Seientifie Intelligence. 165 
nor even additional means, could any effect of the kind be produced. 
‘The committee could not explain the effect, except by supposing 
that the cylindrical form of the apparatus, presenting only a small 
surface to the action of the wind, was favorable, and that the form 
of the small apertures in this cylinder, occasioning a great number 
of contrary currents, produced almost a perfect neutralization of the 
foree of the wind. Whatever may be the cause, the apparatus offers 
a cheap and effectual remedy for smoky chimneys, when this fault in 
them, is dependent upon the pressure exerted by winds upon the up- 
per aperture of the flue. — Quarterly Jour. of Sci. §¢. Jan. to June, 
48295. 
9. Conductibility conferred by water. (Bib. Univ. 11. 205.)—In 
the second volume of this series, p. 465, we noticed the curious fact, 
observed by M. de la Rive, that a fluid (bromine) having no con- 
ducting powers for electricity, was competent, when taken into solu- 
tion by water, very much to increase the conducting powers of the 
latter. M. de la Rive has added another to the curious facts of that 
kind, there referred to. Fluid sulphurous acid, he finds to be a sub- 
stance which does not conduct voltaic electricity. The platina wire 
of the voltaic pile, when plunged into it, allowed of no transference 
of electricity from one to the other; but so soon as a little water was 
‘added to the acid, then the current passed, and action immediately — 
appeared. The sulphur of the acid, and the hydrogen of the water, 
went to the negative pole, and the oxygen of both to the positive 
pole ; and the galvanometer was now influenced by the current, 
‘which passed through it in the ordinary manner.—Idem. 
CHEMICAL PHILOSOPHY. 
1. Litmus Paper.—In a memoir containing popular directions for 
the examination of the different kinds of potash, known in commerce, 
Gay Lussac recommends the following mode of preparing test paper. 
“Take letter paper, or any other that is well sized, and color it on 
one side only, with the tincture of Litmus, or Tournesol (prepared by 
boiling powdered litmus in water,) by means of a brush. When dry, 
it should have a tender blue color ; and if not deep enough, it may 
receive a second coat. The paper is then cut into strips about one 
third of aninch wide. The color is not changed by alkalies and. neutral 
‘substances, but it becomes red by a very small portion of acid.— 
