Account of a new Eudiometer. i-i 



Tiie stopper S would hiive injected the fluid with greater 

 velocity had it been straight ; but it would not then have 

 been so convenient in the analysis of compound gases, where 

 both mercury and hot solutions are occasionally employed, 

 ns the mercury would have so compressed the fluid in the 

 bottle, in introducing it under that metal, as to have thrown 

 out a portion of its contents, and also have robbed the hot 

 solutions of the temperature which was necessary for their 

 perfect action. 



As to the size of the measure M, I have generally pre- 

 ferred the cubic inch divided into hundred parts. This is 

 easily effected by taking a stout glass tube about half ati 

 inch calibre, sealing one end, then weighing 3422 grains 

 of mercury, equal to 252 grains of distilled water, at tem- 

 perature 50° Fahrenheit. This is introduced into the lube; 

 the extra length is cut off" with a sharp-edged file, care being 

 taken to leave a suflScient portion to grind the perforated 

 stopper S into its mouth. 



The divisions are obtained by a small measure, made from 

 a glass tube sealed at the end, and cut off exactly to the hun- 

 dred parts of a cubic inch, equal to 34*2 grains of mercury, 

 which being ground flat, is stopped by a piece of plate glass, 

 and the divisions marked by the diamond upon the intro- 

 duction of each hundred part of mercury into the mea- 

 sure M, 



The lube T is divided into tenths of the measure M, or 

 thousand parts of a cubic inch. This is done by measuring 

 one hundred part of a cubic inch into the tube, and dividing 

 it into ten parts, marking the divisions with fluoric acid or 

 black enamel. 



To prove the accuracy of the instrument, I shall proceed 

 to relate a few experiments made with it. 



The elastic bottle being filled with the solution of sulphate 

 of iron impregnated with nitrous gas, and the measure with 

 atmospheric air, they were united, and by gentle injection 

 •f'o'./'o were absorbed. - 



- If the experiment is niade hastily, the impregnated solu- 

 tion loses a portion of its nitrous gas, which must be again 

 absorbed by a solution of green sulphate of iron. 



For 



