lvi Historical Sketch of the Physical Sciences, 1818. 
and in Germany, about the same time, without any concert what- 
ever between those who imposed that, name. : 
' The preceding sketch contains the discovery of no fewer than 
seven new acids ; namely: 
1. Hydrosulphurous acid. 5. Ellagic acid. 
2. Uranic acid. 6. Lampic acid. 
3. Manganesic acid. 7. Pyromucic acid. 
4, Purpuric acid. 
Three acids, hitherto considered as peculiar, have been shown 
to be the same with three others which have been long known. 
- (1.) Malic and sorbic acids have been shown to be the same. 
(2.) Rheumic acid is merely oxalic acid. 
(3.) Zumic acid is the same with lactic acid. 
VI. ALKALIES,. 
This department of the science promises fair to be enriched 
likewise with a variety of new vegetable bases possessing the 
characters of an alkali. Sertiirner’s paper on morphia has drawn 
the attention of chemists to this subject, and the discovery of 
several new substances possessing similar properties has already 
rewarded their exertions. 
1. The discovery of lithina by M. Arvedson was announced in 
the Historical Sketch for last year, and the properties of that new 
mineral alkali, as far as they had become known, were given, 
I had not at that time made any experiments on the analysis of 
petalite or spodumene, the two minerals in which it had been 
found; but it may, perhaps, be worth while to mention the 
methods of analysis which I have found successful. If petalite 
reduced to a fine powder be fused with nitrate or carbonate of 
barytes, it becomes soluble in muriatic acid. The earths may be 
separated in the usual manner by means of sulphuric acid and 
carbonate of ammonia, and the sulphate of lithina obtained is 
readily decomposed by carbonate of barytes. By this method, 
which appears sufficiently simple, the lithina may be obtained in 
a state of purity. 
I do not know the method which M. Arvedson employed to 
obtain this alkali, as I have not yet seen his paper upon the sub- 
ject. It is stated in the Institution Journal, vi. 226, that petalite 
may be analyzed in the usual way by means of potash. The 
muriate of lithina may be easily separated from the muriate of 
potash by means of alcohol, \in which it is very soluble. I have 
not tried this method. To sueceed by it, I suppose the alcohol 
must be strong; for muriate of potash is sensibly soluble in 
alcohol of the strength at which it is usually sold in the shops. 
2. Morphia.—Choulant’s method of obtaining this substance, 
of which an account has been given in the Annals of Philosophy, 
xl. 153, seems better than any of the processes employed either 
by Sertiimer or Robiquet. 
