Notices . 
175 
Mr. J. Conrad is about publishing Davy’s Chemical Elements 
©f Agriculture : and Mr. Dobson goes on with Bancroft on per- 
manent colours. I have perused both works ; and they are well 
worth recommending to those who are interested in the pursuits 
they relate to. I rejoice to hear also of a new edition of Dr, Bar- 
ton’s Botany. 
Mr. J. Cutbush has published the Artists Manual , 2 vols. Svo„ 
closely printed : (Johnson and Warner, and Fisher, South Fourth 
street.) This work contains the substance of Aikin’s Chemical 
Dictionary, the Domestic Encyclopedia, and some similar publi- 
cations. I do not know any book that includes so much scientific 
knowledge bearing upon manufactures, in the same compass, or at 
so small a price. I regard it as a compilation, made with judg- 
ment, and great industry, and a valuable addition to the useful lite- 
rature of the country 
I have not room in this number for an account of the loom that 
weaves by water power, or steam, invented, as I am informed by 
Mr. Siddal, at the calico printing works, about half a dozen miles 
on the New York road from Philadelphia. I shall gladly say more 
on this very important improvement. I have examined it with 
great satisfaction. 
NEW DISCOVERY. 
Thursday Evening , January 20, 1814. 
Iode o* Violaceous Gas. The Royal Society met after 
the holidays, when a paper from Sir H. Davy was read, describ- 
ing a new and important discovery. About two years ago, a Pari- 
sian manufacturer of salt-petre, using all kinds of sea weed as a 
substitute for Barilla, discovered that his vessels were excessively 
corroded by a particular substance of a beautiful violet colour ; he 
communicated the fact to some Paris chemists, but no particular 
notice was taken of it until Sir H. Davy went to Paris. 
This new substance is easily procured by pouring sulphuric 
acid on the residuum of sea weed after the carbonat of soda has 
been extracted. It appears that all the vegetable products of the 
sea shore, yield it when thus treated. By pouring the acid on the 
residuary ashes of the sea weed, this new and most beautiful violet 
coloured gas is obtained. 
