104 
MAGAZINE OF SCIENCE AND ART. 
The Power that has, in so wonderful a manner, 
adapted everything in creation to its allotted pur¬ 
pose, has ordained that in accordance with the 
organic laws ot animal existence, the atmosphei'e 
we breathe shall be composed of such materials 
and in such proportions as best lit it for sustaining 
i life, and, I need scarcely add, that these proportions 
never vary in nature, whether the air examined be 
taken from the level of the sea or from the top of 
the highest mountain. By the process of respira¬ 
tion, this air taken into the lungs comes into con¬ 
tact with the blood, which is continually circulating 
through them, and there produces such changes in 
it as arc necessary to make it fit for the nourish¬ 
ment of the body. Any change, therefore, in the 
proportions of the gases composing the atmosphere, 
the abstraction of either of them, or the addition 
of others, renders it more or less unfit for {improper 
performance of its functions, and the blood becomes 
a poisonous instead Of a nutritive fluid. 
But respiration, combustion, and the decom¬ 
position of animal and vegetable substances, are 
continually changing the air, convertingits oxygen 
into carbonic acid, and adding to it hydrogen and 
carbonated and sulphuretted hydrogen, ammoniacal 
and other gases, and were it not that there is an 
inexhaustible supply of pure air forty or fifty miles 
high around us, and that winds tend to disperse 
these substances, while vegetation and the che¬ 
mistry of nature are perpetually at work collecting 
and re-combining them, the world would soon 
cease to be habitable. But civilised man continues, 
in no small degree, to counteract these beneficent 
operations; hence our streets are undrained, our 
houses and public buildings erected without the 
least regard to temperature or ventilation, the 
town population is overcrowded, and the air around 
it poisoned with the exhalations from various 
trades, and neglect of proper cleanliness. 
In this state of things a peculiar class of diseases, 
epidemic, endemic, and contagious, has its origin. 
Of the laws which determine the occurrence of 
these maladies we as yet know nothing. AV'e can 
only suppose that they are influenced by particular 
modifications of telluric and meteorologie con¬ 
ditions (in which I believe electricity has a con¬ 
siderable share), and when, by these means, the 
epidemic influence begins to operate, its first 
victims arc invariably those whose vital powers are 
depressed by a residence in dirty, ill-drained, ill- 
ventilated, and overcrowded districts. 
“There is one thing established in medicine,” 
says Dr. Neale, when before a select committee of 
the House of Commons, “and that is that any 
deleterious condition of the air, any noxious 
effluvia, by lowering the powers of the system 
generally, renders it more likely to take on disease 
and the Times newspaper, in an ably written article 
on tile Report of the London Board of Health, in 
1849, has the following observations“ It is not 
remarkable that diseases so externally difl'erent as 
plague, typhus, scarlatina, yellow fever, influenza, 
and cholera, should have been thought to depend 
each on their own specific contagions, but the 
report before us enumerates the following impor¬ 
tant conditions ns characterising the entire class:— 
‘They are all fevers; they are all dependent on 
certain atmospheric conditions; they all ohey 
similar laws of diffusion ; they all infest the same 
sort of localities ; they all attack chiefly the same 
classes, and, for the most part, persons of the like 
ages; and their intensity is increased or diminished 
by the same sanitary and social conditions.’ In 
fact, there is not wanting evidence to show that 
epidemics, in all ages, have resulted from the same 
infraction of sanitary rules, and that the particular 
form assumed by each at its outbreak is determin¬ 
able by the accident of atmosphere or season. 
AVhat is influenza one year is cholera the next; 
what is plague in one latitude becomes typhus in 
another." Let not, then, quarantine laws, cordmes 
sanihiires, or any such contrivances, lull us into a 
false security; for if we neglect proper sanitary 
precautions, “ the pestilence that walketh by noon¬ 
day” will surely break out in the midst of us, 
perhaps when we least expect it. Contagion is 
clearly not necessary to the production of diseases 
of this class. There must be, at some time, and in 
some place, a first case occurring irrespective of it, 
and surely the conditions, whatever they may be, 
capable of producing one such case, must be 
equally fit to cause ally number of subsequent ones. 
That any of them may possibly be capable of 
propagation in this manner afierwards is of no 
consequence to my argument. The spontaneous 
outbreak of hydrophobia amongst the dogs in the 
Mauritius, within the last few years, is a case in 
point. 
The habit of attributing bodily suffering, whe¬ 
ther individual or general, to Divine judgment 
upon moral guilt is as old as the Patriarchs, and 
prayers, humiliations, and fastings have been 
considered ail that was necessary to propitiate 
the supposed wrath of God. So the (down in the 
fable is represented as praying to Hercules to lift 
his waggon out of the quagmire into which it 
had sunk. The rebuke he received will equally 
apply to ourselves, if we trust solely to such 
means for relief from physical evils induced by 
our own negligence or ignorance of the laws by 
which the universe is governed. We must first 
put our own shoulder to the wheel, and we may 
then properly appeal to the Throne of Grace for 
a blessing on our end javours. The experience 
of tlie mother-country ought to prove to us the 
danger of delay, and how all but impracticable 
the simplest reforms become when time has al¬ 
lowed the rise of a rampart of vested rights and 
conflicting interests arouud the abuses of our 
social system. Ancient Rome, with its cloaca 
maxima, contrasts, in this respect at least, very 
favourably with our city of the south, which, in 
the 19th century, has been allowed to remain for 
more thau sixty years without a common sewer. 
It is not long since an attempt was made by a 
former Government to alienate a portion of one 
of the “ lungs” of the city for building purposes.. 
It is, however, among the few good tilings to the 
credit of the late Legislative Council, that this 
desecration was prevented. Had this species of 
tubercular disease onco been allowed to gain a 
footing, it would not, I fear, have been long be - 
fore the whole “ lung" would have been invaded. 
The Cleveland Paddocks, a part of which at 
least ought to have been reserved for the use of 
the inhabitants of that portion of the city, have 
been already sacrificed: and Grose Farm ap¬ 
pears to be rapidly following. Fortunately, 
however, for those who can avail themselves of 
it, the railroad comes in as a true sanitary, insti¬ 
tution, since by its means many will bo enabled 
to live out of town, and thus, by spending a 
large portion of their time, and more particu¬ 
larly that part of it devoted to sleep, in a 
