200 ANNUAL OF SCIENTIFIC DISCOVERY. 



vegetable earth. The mixture is repeatedly stirred about with a 

 shovel, and may at once be brought upon the fields. Manm-e 

 prepared thus will contain about 12 per cent, of tribasic phosphate 

 of lime (3 CaO, PO5 ), 2 per cent, of nitrogenous matter. This 

 manure must, from its composition, produce an admirable effect 

 upon grape-vines. Liebig, in generally recommending this new 

 fertilizer, thinks an addition of gypsum an improvement for many 

 kinds of fruits. — Agricultural Report. 



CRYSTALS CONTAINING FLUID. 



Mr. J. B. Dancer lately read a paper before the Literary and 

 Philosophical Society, of Manchester, England, containing a brief 

 history of the discovery of fluids in crystals, including Sir H. 

 Davy's chemical experiments on the fluids and gases obtained 

 from the cavities in quartz crystals ; Sir David Brewster's discov- 

 ery of the pressure cavities in the diamond, ruby, emerald, ame- 

 thyst, chrysoberyl, etc. ; the existence of minute crystals in these 

 cavities and the two new and remarkable fluids, which are immis- 

 cible, but sometimes found together in the same cavity — one a 

 liquid hydrocarbon, named Brewstoline, the other Cryptoline; 

 his experiments and examinations of artificial crystals deposited 

 from aqueous solutions ; his examination of the Koh-i-noor dia- 

 mond and others in the East India Company's museum ; and the 

 geological speculations to which these discoveries gave rise. 



Mr. Dancer mentioned the experiments of his late father and 

 others in producing artificial gems by intense heat, and stated that 

 his own attention %vas drawn to this subject some 24 years since 

 by Sir David Brewster presenting him with a specimen of topaz 

 containing fluitl. Since that time he had examined a larofe num- 

 ber of crj'stals of various kinds, and had found fluid in quartz 

 from South America, Norway, the Alps, Ireland, Snowdon, and 

 the Isle of Man ; and in fluor-spar from Derbyshire. This latter 

 specimen contained a considerable quantity of fluid, which burst 

 the crystal at 180° temperature. [After this paper was written. 

 Sir David Brewster informed the author that the fluid contained in 

 crystals of fluor-spar was water, and that the cavities burst at a 

 temperature of 150°.] He suggested the employment of the micro- 

 scope as a valuable assistance in detecting spurious from real 

 gems. Very few of the latter are perfect, and the flaws and cavi- 

 ties are so distinct in character from those which are so abundant 

 generally in artificial gems that very little experience is sufficient 

 for the purpose. This mode of testing of course is limited to 

 transparent crystals, but might be emplo3'ed when the usual 

 methods are not practicable. He also mentioned Mr. Sorby's dis- 

 covery of fluid cavities in the quartz of granite, in the quartz of 

 volcanic rocks, and also in the feldspar ejected from the crater of 

 Vesuvius, and Mr. Sorby's method of determining the tempera- 

 ture at which various rocks and minerals are formed. At the 

 conclusion of the meeting, crystals containing fluid wore exhibited 

 under the microscope, and the expansion of the fluid by elevating 



