Chemistry. STO 
of a glass, a detonation takes place. The oxygen of the water, 
and that of the oxide are disengaged ; a great quantity of heat 
is developed, and light is produced so sensibly, as to be per- 
ceived where the darkness is not very intense. The same phe- 
nomena take place with silver, platinum, gold, osmium, iridium, 
rhodium, the peroxide of cobalt, &c. 
25. Hyposulyliurk Acid.^A new acid has been recently dis^ 
covered by MM. Gay Lussac and Welther, which they have 
called Hyposulphui'ic Acid, and an account of which was commu- 
nicated to the Institute of France, on the 5th April 1819. They 
obtained it by passing a current of sulphurous acid gas, over a 
solution of peroxide of manganese in water ; then filtering and 
pouring into the liquor, a certain quantity of barytes, and cau- 
sing a current of carbonic acid gas to pass over it, if there is 
an excess of this ; then by pouring upon it sulphuric acid, the 
barytes is thrown down, and the new acid is obtained, which is 
dried under the receiver of an air-pump, by sulphuric acid. 
The greater number of the salts which it forms with earthy or 
metallic bases, are soluble, and crystallize. The hyposulphates 
of barytes and lime are inalterable in air ; and the suberic acid 
and chlorine, do not decompose the hyposulphate of barytes. 
This new acid is composed of two proportions of sulphur, and 
five of oxygen. 
26. New Acid in the Vihufnitm Opulns.^NL. Chevreul has 
discovered in the fruit of the Viburnum Opulus, an acid iii 
every respect similar to the Delphinic Acid, which he had pre- 
viously discovered in the fat of the dolphin. 
27. Purpuric Acid. — M. Vauquelin, we understand, has been 
engaged in repeating the experiments on the Purpuric Acid, 
which Dr Prout has described in \hePhil. Trans. 1818, p. 420. 
He has announced, that he does not agree with Dr Prout 
respecting the existence of this acid, but has not yet published 
any of the details. 
28. Production of Light, hy hreakmg Glass Balls filled with 
Oxygen. — A very curious and important experiment has fie- 
cently been made by M. Biot. It consists in breaking by means 
of a suitable apparatus, a ball of glass filled with oxygen gas, 
-and placed in the receiver of an air-pump, in which as perfect 
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