DECEMBER 31, 1896] 
NATURE 209 
were still productive of such marvellous results at the hands of 
the eminent professors elected by the institution. He there- 
fore gladly embraced the opportunity which recently pre- 
sented itself of acquiring the commodious house immediately 
adjoining the Royal Institution, and submitted a scheme 
to its managers, which met with their fullest sympathy and 
which they readily accepted with unanimity. Work was. 1mme- 
diately commenced to alter the building so as to make it suitable 
for its new purpose, and, thanks to the advice which had been 
freely extended to him by scientific men all over the world, and 
the active co-operation of Lord Rayleigh and Prof. Dewar, of* 
the architect, Mr. Flockhart, and of his son, Mr. Robert Mond, 
to whom he left the selection of the apparatus and the equip- 
ment of the place generally, the laboratory which they asked his 
Royal Highness to inaugurate that day would stand favourable 
comparison with any other laboratory in or out of England as to 
the completeness and convenience of its appliances, and was 
provided with the best instruments made at the present day. It 
was unique of its kind, being the only public laboratory in the 
world solely devoted to research in pure science. In order to 
insure its continued usefulness he had endowed it so as to cover 
the cost of maintenance of the fabric and all necessary current 
expenses. He named it the Davy-Faraday Research Labora- 
tory in perpetual memory of those two great pioneers 
of science who carried out their world-famed and 
epoch-making researches almost on that spot, and 
whose example he hoped would stimulate and inspire every one 
who came to work under that roof. It was a source of very 
great gratification to him that the eminent successors of those 
great men, Lord Rayleigh and Prof. Dewar, had consented to 
undertake the duties of directors of the laboratory, and this 
gratification had been the greater because those gentlemen made 
it a condition of their acceptance of the post that it should be 
without emolument. An experienced superintendent had been 
appointed in the person of Dr. Scott, and nothing was now 
wanting for its success but a number of investigators competent 
and ardent to continue the great work of this century, the un- 
ravelling of the secrets of nature. As soon as his Royal High- 
ness had declared the building open, persons of either sex or 
any nationality would be welcome within its walls who could 
satisfy the Jaboratory committee that they were fully qualified 
to undertake original scientific research in pure and _phys- 
ical chemistry, and preference would naturally be given 
to those who had already published original work. If 
this country had distinguished itself in one way more 
than another in that glorious rivalry with other nations for 
extending our knowledge of natural phenomena and our power 
over the forces of nature it had been by the large number of 
contributors to our knowledge, who on the continent would be 
called amateurs in science—men who devoted their lives to the 
study and advancement of science from pure love for the subject. 
He need only instance the names of Cavendish, Joule, and 
Darwin to say that they included men of the very highest rank. 
In giving this laboratory to the English nation he had done so 
in the firm conviction that this country would continue to bring 
forth in the future, as it had done in the past, men of the same 
rank and of the same devotion to science for its own sake, and 
it was a fond hope of his that such men would find there all 
the facilities and all the necessary appliances for carrying 
out their researches. The further we advanced in the 
study of nature the more accurate and elaborate was 
the apparatus required, and the more difficult it became 
to carry on delicate work in a private laboratory. He 
had placed tnat laboratory in the centre of London because 
he believed that this great city would continue to be the 
intellectual centre of the civilised world, where the brightest 
minds would congregate. He had intrusted it to the Royal 
Institution so as to insure its being open to men and women of 
all schools and of all views on scientific questions. It had given 
him great pleasure that in establishing the Davy-Faraday La- 
boratory, he had been able at the same time to enlarge the old 
laboratories of the Royal Institution, and also to make additions 
to its library and reception rooms, which he hoped would prove 
a convenience to its members. He looked upon that laboratory 
as an important step forward in that great movement for the 
advancement of scientific research in this country, to which his 
Royal Highness'’s revered and illustrious father gave so powerful 
an impulse, and which has been so distinguished a feature of the 
“many-sided and unparalleled progress made by this nation 
during the glorious reign of his mother, her Maiesty the 
No. 1418, VOL. 55] 
Queen. It was a source of specially great satisfaction to him 
that his Royal Highness deemed that laboratory worthy to be 
opened by himself, and he humbly thanked his Royal Highness 
for having come there that day. His presence on that occasion 
would certainly add very greatly to the success of the Davy- 
Faraday Research Laboratory of the Royal Institution. 
The Prince of Wales in reply said :—Prof. Mond, it affords me 
much satisfaction to assist at the opening of the series of beauti- 
fully-arranged and well-equipped research laboratories which this 
country owes to your generosity, and I congratulate the members 
of the Royal Institution of Great Britain upon this most im- 
portant accession to the resources which have been placed at the 
command of the institution for the advancement of chemical and 
physical science. The Royal Institution has long enjoyed a 
world-wide reputation, thanks to the marvellous work of the 
succession of illustrious men whose researches, carried on within 
these walls, have very largely contributed to secure and 
maintain for this country a foremost position as a source 
of great discoveries and important advances in science 
and its applications. The identification of the laboratories 
which you have founded with the names of two of the 
most eminent of former professors of the Royal Institution 
and of English men of sclence—Humphry Davy and Michael 
Faraday—is a graceful act on your part. The fact that the 
present distinguished professors of physics and chemistry, Lord 
Rayleigh and Prof. Dewar, have undertaken the important 
duties of directors of the new research laboratories without any 
remuneration must afford most gratifying evidence to you of the 
great faith entertained by them in the benefit to the promotion 
of science which your wisely-applied munificence is destined to 
realise. 
THE BACTERIA WHICH WE BREATHE, 
EAT, AND DRINK? 
HE surface of the earth is inhabited by bacteria: wherever 
there is dead organic matter, wherever there are human 
or animai excreta, wherever decomposition is going on, in stag- 
nating or in flowing water, within our houses and without, bac- 
teria collect. They are so widely distributed that practically 
everywhere we are surrounded by these minute vegetable cells. 
From the bacteriological standpoint we live amongst de- 
composing matter. Without bacteria there is no decomposition 
or putrefaction ; they reduce the organic matter to ‘‘ dust,” and 
with the atomised matter they are again carried away by air or 
water. Dust is laden with bacteria, and since a great part of 
dust is derived from decomposing matter, it follows that, 
although we do not realise it, we are living in an atmosphere of 
decomposition. 
The air which we breathe, therefore, contains bacteria. These 
vary inamount with certain conditions. If the air is calm their 
number diminishes, but if there is wind or draught, they may 
be present in enormous numbers. Again, in the open country 
air there are, other things being equal, considerably less micro- 
organisms than in the dusty streets of London. Thus there 
is an extraordinary difference between the air in Oxford Street 
and on Wandsworth Common. 
The air may be roughly tested by coating sterile plates of 
glass with gelatine, and exposing them for a given time in the 
locality which we wish to examine. The bacteria will fall on 
the surface of the gelatine, and on incubation at a suitable 
temperature they will develop into visible colonies which can be 
readily counted. The number of colonies is a fair, though not 
an absolute, index of the bacterial purity or impurity of the air. 
The more colonies we find on the surface of the gelatine, the 
more bacteria, of course, the air must have contained. A plate 
exposed in Oxford Street would be covered with colonies, while 
a plate exposed on Wandsworth Common would show only a 
few. This is, of course, only a rough-and-ready method which 
cannot be used for accurate work, but, nevertheless, it gives 
us good comparative results. 
The lantern slides exhibited on the screen demonstrate to you 
that the air which we breathe always contains micro-organisms, 
and that therefore we are always inhaling bacteria. Many 
organisms are incapable of growing at the temperature of the 
body; they require a lower temperature. Such organisms, we may 
assume, cannot thrive in the body of the warm-blooded animal, 
« A lecture delivered at the London Institution, by Dr. A. A. Kanthack 
Lecturer on Pathology, St. Bartholomew's Hospital. 
