CHEMICAL SCIENCE. 203 



to stop, SO as to retain the phenate nearly pure. The acid is now 

 separated and rectified, and soon crystallizes. As a little water 

 prevents its crystallization, Mr. Muller removes it by passing a 

 current of dry air over the phenic acid nearly boiling. 



The crystallization is facilitated by cooling, or by the introduc- 

 tion into it of a small quantity of the crystalliaed acid. 



He insists on the necessity of exposing the alkaline solution of 

 the acid for a long time, to favor the resinification and deposition 

 of the brown matters ; i^henic acid is always impure when it is 

 colored. 



It should be quite pure when employed to make picric acid, 

 because the impurities waste the nitric acid. 



Phenic acid often contains a fetid substance, which appears to be a 

 sulphuretted compound of phenyl or cresyle. It is removed by 

 rectification from oxide of lead. — From Zeitsch. fur Chem., in 

 Journ. de Pliarm., Nov., 1865. 



It was first christened carbolic acid by Runge, a German chem- 

 ist, who discovered it in 1834. But it is not properly an acid ; it 

 is not sour, does not redden litmus paper, nor does it combine 

 with alkalies any sooner than with acids ; hence the names phenol, 

 etc. 



Phenic acid, when pure, occurs in beautiful transparent needle- 

 form crystals. If the crystals be exposed to the air, in a few min- 

 utes they absorb a very small quantity of moisture, and are trans- 

 formed into an oily liquid, which is slightly heavier than water. 

 Although the solid acid is so eager for water, it is satisfied with a 

 very little, and is but slightly soluble in water. It has a burning 

 taste, and a powerful and persistent odor, which people call 

 smoky. It dissolves freely in alcohol, ether, and oils, and is 

 itself a powerful solvent of gum, resins, suljihur, and phosphorus. 

 We cannot more briefly indicate its more useful properties than to 

 say it is often called creosote, and that it is as like the genuine 

 creosote as two peas. It is a poison to all animals and plants, 

 and is especially destructive to insects and their eggs. All ver- 

 min hate the smell of it, and get away from it as fast as they can. 

 But, although it is certain death to the animal, it is kind to the 

 dead body, for it may preserve that forever ; any kind of flesh 

 which has been impregnated with jjhenic acid refuses to decay 

 and return to dust. When decay has commenced, by putrefac- 

 tion or fermentation, phenic acid will stop it instanter, and pre- 

 vent its recurrence. 



The chief source of phenic acid is gas tar, while the genuine 

 creosote is found in wood tar. Both are separated in substan- 

 tially the same way. Phenic acid is probably as powerful an 

 antiseptic as creosote, and for many purposes is a cheajD substi- 

 tute. 



When nitric acid and phenic acid are brought together, picric 

 acid, a sjjlendid dye for yellow and green on silk and wool, is the 

 result. Phenic acid, in the very crude form of gas tar and dead 

 oil, has been used for preserving timber, and by the farmers for 

 killing vermin. In the pure state it is generally known to physi- 

 cians, and is used by many of them. 



