57$ Account of New Publication}, 



nefs, and formed of the fame Subftance, but of different Denfitie?. Relative Warmth of 

 Coverings formed of equal Quantities of the fame Subftance, difpofed in different ways. 

 Experiments made with a view to determining how far the Power which certain Bodies 

 poffefs of confining Heat depends on their Chemical Properties. Experiments with Char- 

 coal, with Lamp-black, with Wood-afhes. Striking Experiments with Semen Lycopodii. 

 All thefe Experiments indicate that the Air, which occupies the Interflices of Subllances- 

 iifed in forming Coverings for confining Heat, a6ls a very important part in that operation. 

 Thofe Subftances appear to prevent the Air from conducing the Heat. An Enquiry con- 

 cerning the Manner in which this is effected. This Enquiry leads to a decifive Experiment, 

 from the refult of which it appears that Air is a perfect Non-condudlor of tieat. Tnis 

 Difcovery affords the means of explaining a Variety of interefting Phenomena in th« 

 OEconomy of Nature. 



Traite de la Sphere et du Calendrier, par Rivard, 5me Edition, revue et augmenteepar 

 Jerome Lalande, i vol. 8vo. avec Gravures, a Paris. A Treatife on the Sphere and 

 the Calendar, by Rivard, revifed and augmented by Jerome Lalande, i vol. 8vo. with 

 Plates. 



THE modern advances in Aflronomy rend ered it necefTary to make fome alterations in 

 this Work, which poffefTes a high chara£ler for Perfpicuity and Accuracy. Cit. Lalande has 

 correfted the Table of Latitudes and Longitudes, and added a Chapter on Time, befides 

 making other Improvements. 



Philofophy of Mineralogy. By Robert Townfon, LL.D. F. R. S. Edin. 8vo, 219 pages, 



with three Engravings. 



THIS performance is the outline of a larger work formerly announced, and intended to 

 have been accompanied by a colledtion of fofhls, but which did not meet with the ex- 

 peded fupport. It confifts of twelve chapters. The three firft contain an introdudlion, 

 with an account of the fimple elementary fubftances of which minerals are compofed, and 

 the laws of aggregation and combination by which they are governed. Thefe are followed 

 by an enumeration of compounds, according to Dr. Babington's excellent " Syflematic 

 Arrangement," and four chapters refpeftively treating upon Stratification, the Irregularities 

 of the Earth's Surface, Veins, and Petrifadlions. The Author then proceeds to confider the 

 value and ufe of the external charadters of Minerals ; and gives a very ample terminology, 

 confifling of the appellations in Englifh, Latin, and German, with their correfpondent de- 

 finitions, under the titles of Colour, Figure, Surface, Luflre, Texture, Struflure, Fraflure, 

 and Fragments ; Tranfparency, Scratch, Score, and Soiling ; Cohefion, AdheGon, Sound, 

 Feel, Coldnefs, Denfity, Smell, Tafte, and Friability : To which he adds the Habitudes, or 

 Refults of Experiment. Two fubfequent chapters indicate the ufe of thefe terms in Claffi- 

 fication, Defcription, and Invefligation ; with fhort Inftruftions for colledting Specimens, 

 and forming Cabinets. The concluding chapter contains a lift of near three hundred 

 works on Mineralogy. 



Proceeding! 



