VOL. LXX.] PHILOSOPHICAL TRANSACTIONS. 667 



the volatile alkali, yielded neutral salts possessing peculiar properties; Dr. Crell 

 was induced to make the following experiments, with the view of ascertaining 

 more exactly the constituent parts of fat, and the nature and properties of the 

 acid extracted from it. 



Exper. 1. He took Ibij. of beef suet, previously melted and strained. With 

 this he filled a glass retort half full, and having applied a receiver and well luted 

 the vessels together, he subjected the suet to distillation in a sand bath. At first 

 there came over a thin oil, which remained fluid, next an acid which settled at 

 the bottom of the receiver, and at the same time an oil which congealed imme- 

 diately as it fell by drops into the receiver. It required l6 hours, and a very 

 strong heat towards the end, before the distillation of all the fluid matter was 

 effected. When the vessels had become cold, most of the oil was found con- 

 gealed, and on loosening the receiver, there came forth an intolerable stench, 

 which irritated the eyes and nose to such a degree as nearly to occasion suffoca- 

 tion. The fluid part being poured oft', it weighed 3i oz. and J- scr. and con- 

 sisted of 2 different kinds of liquid, (separated by means of a funnel) namely, a 

 greenish oil, of the colour of oil of wormwood, weighing 1 oz. 7 dr. 2 scr. and 

 a heavier acid liquor of a gold colour, extremely pungent, and weighing 1 oz. 

 34- dr. The congealed or concrete oil vvliich formed the other part of the pro- 

 duct, and which resembled hog's lard, had still a pungent smell, which was not 

 proper to it, but was owing to the acid from which it could not be totally freed. 

 There remained in the retort a coally matter, which weighed 1 oz. 4-i- dr. 



Exper. 2, 3, 4, 5, 6, 7, 8, Q. In these experiments the coagulable oil was rec- 

 tified by repeated distillations, during which the oily and acid products acquired 

 different shades of yellow, orange, and red; and in one experiment there escaped 

 through the luted joinings of the vessels, an inflammable vapour. 



Exper. 10. The whole of the fluid matter extracted by distillation from the 

 suet was found to consist of 3 oz. 5 dr. of a bright gold coloured acid, and 214 

 oz. of reddish brown oil. If to this weight, viz. 25 oz. 1 dr., of the fluid pro- 

 ducts, be added the weight of the coally residue, viz. 5 oz. 2 scr., collected in 

 the different processes, the loss from the whole quantity of suet operated on, 

 amounts to 1 oz. 6 dr. 1 scr. 



Exper. 11 . It not being possible, as Professor Segner had remarked, to sepa- 

 rate by mechanical means, the whole of the acid from the oil; Dr. C. for this 

 purpose added to the whole quantity of oil he had obtained an equal quantity of 

 water, and then subjected the mixture to a digesting heat, shaking the vessel 

 frequently; after which he found that the water had acquired an acid taste, and 

 effervesced with an alkali. This he repeated until the water ceased to taste sour, 

 or to effervesce on the addition of an alkaline salt. 



> Q 2 



