y article of diet with the natives in this country."[12]

With regard to the time stated for the fermenting process, it must be
noted that since the subject has been investigated so thoroughly, the
time required for fermentation has been found to be nearer ten than
three hours, but this will be dealt with in a subsequent chapter.

Historically it may be gleaned from the fragmentary references which we
have given, that soured milk has, from time immemorial, formed the
principal article of diet of a great many peoples, and the notable
feature in connection with it is, that in some countries where it is in
daily use, the age limit for human beings seems to be very much
extended, and it would appear that there is a direct connection between
the use of soured milk and longevity. In Bulgaria, for example, it is
stated that the majority of the natives live to an age considerably in
excess of what is recognised as the term of life amongst Western
nations, and inquiry has shown that in the eastern part of Southern
Europe, amongst a population of about three millions, there were more
than three thousand centenarians found performing duties which would not
be assigned to a man of sixty-five years of age elsewhere. It is quite
common to find amongst the peasants who live to such a large extent upon
soured milk, individuals of 110 and 120 years of age.[13]

In the ancient dairy practice, as we have seen, soured milk was the
principal product, and the extraordinary ages which are recorded of the
patriarchs, if translated into the modern denomination, would not appear
to be so imaginary after all, when it is considered that we have
thousands of examples at the present day of men and women enjoying quite
as long a term of existence. It has been noticed also, that while these
very old people are able to perform a certain amount of manual labour,
there is not the same tendency to the mental decay which is so prominent
and sad a feature amongst Western nations, at a period of about seventy
or eighty years of age. It would seem, indeed, as if the habit of living
long was well known in ancient times, and that, like many other of the
valuable arts and sciences, it fell under a cloud during the Middle
Ages, or, perhaps, the significance of the use of soured milk fell into
neglect, and, even after the revival of letters in the sixteenth
century, still remained obscure.

The discovery of micro-organisms in perishable products, which is
attri