CELLS. OILS. 
39 
being added to prevent it from melting too rapidly. 
This oil is contained in the cotyledons of the seeds, from 
which it may be extracted by heat and pressure ; when 
sulphuric acid is added to it, copious fumes of gas are 
evolved, and the oil turns black, it is then subjected to 
distillation, stearic acid comes over, and the residue is a 
material like black sealing-wax. This is the principle 
of Price’s patent process. Human fat is capable of 
being separated by pressure into a solid and fluid por- 
tion ; the solid principle is termed margaric acid, the 
liquid glycerine. In animals as well as in vegetables, 
the oil or fat is produced by and stored up in the inte- 
rior of closed cells. 
Castor, croton, linseed, rape, poppy, and numerous 
other oils, are examples of these vegetable fats. An oil 
expressed from the seeds of a species of Jatropho , burns 
exceedingly well in lamps, and gives a steady white light. 
It is manufactured in Bristol by Messrs. Yisger and 
Miller, and sells at four shillings per gallon; but it is 
of a poisonous nature, and cannot be even tasted with 
impunity. A bag of the nuts having accidentally burst 
on the quay at Bristol, many children picked them up 
and eat them, and in a short time numbers of 
the children were taken into the infirmary with symp- 
toms of irritant poisoning. Some of them suffered 
severely, others less so ; but I believe no fatal result 
ensued in any case. A gentleman, well skilled in the 
properties of oils, imprudently dipped his finger into a 
specimen of this oil, and carried it to his mouth, in order 
