364 



Mr. W. Galloway on the Influence 



[Mar. 2, 



f erred to the mixing-cylinder, and after this all the cocks are closed a ad 

 the cylinders disconnected. 



With this apparatus the volumes of gas and air can be measured with 

 considerable accuracy and rapidity. 



The quantity of water remaining in the mixing-cylinder varied in the 

 different experiments from 60 to 300 cubic inches. Accordingly, when 

 this cylinder w r as inverted, the water ran down through the holes in the 

 diaphragms into the lowest compartment, and a corresponding volume of 

 the gases was forced to take the opposite course ; and I found that by 

 inverting it forty times in succession and pausing each time until the 

 sound of the running water had ceased, a comparatively perfect mixture 

 of the gases was obtained for each experiment. The homogeneity of 

 the different parts of these mixtures was attested by the fact that, 

 whereas the whole of the one composed of 1 volume of firedamp and 15 

 volumes of air was inflammable, none of the mixture of 1 firedamp to 16 

 air was so. 



The wick of the lamp (fig. 6) having been carefully trimmed, was 

 drawn down until the flame presented the appearance of a small blue 

 hemisphere, about" J inch high by | inch diameter at the base, and having 

 a conical speck of yellow in the middle near the top ; the tube a was 

 then connected with the top of the mixing-cylinder, and the mixture was 

 forced into the chamber b at the rate of about 2\ cubic inches per second. 

 All other lights were removed from the cabin during this part of the 

 experiment, and the various phenomena were observed in what would 

 have been total darkness but for the feeble light of the lamp itself. 



The different mixtures employed consisted of 1 volume of firedamp to 

 1-i, 15, 16, 18, 20, 25, 30, 40, 50, and 60 volumes of air. The experi- 



The dotted line between 15 and 16 represents the asymptote. 



