June 1, 1865.] THE TECHNOLOGIST. 



ON MAGNESIUM. 493 



rays ; but until recently the cost of isolating it has been so great, that 

 its capabilities have never advanced beyond the rank of a chemical 

 curiosity. Eecent discoveries have, however, facilitated its manufacture, 

 and it has come into partial use among photographers. A negative of 

 Sir Charles Lyell was taken at the recent meeting of the British Asso- 

 ciation. A slight further reduction in cost" [a reduction which has 

 been made since this was written] will enable photographers to use it 

 for the purpose of taking likenesses in the houses of their sitters ; and 

 the sitter's gain in personal comfort will be duly registered in the 

 improved expression of the picture." * 



Nor are portraits taken by magnesium light in any sense makeshifts. 

 It is quite within the truth to say, that they are equal to, and undistin- 

 guishable from, sun-pictures. Of course the skilful handling of the 

 new light is only to be acquired after some practice. 



The light will probably develope a melancholy branch of art — the 

 portraiture of the dead. "We say melancholy, but more in a conven- 

 tional than a sincere sense. The faces of the dead frequently assume a 

 sweet, a saintly, a severe, a statuesque beauty rarely present in life. By 

 the aid of magnesium this beauty may readily be perpetuated and 

 divested of painful accessories. Some such memorials we have seen, 

 and they have only to be known to become common. 



As soon as it was discovered that photography was possible by 

 magnesium, it was suggested that the interiors of the Pyramids, of 

 catacombs, caves, and other underground and dim regions might be 

 revealed in faithful pictures, and studied under the stereoscope. The 

 suggestion was soon acted upon. Professor Piazzi Smyth, the Scottish 

 Astronomer-Royal, having gone upon an exploring expedition to the 

 Pyramids, took with him a quantity of magnesium wire, and thus 

 reports on its use to his friend Mr. Spiller, of Woolwich Arsenal : — 



"East Tomb, Great Pyramid, Feb. 2, 1865. 



" My dear Sir, — We have been here now about three weeks, and are 

 settled down at last to the measuring ; the chief part of the time 

 hitherto having been occupied, in concert with a party of labourers 

 furnished by the Egyptian Government, in clearing away rubbish from 

 important parts of the interior, and in cleansing and preparing it for 

 nice observation. 



"The magnesium wire light is something astounding in its power of 

 illuminating difficult places. With any number of wax candles which 

 we have yet taken into either the king's chamber or the grand gallery, 

 the impression left on the mind is merely seeing the candles and what- 

 ever is very close to them, so that you have small idea whether you are 

 in a palace or a cottage ; but burn a triple strand of magnesium wire 

 and in a moment you see the whole apartment and appreciate the 



* Artble "Photography" in "The Quarterly Review" for October, 1864, 

 page 517. 



