224 
NATURE 
summer left the Institution, our chemical laboratory was 
probably the very worst in London.” 
The physical laboratory remained unchanged; and 
although Professor Tyndall for himself desired nothing 
more than to continue his researches in a place which his 
imagination filled with the recollections of his prede- 
cessors, he still acquiesced in the proposal for rebuilding, 
for the sake of his successors, and in the interest of the 
sister science of his colleague. 
Thus much about the material fabric of our laboratories. 
Next as to the scientific work of which they have been 
the birthplace. 
Of the great names connected with this building fore- 
most in order of time, and very high in scientific rank, 
stands that of Dr. Thomas Young. His “ Theory of Light 
and Colours” will always stamp him as one “ whose genius 
has anticipated the progress of science,” and whose repu- 
tation has risen as men have better understood his worth. 
His first paper on the subject was presented to the Royal 
Society in November, 1801 ; but the earliest printed 
account of his views is to be found in his “Syllabus of 
Lectures at the Royal Institution,” dated January 19, 1802. 
With the criticisms of his theory published in the Zazx- 
burgh Review, with the circumstances which led to his 
withdrawal from the Institution, with his researches in 
Egyptian hieroglyphics, we are not here concerned. But 
it is not too much to say of him, that without the Wave 
Theory of Light (of which he was one of the prime and 
main founders) to serve as a guiding-thread through the 
labyrinth of phenomena, the long series of discoveries 
which have in this place culminated in those of Tyndall 
in Radiation and Absorption, would have been impos- 
sible. 
It is often remarked that little rills, which have threaded 
their way from distant mountains, ultimately discharge 
themselves as mighty streams into the sea. Yet between 
these two stages they flow quietly, but not therefore less 
usefully, past smiling meadows and the haunts of men, 
And here is a little scientific pastoral—if it may be so 
called—flowing out of the highest conceptions of the 
theory of undulations, and furnishing, to use his own 
words—a simple instrument “ for measuring the diameters 
of the fibres of different kinds of wool.’* [The lecturer 
then described and exhibited on the screen the principle 
of Dr. Young’s eriometer.] 
Our next name is that of Davy, an account of whose 
discoveries would require a volume, and a bare recital of 
them would be long. I quote the following notes from the 
pen of our Secretary, and wish that he had been here to 
give life to the dry bones. 
In 1806, when twenty-eight years of age, Davy did the 
work which formed his first Bakerian Lecture, “ On the 
Chemical Agencies of Electricity.” Six years previously 
he had written, “ Galvanism I have found, by numerous 
experiments, to be a process purely chemical.” In the 
interim, water had been decomposed by electricity, 
and Davy began his researches with an inquiry into 
the changes produced in water by electricity. His 
main conclusion was that “the kind of polarity of each 
element determined the electrical and chemical actions 
shown by it.’ The French Academy awarded him a 
medal for this work ; and from these discoveries the fame 
of our laboratories took its rise. 
The next year Davy began a new series of experiments 
on Polarity. He exposed different substances to the 
action of platinum wires coming from a battery of 100 
cells; and on October 6 he wrote in his note-book, 
“Remarkable phenomena with potash.” On the igth 
he made the following entry, “A capital experiment 
proving the decomposition of potash.” He worked at 
the decomposition of other alkalies until the 23rd No- 
* The King at this time had his flock of merino sheep, and Sir Joseph 
Banks had the care of them at Kew. On his recovery from his first mental 
attack the King would only call the P.R.S. his woolstapler. 
vember, when he was attacked by a fever which proved 
nearly fatal to him. 
The importance of these decompositions to the recent 
science of spectral analysis, although not dreamt of at 
the time, can hardly be overrated ; and I will therefore 
venture to interrupt my narrative for a moment by an 
experiment,—a very well-known one, which will serve to 
illustrate the point. [The speaker then exhibited the dark 
absorption line of sodium ; but so arranged as to show 
the dark line zz the centre of, and not entirely obliterating, 
the bright line ; proving that a certain density of vapour 
is necessary for complete absorption. ] 
In 1808 he began to work on the composition of muri- 
atic acid; and with a new battery provided for him 
by subscription, he attacked different substances with 
increased energy. In 1810 he sent to the Royal Society 
his researches on oxymuriatic acid and the elements of 
muriatic acid, on what is in fact now known as chlorine. 
In 1811 he made the acquaintance of Mrs. Appreece, 
and in 1812 wrote to his brother, “ In a few weeks I shall 
be able to return to my habits of study and research. I 
am going to be married to-morrow, and have a fair 
prospect of happiness with the most amiable and-eintel- 
lectual woman I have ever known.” The issue of these 
hopes has been written by his biographers ; but the dis- 
appointment of the last seventeen years of his life is 
illuminated by the invention, not less original in its con- 
ception than benevolent in its object, of the Safety Lamp. 
The great value of this contrivance, and of questions 
arising out of it, will I trust, be sufficient apology for 
diverging again from my story in order to mention some 
very important experiments now in progress by Mr. Gal- 
loway. Explosions, it is well known, occur even in cases 
where the safety lamp is used. And it has been noticed 
that in these cases they occur most frequently after the 
firing of a blasting shot in the neighbourhood ; and as it 
was almost certain that the penetration of the fire-damp 
through the gauze of the lamp was not due to a sudden 
flow of gas from one part of the mine to another, 
experiments have been instituted to determine whether 
the transmission of the sound wave, or wave of compres- 
sion, may not have been the means of producing the 
mischief. Through the kindness of Mr. Galloway we 
have here a tube arranged for making such an experi- 
ment. At one end there is the inflammable current 
burning outside a safety lamp ; in the centre is an elastic 
diaphragm, and at the other end a pistol will be fired, by 
the explosion of which a sound wave will be propagated 
along the tube. On the arrival of the sound wave at the 
extremity of the tube, the combustion will penetrate the 
safety lamp. But I here leave the matter in the hands of 
Mr. Galloway, of whose experiments we hope to hear 
more hereafter. 
(To be continued.) 
PROFESSOR TYNDALL IN AMERICA 
\ \ 7HAT would the readers of any of our daily papers 
think, if they found half-a-dozen of its columns for 
six days on end, filled with verbatim reports of scientific 
lectures? Would not they be inclined to think their 
paper was in its dotage? But this has been done in 
the case of the Mew York Tribune, in whose columns, 
day after day, have appeared verbatim reports, with 
illustrations, of the six lectures which Prof. Tyndall 
delivered on Light in New York during the last days 
of last year? Not only has this been done, but the 
whole series of lectures has been issued on a sepa- 
rate sheet of four pages, each page as large as t 
of any of our daily papers, with twenty illustrations 
somewhat rude no doubt, but quite intelligible. This 
valuable sheet is sold at the astounding price of three 
cents, and as it has nota single advertisement, it must 
’ 
(Fan. 23, 1873 a 
