CHEMISTRY. 221 



Lately, Prof. Siramler, of Switzerland, has added a new theory 

 to the many existhig ones. The diamond often incloses cavities, 

 which in some instances contain a gas, in otliers a liquid. Sir 

 David Brewster, who had given much attention to the suliject, 

 ibnnd, in investigating the nature of the liquid, that its refractive 

 power is less, but its expansive power greater, than that of water. 



In comparing the results obtained by Brewster with tiiose calcu- 

 lated for other liquids, Simmler found the numbers for the expan- 

 sive and refractory power of the liquid referred to, to coincide; 

 singularly with those for liquefied carbonic acid. But other facts, 

 observed by different savans, tend to prove also the presence of 

 this agent in the coating of the most valuable of gems. We men- 

 tion the bursting of such crystals, when exposed to heat, the fre- 

 quent occurrence of two liquids in the cavities, wherefrom the one 

 behaves like water towards heat and light, and the other like liquid 

 carbonic acid. On one occasion it was observed that the liquid 

 contents, in a quartz crystal which was dashed to pieces, were scat- 

 tered around with a great noise, burning holes in the handkerchief 

 ■wound around the hands of the experimenter. The acid content 

 itself had disappeared. Upon these observations Prof, Simmler 

 establishes his theory. If carbon, as he supposes, is soluble in 

 liquid carbonic acid, it would then only be necessary to subject 

 the solvent to slow evaporation, — the carbon would thereby be 

 deposited, and by taking proper care assume crystalline forms. 

 In evaporating quickly, the so-called black diamond might per- 

 haps be produced, which in the state of powder is largely used 

 for polishing the colorless diamond. Thougli the liquid referred 

 to has never been subjected to chemical analysis, the formation of 

 liquid carbonic acid in the interior of our globe may nevertheless 

 be considered as highh' probable. In the gaseous form, we know 

 it to be evolved in immense quantities fi'om fissures, volcanoes, 

 and mineral springs. When, now, this gas is produced in the cav- 

 ity of a rock which is free from fissures, it will finally be com- 

 pressed so highly that it will assume a liquid form by itself. Cer- 

 tain rocks may be considered strong enough to resist the expansive 

 force of this agent. Let, now, carbon be present: if the same is 

 soluble, it will be taken up and deposited again while the carbonic 

 gas is escaping through some newly formed cracks or fissures. — 

 Scientific American. 



At a recent meeting of the scientific department of the Silesian 

 Society, Prof. Goppert read the following contribution upon this 

 sul>ject which we here translate : — 



" In the year 1864, in a paper entitled ' Upon Inclosures in Dia- 

 monds,' which was honored with a prize by the Holland Society 

 of Sciences in Haarlem, I discussed the various theories respecting 

 their formation, the pyrochemic and the Neptunic, together with 

 the arguments pro and con. In view of the inclosures to be met 

 with in diamonds, the nigrescence and the coke-like formation 

 produced in them by combustion, and the conduct of the so-called 

 black diamond when subject to a similar process, and finallj^ by 

 reason of their occurrence in and with Xeptunic formations, I pro- 

 nounced myself in favor of their Neptunic origin, without however 



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