlie dog replaced in the apparatus. On his removal 

 the hourly dissipation of heat and production of carbonic acid were determined, 

 and it became a very simple matter to estimate the change of heat dissipation 

 and of rarbimic acid production which followed the section of the cord. 



The experiments arc as follows: In some of them the heat lost in vaporization 

 was not noted, but the variation in the va])orization before and after section was 

 so slight in the experiments in wliich it was noted, that the omission doi-s not at 

 all invalidate the results. 



Exi'KKIMKNT 25. 

 A dog; wciglit \H puuiulfi. 



1.52 B3.17.M 



(Rain) 



* P M — Cord ml nt 5th ccrrical vcrtrlira ; very little Mecilinfr: (•omploti" pornjilcpio. 

 4:15 r M — Rrrlul tcinprrnturi'. 101°. 5. 



