Scientific Intelligence. 165 



iior 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 

 force 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 fine. — Quarterly Jour, of Sci. ^c. Jan. to June, 

 1829. 



9. Conductibiliiy conferred hy 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 an inch wide. The color is not changed by alkalies and neutral 

 substances, but it becomes red by a very small portion of acid. — 



