1870.] Mineralogy. 125 



green granules, which appear to be isolated cells not unlike those of 

 Frotococcus pluvialis. The new species is accordingly named 

 P. adamantinus. In the second diamond, weighing 345 milli- 

 grammes, the cells are less round and more elongated in form, 

 while they frequently unite so as to form a loose parenchymatous 

 tissue : they find their best representatives in Palmogloea macro- 

 cocca, and Goj)pert has accordingly ventured to name the new 

 diamond-plant Palmogheites adamantinus. 



Once again, the old mistake has been repeated in Australia. 

 In the New England district a stone was found, about the size and 

 shape of a duck's egg, and weighing 6 oz. 13 dwts. 12 grs. troy. 

 Of course it was taken for a diamond, and rumour was soon rife as 

 to its prodigious worth. A few days after announcing the dis- 

 covery, the ' Australian Mail ' coolly adds, " The ' great diamond ' 

 which had created so much sensation has proved to be a piece of 

 crystal-quartz ! " 



Hitherto crystallized quartz has been artificially prepared only 

 by wet processes. But the presence of this mineral in rocks usually 

 referred to an igneous origin, naturally leads to the belief that it 

 may certainly be produced also in the dry way. Acting on this 

 belief, Grustav Kose has recently experimented on the fusion of 

 silica, adularia, and other minerals, in salt of phosphorus and in 

 borax.* His experiments were conducted on a large scale at the 

 furnaces of the Koyal Porcelain Manufactory at Berlin. Crystal- 

 lized silica was thus obtained, but in the form of small six-sided 

 plates, unlike the crystals of common quartz, from which it also 

 differed in having the low density of 2 ■ 3. Kose has thus produced 

 not ordinary quartz, but Yom Bath's curious new species Tridy- 

 mite, which has been already described in this Journal. Whilst 

 he has thus obtained artificial tridymite, he does not despair of 

 forming artificial quartz by a modification of his process. 



Spectrum analysis has been applied, by Vogelsang and Geissler, 

 to the difficult question of determining the chemical nature of the 

 fluid found enclosed in minute quantity in the cavities of certain 

 quartz-crystals. t Fragments of quartz were placed in a small 

 retort, which was connected with an air-pump and exhausted ; then 

 by the application of heat the quartz decrepitated, and the evolved 

 vapour was examined in a Greissler-tube. The presence of carbonic 

 acid was thus abundantly proved, and this was confirmed by the 

 turbidity which it produced in lime-water. 



Among some minerals examined by Herr Petersen from the 

 St. Wenzel mine, near Wolfach, in Baden, he finds a new species 

 belonging to the interesting group of antimonial sulphides of silver 4 



* ' MonatsbericLt d. k. preussichen Akad. d. Wiss.,' 1869, p. 449. 

 t ' Ehein Verhdlg.,' xxv. Sitzungsber, p. 77. 

 % Poggendorff's 'Aunalen,' No. 7, 18G9, p. 377. 



