428 
POPULAR SCIENCE REVIEW. 
a On the Employment of Coloured Glass in Microscopy.” By M. 
Mouchet. “ Note on Silicious Incrustations from the Geysers of the Yellow- 
stone River, Wyoming Territory.” By Prof. Arthur Mead Edwards, 
U.S.A. “ On Angular Aperture of Immersion Objectives.” By Robert B. 
Tolies, Boston, U.S.A. “ The Minute Anatomy of Two Cases of Cancer.” 
By Assist.-Surgeon J. J. Woodward. 11 The Theories of Cell Develop- 
ment.” By I. N. Danforth, M.D., Pathologist of St. Luke's Hospital, 
Chicago, U.S.A. “Draw-Tubes versus Deep Eye-Pieces.” By M. A. 
Prazmowski. 
MINERALOGY, METALLURGY, AND MINING. 
The Datolite from Bergen Hill , JS r . I., has been described by Mr. E. S. Dana 
in “Silliman’s American Journal” for July. The Bergen Hill tunnel is 
famous for the abundance, beauty, and variety of the minerals which it 
brought to light. Datolite, pectolite, calcite, analcite, apophyllite, natrolite, 
stilbite, and others were obtained there during its excavation in a degree of 
perfection rarely equalled by the productions of any other locality. The 
crystallisations of datolite are especially remarkable ; some of the surfaces 
covered with the brilliant crystals being eighteen to twenty-four inches in 
length. The crystals are in general not over a third of an inch across, 
though they sometimes have a diameter of one inch. Those of a single 
specimen have always entire uniformity of habit. The datolite is associated 
on different specimens with most of the other species found at the same 
locality, but it was not found possible to obtain any facts which would throw 
light upon the influence of the associated minerals on the crystalline form. 
Among the varied forms, four different types may be distinguished. 
Ferro- Tungstine. A new Mineral. — Mr. Hugo Tamm describes in the 
11 Chemical News,” a mineral, of which he had procured a very small speci- 
men, but had not been able to find out the place where it was originally 
discovered. Ife gives the following results of his anatysis of it. Eerro- 
tungstine is a dark steel-coloured, heavy, crystalline powder, formed of 
separate and distinct crystals, presenting exactly the appearance of crystallised 
silicium. Its specific gravity, which is considerable, is 12-5. It is a very 
hard substance, which can only be porphyrised with extreme difficulty, and 
it is almost impossible to reduce it to an amorphous powder ; the powder 
obtained after a prolonged porphyrisation remaining still bright, like the 
powder of a crystalline metal or alloy, and crystalline. 
Heated in the air at a low red heat, ferro-tungstine slowly oxidises, and 
is converted into a yellow powder of tungstic acid : and when it is thrown 
in fused nitre, it burns with brilliancy and is thoroughly attacked. 
Eerro-tungstine is composed of 
Metallic tungsten .... 
, 88-05 
Metallic iron ..... 
5-60 
Metallic manganese .... 
0-15 
Undetermined substance . 
0-20 
100-00 
