218 



Aldehydes. 



CINNAMIC SERIES. CaHjn-ioO. 



506. CINNAMIC ALDEHYDE. C 7 H 4 0. 



a. Nearly pure. (Oil of Cinnamon.) 



b. Ditto. (Oil of Cassia.) 



507. VANILLIN. C 7 H 6 (C H 3 )0 3 . 



a. White powder, prepared from coniferin. 



Note. This specimen is some of the first introduced into this country 

 It is not pure vanillin, but contains a proportion of sugar, in which state 

 it was first offered in English commerce. Vanillin is placed here, 

 because it is regarded as the aldehyde of protocatechuic acid in which one 

 molecule of hydrogen is replaced by methyl. See Attjield, Chemistry, 

 6th edition, p. 406. 



KETONES. 



508. ACETONE. C 3 H 6 0. 



a. Colourless liquid. 



Note. For the difference between aldehydes and ketones, see Fowne$, 

 Chemistry, p. 751. 



MONOBASIC ACIDS. 

 ACETIC SERIES, CnH^ 2 . 



509. FORMIC ACID. H C H0 2 . 



a. Colourless fluid, with a pungent odour. 



b. Ditto, sp. gr. T020. 



Note. Specimen a is concentrated ; b is of the strength used in 

 medicine. 



510. ACETIC ACID. HC 2 H 3 2 . 



a. Glacial acetic acid, solid at 50 Fahr. 



b. Acidum Aceticum Fortius, B.P. 



511. BUTYRIC ACID. HC 4 H 7 2 . 



a. Colourless liquid, with a fetid odour. 



512. VALERIANIC ACID. HC 5 H 9 2 . (Valeric Acid.) 



a. Colourless oily liquid. 



513. CAPROIC ACID. HC 6 H n 2 . 



a. Colourless oily liquid, with a fetid odour. 



514. (ENANTHYLIC ACID. HC 7 H 13 2 . 



a. Colourless oily liquid. 



515. MYRISTIC ACID. HC U H 27 2 . (Myristicin.) 



a. Pearly tabular crystalline scales. 



Note. This specimen was prepared by Professor Fluckiger, from 

 crystalline matter obtained during the distillation of oil of nutmeg. 

 See P. J. [3], vol. v., p. 136; small specimens of the myristicates of 

 sodium and barium are enclosed in the same bottle. 



