Mr. Pepys’ Account of a new Eudiometer. 2 53 
introducing it under that metal, as to have thrown out a por- 
tion 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 prefer- 
red the cubic inch divided into hundred parts. This is easily 
effected by taking a stout glass tube about half an inch calibre, 
sealing one end, then weighing 3422 grains of mercury, equal 
to 252 grains of distilled water at temperature 50° Fahren- 
heit. This is introduced into the tube ; the extra length is cut 
off with a sharp-edged file, care being taken to leave a sufficient 
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 hundred 
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 introduction of each 
hundred part of mercury into the measure M. 
The tube 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 
AT? - were absorbed. 
MDCCCVII. L 1 
