In the next Place we are to enquire into the Properties of Milk, and
to find out whence it hath such wonderful Powers in asswaging and
curing this Distemper. There are some Authors, especially the Followers
of _Sylvius_, who according to the chymical Scheme would have Milk
produced from the Blood in the following Manner; Chyle, which is of
a white Colour, may be turned into Blood by the Help of Alcalies;
and again the Blood may be reduced to Chyle by the Help of Acids.
_Junkius_, in his Chymistry, hath noted the Experiments when Milk is
to be turned into Blood: Take a Pound of new Milk, and mix with it an
Ounce of reverberated Salt of Tartar in a large Vessel; in a Quarter of
an Hour the Mixture shall turn into a Blood red Colour, several Fibres
swimming at Top like Cream. When the Blood is to be turned into Milk,
take any Quantity of the foregoing Mixture, and drop in some Vinegar,
and it shall immediately re-assume the Form of Milk. In the first
Experiment they alledge, that the crude Sulphur of the Chyle is by the
Alkali exalted into a red Sulphur; in the second, the exalting Alkali
is depressed by the Acid, whence the Sulphur returns to its original
white Colour. _Junkius_ is very justly doubtful of the Application
of this Experiment; how the crude Sulphur of the Chyle, as they call
it, should in so short a Time be changed into Blood by Alkalies, and
the Blood, exalted by so many Circulations, be again changed into
Milk by Acids, seems very strange. It requires a good deal of Time to
change the Chyle into perfect Blood, and the Blood again into Milk,
notwithstanding that Women who have no Milk find it in their Breasts
soon after Childbirth.