396 British Association Jo?- the Advancement of Science. 



prised to find the product first condensed had a higher specific gra- 

 vity than that which succeeded to it in the distillation. The first 

 being about *900, and the second so low as *830 ; to this, if the di- 

 stillation be pushed far enough, succeed water and an oil which 

 becomes black by keeping. The fluid having specific gravity "900, 

 is a good deal coloured ; treated with animal charcoal its colour is 

 removed ; rectified from a water bath after treatment with animal 

 charcoal, its specific gravity is *911, and its boiling point about 132°. 



In this state it is colourless and inflammable : it has a powerful, 

 and to most persons a very disagreeable smell. Caustic potash de- 

 composes it instantly, acetate of potash being formed, and probably 

 carbonate of potash. Tt forms acetate of lime also when slacked lime 

 is added to it. It softens copal, but dissolves very little of it. When 

 diluted with water it does not comport itself as alcohol of the same 

 specific gravity does ; 50 measures of it mixed with 50 of water at 

 the temperature of 54, were raised in temperature to 61, and a con- 

 siderable quantity of air was extricated ; the mixture brought again 

 to the temperature of 54, measured but 96*5 measures, and its spe- 

 cific gravity was '9861. Alcohol diluted so as to have specific gra- 

 vity •911, when similarly treated, measured 98, and its specific gravity 

 was -9659. 



Litmus paper immersed in it is not reddened, but on exposure to 

 the air the fluid evaporates and leaves the paper permanently red. 



It mixes with water in every proportion, and water may be sepa- 

 rated from it by means of carbonate of potash as from dilute alcohol, 

 but which is not the case with pyroxylic spirit*. 



On the chemical constitution of Fossil Scales, as illustrative of the 



nature of the Animals from which they have been derived. By 



Arthur Connell. 



The difficulty of determining merely from external characters 

 whether a fossil scale has belonged to a fish or to a saurian animal, 

 and the geological interest which that problem frequently possesses, 

 render it desirable to know whether chemical means are capable of 

 solving it. 



Mr. Hatchett ascertained that the scales of recent reptiles consist 

 chiefly of a horny substance, whilst those of fish contain a consider- 

 able proportion of phosphate of lime, and are of the nature of bone. 

 Chevreul confirmed his observation as to fish scales ; and the author 

 has found that the scales of small recent crocodiles contained little 

 more than one per cent, of incombustible earthy matter, although in 

 the carinated dorsal scales the amount extended to about 3 per cent. 

 When fish scales are fossilized we may therefore expect that the bone 

 earth will remain, and the perishable animal substance will either dis- 

 appear without any substitution, or be wholly or in part replaced by 

 siliceous or calcareous matter; whilst, on the other hand, if a saurian 



* [There appears to be great reason to doubt whether the fluid here de- 

 scribed by Mr. Scanlan, be not merely pyroacetic spirit, retaining acetic 

 acid as an impurity.— Edit.] 



