1820.] Pht/sical Science during the Year 1819. 101 



16. Neio Nickel Ore.— This is an ore mentioned by Cronstedt 



as existing in Sweden. It has been recently described and 



"""itrcolo^u^r is lead-grey, the lustre splendent and vitreous the 

 fracture foliated; and it is composed of grauis resembling steel- 

 grained galena. It is opaque, and its specific gravity is 6-129. 

 Its constituents are : 



Nickel 24-42 



Ar^ei-:::: ^ 



a'':;;.:::::;::::::::::;::;::::!o;4^ 



93-14 

 {Annals of Philosophy/, xv. 148.) 



This historical sketch has already extended to so great a length 

 that I -find it impossible to enter into any details respecting the 

 o-eolooical facts and discussions which have been laid betore the 

 Sublic since last year. I am not aware of any new geological 

 fact of any great importance. But a good many papers have 

 been published containing interesting descriptions ot ditterent 

 parts of Great Britain and other parts of the world, ihis is ot 

 great importance towards the progress of the science. Geolo- 

 Jists will have it in their power to speculate with some chance 

 of success when they have made themselves acquainted with ail 

 the phenomena, and when every portion of the surface ot our 

 globe has been accurately examined and described. 



XV. Manufactures. 



1. New Method ofprepariiis Pharmaceutical Extracts. —This. 

 method, for which Mr. Barry has taken out a patent, consists in 

 evaporating the extracts to the requisite consistency in vacuo. 

 The advantages are, that the air is excluded, and the heat never 

 raised hi-her than 90° or 100°. The extracts m consequence are 

 much stronger, and quite different in their characters trom those 

 prepared in the usual way. The vacuum is produced by means 

 of steam. The method," which has been long laiown, will be 

 sufficiently understood by inspecting the sketch of the apparatus 

 in the Annals of Philosophy, xiv. 390. 



I have no doubt that this method is, a good one. I have 

 myself been in the habit for some years of drying vegetable 

 extracts by placing them in the exhausted receiver ot an mr- 

 pump along with a quantity of sulphuric acid. Ihis method is, 

 perhaps, still better than that of Mr. Barry. I do not know 

 whether it might not be applied to the laboratory of an apotlie- 



^^T New Method of Dr/eing lW/o?f'.-Braconnot has given the 

 following formula for dyeing with sulphuret of arsenic, which he 

 affirms to form a most beautiful and indehble yellow colour. 



