136 OILY OXIDES, SAPONIFIABLE. 



lard. And this is the case. The stearin constitutes about thre e- 

 fourths of ox tallow. It is now separated on a great scale to be 

 manufactured into candles. The method employed is to melt 

 the tallow, and to stir it incessantly while in the act of congeal- 

 ing. It is then exposed to pressure in woollen cloths at the 

 temperature of 95. The elain forced out still retains a consi- 

 derable quantity of stearin. This elain is cooled flown a few de- 

 grees below 95, and subjected to pressure again, by which an 

 additional portion of stearin is obtained. And this process is re- 

 peated sinking the temperature every time, till at last it is re- 

 duced as low as 36. At last an elain is obtained, which is quite 

 liquid, and which does not become solid though cooled down se- 

 veral degrees below 32. 



The stearin thus obtained is white, granular, and crystalline. 

 It melts at 111, and may be cooled down to 102 before it be- 

 gins to congeal ; but then the temperature rises to 1 1 1, and con- 

 tinues so till the whole stearin is congealed. This stearin has 

 about the same translucency as white wax. Its feel is not greasy, 

 and it burns with a light similar to that of wax ; 100 parts of 

 absolute alcohol at the boiling temperature dissolve 15-48 parts of it. 



The elain from ox fat is colourless, and almost without smell. 

 Its specific gravity is 0-913. 100 parts of absolute alcohol dis- 

 solve 123-4 of it at the temperature of 167. 



Candles made of the stearin of ox tallow are little inferior to 

 wax candles. The stearin being brittle and apt to crystallize, it 

 has been found necessary to mix it with a little white wax, in 

 order to deprive it of these qualities. 



There is an oil obtained from the feet of oxen, and therefore 

 known in this country by the name of Neat's Foot Oil, which de- 

 serves to be noticed. It remains liquid though cooled down to 

 below 32, and therefore is used very much to oil machinery, in 

 order to diminish friction. 



To obtain it tlie hair and hoofs are removed, and the inferior 

 part of the bone of the foot being rasped down is boiled in water 

 together with the surrounding parts. The oil swims on the sur- 

 face of the water. It is nearly colourless, and may be kept a con- 

 siderable time without alteration ; but at last it deposites some 

 solid matter having the aspect of stearin. 



3. MUTTON SUET. 



This is the name by which the fat of the sheep (Ovis aries) 



