234 



FAT. 



dissolves in the fat and volatile oils, and is in 

 part deposited as the solution cools. Alcohol 

 always extracts a small portion of oil from the 

 spermaceti of commerce ; as the boiling alco- 

 holic solution cools, it deposits the purified 

 spermaceti in white crystalline scales, and in 

 this state, Chevreul terms it cetine. Cetine 

 does not fuse under 120; it forms, on cooling, 

 a lamellar, shining, inodorous, and insipid 

 mass, which is volatile at high temperatures, 

 and may be distilled without decomposition. 

 It burns with a brilliant white flame, and dis- 

 solves in about four parts of absolute alcohol ; 

 it is very difficultly saponified ; digested for 

 several days at a temperature between 120 and 

 1 90, with its weight of caustic potassa and two 

 parts of water, it yields margarate and oleate of 

 potassa, and a peculiar fatty matter, which 

 Chevreul calls ethal* and which amounts to 

 about 40 per cent, of the cetine used. To ob- 

 tain it in an insulated state the results of 

 the saponifi cation of cetine are decomposed by 

 tartaric acid, which separates the margaric and 

 oleic acid, together with the ethal ; the fat 

 acids are saturated with hydrate of baryta, and 

 the resulting mixture well washed with water 

 to separate all excess of base ; it is then well 

 dried, and digested in cold alcohol or ether, 

 which takes up the ethal and leaves the barytic 

 salts ; the former is then obtained by evapora- 

 tion of the solvent. Ethal is a solid, transpa- 

 rent, crystalline, fatty matter, without smell or 

 taste; when melted alone it congeals at 120 

 into a crystalline cake ; it is so volatile that it 

 passes over in vapour when distilled with water. 

 It burns like wax, and is soluble in all propor- 

 tions in pure alcohol at a temperature below 

 140. It readily unites by fusion with fat and 

 the fat acids, and when pure is not acted upon 

 by a solution of caustic potassa; but if mixed 

 with a little soap it then forms a flexible yel- 

 lowish compound, fusible at about 145, and 

 yielding an emulsive hydrate with boiling 

 water. 



The ultimate composition of train oil, sper- 

 maceti oil, spermaceti, cetine, and ethal, are 

 shewn in the following tables : 



TRAIN OIL. SPERMACETI OIL. 



Berard. Ure. 



Carbon 76.1 79.0 



Hydrogen.. 12.4 10.5 



Oxygen.... 11.5 10.5 



100.0 100.0 



SPERMACETI. CETINE. 



Berard. Chevreul. 



Carbon 79.5 81.660 



Hydrogen.. 11.6 12.862 



Oxygen.... 8.9 5.478 



100.0 100.000 



* From the first syllables of the words ether and 

 alcohol, in consequence of a resemblance in ultimate 

 composition to those liquids. 



1 128 100.00 100.000 



9. Phocenine is a peculiar fatty substance 

 contained in the oil of certain species of por- 

 poise (Delphinus phocena and globiceps). 

 When this oil is saponified, it yields margaric 

 and oleic acid and cetine, and a peculiar vola- 

 tile acid obtained by a process similar to that 

 for separating hircic acid, and which has been 

 termed phocenic acid* It is a thin, colourless, 

 strong-smelling oil, of a peculiar acrid, acid, 

 and aromatic taste; its specific gravity is .932 ; 

 it does not congeal when cooled down to 14. 

 Its boiling point is above 212. In this state 

 it is an hydrate, containing 9 per cent, of water, 

 from which it has not been freed. It is solu- 

 ble in all proportions in pure alcohol. 



The neutral salts of this acid (phocenates) 

 are inodorous, but any free acid, even the car- 

 bonic, in a gentle heat, evolves the odour of the 

 phocenic acid. Heated in the air they exhale 

 an aromatic odour, dependent upon the forma- 

 tion of a peculiar product. By dry distillation 

 they blacken, evolve olefiant gas and carbonic 

 acid, and a thin, odorous, yellow oil, insoluble 

 in potassa. The phocenates of potassa, soda, 

 and ammonia, are deliquescent ; the phocenate 

 of baryta forms efflorescent prismatic crystals ; 

 and that of lime, small acicular prisms. The 

 neutral phocenate of lead, evaporated in vacuo, 

 yields flexible lamellar crystals, which are 

 fusible and easily become basic when heated ; 

 the subphocenate of lead is difficultly soluble 

 and crystallisable, and decomposed by the car- 

 bonic acid of the air. 



According to Chevreul, the anhydrous pho- 

 cenic acid (as existing in its anhydrous salts) 

 consists of 



Experiment. 

 65.00 



Atoms. Equivalents. Theory. 



Carbon.. 10 60 65.93 



Hydrogen 7 7 7.69 825 



Oxygen.. 3 24 26.38 26.75 



91 100.00 100.00 



And the oily hydrated acid is a compound of 

 1 atom of dry acid and 1 atom of water, or 

 91 4- 9 = 100. 



10. The fat of birds has been but little exa- 

 mined ; Chevreul states that the fat of geese 

 concretes after fusion at about 80 into a gra- 

 nular mass of the consistency of butter. Ac- 

 cording to Braconnot it yields by pressure at 

 32, 0.68 of yellowish elain, having the odour 

 and taste peculiar to this kind of fat, and 0.32 

 of stearin, fusible at 110, and soluble in rather 

 more than three parts of anhydrous alcohol. 

 When saponified, it yields margaric and oleic 

 acid and glycerine. 



* The same acid is contained, according to 

 Chevreul, in the ripe berries of the Viburnum opulus. 



