Analyses of the Chrysoberyls from Haddam and Brazil. 109 
the mineral with potash and muriatic acid, to be silica. 
This will explain why their results differ so essentially from 
ne. 
After having thus satisfied myself of the composition of 
the residue above mentioned, | resumed my preliminary 
experiments, and proceeded to examine the muriatic solu- 
tion obtained from the treatment of the mineral with pot- 
ash and muriatic acid. From this solution some silica was 
separated. A portion of the liquid was treated with caus- 
tic ammonia, and then tested for /tme with oxalate of pot- 
ash, but ndne of it could be detected. ‘To the remaining 
liquor a considerable excess of subcarbonate of ammonia 
was added, and the precipitated matter was digested twen- 
ty-four hours. It was then separated by filtration, and the 
fluid was boiled till all the ammonia was expelled. No 
glucina was thus precipitated. Hence we conclude, that 
the very small portion of titanium above mentioned, ren- 
dered the whole of the glucina so refractory. ‘The alumi- 
na precipitated by the subcarbonate of ammonia was mix- 
ed with a small quantity of oxide of iron. It was soluble 
in caustic potash, and with this alkali and sulphuric acid it 
ave regular octedral crystals ofalum. The liquor, when 
tested with phosphate of soda and ammonia, was found to 
contain no Magnesia. 
After the preliminary experiments, I commenced the 
following 
ANALYSIS OF THE CHRYSOBERYL FROM HADDAM. 
Al. Five grammes of the mineral, reduced to small frag- 
ments in an iron mortar, were carefully pulverized in one 
of agate, from which it acquired the additional weight of 
0.13 grammes. The 5.13 grammes were then exposed to 
a red heat, and thereby suffered a diminution of 0.40 per 
100. 
B. The calcined mineral (4) was heated, during one 
hour, in tne silver crucible, with caustic potash, and the 
product was treated with diluted muriatic acid ; the solu- 
tion was of a lemon yellow colour. here remained a 
white insoluble residue, which after calcination weighed 
1.47 grammes. It was repeatedly calcined with caustic 
