Mr Deuciiar on flie Nature of Flame. S85 
derived ; and we may admit that they all so far unite to disen- 
gage it. 
But, again, when we consider the nature of the caloric, the 
simplicity of the electric fluid is also lost. The condensed 
caloric may be attached to some disengaged gaseous fluid ; it 
may proceed by vibrations ; or it may exist by itself, quite dis- 
tinct for the momentary period of its being visible, as it were in 
an insulated form, somewhat analogous to radiation. 
From the various results obtained in a number of experi- 
ments, and particularly in some undertaken for the express pur- 
pose, I am rather inclined to adopt the last of these conjectures 
regarding the state in which the caloric exists during its rapid 
movement. It would be tedious to detail the whole of the ex- 
periments which seem to prove this. One, therefore, may be se- 
lected, which, of itself, seems conclusive. 
Exp. 23. — When we put a piece of tinder into a condensing 
syringe, and force down the piston, the tinder is inflamed. From 
this fact it may be concluded, that in the case of Colonel Yule’s 
apparatus, were the flame accompanied by moving air, or were 
it the result or quality of compressed air, it would inflame a 
piece of tinder put in any of the joinings of the tube : the ex-* 
periment was therefore repeatedly tried, using the finest Ger- 
man tinder, but no inflammation took place. To render the ex- 
periment more complete, trial was made if the flame would act 
upon the tinder when in contact with the air at the bottom of 
the tube, and it was found that it did so. 
There are several other circumstances connected with the 
nature of caloric, which may be so far elucidated by means of 
this apparatus; but these I shall delay for some future commu- 
nication, when I hope, by varying the experiments, to make 
the conclusions more perspicuous. 
Exflanatiim of Plate IX. 
Fig. 1. Shews the whole of the Apparatus used in Mr BeuchaFs 
Experiments, on a scale of /j^ths to 1 inch. AB a thick 
brass tube, meant to represent the touch-hole of a gun ; it is 
15 inches long, and can be shortened at a, b, c, and f ; C is 
VOL. IV. NO. 8 . APRIL 1821. B b 
