264 ANNUAL OF SCIENTIFIC DISCOVERY. 



the want of a sufficient number of large glass shades, and the peculiarly 

 constructed vessels attached to them, which I employ in these experiments, 

 obliged me to abandon my intention so to do for the present. Sulpho-cyan- 

 ide of potassium, like the ferrocyanide of the same base, is innocuous, rich 

 in nitrogen, and very soluble. Uric acid contains a larger proportion of 

 nitrogen, but is very sparingly soluble. I have no doubt that both substan- 

 ces will be found capable of ministering to the wants of vegetable life. It is 

 also probable that ferrocyanide of potassium is capable, like its kindred sub- 

 stance, the yellow prussiate, of rendering up its nitrogen on the demand of 

 the plant. Chemical News. 



ON THE FORMATION OF CARBONATE OF LIME AND MAGNESIA. 



Mr. T. S. Hunt, of the Canadian Geological Survey, states as the result of 

 his recent researches, that " if we mingle in equivalent proportions the chlo- 

 rides of calcium and magnesium in concentrated solution, and then, having 

 precipitated the bases by a slight excess of carbonate of soda in the cold, 

 expose the mixture for a few houi's in a closed flask to a temperature of 200 

 212 F., the pasty mass is entirely transformed into a beautiful granular 

 powder, made up of spherical, translucent, crystalline grains, which are 

 sparingly soluble in cold, dilute, acetic acid, and are a double carbonate of 

 lime and magnesia. In my previous and published trials, at temperatures of 

 300 400 F., the product was much less beautiful, and was mingled with 

 carbonate of magnesia. It now remains to be seen whether the combi- 

 nation may not be slowly effected at a temperature much below 200 J F., and 

 experiments upon this point are in progress." 



ON THE PRODUCTION OF OZONE BY MEANS OF A PLATINUM WIRE 

 MADE INCANDESCENT BY AN ELECTRIC CURRENT. BY M. LE 

 ROUX. 



If a platinum wire, not too large, be made incandescent by an electric 

 current in such a manner that the ascending flow of hot air which has sur- 

 rounded the wire comes in direct contact with the nostrils, an odor of ozone- 

 is perceived. The experiment maybe made in the following manner: A 

 very fine platinum wire is taken, formed in any shape, and supported in an 

 almost horizontal position in any suitable manner. A glass funnel is placed 

 over this, so that the air has sufficient access to the wire, on which is adjusted 

 a glass chimney of a suitable length ; the object of which is to cool the gases 

 heated by the wire. The wire is then made incandescent by means of twelve 

 or fifteen Bunsen's cells. The gas issuing from the chimney is found to have 

 the odor of ozone; iodized starch-papers are altered in a few minutes when 

 placed over the chimney. In this case, the air passing over the incandescent 

 wire undergoes a peculiar modification by which it acquires the properties of 

 ozone; but whether this is effected by the electricity acting as a source of heat, 

 or by its OAvn proper action, must be reserved for further experiments. 

 Comptes Rendus, 18oO. 



RESEARCHES BY M. HONZEAU ON OXYGEN IN THE NASCENT STATE. 



When peroxide of barium is acted upon at ordinary temperatures by mono- 

 hydrated sulphuric acid, the ox} T gen evolved possesses very active oxidizing 



