252 



REGNAULT AND EEISET S APPARATUS. 



is to be investigated, is secured in a closed vessel, and the gases so obtained are 

 analysed. 



II. The most important apparatus for this purpose are those of (a.) Scharling 

 (Fig. Ill), which consists of a closed box, A, of sufficient size to contain a man. 

 It has two openings an entrance opening, z, and an exit, 6. The latter is con- 

 nected with an aspirator, C, a large barrel filled with water. When the stop-cock, 

 h, is opened and the water flows out of the barrel, fresh air will rush in continu- 

 ously into the box, A, and the air mixed with the expired gases will be drawn 

 towards C. A Liebig's bulb, d, filled with caustic potash, is connected with the 

 entrance tube, z, through which the in-going air must pass, whereby it is com- 

 pletely deprived of C0 2 , so that the person experimented on is supplied with air 

 free from (J0 2 . The air passing out by the exit tube, b, has to pass first through 

 e, where it gives up its watery vapour to sulphuric acid, whereby the amount of 

 watery vapour is estimated by the increase of the weight of the apparatus, e. 

 Afterwards the air passes through a bulb, /, containing caustic potash, which 

 absorbs all the C0 2 , while the tube, g, filled with sulphuric acid, absorbs any 

 watery vapour that may have come from f. The increase of weight of / and y 

 indicate the amount of COg. The total volume of air used is known from the 

 capacity of C. 



(6.) Kegnault and Keiset's Apparatus is more complicated, and is used 

 when it is necessary to keep animals for some time under observation in a bell-jar. 

 It consists (Fig. 112) of a globe, K, in which is placed the dog to be experimented 

 on. Around this is placed a cylinder, cj y (provided with a thermometer, t) which 

 maybe used for calorimetric experiments. A tube, e, leads into the globe, R; 

 through this tube passes a known quantity of pure oxygen (Fig. 112, 0). To absorb 



CaCli 



112. 



Scheme of the Respiration Apparatus of Eegnault and Reiset R, globe for 

 animal ; g g, outer casing for R, provided with a thermometer, t; d and e, 

 exit tubes to movable potash bulbs, KOH and KoA; 0, in-going oxygen; C0 2 , 

 vessel to absorb any carbonic acid; CaCl 2 , apparatus for estimating the 

 amount of supplied; /, manometer. 



