468 Miscellaneous Intelligence, 



from bisulphate ; and on repeating the attempt to procure it exactly 

 as before, obtained "a large quantity of bisulphate, and a small quan- 

 tity of the peculiar salt ; although the quantity of water present is 

 known to have an important influence on the nature of the sulphates 

 produced, yet the precise circumstances on which the formation of 

 sesquisulphate depends, are at present unknown. ^ — Phil. Mag. 

 N. S., ii. 429. 



10. On certain Properties of Sulphur. — The effect of heat upon 

 sulphur in first fusing it, but afterwards causing diminution of fluidity 

 in a certain degree proportionate to the temperature, has been long 

 and generally known, as well also as the peculiar soft state into 

 which the sulphur may be brought, by pouring it, when hot and 

 thickened, into cold water. M. Dumas has been led to examine 

 these phenomena for the purpose of acquiring a precise and partir 

 cular knowledge of the effects and changes. 



Fused sulphur began to crystallize between 226° and 228°. Its 

 fusing point may be considered as 226°.4. Between 230° and 284° 

 it is as liquid as a clear varnish, and of the colour of amber ; 

 at about 320° it begins to thicken, and acquire a red colour ; on 

 increasing the heat, it becomes so thick, that it will not pour. This 

 effect is most marked between 428° and 572° ; the colour being 

 then a red-brown. From 572° to the boiling point it becomes 

 thinner, but never so fluid as at 248°. The deep red-brown colour 

 continues until it boils. 



When the most fluid sulphur is suddenly cooled, it becomes 

 brittle, but the thickened sulphur, similarly treated, remains soft, 

 and more soft as the temperature has been higher. Thus, at 230°, 

 the sulphur was very liquid, and yellow ; and cooled suddenly by 

 immersion in water, it became yellow and very friable ; at 374° it 

 was thick, and of an orange colour, but by cooling, became at first 

 soft and transparent, but soon friable, and of the ordinary appear- 

 ance ; at 428°, it was red and viscid, and when cooled, soft, 

 transparent, and of an amber colour ; at the boiling point it was 

 deep brown red colour, and when cooled very soft, transparent, 

 and of a red-brown colour. 



It is not necessary, as is sometimes stated, to heat the sulphur 

 a long time to produce this effect ; all depends upon temperature. 

 The only precaution necessary is, to have abundance of water, and 

 to divide the sulphur into small drops or portions, that the cooling 

 may be rapid. If it be poured in a mass, the interior cools slowly, 

 and acquires the ordinary hard state. A¥hen the experiment is 

 well made at 446°, the sulphur may be drawn into threads as fine 

 as a hair, and many feet in length. 



M.Dumas, in remarking upon this curious effect of sudden 

 cooling, classes it with the similar effect which occurs with bronze. 

 Although difficult to assign the exact cause, yet he notices that the 

 tendency to crystallize can evidently be traced as influential over 

 some of the appearances, the hardness and opacity, for instance. 



