114 A CHEMICAL SIGN OF LIFE 



furnished by Eimer & Amend when the biometer is 

 ordered.) Each of the chambers has a capacity of 20 

 to 25 c.c. and is provided with the platinum electrodes 

 n and m for stimulation purposes, and also with a 

 glass stopper 5 or R, which can be sealed with mercury. 

 The air pump is connected through / and the barium 

 hydroxide solution is introduced through V to d and /, 

 where the drops are to be formed. 



How to set up the biometer. In order to get up this 

 apparatus, the following materials will be necessary: 

 one biometer proper; two ordinary three-way stopcocks; 

 one nitrometer; one ordinary glass stopcock; one 

 water pump; one mercury burette, made of four or five 

 inches of any broken burette; one bottle with a side 

 neck at the bottom of about 300 c.c. capacity (aspirator 

 bottles); two large carboys; one capillary J-tube to be 

 bent to fit the biometer proper at Q and F; three 

 pinchcocks; one empty acid bottle for a half-saturated 

 solution of barium hydroxide; two CaCl 2 tubes or wash- 

 bottles to protect barium hydroxide, and one carboy; 

 one lo-pound can of Greenbank alkali; 500 g. of C.P. 

 barium hydroxide; one yard of thick- walled pressure 

 tubing; one yard of good antimony tubing to fit the 

 ordinary glass tubing; a little sealing wax; 200 c.c. of 

 redistilled mercury; a few yards of glass tubing of or- 

 dinary sizes. 



Excepting for the biometer proper, most of the 

 materials mentioned above can be found in an ordinary 

 laboratory or can be substituted with homemade appa- 

 ratus without losing the accuracy of the method. 



With these materials on hand, the apparatus can be 

 set up without any difficulty if one follows the figure very 



