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A MANUAL OF PHYSIOLOGY 



6. Estimation of the Quantity of Water and of Carbon Dioxide 

 given off by an Animal (Haldanes Method). (i) Connect the 

 apparatus shown in Fig. 101 with the water-pump. Allow a negative 

 pressure of 5 or 6 inches of water to be established in it, as shown 



FIG. 101. HALDANE'S APPARATUS FOR MEASURING THE QUANTITY OF CO 2 

 AND AQUEOUS VAPOUR GIVEN OFF BY AN ANIMAL. 



A, chamber into which the animal is put ; i and 4, Woulff s bottles filled with 

 soda-lime to absorb carbon dioxide ; 2, 3, and 5, Woulff's bottles filled with pumice- 

 stone soaked in sulphuric acid to absorb watery vapour ; R glass bell-jar suspended in 

 water, by means of which the negative pressure is know", ; P, water-pump which sucks 

 air through the apparatus ; i and 2 are simply for absorbing the carbon dioxide and 

 water of the ingoing air. 



by the rise of water in the bell-jar, B. Then close the open tube of 

 carbon dioxide bottle i, and clamp the tube between the water-pump 

 and the bell-jar. If the negative pressure is maintained, the arrange- 

 ment is air-tight. Now weigh bottle 3 and bottles 4 and 5, the last 

 two together. Place a cat in the respiratory chamber A, connect the 



A, soda-lime tube ; B, sulphuric 

 acid tube ; C, wooden frame, in 

 which A and B are supported by 

 wires d ; b, wire hook, which grips 

 the glass tube firmly, and by 

 means of which the tubes are lifted 

 out of the frame in order to be 

 weighed ; a, short piece of glass 

 tubing, by taking out which the 

 absorption tubes are disconnected 

 from the rest of the apparatus ; c. 

 glass tube going off to animal 

 chamber. The right-hand glass 

 tube of B should not touch the 

 sulphuric acid as depicted. 



FIG. 102. ABSORPTION TUBES FOR CO 2 AND MOISTURE. 



chamber directly with the water-pump, and test whether it is tight. 

 Then take the stopper out of bottle i, and adjust the rate at which 

 air is drawn through the apparatus. Let the ventilation go on for a 

 few minutes, then insert bottles 3, 4, and 5 again. Note the time 

 exactly at this point, and after an hour disconnect 3, 4, and 5, and 

 again weigh. The difference of the two weighings of 3 shows the 



