j 2 On the Solaf and Lunar Period 6f6oo Years* 



in a wind furnace, and increafe the fire fuddenly, fa as \6 

 bring the crucible to a white heat, for the fpace of fifteen 

 minutes. Pulverifethc mafs when it is coo), and preferve it 

 in a bottle clofcly flopped l 



To prepare the liquor, put 120 grains of this powder and 

 120 grains of cream of tartar (acidulous tartaritc of pot- 

 afli) into a flrong bottle ; fill ihe bottle with common water, 

 which boil for an hour, and then let it cool ; clofe the bottle 

 immediately, and fhake it for fome time : after it has re- 

 mained at reft to fettle, decant the pure liquor, and pour it 

 into fmall phials capable of holding about an ounce each, 

 firft putting into each of them 20 drops of muriatic acid. 

 They muft be flopped very clofcly with a piece of wax, iri 

 which there h a fmall mixture of turpentine. 



One part of this liquor mixed with three parts of fuf- 

 pc&ed wine, will difcoyer, by a very fenfible black precipi- 

 tate, the leafl traces of lead, copper, &c* but will produce 

 no effccl: upon iron, if it contains any of that metal. When 

 the precipitate has fallen down, it may flill be difcovercd 

 whether the wine contains iron, by faturating the decanted 

 liquor with a little fait of tartar (tartarcous acidulum of 

 potalh), by which the liquor will immediately become black. 



Pure wines remain clear and bright after this liquor has 

 been added to them. 



VIII. On the Solaf and Lunar Period of Si.r Hundred Years; 

 By Profe/Jbr BuRJA, Memhey of the Rojal Academy of 

 Sciences at Berlin. Extracled from a Paper read tn the 

 \$ib of December ijgi. 



1 HE hiftoriart Jofephus fays that God prolonged the*" 

 lives of the patriarchs to at leafl fix hundred years, that they 

 might become more perfect in the knowledge of aftronomy, 



beeaufe 



