58 SEVENTH REPORT—1837. 
On an Antimonial Compound applicable as a Pigment. 
By Dr. TRAILL. 
It is made by adding a solution of ferrocyanide of potassium to the 
muriate of antimony. The precipitate, which is of an ultramarine 
colour, Dr. Traill considers to be composed of prussic acid, iron, and 
oxide of antimony. 
On the non-production of Carbonic Acid by Plants growing in the 
Atmosphere. By Dr. DALton. 
Dr. Dalton calculates, that in 5000 years, animals supposed to live 
upon the earth, would produce by their breathing in the atmosphere 
but =, part by weight of carbonic acid, therefore the assistance of 
plants to purify the air is not necessary. By experiment he found, 
that a hot-house does not contain more or less carbonic acid, by night 
or by day, than the external air, and the results were the same in a 
number of repetitions of the experiments. This paper was said to have 
been penned during the convalescence of its illustrious author from a 
late attack of illness. 
On the Action of Water upon Lead. By T. J. PEARSALL. 
On a New Form of Iron Bottle for obtaining Oxygen from Peroxide 
of Manganese. By Mr. J. Dick, of Cambridge. 
Mr. Griffin exhibited chemical apparatus adapted for experiments on 
a small scale. 
Mr. J. Murray presented to the Section a phial of the milk of the 
Cow-tree, with an account of its chemical and other properties ; also, 
specimens of two sorts of paper manufactured from the phormium tenax 
and the musa textilis. 
On the Influence of Electricity on the Process of Brewing. 
By W. Buiack. , 
According to the author's statements, a thunder-storm not only 
checks the fermentation of worts, but even raises the gravity of the 
saccharine fluid, and developes in it an acid. This effect is principally 
witnessed when the fermenting tun is sunk in moist earth, and may be 
obviated by placing it upon baked wooden bearers, resting upon dry 
bricks or Wooden piers, so as to effect its insulation. Mr. Black also 
stated, that during the prevalence of highly-electrified clouds, the fa- 
brication of cast iron does not succeed so well as in other states of the 
atmosphere. . 
