92 WRITINGS OP JAMES SMITHSON. 



or two it is dry, and may be taken up, and put into the 

 flame, without the clay exploding, as not unoften happens' 

 when more of it is used. Particles of the least visible mi- 

 nuteness may be thus submitted to trial with the utmost 

 facility. The contact of the particle with the wire may, iu 

 general, be so managed as to be extremely slight, as the 

 slenderest point is sufficient to support it. However, when 

 the utmost heat possible is desired, a fragment of a less 

 conducting matter may, if deemed necessary, be interposed. 



There may bo cases in which the presence of the clay is 

 objectionable. I conceived that some of the body itself to 

 be tried, would on these occasions, supply its place. Flint 

 was the least promising of any in this respect. It was se- 

 lected for the experiment. With a paste of its powder and 

 water, pieces of flint were successfully cemented to flint, 

 and some of this paste taken on the end of a wire, served, 

 if not quite as well as clay, yet very sufficiently. After sev- 

 eral times igniting and quenching iu cold water, the redac- 

 tion of very hard matters to subtile powder is attended with 

 no difficulty. 



Earth of alum would perhaps be preferable to pipe-clay 

 for making the triangles on strips, and for agglutinating 

 objects to them. It would even have the advantage over 

 sappare of being a simple substance. Some from the Paris 

 shops acquired only little solidity in the fire j but I after- 

 wards learned that it had been obtained from alum by fire. 



Since I have been in possession of this means of so effec- 

 tually confining the subjects of examination as to be able to 

 continue during pleasure to act on them, I have directed 

 but little attention, to the fusibility of matters. Quartz, 

 whose fusion has been called in question by M. Berzelius,* 

 has seemed to be quite refractory. On some few occasions 

 when it has proved otherwise, the phenomena have neither 

 corresponded with M. de Saussure's account, nor been 

 always the same, which certainly admits of the fusion being 

 attributed to an accidental cause. 



*De I'omploi du Ohalumeau, p. 108. 



