120 M. Thenard on Oxi/genaled Water. 



volume of oxygen at the pressure of 0" 76 (30 inches nearly,) 

 and temperature of 14° (57.2 Fahr.) This proof is readily made 

 by taking a small tube, on which a line is marked, and filling it 

 •with the fluid up to the line, and then diluting this quantity, 

 which, in my experiments, was always ^^^ ^^ * centilitre, 

 (0,030514 of c:i :) with twelve times its volume of water, and 

 decomposing a certain quantity of this last fluid by oxide of 

 manganese. This last experiment consists in filling a tube 15 

 or 16 inches long, and 7 or 8 lines wide, with mercury to within 

 an inch of the top ; then introducing the portion of diluted fluid, 

 of which the analysis is to be made, using for this purpose a small 

 tube of known capacity, afterwards filling the tube with the 

 water used to wash the small measure, or partly with mer- 

 cury, and then, by closing the tube with a valve, covered with 

 tallow, inverting it, and passing in a little oxide of manganese 

 diff'used in water. The oxygen will be immediately disengaged, 

 and nothing further is required than to close the tube with the 

 hand, and shake it in different directions, that the contact of the 

 oxide of manganese and the water may be ensured, and to 

 measure the gas. 



Annates de Chim. xi. p. 208. 



Art. X. Desciiption of Messrs. Taylors and Mar- 

 TiNEAu's Patent Apparatus, for the production of Gas 

 from Oil, S^c. 



The annexed engraving (Plate I.) represents a complete 

 double apparatus, such as has lately been erected at Apothe- 

 caries' Hall, London ; and includes all, the improvements which 

 have been suggested by the experience of the inventors, from the 

 extended use of them in various places. 



A general idea of the process may be formed from the follow- 

 ing account of it : — 



A quantity of oil is placed in an air-tight vessel, in such a 

 manner, that it may flow into retorts which are kept at a moderate 

 red heat : and in such proportions as may regulate the produc- 



1 



