- 
Pt ee | Rl’, 
er la France et de la Belgique.” 

> Lie x 
/Fepruary 24, 1923 3 
NATURE 
265 

His published re- 
search on the correlation of function, form and sfeuienaiel 
of plant organs is as remarkable for its simplicity and 
clearness of style as for its scientific value. His 
journalistic contributions to Le Temps were appreciated 
by all its readers. 
Prof. Bonnier played a most important part in the 
| reform and extension of the teaching of the natural 
sciences in France. To his students and research 
workers, including men and women of many national- 
ities, he was friend, guide and master. 
The French president, the University of Paris, and 
many scientific bodies were represented at the obsequies, 
which took place with military honours. 
Current Topics and Events. 
On February 14, Mr. Fisher presented to the House 
of Commons the usual petition from the Trustees 
of the British Museum praying for further support. 
Though this is merely a form arising out of the 
peculiar mode of government of the museum, we 
may be permitted on this occasion to emphasise the 
desirability of doing nothing that should hinder 
the performance of this trust “ for the general benefit 
of learning and useful knowledge.’’ The British 
Museum, a term which includes the Natural History 
Departments, is not one of those Government estab- 
lishments that swelled its ranks and its expenses 
under stress of war, nor has it shown a reluctance to 
reduce them in the difficult times of peace. On the 
contrary, it has only just brought its scientific staff 
back to the pre-war level, and it has conscientiously 
reduced its estimates as required by the Geddes 
Commission. Its scientific publication is almost, 
if not entirely, suspended. This is a state of affairs 
we may lament, but must endure. What we are not 
prepared to suffer without protest is any further 
demand for reduction. There are rumours of such 
a demand, amounting to several thousands of pounds. 
This could only result in a diminution of the valu- 
able work accomplished by this great establishment, 
work already most seriously hampered by the in- 
adequate size of the staff. To choke one of the 
great founts of ‘learning and useful knowledge ”’ 
can never be an economical proceeding, and any 
attempt to do so will meet with the united protest 
of all scientific workers. 
Tue Home Secretary has appointed a committee 
to inquire into the desirability of extending the 
Workmen’s Compensation (Silicosis) Act of 1918, 
which provides compensation for men injured by 
silica in specified industries. The association of 
miner’s phthisis (fibrosis of the lungs with superadded 
tuberculosis) with the inhalation of hard dust, as 
in quartz mining or knife grinding, has long been 
_ known, and its recognition has led to the introduction 
of appropriate preventive measures. Collis pointed 
_ out that the danger of a dust was in proportion to 
its content of free silica, and Mavrogordato found that 
coal dust was actually an antidote when mixed with 
rock dust, which by itself was highly injurious. Later 
experiments by Gye and Kettle have shown that the 
action of silica is chemical rather than mechanical, 
and that colloidal silica is distinctly poisonous. 
Chronic silica poisoning in rabbits causes degenerative 
changes in the liver and kidneys, and, though the 
applicability of these results to the occurrence of 
similar lesions in men is at present quite an open 
_NO. 2782, VOL. r11] 
question, it is evident that the harmful effects of this 
common substance may prove to be much more 
widespread than is at present supposed. 
Tue New York correspondent of the Times, in the 
issue of February 13, refers to some successful experi- 
ments upon the dissipation of clouds by the Army 
Air Service of the United States at Dayton, Ohio, 
under the direction of Prof. Bancroft of Cornell 
University and Mr. Francis Warren. The process 
consists in scattering electrified sand with the pro- 
peller of an aeroplane moving 500 ft. above the tops 
of clouds. The sand is said to be charged to 10,000 
volts, and the result is referred to in the headline of 
the note as ‘‘ rain-making.’’ The coalescence of the 
cloud particles in consequence of the diminution of 
surface-tension is suggested as the proximate cause 
of the disappearance of the clouds, which are stated 
to have varied from several thousand feet to several 
miles in length and breadth, and in thickness from 
500 ft. to 1500 ft. The general conclusion of the 
correspondent is that fogs ‘‘ need be no more and, 
given only clouds, rain can be had wherever it is 
wanted.’ An important question is, of course, how 
much? “ The time required to precipitate the 
moisture . . . rarely exceeded ten minutes,’’ and in 
the case of very thin clouds the moisture evaporated 
before reaching the ground. Further particulars will 
be awaited with interest. In the meantime the 
announcement brings once more into prominence the 
need for special laboratories for the practical physics 
of the atmosphere, for which a good deal of work 
has long been waiting. The coalescence of water- 
drops, the correlative pulverisation of water and 
their relation to electrification, are not by any means 
fully explored. The energy-relations are very com- 
plicated. It is known, for example, that a bucketful 
of water tossed out of an aeroplane would be pul- 
verised into an electrified cloud by its own gravita- 
tional energy. To get it back again into a con- 
tinuous mass of water at the ground by the use of 
electrified sand will be a very interesting completion 
of the cycle when we understand it. 
A TELEGRAM recently received at the Linnean 
Society from Tiflis announced that an eminent 
foreign member of the Society, Prof. Serge Gabrilo- 
vitch Navashin, of the Botanic Garden, Tiflis, Georgia, 
was to celebrate on February 18 his fortieth year of 
scientific work and the twenty-fifth anniversary of 
his announcement of double fertilisation in plants. 
This message recalls the new era in the study of the 
embryogeny of the flowering plants which followed 
