liUcUigcnce and Miscellaneous Articles. 8S 



is unbroken continuity. All attempts to produce explosion of the 

 gases in this tube, or to compel the Harae to return through it, have 

 been ineffectual. Before the Society of Arts, Mr. Hemniingexploded 

 the gases repeatedly in the improved safety chamber, now employed 

 in Gurney's blow-pipe, by permitting s-mall portions of water from 

 the well to enter with them, but he could not explode tiiem in his im- 

 proved tube under precisely the same circumstances, although they 

 were ignited at the aperture (nearly three-quarters of an inch in 

 diameter,) after the jet piece was removed. 



Mr. Hemming kept the gases ignited at this large aperture 

 until the extremity of the tube was in a state of active combustion, 

 which was evident by the dense green flame produced ; and although 

 the cooling influence was then greatly diminished, no explosion oc- 

 curred. 



The simplicity of its construction will render the manufacture of 

 the article easy and occonomical ; and its perfect safety will enable 

 the chemical operator to dispense with a very expensive and deli- 

 cate article of apparatus, in the use of which there is always danger 

 and uncertainty. 



CONVERSION OF HYDROCYANIC ACID AND CYANURETS INTO 

 .;,;^ AMMONIA AND FORMIC ACID. 



■' M. Pelouze concludes, from numerous experiments, — 



1st, That hydrocyanic acid is converted into ammonia and 

 formic acid by the action of the sulphuric and muriatic acids, and 

 probably by a great number of other acids. 



2ndly, That cyanuret of potassium, when a concentrated solu- 

 tion of it is heated, is changed into ammonia and formiate of 

 potash. 



3rdly, That the same salt at a high temperature, when influenced 

 by an excess of potash, yields hydrogen, ammonia, and a residue of 

 carbonate of potash. 



4thly, That one proportion of cyanuret of mercury acting upon 

 one proportion of muriatic acid, gives one proportion of hydro- 

 cyanic acid, and one of perchloride of mercury. 



5thly, That cyanuret of mercury with an excess of muriatic acid 

 produces double chloride of ammonia and mercury, formic acid, 

 and a very little hydrocyanic acid. 



6thly. That formiate of ammonia, when heated to about 360^ 

 Fahrenheit, is converted into water and hydrocyanic acid. — Ann. 

 de Chim. et de Fhys. vol. xlviii. p. 395. 



ISOMERIC MODIFICATION OF TARTARIC ACID. BY M. BRACONNOT. 

 It is well known that the tartaric and racemic (paratartaric) acids 

 were the first well-defined examples of isomerispi. T he judicious 

 reflections of M. Dumas on this extraordinary ph.nenomcnon hav^j 

 recalled a fact belonging to it, and which 1 had occasion to ob- 

 Kcrve, rcipccling tartaric acid. ■" ■ ■ >-<■■ 



U 2 



