Intelligence and Miscellaneous Articles. 339 



Boracic acid 66*7 



Carbon 19'8 



Hydrogen 4*4 



Oxygen (estimated by loss) . 9*1 100*0 



The author observes that the carbon and hydrogen are in the same 

 proportions as in aether, while the oxygen is obviously in excess. 

 The formula BO 6 O H 5 O is the nearest approach to the above 

 mean ; it gives — 



Boracic acid . . 8720 65 A 



Carbon 3000 224 



Hydrogen .... 62*5 47 



Oxygen 1000 7'6 



13345 100-0 



M. Ebelmen observes that the difference between the results of 

 experiment and calculation are too considerable to be attributed to 

 errors of analysis. It must be admitted, he says, that the boracic 

 aether contains a certain excess of boracic acid disseminated uni- 

 formly throughout the vitreous mass ; this supposition, he further 

 observes, is not at all improbable, when the mode of preparing bo- 

 racic aether is considered. — Ann. de Ch. et de Phys., Fevrier 1846. 



ACTION OF BORACIC ACID ON PYItOXYLIC SPIRIT. 



M. Ebelmen states that the action of boracic acid upon pyroxylic 

 spirit is similar to that which it exerts upon alcohol ; when equal 

 weights of them are mixed, great increase of temperature is pro- 

 duced. On heating the retort from 212° to 230° Fahr., but little 

 distilled product is obtained ; on allowing the retort to cool, and 

 treating the matter which it contains with anhydrous aether, and ope- 

 rating in other respects as for boracic aether of alcohol, boracic me- 

 thylic aether is obtained, the properties of which are perfectly compa- 

 rable with those of boracic aether. It is soft and may be drawn into 

 threads at common temperatures ; when treated with water it is im- 

 mediately decomposed, with the disengagement of much heat, into 

 boracic acid and pyroxylic spirit ; it burns like boracic aether, with a 

 fine green flame. 



Pyroxylic spirit is preferable to alcohol as a reagent for determi- 

 ning the presence of boracic acid by the colour of the flame ; when 

 the alcoholic solution does not contain much boracic acid, the edges 

 only of the flame are green, and it is often difficult to discover it. 

 But with pyroxylic spirit it requires only a small quantity of the acid 

 to give the whole flame a green colour ; this result is doubtless de- 

 pendent upon the fact, that the flame of the pyroxylic spirit by itself 

 has less colour than that of alcohol. 



When pyroxylic spirit is distilled with a great excess of boracic 

 acid, a colourless gas is obtained which is soluble in water, and whose 

 properties resemble those of boracic methylic aether, C 2 H 3 O ; the 

 mode in which boracic methylic aether is decomposed is therefore en- 

 tirely different from that of the corresponding compound of alcohol. 



M. Ebelmen found that boracic methylic aether yielded 69 -5 and 

 70*6 per cent, of fused boracic acid by ammonia ; the acid was black 

 and contained a small quantity of charcoal disseminated through it ; 



2 A 2 



