50 F. F. Runge on the Products [Jan. 



Carbolic acid dissolves in water. The solution is colour- 

 less and the acid is easily rendered conspicuous with nitric 

 acid. The water is at first yellow or orange, and afterwards 

 reddish brown ; a stick of fir plunged in dilute carbolic 

 acid, takes after being moistened with muriatic acid in half an 

 hour, a blue colour. The vapour of muriatic acid also tinges 

 shavings moistened with carbolic acid of a blue colour. 

 This tinge withstands the action of chlorine in a high degree. 



The salts of carbolic acid are colourless, and many of 

 them can be crystallized ; their aqueous solutions present 

 the same appearances with fir as the solution of carbolic 

 acid. Carbolic acid precipitates albumen, prevents organic 

 substances from putrifying, and removes the putrid smell 

 of meat when digested with an aqueous solution, much 

 better than chlorine. The presence of carbolic acid may be 

 detected in coal oil by mixing it with lime water, filtering 

 and evaporating to the consistence of a syrup. Muriatic 

 acid separates impure carbolic acid from this mass, which is 

 impure carbolate of lime. 



2. Rosolic Acid. 



This acid (rose oil) is a product of the chemical decom- 

 position of coal oil, and contains what is remarkable, a 

 true pigment. It produces red and lake colours which are 

 equal in beauty to saffron, cochineal and madder. 



Rosolic acid is a resinous mass which may be reduced to 

 powder, and assumes an orange yellow colour. 



The principle from which rosolic acid is formed has not 

 yet been detected ; but its presence may be easily demon- 

 strated by mixing lime water with coal oil, filtering the 

 watery solution, and allowing it to stand for some hours. 

 The colourless or yellow solution now becomes red ; which 

 is occasioned by the precipitation of the rosolate of lime. 



3. Brunolic Acid. 



Brunolic acid is formed in the same way as the rosolic. It is 

 vitreous, shining, easily pulverized, and resembles asphal- 

 tum. Most of the compounds of brunolic acid are brown 

 and insoluble, while those of rosolic acid are red and soluble. 



Besides these six substances, there is still another which 

 has not been obtained in a separate state. 



