264 
Radiation and Absorption of Heat, and on Calorescence. 
In these he established the important fact that if the 
various gases be arranged in order according to their 
power, first of radiating heat, and secondly of absorbing 
radiant heat, the order will be the same in both cases. 
He further proved that the chief absorbing action of our 
atmosphere on non-luminous heat is due to its aqueous 
vapour. He applied his discovery to the explanation of 
many meteorological facts : e.g. the great daily range of 
the thermometer in dry climates ; the production of frost 
at night in the Sahara; the cold in the table-lands of 
Asia, &c. 
He discovered also the means of separating the in- 
visible from the visible radiations, and proved that in the 
case of the electric light the former is no less than eight 
times as powerful as the latter. Healso made the daring 
experiment of placing his eye at a focus of dark rays 
capable of heating platinum to redness. 
Since 1866 his attention has been largely occupied in 
examining the action of heat of high refrangibility (instead 
of low), as an explorer of the molecular condition of 
matter 
In this investigation one obstacle to be overcome was 
the presence of the floating matter in the air. The pro- 
cesses of removal of these particles became the occasion 
of an independent research, branching out into various 
channels ; on the one hand, it dealt with the very practi- 
cal problem of the preservation of life among firemen ex- 
posed to heated smoke ; and, on the other, it approached 
the recondite question of spontaneous generation. 
He subjected the compound vapours of various sub- 
stances to the action of a concentra'ed beam of light. 
The vapours were decomposed, and non-volatile products 
were formed. The decompositions always began with a 
blue cloud, which discharged perfectly polarised light at 
right angles to the beam. This suggested to him the 
origin of the blue colour of the sky ; and as it showed the 
extraordinary amount of light that may be scattered by 
cloudy matter of extreme tenuity, he considered that it 
might be regarded as a suggestion towards explaining the 
nature of a comet’s tail. : 
(The lecturer then exhibited the polarisation of light 
scattered by small particles suspended in the medium 
traversed by a beam from the electric lamp, employing 
for the purpose the chromatic effects due to the circular 
porlarisation of quartz. ] 
His volume of contributions to molecular physics in the 
domain of radiant heat, which contains only his original 
investigations on this subject, would alone suffice to show 
what is doing in the laboratory of our Institution. 
If we compare him to Faraday at the same time of life, 
he has still many years of intellectual energy, the conver- 
sion of which into its scientific equivalent may, perhaps, 
be effected within these walls. 
No one has regretted the destruction of the laboratory 
of Davy and of Faraday more than Prof. Tyndall. He 
almost prayed for the preservation of the place where 
their discoveries had been made ; but as soon as he saw 
that in our struggle for existence such material aids as 
improved buildings would conduce alike to the progress 
of science and to the permanence of the Institution, he 
withdrew his objections, and threw all his powers into 
making the new laboratories as perfect as possible for the 
good of his successors. 
I add a few words on the reasons which led the mana- 
gers to recommend the rebuilding of our laboratories, and 
the consequent demolition of the place where the great 
discoveries that I have touched upon were made. In the 
opinion of those best qualified to judge, our chemical 
laboratory was badly ventilated, badly lighted, badly 
drained, and quite unfit to be occupied for many hours 
daily. It was probably the very worst, and certainly all 
but the worst chemical laboratory in London ; and com- 
pared with more modern ones both at home and abroad, 
NATURE 
- [Feb. 6,1873 
it was nowhere. The physical laboratory had remained 
for nearly seventy years in its original state. At first it 
was said to be equal to any laboratory ; but then there were 
hardly any in existence in this country ; and during the 
last few years such splendid edifices have arisen in Lon- 
don, in Oxford, in Cambridge, inManchester and in Glas- 
gow, and elsewhere, that the laboratory of Davy, of 
Faraday, and of Tyndall was much inferior to the private 
laboratories of the professors who carry on their course 
of instruction in public rooms of still greater size and 
extent of resource. The main purpose of our laboratories 
is research, and instead of offering by their excellence an 
inducement to professors to come and to stay, the one 
was a makeshift, the other a noble relic. Neither afforded 
facilities which were not offered in a larger measure else- 
where. And those only who know what is going on both 
at home and abroad can form an adequate idea of the 
competition which, in this respect alone, will prevail for 
a generation to come. 
By the construction of new laboratories this material 
disadvantage will be removed. Future professors will 
have buildings constructed to aid research. Your libe- 
rality has spared no judicious expense ; and, so far as the 
site would admit, our laboratories will be as perfect as 
the skill of our architect and the advice of our professors 
can make them. 
In conclusion, let me lay before you what must still be 
done, in order that there may be earned for the new 
laboratories a reputation comparable with that which has 
hitherto proved both our glory and our support. 
Our first and foremost object, beyond bricks and 
mortar, and money, and apparatus, must be to find a suc- 
cession of professors of the old type; men who love 
research. But even Faraday would perhaps have been 
compelled to leave us, on account of the smallness of the 
sum which we could afford him, had not the endowment 
of the chemical chair, with 1oo/. a year, by the late Mr. 
Fuller, happily intervened. This timely endowment was 
probably a critical turning point in the history of the 
Institution. We may not easily find successors worthy 
of the great names who have gone before them; biit we 
may do much toward preventing mistakes in future 
appointments by keeping steadily in view, that the pro- 
motion of natural knowledge is our main object; and 
that instruction and amusement, and brilliant audiences 
are all secondary to our principal purpose. Not that 
these subsidiary purposes are to be neglected or despised ; 
and I, as your Treasurer, should be the last to undervalue 
them, but we feel confident that if the main purpose is 
effected, all the others will follow as a simple sequence. 
Secondly, when we have found professors of the type 
that I have described, our next need is that we may be 
able, from independent resources at the disposal of the 
Institution, to offer them a remuneration which, all things 
taken into account, shall be an equivalent to what they 
would receive elsewhere. So that neither Government 
appointments, nor University professorships, nor the 
liberality of mercantile men, should be able to lure them 
from the path of discovery, to tuition, to arts, or to manu- 
factures, i 
The one act of wisdom, among the many aberrations 
of an eccentric member of Parliament, saved Faraday to 
us, and thereby, as seems probable, our Institution to the 
country. The liberality of a Hebrew toy-dealer in the 
East of London has made the rebuilding of our labora- 
tories possible. 
It is said that Mr, Fuller, the feebleness of whose con- 
stitution denied him at all other times and places the rest 
necessary for health, could always find repose and even 
quiet slumber amid the murmuring lectures of the Royal 
Institution ; and that, in gratitude for the peaceful hours 
thus snatched from an otherwise restless life, he be- 
queathed to us his magnificent legacy of 10,0007. If this 
evening’s discourse shall have ensured one such blissful 
* 
