SALICYL. 871 



crystalline yellow powder, C 42 H 25 C1 4 O 22 , produced at the ordi- 

 nary temperature ; the other formed about 140, a red oily 

 liquid, C 42 H 18 C1 7 18 . 



Rutilin. This name is applied by Braconnot to the product 

 of the decomposition of salicin by sulphuric acid. Alkalies 

 change its tint to a deep purple. 



SECTION II. 



SALICYL SERIES OF COMPOUNDS. 



Salicyl, C 14 H 5 O 4 =Sa ; the hypothetical radical of salicylous 

 acid, salicylic acid and some other compounds : equivalent to 

 benzoyl plus 2 atoms of oxygen.* 



Salicylous acid, spiro'iihydric acid, H + C 14 H 5 O 4 H,Sa. This 

 substance was obtained by M. Piria by distilling salicin with 

 dilute sulphuric acid and bichromate of potash, and has been 

 shewn by Dumas and by Ettling to be the principal constituent 

 of the oil obtained by Pagenstecher by distilling the flowers of the 

 Queen of the meadow (spiraea ulmaria), and which M. Lcewig had 

 analysed and described under the name of spiroilhydric acid. 



The proportions lately recommended by Dr. Ettling for 

 preparing salicylous acid from salicin are : 



3 parts of salicin 



3 parts of bichromate of potash 



4j parts of concentrated sulphuric acid 



36 parts of water. 



* The name salicyl was applied by Dumas and Piria to this hypothetical 

 radical, which was viewed as a higher degree of oxidation of benzoyl. The oil of 

 spiraea ulmaria, or salicylous acid, is represented as the hydruret of this radical, 

 which also exists in couibination with potassium, &c., iu the salicylites. An objec- 

 tion to and source of some confusion attending this view is that it represents 

 salicyl as a salt radical or halogen body, combining directly with metals, and not 

 as a basyle, like benzoyl, ethyl, and the other radicals with which it is associated. 



M. Liebig points to an explanation of the isomerism of salicylous and benzoic 

 acids and their salts, in the circumstance that while benzoic acid is monobasic, 

 salicylous acid may have its equivalent multiplied by 2 or by 3, and be a bibasic 

 or u tribasic acid. This supposition, however is not supported by the density 



