4 Dr. Colquhoun on anew Foi'm of Carbon* [July, 



way. And in so far as the eye of even the metallurgist could 



fuide him, their whole appearance would indicate that they had 

 een in a state of fusion at the moment of their formation. 

 These are some of the^cliaracteristics of the more perfect 

 specimens which I have yet obtained of this variety of pure 

 carbon. But a much more imperfect formation, in which the 

 colour, form, and texture, of more common specimens were 

 blended and mixed with some of those distinguishing the kind 

 just described, occurred not unfrequently in Uie course of my 

 superintendence of the steelifying process. Sometimes the 

 hairs were short, ragged, and uneven ; sometimes quite destitute 

 of lustre; and sometimes they existed so immingled in a loose, 

 mossy, or spongy mass of carbon, as to be scarcely distinguish- 

 able. 



I am quite aware that a species of appearance so imcommon 

 and extraordinary, notwithstanding the very unequivocal circum- 

 stances under which it occurred, cannot be admitted to exist in 

 a substance composed of pure carbon without the matter being 

 put thoroughly to the test of repeated experiments. And I shall 

 now, theretbre, detail one or two of those which I immediately 

 tried with a view to the determination of this point, and which 

 seem to be satisfactory and conclusive. 



When a few of the filaments above described were heated to 

 redness in a glass tube, they gave off neither smoke nor vapour, 

 and retained in all respects their original form unaltered, and 

 their lustre unimpaired. Upon being again heated to redness in 

 the flame of a candle, they remained in like manner entire and 

 unchanged. But when they were intensely ignited in the inte- 

 rior flame of the blowpipe, they rapidly underwent combustion, 

 the silent progress of which was occasionally interrupted by 

 vivid coruscations, and by this treatment, they were quickly and 

 completely dissipated. 



1 further found that these filaments possess the property of 

 decomposing certain substances which part readily with oxygen, 

 and of deflagrating with them exactly after the manner of char- 

 coal or plumbago. 



A quantity of the filamentous substance, to the weight of 

 about half a grain, was taken, and intermixed thoroughly by 

 trituration with upwards of thirty times its weight of chlorate of 

 potash : the whole was then exposed in a platinum crucible to a 

 strong red heat over a spirit-lamp. On the commencement of 

 liquefaction in the salt, a few slight flashes broke out from those 

 parts of the mixture near the heated sides of the crucible ; but 

 m a short time the whole salt had passed tranquilly into a state 

 of fusion without undergoing any other apparent alteration. 

 After the heat had been continued for some time longer, there 

 took place an instantaneous and vivid deflagration, while the 

 whole mixture became at once intensely red-hot. The saline 



