84 ANNUAL OF SCIENTIFIC DISCOVERY. 



A REMARKABLE SOLVENT. 



It is now discovered, it appears, that if a piece of copper be dis- 

 solved in ammonia, a solvent will bo obtained, not only for lii^nine, 

 the most important principle of all woody fibre, such as cotton, 

 flax, paper, etc., bnt also for substances derived from the animal 

 kingdom, such as wool and silk. By the solution of any of these, 

 an excellent cement and water-proofer is said to be formed ; and, 

 what is equally important, if cotton fabrics be saturated with the 

 solution of wool, they will be enablcMl to take the dyes, such as 

 the lac dye and cochini'al, hitherto suited to woollen goods only. 

 Hydriodide of ammonia, we may also observe, was not long since 

 discovered to be an cipially remarkaide solvent of the most refrac- 

 tory, or, at least, insolulde mineral substances. Now it is an inter- 

 esting circumstance that ammonia, according to Van Ilelmont, 

 and other old chemists and alchemists, was one of th<! requisite 

 materials in the formation of the "alkahest," or "universal sol- 

 vent," of the ancient sages. 



THE JL4GNESIUM LAMP. 



A lamp for the pui-pose of burning the wire has been invented by 

 Mr. A. Grant. He sei-ks to make magnesinm cluiaper than the 

 best stearine, and statics that b}' Ijurning a strip of zinc in conjunc- 

 tion with two strii)S of magnesium, he is able to reduce the cost 

 of the light two-thirds. Il(! even predicts that magnesium will 

 become as cheap as zinc, and that in the course of time it will be 

 possible to illuminate a street a mile long at the rate of a half- 

 penny an hour, it is not a small thing to be able to record that 

 photography is no longer dependent upon tlu; action of the sun. 

 The value of magnesium as an illuminator for Ihv, })urpose of 

 " signalling" is ol)vious. The portable nature of the contrivance, 

 and its perfect immunity from risk of explosion, together with 

 some other evident advantages, render its vivid light all th(; more 

 practically valual)l(;. It may bo used with advantage on the 

 stage. — CivU Enyineers' and Architects'' Journal, Jan., 1865. 



Four wires, weighing three grains per foot, each l)uruiiig at the 

 rate of eight inches per minute, or eight grains in that time, give 

 a light equal to two hundred and eightj-eight sperm candles, or 

 twenty-one and one-quarter Argand gas-burners. At this rate of 

 consumj^tion, one ounce of wire, costing six dollars and fifty cents, 

 would last an hour. — Franklin Journal, Now, 1865. 



Several arrangements have been devised, more or less ingen- 

 ious, to burn the metal in the form of wire or ribbon ; but the 

 great difficulty in all such arrangements has been, that it required 

 clockwork to feed it forward. In order to avoid this difficulty, 

 ]\lr. Larkin, after many trials, has succeeded in constructing a 

 magnesium lamp, a specimen of which we describe. The dis- 

 tinguishing peculiarity of these lamps is, that they burn magne- 

 sium in the form of powder, instead of ribl)on or wire ; and that 

 they do not depend on clockwork or any similar extraneous mo- 



