SCIE:^TIFIC SUMMAliY. 
441 
adult state. The number of individuals agamogenetically produced bore a 
strict relation to the conditions under which their immediate progenitors 
were placed. 
The Physiology of Pain. — Professor Polleston, who read a paper on this 
subject at the British Association^ said it was a common mistake to sup- 
pose that pain was an exaltation and excitement of function, for it might 
also be occasioned by a lowering of functional activity, brought about 
mainly by starvation or shock. The pain from shock was produced by a 
sudden impact without the intervention of blood-vessels, though not without 
the intervention of the tubes containing nerve matter. The author adverted 
to a number of facts bearing on these theories, humorously concluding with 
the observation that they would side with either of two theories, both of 
which (in defiance of metaphysicians) he was inclined to hold. 
METALLUEGY, MINERAI.OGY, AXD MINING. 
The Gold Mines of Transylvania. — A paper on these mines was some time* 
since read, says the Pnylish Mechanic, by Herr Tschennak before the Imperial 
Geological Institute. It appears that the precious metal is found dissemi- 
nated in almost imperceptible particles in the tracli}'tic rocks in the environs 
of Ealathna and D'Abrud Bau}va, where it is still worked by the most pri- 
mitive methods. There are 300 families or partnerships, consisting each of 
three individuals, or thereabouts. A thousand quintals of the rock yield 
about 8,500 grains of pale yellow gold, which contain a little silver. The- 
rolled debris of the crystalline rocks found in the valley of I’Aranyos is care- 
fully washed, and yields about half an ounce of gold to 31,000 quintals of 
stuff. This gold is of a deeper colour and contains less silver. They also 
find gold in a peculiar freestone {Carpathiqnes hocardes), which is of a pale 
colour, like that found in the trachytes. The gold mines of Transylvania 
have been worked from the earliest historic times, yet they still furnish 
above 2,000 lbs. avoirdupois annually. 
The Chemical nature of Cast-iron. — At the meeting of the British Associa- 
tion the report on this point by Dr. Matthiessen and Dr. Eussell was read by 
the latter and led to some discussion. It seems, that though no less than, 
seventy experiments were made in the production of pure metallic iron from 
its various compounds, the reporters had not succeeded in obtaining anj" iron, 
perfectly free from sulphur. Dr. Matthiessen hoped, however, by continuing 
his researches, yet to obtain a perfectly pure sample of metallic iron. In 
the course of the discussion which followed, Mr. Sutton suggested that 
probably the presence of sulphur in iron was only another instance of the 
persistence of that element in the atmosphere, as shown by the experiments 
of Mr. W. E. Barrett, who first devised the method of detecting the pre- 
sence of sulphur upon the surfaces of bodies exposed to the air by projecting 
upon them a flame of hydrogen, a magnificent blue flame resulting there- 
from. 
The Phosphorescence of Minerals. — M. Kindt has recently made known the 
nature of the phosphorescence developed by heat in three minerals, chloro- 
YOL. YII. NO. XXIX. H H 
