SALTS 



It is anhydrous also when obtained by precipi- 

 tation* It is not unlikely that there occurs also 

 a bichromate of a red colour, composed of 



2 atoms chromic acid 13 



1 atom protoxide of lead I 4 



27 



10. Molybdate of lead. This salt occurs na- 

 tive in Corinthia. It is usually crystallized in 

 small rhomboidal plates ; it has a pale yellow 

 colour, and a certain degree of transparency ; it 

 is tasteless and insoluble in water, and perfectly 

 anhydrous. Its constituents are 



1 atom molybdic acid 9 



1 atom protoxide of lead 14 



23 



11. Bitungstate of lead. This salt likewise oc- 

 curs native ; for it has been found at Zinnwalde 

 in Bohemia in very acute four-sided pyramids, 

 having a brown colour, and perfectly tasteless, 

 and insoluble in water. I am not aware that any 

 analysis of the native tungstate of lead has been 

 made ; but the artificial tungstate, formed by 

 mixing solutions of bitungstate of ammonia and 

 nitrate of lead, was examined by Berzelius. 

 From his experiments it appears to be a bitung- 

 state ; consequently, its constituents must be 



