20 



tor, which we can improve to some of the noblest 

 sciences, and most excellent uses of our own globe. 



One species of lucid bodies are termed 

 of which some are natural, others artificial. Natural 

 phosphori emit light without a;iy art or preparation. 

 Such are glow-worms, and several sorts of shining in- 

 sects. Such are rotten wood : the eyes, blood, scales* 

 flesh, and leathers of some animals. Diamonds likewise 

 when rubbed emit light, to one who has stayed some time 

 in the dark. But before the diamond is brought into 

 the dark room, it should lie eight or ten seconds in the 

 sun-shine. It will then shine in the dark twelve or thir- 

 teen minutes : but its light gradually weakens all the time. 



But it is remarkable, that some diamonds have this 

 property of imbibing the sun's rays, and shining in the 

 dark, mid others not, though there is no other discerni- 

 ble difference between them. Nor is there any rule 

 of judging, which diamonds have this property, and 

 which have not. Their brightness, their purity, their 

 size, their shape, contribute nothing to it. 



Sulphur and sugar when pounded in the dark, will 

 likewise emit liglit ; as will the backs of horses or cats, 

 when rubbed with the hand, and sea-water, yea and some 

 mineral waters, briskly agitated. But no natural phos- 

 phorus shines always, or gives any heat. 



Artificial phosphorus is made chiefly from human 

 urine. But it may be made from blood, or hair; or in- 

 deed from any part of an animal, which yields an oily 

 distillation. It is at first of the consistence of hard 

 wax; but dissolves in all kinds of distilled oil. With 

 solid phosphorus one may write on paper as with a pencil, 

 and the letters will shine in the dark. A little piece of' it 

 rubbed between two papers, takes fire presently. It 

 burns vehemently, and penetrates deeper into the flesh 

 than common fire. It neve^r spoils, if kept in a phial 

 full of water. Liquid phosphorus does not keep long* 



