498 SCIENTIFIC RECORD FOR 1884. 



Iodide of Xitrogen and its Use in Actinometry, by Antony Guyard. — 

 The author prepares iodide of nitrogen by acting on one gram of iodine 

 with 8 c. c. of aqua anmionia at 22° B. With less ammonia, the am- 

 mouiura iodide which forms removes some of the iodine from the prod- 

 uct. Exposed to direct or diffuse sunlight, the iodide of nitrogen is 

 immediately decomposed, with liberation of nitrogen, and the reaction 

 is so clean as to be useful in actinometry. Explosions result occasion- 

 ally if the iodide be subjected to the action of light under water, but 

 under ammonia at 22° B. the decomposition ensues quietly, with effer- 

 vescence. By determining the weight or volume of the nitrogen liber- 

 ated in a specified time, the reaction may be applied to measurement of 

 the energy of sunlight. The reaction is expressed thus: 2 NH2l = 

 NH4I2 + N. Iodide of nitrogen is decomposed rapidly, sometimes with 

 explosions, by dilute sulphuric and hydrochloric acids; it dissolves 

 without danger in sodium hyposulphite and in potassium sulphocyanide, 

 ammonia being set free. {Bull. soc. cliim. [2], XLI, 12.) 



Antiseptic Value of Carbon Bisulphide. — In October, Prof. Eug. P^ligot 

 presented a paper to the French Academy of Sciences on the utility of 

 an aqtieous solution of carbon disulphide in the treatment of the vine 

 attacked by phylloxera. He showed that the liquid is far more soluble 

 in water than the determinations made by Mr. Ckiandi established ; at 

 ordinary temjDeratures water dissolves 3.5 c. c. per liter, or 4.52 grams, 

 its density being 1.293. Its antiseptic properties have also been fully 

 confirmed by the further investigations of Pasteur, who anticipates that 

 it will become the most efficacious of all antiseptics, it being also the 

 cheapest, costing only a few centimes per liter. It is, moreover, the 

 best known insecticide, and has already rendered great services in the 

 destruction of phylloxera. At present 30,000 hectares (about 74,000 

 acres) of vineyards are yearly treated with over 4,000,000 kilograms 

 of carbon disulphide, with excellent results. When applied in the form 

 of potassium sulphocarbonate, it has a double action, the sulphur deriv- 

 atives killing the insect and the potash enriching the soil. {Nature, 

 XXX, 028.) 



Disinfection by Combustion of Carbon Disulphide. — Carbon disulphide 

 forms on burning, carbon dioxide and sulphur dioxide. In consequence 

 of the yield of the latter product, the liquid has been recommended by 

 a French commission as the best material for disinfecting rooms in 

 which patients suffering from contagious diseases had sojourned. The 

 licpiid carbon disulphide is more easily burned than sulphur, and is less 

 injurious to furniture or metallic articles in the apartments. 



Presence of Carbon in ordinary Phosphorus, by Ira Remsen and E. H. 

 Keiser. — As a contribution to the question regarding the action of moist 

 phosphorus on carbon monoxide, Professors Ecmsen and Keiser have 

 quantitatively determined the amount of carbon in ordinary phosphorus. 



