RESPIRA T10N. 141 



imal cage, fitted with delivery tubes, and with a cork 

 impregnated with paraffin; siphon apparatus, as figured, 

 consisting of two 8 liter bottles with paraffined corks 

 and tubes; analytical balances; laboratory balances 

 (correct to 0.01 gm.); drying oven; chemicals, KOH, 

 Ba(OH) 2 , CaCl 2 ; any small animal whose weight in 

 grammes does not exceed \ the volume of the animal 

 cage expressed in cubic centimeters. 

 2. Preparation. 



(1) Fill the calcium chloride tubes; put them into the 

 drying oven, where they are to be kept at a tempera- 

 ture of 100 to 120 C. for several hours; cool in a des- 

 iccator and weigh upon the analytical balances the 

 tubes e and f, recording the weight in milligrammes. 



(2) Fill the Woulff bottle and the Geissler's bulbs with 

 a strong solution (50% or more) of KOH. Fix into 

 position upon the Geissler bulb, its filled and desic 

 cated CaCl 2 attachment, and fit to each end a rubber 

 juncture; clamp with strong serre-fine forceps and weigh 

 upon the analytical balances. 



(3) Fill the flasks b and h with a strong solution of 

 Ba(OH) 2 . These flasks serve simply to show 

 whether or not the CO 2 gas has all been absorbed by 

 the KOH through which it has just passed. 



(4) Pieces e, f and g should be fixed to a light wooden 

 rack, by which they may be moved; if this is not con- 

 venient clamp them to supports. 



(5) Join up apparatus a, b and c. 



(6) Fill siphon apparatus. 



(7) Weigh the animal cage. 

 j. Operation. 



(1) Put the animal into the jar; fix the cover so that it 

 will not leak air. 



(2) Join animal cage with c and with siphon appa- 



