Researches respecting the radical of Benzoic Acid. 273 



but fumes strongly upon a slight elevation of temperature. It is com- 

 bustible and burns with a bright and smoky flame. 



By water it is slowly decomposed. Warmed under the same, it 

 becomes a brownish oil, and after long boiling separates into the hy- 

 drobromic and crystallized benzoic acids. 



In alcohol and ether it is readily soluble without decomposition. 

 By dilution it may be obtained from both in a crystalline form. 



lodobenzoyl. — This compound seems not to be formed by the di- 

 rect union of its constituents. It may however readily be formed by 

 warming iodide of potassa with chloride of benzoyl. It may be dis- 

 tilled over as a brown fluid, which congeals to a brown crystalline 

 mass. It then contains iodine dissolved. In its pure state it is a 

 colorless, foliated, crystalline substance, easily fusible, but by this ope- 

 ration is always decomposed with the formation of some iodine. In 

 odor, behavior to water and alcohol, and in inflammability, it does 

 not differ from the preceding compound. 



Sulphuret of benzoyl. — This may be obtained by distilling the 

 chloride with sulphuret of lead. It passes over as a yellow oil, which 

 congeals to a yellow, soft and crystalline mass. It possesses a disa- 

 greeable odor resembling sulphur. It seems not to be decomposed 

 by boiling with water. With a boiling solution of caustic potassa, it 

 slowly forms benzoate of potassa and sulphuret of potassium. With 

 alcohol it is not decomposed. It is inflammable and burns with a 

 bright, sooty flame, evolving sulphurous acid. 



CyanobenzoyL — Hydrobenzoyl dissolves a certain quantity of cy- 

 anogen and receives also its odor, but by warming this gas may be 

 again expelled without change. 



The true compound we obtained by distilling chlorobenzoyl over 

 cyanuret of mercury. The compound passes over as a gold colored 

 oil, and mercury remains behind. 



In its pure, fresh state, the cyanobenzoyl, (cyanuret of benzoyl) is 

 a colorless fluid, but it rapidly changes to yellow. It possesses a pun- 

 gent odor, strongly exciting tears, and at a distance resembles oil of 

 cinnamon. Its taste is biting, sweetish, and afterward much like 

 prussic acid. 



It is heavier than water, in which it sinks as an oil, and by which 

 it is soon converted into benzoic and hydrocyanic acids. If a drop 

 be suffered to spread upon water, it will be found completely chan- 

 ged in a day by the sun's light into benzoic acid crystals. By boil- 

 ing with water, it is rapidly decomposed into the benzoic and prussic 



