Steatites. — Germination. 283 



cameos, gems, and fmall toys, which \n point of foHdity would 

 not be inferior to thofe of the ancients. The author made a 

 feries of experiments on the method of giving a durable dye 

 to hardened fteatites, bv which it appears that it mi.y be made 

 to imitate the moft cftepmed and molt beautiful kinds of ftone. 

 In the fpecimcns of the coloured Iteatites laid before the So- 

 ciety, fume of which had heads cut on them, the members 

 admired in particular the high d«.-gree of polilh of which 

 burnt fteatites is ful'ceptible, and in which it exceeds even 

 agate. Thefe experiments are curious, and of the utmoft 

 importance to the arts. 



Profeflor J. Bartholomew Trommfdorf gave at the fame 

 time a chemical analyfis of fteatites, bv wliich it appears that 

 filiceous earth and talckv earth are the principal component 

 parts of this foflil. The profelfor, however, obferved alfo a 

 fmall mixture of argillaceous earth, wl>ich Klajjroth, during 

 his refcarches, did not find, but which, according to the 

 author, was perhaps accidental. 



Prince Demitri von Gallitzin gave an account of the expe- 

 riments which he made with different kinds of air in regard 

 to the germination of vegetables. He fowed garden-crefles 

 in thirteen kinds of air, and kept them all at an equal tem- 

 perature. The following were the refults :— ] (l, In oxvgcn 

 gas, and in air corrupted by refpiration and l)urnt bodies, 

 germination took place as well as in common air. 2d, In hy- 

 drogen gas and in carbonic acid ga«, extrael:ed from different 

 bodies, and by various procefles, there was no germination. 

 The feeds of the creffcs fwelled up a little, but in the courfe 

 of eight days there was not the fmallell fign of growth ; 

 though the feeds in atn:ofpheric and oxygen air, and air cor- 

 rupted bv refpiration, produc<;d in the lame period four leaves. 

 Atmofpheric air being adniitted into the glaffes which con- 

 tained the carbonic acid, and hydrogen gafcs, the feeds in 

 forty-eight hours threw out two leaves. From this it fcems 

 to follow, that carbonic acid aud hydrogen gafcs check 

 apd retard germination, but do not deftroy it. 3d, Nitrous 

 air deftroyed the feeds, gave them a black colour, and 

 rendered them incapable of germinaiing in other kinds of 

 4iir. 



o ^ ThU 



