SCIENTIFIC NEWS. 
First or Millstone grit. The average thickness of this rock 
is aboitt 140 yards. It is generally a white or yellowish coarse 
grained freestone in thick beds ; but at the upper part of the 
rock is a considerable thickness of soft micaceous thin beds. 
Its organic remains are large reeds and flags, and occasionally 
corralloids of a hone-like appearance. 
Coal Formation. This lies on the Milstone grit, and consists 
of eighteen beds of grit and of shale, the aggregate thickness 
of which is JOQ yards, and presents the usual characters of 
the independent coal formation. 
Abridged Account , or Abstract of the “ Elements of Crystal- 
lography, by F. Accum,” in 1 vol. Svo. Fp. 391, with 4 
copper plates and numerous wood cuts. Longman and Co. 
THIS author in his preface remarks, that considering how 
much the philosophy of the mineral kingdom has of late been 
advanced and perfected, by the application of Haiiy’s theory, 
and the light it has thrown on some of the most obscure 
branches of Mineralogy, it is surprising that no English work on 
the structure and formation of crystals has yet appeared ; whilst 
on other departments of the science of minerals, many excel- 
lent works have been published. He offers the present Treatise 
for the purpose of initiating into the principles of crystallo- 
graphy, those who possess no previous knowledge of it. 
As the theory which explains the production of crystalline 
forms, aud their metamorphoses, abounds in mathematical and 
algebraic calculations, and cannot be studied with ease and 
success, by such as are unacquainted with the mathematics $ 
he has thought it desirable, as has before been announced in this 
Journal, to prepare sets of models to which reference is made in 
this work. 
The dissected models, are so constructed, that they can readily 
be taken to pieces, and put together again in various ways, to 
give a distinct conception of the laws of that geometry of 
nature which are followed by the integrant particles ofcrystallis- 
able 
