2i 



BLXtH SJIfVD 6S Ittit BANKS OP THE DON, 



More oxide of ^. The brown-coloured matter which had been precipi- 

 tated by the potash, when dried upon the stean)-bath, 

 weighed 20*2 grains. It dissolved with effervpsceiice in 

 muriatic acid. The solution had the appearance of the 

 yolk of an e<jg. When boiled for some time, and then di- 

 luted with water, it became white, and let fall li curdy pre- 

 dpifate, ^♦hich weighed, when dry, 4*6 grains, and possessed 

 the properties of oxide of titanium. 



9. The residual liquor, being mixed with an excess of 

 simmonia, let fall a brown matter, which, after being dried, 

 drenched in oil, and heated to redness, weighed 6 grains. 

 It was strongly attracted by the magnet, but was of too 

 light a colour to be pure oxide of iron» I therefore dis- 

 solved it in muriatic acid, and placed it on the sand-bath, 

 in a porcelain capsule. When very much concentrated by 

 evaporation, small white needles began to make their ap- 

 pearance in it. The addition of hot water made them dis- 

 appear; but they were again formed, when the liquor 



Ars«nic. became sufficiently concentrated. These crystals, when 



separated, weighed 1^3 grains, and proved, on examination, 

 to be white oxide of arsenic. During the solution of the 

 6 grains in muriatic acid, a portion of black matter sepa- 

 rated. It weighed 0*2 of a grain, and was totally dissipated 

 before the blowpipe in a white smoke. Hence, it must have 

 been arsenic. These 1'5 gr. are equivalent to rather more 

 than 1 grain of metallic arseriid. Thus it appears, that 

 the 6 grains contained 1 grain of arsenic, which explains 



Iron. t^6 whiteness of their colour. The rest was iron. It can 



scarcely be doubted, that the proportion of arsenic present 

 was originally greater. Some of it must have been driven 

 off, when the iron oxide w^s heated with oil. 



More oxide of ^^' The insoluble residue (No. 4) was with great diffii. 



titanium. culty dissolved in sulphuric acid. When the solution wa$ 



mixed with ammonia,- a white powder fell, which weighed 

 0*8 of a grain. It was accidentally lost, before I examined 

 its properties. But I have no doubt, from its appearance^ 

 that it was oxide of titanium. 



KesuUsofth© 11. Thus, from the 100 grains of iroti-sand, the follow- 



anaiysis. -^j^ constituents have been extracted by analysis: 



PlacV 



