Researches respecting the radical of Benzoic Acid. 263 



venture to assert, that it would be improper to look for this in die 

 camphorid, whose very existence appears to us questionable, al- 

 though it is placed here by Dumas without a single demonstrative 

 experiment. A series of phenomena intimately connected with each 

 other was the only guide which presented itself to our view. Suffer 

 us to say that to a certainty we believe a multitude of similar radicals 

 will readily be discovered by calculation and spontaneous changes in 

 the analyses of organic substances, which chemists have undertaken; 

 but here we stop, for science is but little profited by the raising of 

 expectations, as yet unsupported by facts. 



Bitter Almond Oil. — The crude oil, which served as the materi- 

 al for our experiments possesses a faint yellow color, the well known 

 peculiar odor and proved itself in all its reactions, and other relations 

 to be a decidedly pure product. We are indebted for it to the kind- 

 ness of Mr. Pelouze. 



Treated with alkali, acid, or a salt of iron, this oil contains a con- 

 siderable quantity of prussic acid, and apart from the air, either by 

 itself or with potassa, readily changes into benzoic acid. 



We were soon convinced that the content of prussic acid bears no 

 relation to the formation of benzoic acid, and endeavored therefore 

 to obtain a pure oil, free from the benzoic and prussic acids and 

 from water. This purpose was fully accomplished in the following 



manner. 



The crude oil was carefully mixed with hydrate of potassa and a 



solution of chloride of iron by strong agitation and then submitted to 

 distillation. The whole of the oil passed over with the water, and 

 perfectly free from prussic acid. By means of a tube, it was separat- 

 ed from the water, and redistilled in a dry apparatus over freshly 

 burned, powdered chalk. 



The oil obtained in this manner is pure, free from benzoic and 

 prussic acids and water, perfectly colorless, very fluid, and has a 

 strong refractive power ; its odor is but little different from that of 

 the crude oil ; its taste is burning aromatic. It is heavier than water, 

 its sp. gr. being 1*043. Its boiling point is so high that we could not 

 determine it with our thermometers, which extended not above 130° 

 centigrade.* It is easily inflammable, burning with a bright sooty 

 flame. 



* When temperature is mentioned in this essay, the degrees will be understood to 



refer to the centigrade thermometer. — J. B. 



