l-i^ Intelligence and Miscellaneous Articles, 



by the fire of the brass wire still hot, there is produced exactly the 

 heat necessary to continue it incandescent. If the spirals of a brass 

 wire approach each other without touching, the vapour of the alcohol 

 oxidizes, and can act on a large surface ; the heat is so much in- 

 creased by it, that the spirals remain red-hot ; if the spirals be further 

 removed from each other, ignition ceases, the heat produced by the 

 imperfect combustion not being sufficient to heat the spirals, which 

 before almost touched. 



As to what relates to spongy platina, the globules are surrounded 

 with an atmosphere of hydrogen, oxidation takes place at the same 

 time, heat is consequently developed by the large surface of the 

 spongy platina, and a reiterated contact of the gases so increases 

 the heat, that the gas is inflamed. Platina would not possess this 

 specific quality if it were not so refractory as not to fuse by the heat 

 of inflamed hydrogen. 



M. Reinsch has also found that this property belongs to metals 

 which fuse readily and are not capable of being made into wire. 

 He made the following experiment : some asbestos was moistened 

 with a solution of these metals, and after having made it red-hot, and 

 it had become brittle by the ignition, it was moistened with a little 

 alcohol, after which it was cautiously rolled round the wick ; the 

 metallized asbestos was kept for some time red-hot in the flame of 

 the alcohol, a glass tube being held over it : asbestos M'hich had 

 been prepared with chloride of platina remained vividly red-hot. 

 Iron answers best for this experiment : asbestos moistened with a 

 solution of sulphate of iron and then immersed in solution of am- 

 monia, and washed in water and dried quickly, remains red like 

 an iron wire. Asbestos moistened with a solution of gold and 

 heated to redness, remains red-hot in the vapour of alcohol like a 

 platina wire. The same occurs when asbestos is moistened with a 

 solution of silver. It has been above stated that gold and silver 

 wires possess the property of ignition but imperfectly ; which shows 

 that they are subject to soften readily. A wire ):)repared with 

 chloride of tin and oxalate of ammonia, remains only a few seconds 

 red, even under the glass tube, the tin being too suddenly converted 

 into oxide. The case is nearly the same with lead, but it remains 

 red rather longer. Cobalt and nickel possess the property of igniting 

 like iron. Manganese and chromium remain red for a very short 

 time. Arsenic is suddenly volatilized, the wire however remains 

 red for a few seconds ; the same occurs with mercury. Bismuth 

 possesses this property of ignition in a rather less degree than iron. 

 Cadmium resembles tin. Zinc is the only metal which does not at 

 all ignite. 



The author is of opinion that platinized asbestos maj' become an 

 important substance for the condensation of several gases, as also 

 for the preparation of vinegar. — Journ. dePharm. et de C/i.,Nov. 1846. 



ON THE DISTILLATION OF MERCURY. BY M. M. E. MILLON. 



When mercury is distilled, it is observable that the volatilization 

 takes place more slowly at the period in which the last portions of 



