1864.] 
of oxygen commences; the wine 
loses some of its qualities and ac- 
quires new ones. In a word, it ac- 
quires age. But this absorption 
may be hindered or interrupted by 
the production of many kinds of 
vegetables ; true parasitic growths, 
which act like ferments, and so form, 
by their own peculiar influence, 
those wines which are commonly 
named in France sour or acid wines, 
sweet, bitter, turned, and dry wines. 
M. Pasteur, without any hasty at- 
tempt at imposing new names on 
each of these vegetable forms (and 
in this respect how few botanists 
would have imitated him), regards 
them, nevertheless, as so many dis- 
tinct species, which, by their special 
action, cause the disagreeable char- 
acters of which we have just spoken ; 
and he adopts this practical applica- 
tion well worthy of attention. 
The disagreeable flavour of acid 
wines, of those which are sweet, 
bitter, changed, &c., cannot be re- 
cognized by taste until the change 
is far advanced, and it is no longer 
possible to apply a remedy to the 
mischief; while by microscopic ex- 
amination the destructive crypto- 
gam may be discovered as soon as it 
is fairly developed, and its increase 
may then be checked. A wine may 
thus be out of condition for a long 
time before its state is really sus- 
pected, and microscopic examination 
alone can ensure the detection of this 
state, or watch over its progress. 
Doubtless it will be long before 
full use is made of these scien- 
tific data, as well as of the micro- 
scope ; but we shall not be the less 
indebted to M. Pasteur for having 
entertained the happy idea of apply- 
ing his researches, tirst undertaken 
from high and purely theoretical 
views, to the benefit of a branch of 
industry so widespread as that of 
the manufacture and preservation 
of wines. 
Although the variability in a spe- 
cies is considered by some natural- 
ists to be unlimited in extent, yet in 
Notes and Correspondence. 
577 
the case of man the races to which 
it has given rise are, some of them 
at least, so characterized and fixed 
as to have been regarded by cer- 
tain ethnologists as distinct spe- 
cies. Now, however, the impression 
exists, and in this there is very 
general agreement, that only one 
single species should be admitted 
for the human race. But this very 
intricate and difficult question still 
remains to be solved: Do the dif- 
ferent human races spring from one 
and the same stock very widely 
modified, or were they distinct at 
their origination ? 
The perplexity we experience 
in giving a satisfactory answer to 
this query must cause us to wel- 
come with the most lively interest 
all observations which are able to 
throw any light upon it; and in 
this view we shall here refer to the 
researches that M. Tremaux has 
just laid before the Academy of 
Sciences, for the purpose of showing 
that in spite of the most distinctive 
characteristics which appear to 
divide these races, they may still 
merge one into another. M. Tre- 
maux was induced, by a concurrence 
of private events, to undertake a 
long expedition towards the source 
of the Nile, and whilst there he was 
led to make some observations, 
the results of which, if they are 
confirmed by subsequent inquiry, 
will become of very material value. 
He has remarked that the physical 
characteristics of the white races 
are changed into those of the black 
to the south of the mountains 
of Upper Egypt, and that on the 
other hand the black races become 
white towards the north. In deli- 
neating upon a map the position 
of the peoples of the Soudan, he has 
drawn tortuous lines, representing 
promontories, gulfs, and islands, as 
the limits of the various tribes, and 
corresponding to the variations in 
the tribes; and he has found that 
this map, originally intended only 
to give an idea of the ethnography, 
has proved in reality to be the 
geological map of these countries. 
