1919.] The Sixth Indian Science Congress. CXXix 
used, neon was the main product. No helium or neon was 
obtained from calcium or glucinum oxi 
y Egerton repeated some of the sipertite which 
have sak " disodhad: and obtained only negative results. He 
also attempted to show by calculation that under the condi- 
tions of the experiments, it was unreasonable to expect any 
detectable amount of cto to be produced from hydrogen in 
less than about 10 years. The calculation, however, was based 
on certain assumptions foe the mechanism of the process, 
and regarding its energy requirements, in respect to both o 
which we know nothin 
o survey of this nature would be complete without refer- 
ence to the results obtained by Sir J. J. Thomson by his posi- 
tive ray method, particularly as his opinions have been cited 
both in support of and against the transmutation hypothesis. 
obtained helium from a large number of substances, many of 
which had been purified in such a way as to exclude the 
may be regarded as a model of caution, fortunately do not 
affect his experimental results, which are, qualitatively, similar 
to those of Collie. But the positive ray method is so exceed- 
ingly sensitive that it is better, for our purpose, 2 rely mainly 
on the velgis coca: previously described, in many of which the 
iivglidats positive ones heaps all the conditions are e known an 
understood. In the work under discussion this is far from be- 
ing the case. Those chemists who have obtained positive 
results have obtained still more proccie ones, under apparent- 
ly identical conditions. In one ance, as we have seen, a 
small coil with a hammer break was satfedtive when a more power- 
ful one with a mercury break was not. It may not be out of 
place to call attention to the extraordinary behaviour, recorded 
by Gray and Ramsay (J.C.S. Trans. 1909, 95, 1083), of a 
f 
paraffin, was placed outside the bulbs containing it, gradually 
ceased to evolve the gases, the weekly volume of which dwindl 
to 0°5 c.c., until the apparatus was removed, after which the 
normal rate of evolution was recovered. Attempts were m 
