W. E. Geyer—A new Sensitive Singing Flame, 341 
noises ; (3) a sensitive flame, which only sounds while disturbed ; 
or (4) a flame that sings continuously except when agitated by 
external sounds. The last two results, so far as known to me, 
On pronouncing the word “sensitive,” it sings twice ; and in 
general, it will interrupt the speaker at almost every Mg! OF 
other hissing sound. 
excellent results. Glass tubes, however, drawn out until the 
internal diameter is between one sixteenth and one thirty- 
t important: 
T have pee used a piece which had been rounded for 
heating flasks ; it contained about 28 meshes to the ine 
The tube chiefly determines the pitch of the note, shorter or 
