H4 Notices respecting Neio Books. 



*' From the above table it appears, that tlie proportion of il- 

 luminating power between gas from lamp oil, and gas from Can- 

 nel coal, by the common method of operation and the mean time 

 of the distillation, is as 190 to 170, and from common coal as 

 190 to 140." 



We only add one remark. To increase the product of a chal- 

 dron of coals from 10,000 to 25,000 cubic feet, and at the same 

 time of a superior quality, is incomparably the greatest improve- 

 ment that has yet been made since gas was introduced for the 

 purpose of general illumination. 



u4n Introduction to Solid Geometry, and to the Study of Crys- 

 tallography, containing an Investigation of some of the PrO' 

 perties belonging to the Platonic Bodies independent of the 

 Sphere. By N. J. Larkin, M. G. S. Teacher of Crystallo- 

 graphy and Mathematics. Illustrated with four jjlates from ori - 

 ginal drawings by the Author. 8vo. pp. 140. 

 The work under consideration contains a description of a va- 

 riety of solids hitherto uimoted, and a number of new and re- 

 markable j)roperties of those solids that have been long known. 

 In tracing the properties of the Platonic bodies, the author shows 

 that thev naturally divide themselves into two series, each con- 

 sisting of five solids ; and what is remarkable, that each individual 

 solid, in one of the series, is to be fomid in great abundance 

 among crystals, whereas not a single individual in the other se- 

 ries has ever been found among such productions. The first he 

 calls the natural; the other, the artificial series. These two se- 

 ries bear a strong resemblance to each other; inasmuch as the 

 last in each series contains all the foregoing in the same series : the 

 angular points of the contained solids may l)e traced out in the 

 surface of the last solid; and what perhaps is equally remarkable, 

 is, that the whole of the solids, composing the natural series, are 

 commensuraljle with each other when tiie first four are contained 

 in the last, and that thev are to each other as the numbers I, 3, 4, 

 6, and 8. There is another solid whose extremities may be traced 

 out in tlie surface of the last of the natural series ; which solid 

 the author calls a cuboctahedron on account of its being inter- 

 mediary between tlie cube and the octahedron : this solid, though 

 it is commensurable with the rest, is not so simple, being as 5 -^^ : 

 consequently it is somewhat less than the fourth, being to it as 

 80: SI. The author has combined the solids belonging to the 

 natural scries in pairs, in every possible manner, and given the 

 ratiosof their volumes in two tables : he has likewise given the ra- 

 tios of a number of remarkable lines in or upon these solids, and 

 has shown how each may be extracted from the others. The ratios 

 between the members of the artificial series appear to be incom- 

 mensurable^ 



