J. W. Mallet on the Atomic Weight of Lithium. 351 
in contact with muriatic acid in a gas cylinder filled with mer- 
eury, and the carbonic acid evolved was measured. It was 
found in one experiment =60°98, and in another 61-00 per cent 
of the carbonate of lithia. Hermann also dissolved this carbon- 
ate in sulphuric acid, evaporated to crystallization, and dried the 
crystals of sulphate of lithia over a spirit-lamp. 100 parts of 
the dry salt gave an amount of sulphate of baryta correspond- 
ing to 74 parts of sulphuric acid. 
In 1831 Berzelius* repeated the experiments of Hermann, 
and with the following results. 4:4545 grm. of fused carbonate 
of lithia dissolved in sulphuric acid gave 6653 grm. of sulphate 
of lithia; and 1°874 grm. of this anhydrous sulphate gave 3°9985 
grm. of sulphate of baryta. ‘ 
In 1889 Hagent+ reéxamined with accuracy some of the min- 
erals containing lithia, and discovered that this alkali occurred 
in them, not pure, as it had been previously supposed, but ac- 
companied by soda; and as in the preparation of lithia salts for 
were necessarily quite erroneous; and that the results of Ber- 
zelius and Hermann alone deserved any confidence, the salts 
analyzed by them having been prepared from precipitated car- 
bonate of lithia. 
Hagen himself found that 1:002 grm. of pure sulphate of 
lithia in crystals left on being strongly heated ‘852 grm. of the 
anhydrous sulphate, and being redissolved and precipitated with 
a salt of baryta gave 1°8195 grm. of sulphate of baryta. 
_ The above are the results of the experiments which have been 
made up to the present time. I have not kis alon with each 
the equivalent number deduced by the analyst himself, but have 
preferred to make the calculation in each case, using the most 
recently determined equivalents for the other substances involved 
° ~ several processes, and I here present the results in tabu- 
ar form—. 
' Poss. Ann, xvii, 379. Berz. Jahresb. x, 96. 
. Ann. xlviii. 361, ee eat 
t Rei that Trtecded his sulphate of lithia by dissolving the car- 
prepares : 
bonate in sulphuric acid; but this carbonate mary to have been obtained by precipi 
ne. in tag ee : 
orine,- = + > 44828 (Marignac). 
- - 200° 
Se a ae 
- = « 184966 (Marignac). 
Rican eines! wife Ores (varignse) 
