90 
POPULAR SCIENCE REVIEW. 
at the above-mentioned blocks, through noticing that they contained a 
mineral of a purple colour ; this proved to be fluor, which occurs sparingly 
throughout the Leinster granite. Associated with the fluor was a pretty 
considerable quantity of a white mineral, occurring in aggregations of 
minute crystals ; this appeared to him to be so like Albite that he considered 
it deserving a careful examination. He brought some of it to the Rev. 
Professor Haughton, F.R.S., who agreed with him in thinking that it had a 
very albitic look, and kindly undertook to have it analysed, which has been 
done with the following result : — 
Silica . 
• • i 
. 64-70 
Alumina 
. 21-80 
Potash 
, # 
. 2-84 
Soda . 
. 9-78 
Loss 
. 
. 0-30 
99-42 
Geological Magazine , Dec. 
‘Successor to the late Mr. Jukes. — Mr. Edward Hull, M.A., F.R.S., F.G.S., 
has been appointed Director of the Geological Survey of Ireland, and Pro- 
fessor of Geology in the Royal College of Science, Dublin, in the room of 
the late Mr. Jukes. Mr. Hull had not long before been chosen a District- 
Surveyor on the Geological Survey of Scotland. 
Crystals of Quartz and Crystals of Chalcedony . — In a very handsomely 
illustrated paper in the Geological Magazine for December, Mr. J. Ruskin 
after pointing out some of the difficulties of the particular department on 
which he wrote, states that one generalisation presents itself which is of great 
value. Whenever iron, whether oxide or sulphide, is associated with sta- 
lactitic chalcedony, it is always in the centre of the mass ; but when iron, 
whether oxide or sulphide, is associated with quartz crystals, it is always 
(if determinately placed at all) either on the outside, or at a slight depth 
below the surface, under an external coat of clearer crystal. It may be in- 
determinately placed, in dispersed stars or cubes ; but, if ordered at all it is 
ordered so. Briefly, a crystal of quartz never has a centre of iron, and a 
crystal of chalcedony never a coat of it. 
The new French Annales de Geologie. — A new French periodical, devoted 
to geology and palaeontology, has been commenced. It is published by 
Messrs. V. Masson et Fils, of Paris, and in general plan resembles the well- 
known natural-history journal, the Annales des Sciences naturelles. Its title 
is the Annales des Sciences gtologiques , and the geological part is edited by 
M. Hebert, of the Sorbonne, and the palaeontological by M. Alphonse Milne- 
Edwards. The first number, which has been issued this month, contains an 
elaborately-illustrated memoir by M. Lartet, on the Geology of Palestine. 
The subscription is 15 francs a year. 
The new Cave at Portland . — A correspondent, writing to Scientific Opinion 
of December, gives an account of this cave. “ The mouth of the cave, which 
is in a quarry about 50 ft. below the level of the road, is about 3 ft. wide, 
and is now furnished with a door. One of the quarrymen went with us and 
gave us each a candle. The average width is about 3 ft. ; but there were a 
few ‘rooms’ from 10 to 18 ft. in diameter. The average height is about 
