FAT. 



233 



FAT. ELAIN. 



Carbon........ 79.000 78.566 



Hydrogen 11.416 11.447 



Oxygen 9.584 9.Q87 



100.000 100.000 



3. The fat of beef when melted begins to 

 concrete at 100: it requires for solution 40 

 parts of boiling alcohol, and contains about 

 three-fourths its weight of stearin, which is 

 obtained by stirring the melted fat whilst it is 

 concreting, and then pressing it in woollen 

 cloths at a temperature of about 95, by which 

 the elain is squeezed out, together with a por- 

 tion of stearin, which is deposited at a lower 

 temperature, for the elain does not congeal at 

 32. The stearin is white, granularly crystal- 

 line, fusible at 112, and may be cooled to 100 

 before it congeals, when its temperature rises to 

 112. It looks and burns like wax. 100 parts 

 of alcohol dissolve 15 of this stearin : when 

 saponified, it yields 0.95 of fat acids, which 

 fuse at 130. The elain of beef fat is colour- 

 less and almost inodorous, and soluble in less 

 than its weight of boiling alcohol. Candles 

 made of the stearin of this fat, with a small 

 addition of wax to destroy its brittle and crys- 

 talline texture, are little inferior to wax candles. 



4. Neat's foot oil is obtained by boiling the 

 lower ends of the shin-bones of the ox, after the 

 removal of the hair and hoofs, in water. This 

 oil remains fluid below 32, and after the sepa- 

 ration of the stearin, is used for greasing turret- 

 clocks, which are often so exposed to cold as to 

 freeze other oils. 



5. Goafs fat is characterized by its peculiar 

 colour, which seems to depend upon the pre- 

 sence of a distinct fatty matter, which, in the 

 separation of the stearin and elain, is asso- 

 ciated with the latter, and which Chevreul has 

 called hircin. When the elain is saponified, 

 a liquid volatile acid is formed, which may be 

 separated as follows : four parts of the fat are 

 made into soap with one of hydrate of potassa 

 dissolved in four of water : the soap is after- 

 wards diluted, and decomposed by phosphoric 

 or tartaric acid, by which the fat acids are sepa- 

 rated : these are distilled with water, taking 

 care that the contents of the retort do not boil 

 over : the distilled liquid is saturated with 

 hydrate of baryta, evaporated to dryness, and 

 decomposed by distillation with sulphuric acid 

 diluted with its weight of water : the acid is 

 separated in the form of a colourless volatile 

 oil which floats upon the distilled liquid ; 

 Chevreul terms it hircic acid: it congeals at 

 32: it has the odour of the goat, blended 

 with that of acetic acid ; it reddens litmus, 

 dissolves difficultly in water, and readily in 

 alcohol : it forms distinct salts with the bases : 

 the salt of ammonia has a strong hircine 

 odour : that of potassa is deliquescent, and that 

 of baryta difficultly soluble in water. 



6. Mutton fat is whiter than that of beef, 

 and acquires a peculiar odour by exposure to 

 air ; when melted it begins to concrete at about 

 100. It requires 44 parts of boiling alcohol 

 for solution. Its stearin, when fused, begins 



to congeal at 100, and its temperature rises on 

 solidification to 113. 100 parts of alcohol 

 dissolve 16 of it. Its elain is colourless, 

 slightly odorous, sp. gr. 0.913, and 80 parts of 

 it are soluble in 100 of boiling alcohol. When 

 saponified, it yields a very small quantity of 

 hircic acid. This species of fat, together with 

 its stearin and elain, are composed as fol- 

 lows : 



FAT. STEARIN. ELAIN. 



Carbon 78.996 78.776 79.354 



Hydrogen .l 1.700 11.770 11.090 

 Oxygen .... 9.304 9.454 9.556 



100.000 100.000 100.000 



7. Whale oil, or train oil, (from whale blub- 

 ber,) sp. gr. .927, when cooled to 32, deposits 

 stearin ; the filtered oil is then soluble in 0.82 

 of boiling alcohol. Aided by heat it dissolves 

 arsenious acid, oxide of copper, and oxide of 

 lead ; sulphuric and muriatic acids render the 

 latter combination turbid, nitric acid tinges it 

 dark brown with effervescence ; and it is coa- 

 gulated by potassa and soda. This oil is easily 

 saponified when mixed with 0.6 its weight of 

 hydrated potassa, and five parts of water ; the 

 soap is brown, soluble in water, and when de- 

 composed by tartaric acid and the sour liquid 

 distilled, it yields traces of phocenic acid, also 

 glycerine, and oleic and margaric, but no 

 stearic acid : these acids are accompanied by a 

 greasy substance which has the odour of the 

 oil. The stearic portion of train oil, when 

 freed from adhering elain by washing with 

 weak alcohol, concretes, after having been fused, 

 at a temperature between 70 and 80; it is 

 soluble in 1.8 parts of boiling alcohol, and is 

 deposited in crystals as it cools, leaving a dark 

 thick mother-liquor. When saponified, 100 

 parts yield 85 of margaric and oleic acids, 4 of 

 a brown substance infusible at 212, and per- 

 fectly soluble in boiling alcohol, 7 of bitterish 

 glycerine, and traces of phocenic acid. 



8. Spermaceti oil, the produce of the sper- 

 maceti whale,* is lodged in the cartilaginous 

 cells of a bony cavity on the upper part of the 

 head ; as it cools, it deposits its peculiar stearic 

 portion in the form of spermaceti; this sub- 

 stance is further separated by pressure in wool- 

 len bags from the oil, and is then washed with 

 a weak solution of caustic potassa, melted in 

 boiling water, and strained; it is commonly 

 cast into oblong blocks, and if the interior 

 liquid portion is drawn off when the exterior 

 has concreted, the cavity exhibits upon its sur- 

 faces a beautiful crystalline texture. Sperma- 

 ceti, as it occurs in commerce, is in semi-trans- 

 parent brittle masses of a foliated fracture, and 

 soapy to the touch ; it has a slight odour and a 

 greasy taste, and when long kept becomes yel- 

 lowish and rancid. Its specific gravity is .943 ; 

 it fuses at about 114. 100 parts of boiling 

 alcohol, sp.gr. .823, dissolve 3.5 spermaceti, 

 and about 0.9 is deposited on cooling. Warm 

 ether dissolves it so copiously, that the solution 

 concretes on cooling; by the aid of heat, it 



* Physeter macroccphalus, or Cachalot. 



