108 KETONES. 



PTT3 } 



Ordinary valeric aldehyde, C 5 H 10 = 3 1 CH.CH 2 . 



CHO. Colorless liquid, of a pleasant, fruity, slightly 

 suffocating odor ; specific gravity, 0.822 at ; boiling 

 point, 92.5. 



6. Caproic aldehyde, C 6 H 12 0. Liquid of a disagree- 

 able odor; boiling point, 121. 



7. CEnanthylic aldehyde (oenanthol), C 7 H 14 0. Is most 

 readily obtained by dry distillation of castor oil. The 

 aldehyde is separated from the distillate by the process 

 above described. Liquid, of an unpleasant odor ; spe- 

 cific gravity, 0.827 ; boiling point, 152. 



8. Palmitic aldehyde, C 16 H 32 0. From cetylic alcohol. 

 "White, indistinctly crystalline mass ; fusing point, 

 46-47. 



E. KETONES (ACETONES). 



Ketones are compounds, which consist of two 

 monovalent hydrocarbon groups, held together by the 

 bivalent group (CO). They stand in close relation to 

 the aldehydes, and can be considered as aldehydes, in 

 which the hydrogen-atom of the group COH is re- 

 placed by a monovalent residue of hydrocarbon. They 

 are produced by careful oxidation of the secondary 

 alcohols, the group CH.OH, common to these alcohols, 

 being hereby converted into CO, by a loss of two 

 hydrogen atoms ; further, by subjecting the salts of 

 the fatty acids to dry distillation, by the action of 

 zinc methyl, zinc ethyl, etc., on acetyl chloride and 

 the homologous chlorides, etc. Most of them form 

 crystallizing compounds with the bisulphides of the 

 alkalies. Nascent hydrogen converts them into secon- 

 dary alcohols (the group CO being changed to CH.OH). 

 When oxidized with potassium bichromate and sul- 

 phuric acid, they are resolved into simpler compounds, 

 in the following manner. One of the hydrocarbon 

 residues (where the residues are different, that which 



