fatty Substances, and on their Combinations with the Alkalis. \^ 



'treated it with boiling alcohol * we dissolved the combination 

 of potash, and a little of those of lime and oxide of iron, while 

 the latter, insoluble or much less soluble than the former, formed 

 the residue. 



I convinced myself of these facts by treating in the following 

 wav the depositions which were separated from the alcoholic 

 washings by cooling and concentration f comparatively with the 

 residue. I put some very dilute muriatic acid into two porcelain 

 capsules : to the one I added some mother of pearl substance 

 Vhich was soluble in alcohol, and to the other the residue. On 

 heating them the acid was combined with the salifiable bases, 

 and the melted fatty substance was separated from the liquid. 

 After keeping this substance in fusion in distilled water, and 

 leaving it to become solid by cooling, I added the washings to 

 the acid liquids, and evaporated to dryness. I found that 100 

 parts of soluble matter had given to the muriatic acid 0*06 of 

 lime and oxide of iron, and 8*07 of potash, while the residue 

 had given to this acid lime, oxide of iron, and a mere atom of 

 potash. 



5. The fatty substance, separated from the salifiable bases, 

 was dissolved in boiling alcohol : on cooling, it was obtained 

 crystallized and very pure, and in this state it was examined. 

 As it has not been hitherto described, it ought to be distinguished 

 from other substances by a peculiar name : consequently I pur- 

 pose to call it margarine, from the Greek word signifying pearl, 

 because one of its characters is to have the appearance of mo- 

 ther of pearl, which it communicates to several of the combina- 

 tions which it forms with the salifiable bases. 



Of Margarine, 



6. It is of a pearly white, and tasteless. Its smell is feeble, 

 and a little similar to that of white wax. It is lighter than 

 water. At 45"2-5 Reaumur it melts into a very limpid colourless 

 liquid, which crystallizes upon cooling into brilliant needles of 

 the finest white. 



.7. When we distilled it, it melted, and exhaled a white vapour 

 which weis deposited in a farinaceous-like matter in the neck of the 

 retort. It boiled, and soon afterwards emitted an invisible vapour, 



* A process somewhat similar has been adopted in this country to make 

 what is called " transparent soap."— Translator. 



t Every washing was separated from its deposition, and the filtered li- 

 quor was concentrated to two-thirds its primitive volume, afterwards cooled 

 and filtered. The depositations in the filter were washed with cold alcohol, 

 then pressed in Joseph paper, and by this means I obtained the mother of 

 pearl substauce in a state of purity. 



N 2 which 



