the Amorphism of' Solid Bodks. 2T5 



which is the form we also assign to all liquids, and which per- 

 haps may not improperly be termed the mother Jhrm of the 

 corporeal world. Amorphous compact bodies have in fact, apart 

 from their solidity, a strong resemblance to liquids, and I would 

 name them solid liquids, if this were not, according to our present 

 notions, a contradictio in adjecto *. 



The following additional remarks, by Professor Fuchs, on the 

 subject of Amorphism, are extracted from a recent number of 

 PoggendorfTs Annals. 



•■' I have already stated it to be my opinion that flint is a mix- 

 ture of quartz and opal. In order to ascertain this, several thin 

 fragments were exposed for ten minutes to the action of concen- 

 trated solution of potash. They became white and opake, but 

 had not lost more than 1.7 per cent, in weight. Powdered flint, 

 boiled half an hour with diluted solution of potash, lost 7.5 per 

 cent, silica, which was dissolved by the potash. It is thus proved 

 that flint really contains opal, but less than calcedony. It is evi- 

 dent that no constant relation is here to be expected. 



" Compact quartz is therefore to be divided into that containing 

 opal, and that which contains no opal. To the former belong 

 flint and calcedony and the substances connected with them, and 

 to the latter cacholong, hornstone, flinty slate, &c. In many 

 sandstones, opal seems to be present as a cementing material.'" 



Remarks on the Nature of' the Evidence in support of a Theory 

 of Light. By the Rev. Baden Powell, M. A., F. R. S., 

 Savilian Professor of Geometry, Oxford. Communicated 

 by the Author. 



" Omnis enim philosophiae difficultas in eo vestari videtur, ut a phjenome- 

 uis motuum iiivestigemus vires naturae : deinde ab his viribus demonstreruus 

 phaenotnena reliqua." — Newtox, Princip. PrcBf. 



The phenomena of optics, until a very recent period, have 

 been by no means sufficiently extended or matured to offer a le- 

 gitimate field for the speculations of theory. Theories, how- 



• From Sekweigger.SeideVs Sieves Jahrbueh der Chemie und Physik, vol. vii. 

 |>. 418. 



