370 CONSIDERATION OF CARBON COMPOUNDS. 



sides cresol, C 7 H 7 OH, and other substances. It is a reddish-brown 

 liquid of a strongly empyrenmatic and disagreeable odor. 



By fractional distillation of the crude carbolic acid, the pure acid 

 is obtained, which forms colorless, interlaced, needle-shaped crystals, 

 sometimes acquiring a pinkish tint ; it has a characteristic, slightly 

 aromatic odor, is deliquescent in moist air, soluble in from 15 to 20 

 parts of water, and very soluble in alcohol, ether, chloroform, glycerin, 

 fat and volatile oils, etc. ; it has, when diluted, a sweetish and after- 

 ward burning, caustic taste; it produces a benumbing and caustic 

 effect, and even blisters on the skin ; it is strongly poisonous, and a 

 powerful antiseptic agent, preventing fermentation and putrefaction 

 to a marked degree ; fusing-point about 35 C. (95 F.), boiling- 

 point 188 C. (370 F.), specific gravity 1.065. 



Phenol, though generally called carbolic acid, has a neutral or but 

 faintly acid reaction, and the constitution of an alcohol, but it readily 

 combines with strong bases, for instance, with sodium, forming 

 sodium phenoxide or sodium phenolate : 



C 6 H 5 OH + NaOH = C 6 H 5 ONa + H 2 O. 



Phenol obtained by synthetical processes is now sold in a state of 

 great purity ; it has comparatively little odor. 



As antidotes may be used olive oil or castor oil, a mixture of both, or a mix- 

 ture of magnesia and oil. 



Tests for carbolic acid. 



(Use an aqueous solution.) 



1. It coagulates albumin and collodion. 



2. It colors solutions of neutral ferric chloride intensely and per- 

 manently violet-blue. (Plate VI., 1.) 



3. Bromine water produces, even in dilute solutions, a white pre- 

 cipitate of tri-brom-phenol, C 6 H 2 Br 3 OH. 



4. A fresh-cut slip of pinewood moistened with carbolic acid, and 

 then exposed to hydrochloric acid fumes, turns blue on exposure to 

 sunlight. 



5. On heating with nitric acid it turns yellow, picric acid being 

 formed. 



Creosote, Creosotum. This is a liquid product of the distilla- 

 tion of wood-tar, especially of beechwood-tar, which contains some- 

 times as much as 25 per cent, of creosote ; it resembles carbolic acid 

 in many respects, especially in its antiseptic properties and its action 



