2C0 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



rises too high say above 210 the manganous nitrate de- 

 composes, giving nitrous vapors. 



Kara merer has proposed a very simple and efficient way of 

 showing the direct combustion of nitrogen as a lecture ex- 



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periment. Ajar of about half a gallon capacity, filled with 

 air, has thrust into it a piece of burning magnesium ribbon 

 from twelve to fifteen inches lono-. After the combustion of 



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the magnesium is completed, the odor of nitrogen tetroxide 

 is observable, and after the magnesia has subsided its color 

 may even be discerned. Shaken with potassium iodide solu- 

 tion containing a little acetic acid, the liquid becomes brown 

 from free iodine, and strikes the characteristic deep-blue color 

 when a little solution of starch is added. 



Warington has given in Nature a statement of the results 

 obtained at Rothamsted in testing the new theory of nitrifi- 

 cation proposed by Schloesing and Muntz, which completely 

 confirm those of the French chemists. According to their 

 view, nitrification, instead of being brought about by purely 

 chemical forces, is, in fact, the work of a living organism. In 

 proof of this they show that the process, however active, is 

 stopped at once by the vapor of chloroform, and also by a 

 temperature of boiling water. It must therefore be that the 

 production of nitre in the soil is due to oxidation brought 

 about by these living mycoderms. 



Gilm has shown that a regularly tinted and beautiful 

 green boric-acid flame is best obtained by passing the vapor 

 of boric ether through a kind of Bunsen burner, made by en- 

 closing a small narrow glass tube in a vertical one, so that 

 the gas may mix with air previous to ignition at the upper 

 end of the tube. An ordinary Bunsen burner may be used 

 for the experiment, if only care be taken to heat the tube 

 previously to prevent condensation. In qualitative testing 

 it is most convenient to use a small flask provided with a 

 cork, through which passes a short glass jet drawn out to a 

 point, a wider tube being placed over the latter, and the gas 

 ignited at the top. After the addition of hydrochloric acid, 

 very small quantities of boric acid may be detected by this 

 means. 



Laufer has suggested an improved method of determining 

 the silica which exists as quartz in rocks, and of separating 

 it from the silica contained therein in combination as silicates, 



