614 
what we call the body bring about changes 
in what we call the mind. When we alter 
the one, we alter the other. If, as the 
whole past history of our science leads us 
to expect, in the coming years a clearer and 
deeper insight into the nature and condi- 
tion of that molecular dance which is to us 
the material token of nervous action, and a 
fuller, exacter knowledge of the laws which 
govern the sweep of nervousimpulses along 
fibre and cell, give us wider and directer 
command over the moulding of the grow- 
ing nervous mechanism and the maintenance 
and regulation of the grown one, then as- 
suredly physiology will take its place as a 
judge of appeal in questions not only of the 
body, but of the mind; it will raise its voice 
not in the hospital and consulting-room 
only, but also in the senate and the school. 
One word more. We physiologists are 
sorely tempted towards self-righteousness, 
for we enjoy that blessedness which comes 
when men revile you and persecute you 
and say all manner of evil against you 
falsely. In the mother-country our hands 
are tied by an Act which was defined by 
one of the highest legal authorities as a 
‘penal’ Act; and though with us, as with 
others, difficulties may have awakened ac- 
tivity, our science suffers from the action 
of the State. And some there are who 
would go still farther than the State has 
gone, though that is far, who would take 
from us even that which we have, and bid 
us make bricks wholly without straw. To 
go back is always a hard thing, and we in 
England can hardly look to any great bet- 
terment for at least many years to come. 
But unless what I have ventured to put be- 
fore you to-day be a mocking phantasm, 
unworthy of this great Association and 
this great occasion, England in this respect 
at least offers an example to be shunned 
alike by her offspring and her fellows. 
MicHAEL Foster. 
CAMBRIDGE UNIVERSITY. 
SCIENCE. 
[N. 8S. Vou. VI. No. 147. 
CHEMISTRY AT THE BRITISH ASSOCIATION. 
THE work of the Chemical Section of the 
British Association was inaugurated with 
the address of its President, Professor Ram- 
say: ‘An Undiscovered Gas.’ Starting with 
a discussion of the history of the various 
periodic relationships which have been 
shown to exist among the elements, and of 
the definition of the properties of unknown 
members of several of the Groups prior to 
their isolation, the attempt was made to 
establish the probability of the existence, 
and to prophesy the characteristics of an 
element, as yet unknown, forming a ‘ triad’ 
with helium and argon. Between fluorine 
and manganese lies chlorine ; between oxy- 
gen and chromium, sulphur; between nitro- 
gen and vanadium, phosphorus; between 
carbon and titanium, silicon, etc. The in- 
termediate element possesses an atomic 
weight greater, on the average, by 16 units 
than that of the lightest member of the 
triad, and less by 20 units than that of the 
heaviest. Between the lightest and the 
heaviest, therefore, the difference in atomic 
weight is approximately 36 units, which is 
also the difference between the accepted 
atomic weights of helium (4) and argon (40). 
“There should, therefore, be an undiscoy- 
ered element between helium and argon, 
with an atomic weight 16 units higher than 
that of helium, and 20 units lower than 
that of argon, namely 20. And if this un- 
known element, like helium and argon, 
should prove to consist of monatomic mole- 
cules, then its density should be half its 
atomic weight, 10. And, pushing the anal- 
ogy still farther, it is to be expected that 
this element should be as indifferent to 
union with other elements as the two al- 
lied elements.”’ 
Professor Ramsay next reviewed his vari- 
ous efforts to obtain the third member of 
the helium-argon triad. The most promis- 
ing method—that of systematic diffusion of 
the individual gases—failed to show the 
