236 



some -parts it has been computed,, its thickness is only 

 the 3.150.000(h part of an inch; and yet with this 

 amazing thinness, it is still a perfect cover for the 

 silver, nor can the best eye, or even the best micros- 

 rope discern the least chasm or discontinuity. Nay, 

 there is not an aperture to admit alcohol of wine, one 

 of the subtlest fluids in nature : no, nor light itself. 

 So closely connected are the particles notwithstanding 

 their inconceivable thinness. 



Silver approaches the nearest to gold in ductility 

 and resisting fire. Like the ore of all other metals, 

 it is found in the earth, under different forms and co- 

 lours. But it usually affects somewhat of a pointed 

 regular form like crystals. It is never found in sand 

 or grains as native gold is. It is sometimes ash. co- 

 loured, sometimes spotted with red and blue, some- 

 times of changeable colours, many times almost black. 



Although the history of fossils has been diligently 

 cultivated especially by the moderns, yet it must be 

 owned, that amidst the vast variety of thorn, there 

 is still room lor m w inquiries. No wonder, there, 

 fore, that among the great variety of saits, ores, and 

 other concretes, new mixtures should daily be dis- 

 covered. But that among bodies so simple as metals,, 

 any should still remain unknown, will appear extra- 

 ordinary. 



Yet so it is : there has been discovered in New 

 Spain, an original me(al between gold and silver. The 

 Spaniards call it PJatina. from the resemblance in co- 

 lour which it bears to silver. It is of an uniform 

 texture, bright and shining. It takes a fine polish, 

 and does not tarnish nor rust It is \cry hard and 

 compact, but exiremel'y brittle, and maileaule but ia 

 a small degree. 



It is found chiefly in small grains, yet not pure, but 

 mixed with a shiny black sand. There are likewise 

 usually mixed with it, a few shining pa-ticlos ot a 

 golden colour. 



When exposed by itself to the fire, it is extremely 

 hard to melt. It has been kept for two hours in an. 



