98 
that if the rays were visible the appearance 
would be that of a room filled with smoke and 
lighted up by a candle. When a plate imper- 
vious to the rays is placed between a fluores- 
cent screen and a source of the rays the pla- 
tinocyanide of barium nevertheless becomes 
luminous, and this luminosity is visible even 
when the screen lies directly upon the plate. 
If, however, the screen placed on the plate is 
covered by a cylinder of lead 0.1 em. in thick- 
ness surrounding the fluorescent screen the flu- 
orescence disappears. Professor Rontgen has 
further been able to measure the intensity of 
the rays and to study the influences on which 
this depends. Dr. Brandes’ observations that 
the X-rays may be made visible, presumably 
by causing fluorescence of the retina, are con- 
firmed. Professor Réntgen sums up the present 
state of our knowledge in regard to the rays as 
follows: (1) The rays proceeding from the dis- 
charging apparatus are a mixture of rays vary- 
in absorbability and intensity. (2) The com- 
position depends chiefly on the duration of the 
discharging current. (8) Different bodies ab- 
sorb different kinds of rays. (4) The X-rays 
are produced by the cathode rays and the phe- 
nomena of both are probably of the same 
nature. 
THE compilation of the statistics of coal 
production in the United States in 1896, which 
has just been completed by Statistician E. W. 
Parker, of the U. S. Geological Survey, shows 
that the product in 1896 was 190,639,959 short 
tons, valued at $195,557,649, against 193,117,- 
530 short tons, valued at $197,799,043 in 1895, 
a decrease of 2,477,571 short tons in amount, 
and of $2,241,394 in value. The decrease in 
product was entirely in that of Pennsylvania 
anthracite. The output of bituminous coal 
shows an increase of about one and three- 
quarters million tons. The anthracite product 
of Pennsylvania decreased nearly four and a 
quarter million tons. It is a notable feature, 
however, that there was a decrease in the 
value of the bituminous product of over $1,600,- 
000, notwithstanding the increased output, 
and that there was a comparative increase in 
the value of anthracite, although, on account of 
the smaller production, it did not equal the 
value in 1895. The average price obtained for 
SCIENCE. 
[N. S. Vou. VI. No. 123. 
anthracite at the mines increased from $1.41 in 
1895 to $1.51 in 1896. The average price for 
bituminous declined from 86 cents to 83 cents. 
AT the coming International Leprosy Confer- 
ence, to be held in Berlin on October 11th, Dr. 
Hutchinson, of London, will report on alimen- 
tation and leprosy; Professor Virchow on the 
pathological anatomy of leprosy ; Dr. Neisser, 
of Breslau, on its origin; Dr. Bernier, of Paris, 
on its etiology, and Professor Koch will discuss 
the question of its infectiousness. 
WE learn from Natural Science that the 
Natural History Museum of Halifax, which was 
handed over to the County Borough Council 
about eighteen months ago by the Literary and 
Philosophical Society, has now found a perma- 
nent home in the old mansion named Belle Vue. 
The geological and botanical collections are 
very extensive and valuable, but zoology is as 
yet very imperfectly represented. The her- 
barium has lately been much enriched by the 
fine Gibson collection of British plants, the gift 
of Lady Trevelyan. The Curator, Mr. Arthur 
Crabtree, is making an attempt to render the 
Museum of general educational value by ade- 
quate labelling, and wishes to secure a com- 
petent committee of management to direct and 
second his efforts. 
UNIVERSITY AND EDUCATIONAL NEWS. 
THE Supreme Court of New York State is- 
sued on July 6th its final decision in the Fayer- 
weather will case. The executors were required 
to distribute within ten days the three million 
dollars in question to the twenty colleges to 
which they were bequeathed. 
THE only colleges so far as we have noticed 
which have this year given the Ph. D. degree 
causa honoris are Union, Dartmouth and Tufts. 
These colleges have acted unwisely and Union 
College, as we understand it, illegally. 
PROFESSOR WILLIAM A. RoGERS, who recently 
accepted the Babcock professorship of physics in 
Alfred University at Alfred, N. Y., delivered 
the principal address at the laying of the corner- 
stone of the Babcock Hall of Physics at Alfred 
on June 22d. The hall is named after the late 
George H. Babcock, of Plainfield, N. J., who 
left $100,000 to Alfred University. 
