152 Intelligence and Miscellaneous Articles. 



cated with the battery and galvanometer by platina wires j and the 

 deviation of the needle was scarcely sensible. A few drops of bro- 

 mine were then added to the water, which soon imparted a yellow 

 colour to the water } being now included in the voltaic circuit, the 

 galvanometer needle was deviated 70°, and an abundant disengage- 

 ment of gas took place from the platina wires. There were oxygen 

 and hydrogen in the usual proportions, showing that water only had 

 been decomposed. From these experiments it results, that a body 

 which conducts voltaic electricity very imperfectly, namely, pure water, 

 may be rendered a good conductor by holding in solution a very mi- 

 nute quantity of a perfectly non-conducting substance, namely, bro- 

 mine : the same fact occurs with iodine, and iodine and water. - 



Ibid. xxxv. p. 161. 



EFFECTS OF HEAT UPON SULPHUR. 



According to M. Dumas fused sulphur begins to crystallize between 

 226° and 228° 3 between 230° and 284° it is as liquid as a clear var- 

 nish, and of an amber colour j at about 320 a it begins to thicken, and 

 acquire a red colour j on increasing the heat, it becomes so thick, 

 that it will not pour. This effect is most marked between 428° and 

 572° j the colour is then a red brown : from 572° to the boiling point 

 it becomes thinner, but never so fluid as at 24-8° 5 the deep red brown 

 colour continues till it boils. When the most fluid sulphur is sud- 

 denly cooled, it becomes brittle 3 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 3 and 

 cooled suddenly by immersion in water, it became yellow and very 

 friable 3 at 374° it was thick, and of an orange colour 3 but by cooling 

 became at first soft and transparent, but soon friable and of the or- 

 dinary appearance : at 428° it was red and viscid 3 and when cooled, 

 soft, transparent, and of an amber colour 3 at the boiling it was deep 

 brown red colour 3 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 3 all depends upon tem- 

 perature. The only precaution necessary is, to have abundance of 

 water, and 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. When the experiment 

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

 as a hair, and many feet in length. 



Ibid, xxxvi. p. 83. 



PEROXIDE OF BARIUM. 



M. Quesneville recommends the following process for preparing 

 this compound. — Put nitrate of barytes into a coated earthenware re- 

 tort, to which a tube is to be attached, for the purpose of conveying 

 the liberated gases to a water-trough. The heat is to be continued 

 until pure oxygen gas comes over, and the operation is then to be 

 stopped. The peroxide of barium thus obtained falls to pieces in wa- 

 ter without producing heat 3 when boiled in water, oxygen gas is evol- 

 ved, 



