134 ■ Memoir on the Nalure offal Substances. 



strongly a (inantity of annnonia, which the potash renders very 

 sensible. The adipocirous matter which remained in the cloth 

 after expression, was redissolved in warm alcohol: the mass, 

 when cooled and again squeezed, was afterwards pressed in gray 

 paper, and we obtained a white adipocire greatly resembling 

 those produced by the action of the acids on suet ; nevertheless, 

 it seems to have a greasier aspect, since it can also be reduced to 

 powder: it is also a little more fusible, since it enters into fusion 

 at 50^ R. Besides, it is dissolved with the same facility in alco- 

 hol, ether, and the alkalies; whicli we do not observe in most of 

 the fats, if it be not the adipocire of dead bodies. 



When combined with potash it produces a very hard soap, 

 which when diluted in water does not form a thick mucilage 

 like that which results from the union of the oily matter of the 

 soap of suet with potash. With anmionia it furnishes a soapy 

 emulsion, which is precipitated in large flakes by an excess of 

 ammonia, probably because the water has more afHnitv with 

 this alkali than with this ammoniacal soap : nevertheless, the 

 latter appeared to me to form a more permanent solution with 

 water than the ammoniacal soap Avith the basis of adipocire, 

 proceeding from the alteration of the suet by the acids. We 

 see that all those adipocirous substances, whether they have been 

 formed by the action of the acids or the alkalies upon suets, 

 differ among themselves by shades so slight that we may safely 

 consider them as so many varieties of one and the same species. 



Action of Potash on Spermaceti. 

 This substance, which we may regard as a species of crystalli- 

 zable suet, appeared to me to have less aptitude to saponify than 

 the other suets, which require in general a long interval of time. 

 In the soap of potash and of spermaceti, this last substance has 

 absolutely lost all its characteristic properties ; it does not cry- 

 stallize any longer, becomes infinitely more soluble in alcohol, 

 ether, and the alkalies, and partakes precisely of all the properties 

 of the adipocire formed by the action of the alkalies on the suets. 

 But what appears to me very singular is, that the spermaceti 

 did not undergo the same metamorphosis from the ajjplication of 

 the concentrated sulphuric acid, which apjjeared to have little 

 action upon it. 



Analysis of Marseilles Soap. 

 Twenty-five grammes of white soap of oil of olives, as sold in 

 the shops, and of a good consistence, were cut into thin slips, 

 and exposed to the heat of a sand-bath for several days, until it 

 became very dry and brittle. It lost by this desiccation five 

 grammes 34 centigrammes of water. It was dissolved in boiling 



water. 



