October 29, 1870.] 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
355 
tout has this peculiarity, that it dissolves easily in a mix¬ 
ture of alcohol and ether. He put into a tube a plug of 
this gun-cotton, and then, by means of an aspirator, he 
drew air through this strainer for a long time, until he 
had collected quite a quantity of dust. He then took 
this gun-cotton with the dust upon it, and put it into a 
t;ube, where he poured alcohol and ether upon it until 
the cotton was dissolved, and nothing left but the dust. 
In that manner he got the lightest portions of the dust 
and the heavier portions by themselves, as they very 
soon subsided in the liquid in which the gun-cotton had 
been dissolved. He then poured fresh alcohol upon them, 
.so as to thoroughly cleanse them, and then put them 
under the microscope, in order to examine the particles 
of which they consisted. He found in this dust a great 
many particles of sand, calcic carbonate, and other 
mineral particles, as would naturally be expected, and 
also a great quantity of organic matter—little particles 
of cotton wool, wood, and so on, and mixed with these 
'he found some little spherical or oblong particles of very 
different sizes, and. of some considerable varieties of 
shape. Some of these little round particles he found 
-consisted of mere starch, and many of you are, no doubt, 
aware that starch consists of little spheroidal masses of 
different sizes. These he got rid of by a solvent, and 
others were then left, which resembled in their appear¬ 
ance so closely the germs of various fungi and organisms 
of those kinds and eggs of animalcules that they were, 
to outward appearance, undistinguishable from them. 
He then took a liquid which had been boiled, but which 
was capable of decomposing—such a one as I mentioned 
here—by the action of any of these substances, and he 
put it into a flask, with precautions which I will not de¬ 
tain you by mentioning now, more than to say that he 
slid into this liquid, which had not got anything present 
to induce the formation of organisms, some of the gun¬ 
cotton with the dust yet in it. It was the same thing as 
T mentioned before, only that the substance had got 
some of this dust from the air added to it; and he found 
/that he also got the formation of organisms very readily 
< and abundantly. He found that these little particles, 
which were to the eye undistinguishable from germs and 
■spores, behave towards liquids of this kind just as if they 
were so. In various other ways the same form of expe¬ 
riment has been repeated, and uniformly with the same 
result, viz., that when Little particles collected from the 
air, particles of extreme tenuity, are put into a liquid 
susceptible of undergoing decomposition, a great variety 
of organisms will make their appearance, just as if their 
seed had been sown in the liquid. This circumstance is 
one which, I think, will justify us in going back to what 
I told you of Pastern'’s previous observations. I told 
you that he opened a number of the little bulbs which 
had contained yeast-water and sugar, so as to allow the 
-air to rush into them. He found that, in some cases, he 
-got one kind of organism produced, and in others an¬ 
other ; in fact he got a great variety. But if, instead of 
allowing the air to go into these bulbs in this way, he 
poured the liquid out into an open vessel, he always got 
ihe same sort of organisms; there was no variety. The 
appearance of the particles which resembled germs is, as 
I said, exceedingly various, and there are many reasons 
to suppose that if there are the germs of these organisms 
in the air, there must be an.immense variety of them, a 
•variety so great that we could not even venture to guess 
.at its extent at present. When the liquid had free ac¬ 
cess to all of them, it is found, for reasons which would 
oasily suggest themselves, on reflection, to anybody, that 
some of them, those which can thrive best upon the par- 
iicular substance, develope themselves to the exclusion of 
-the rest. I will give you one or two examples of the 
influence of food upon the development of ferments, in¬ 
stances which are well known, and are of some im¬ 
portance, as serving to prove the point which I have 
just mentioned. You are aware that the mixture which 
J have been speaking of, yeast-water with sugar, can be 
made to undergo alcoholic fermentation. I have already 
referred to it repeatedly in that point of view. We can 
make it undergo alcoholic fermentation if we put some 
alcoholic ferment into it, and keep it at a proper tem- 
pei'ature; but if, instead of putting some number of 
cells—and even a few grains weight consist of an enor¬ 
mous number of cells—if, instead of that, we were merely 
to leave some of this liquid in contact with the air, we 
should have no alcoholic fermentation set up in it. That 
particular mixture of yeast-water and sugar does not, 
when exposed to all these germs, get yeast-cells deve¬ 
loped in it, at all events not to any perceptible extent. 
Instead of that, it gets cells formed which are similar 
to those in the second bottle I showed you, which is 
forming lactic acid, that is to say, the lactic fermentation 
will set in. The fact is, that the liquid is unwholesome 
for these particular cells; and does not agree with the 
alcohol cells, or yeast-cells, so that if a gx-cat number of 
various germs are thrown into these particular sub¬ 
stances, those which can thrive better, which are the 
lactic acid cells, develope themselves, and the alcohol 
cells do not. Again, if instead of taking this decoction 
of yeast and sugar, you were to take some grape juice, 
you would have alcoholic fermentation at once. That 
is the way it is done. If I were to leave a decoction of 
malt in contact with the air, in the same manner you 
would get the same thing set in as a rule. Again, if 
some of the liquid which I have in the glass dish here— 
some of the yeast-water with a little alcohol and acetic 
acid—be left in an open vessel, it gets an organism formed 
upon it; in fact, that is a process which Pasteur recom¬ 
mends for getting vinegar cells, if you want any. He 
says the air will, if you give it time, and supply the re¬ 
quisite conditions, start these cells in that mixture, but 
no alcohol cells, nor lactic acid cells, can be grown in it. 
It does not suit them; it is a substance which stfits 
vinegar cells, and them only. Whatever may be the 
variety of the cells present in the air, it only developes 
those of that particular kind. 
(To be continued.) 
ASSOCIATION OF MEDICAL OFFICERS OF 
HEALTH. 
The First Meeting of this Association for the season 
was held on Saturday, October 15, at the Scottish Cor¬ 
poration Hall; the President, Dr. Druitt, in the chair. 
Specimens of the new antiseptic chlor-alum, White- 
head’s soup squares and meat preserved by Mr. Richard 
Jones’s process were exhibited. 
Mr. Rogers introduced the subject of the registration 
of disease, which he advocated with great earnestness. 
Dr. Druitt read an address on the Sanitary Topics of 
the Day. Alluding to the prevalence of scarlet fever in 
the metropolis, he said that this was the season when it 
might be expected to increase after a partial diminu¬ 
tion during the summer months. In the week ending 
October 8, 192 deaths from this disease were reported, 
being the largest number registered since last December. 
It was clear that we wanted a registration of disease, 
coupled with a provision for making its existence known 
to the sanitary authorities. The existence of scarlet 
fever in a house instead of being made known, is, from 
various reasons, studiously concealed. It was clear that 
scarlet fever is propagated by the bodies of the sick, and 
the clothes, apartments, etc., contaminated by them, or 
by such causes as fermenting heaps of impurities, recep¬ 
tacles of excretions, drains, and the like. He believed 
scarlet fever to be emphatically a product of sewer 
gases. In disinfecting pipes and sewers by carbolic 
acid a sufficient quantity should be used to drench the 
whole canal, as infusoria in putrid water are not killed 
until the acid is freely used. As a disinfectant for rooms 
and bedding, he preferred the fumes of burning sulphur 
to any other. He advocated periodic fumigations of 
crowded houses; the drenching of drains, closets and 
