power will be contrary to that of one of the tartrates,
and will exalt that of the other. What will be the out-
come of this internal conflict on the physical and chem-
ical properties of the compound? It does not seem,
a priori, that it will be expressed externally in the same
way as the harmonious dissymmetry of the tartrates.
What does experiment say?

Impelled by this ingenious and original idea, which,
let us remark, was, moreover, from the point of view
of the history of his mind, a logical consequence of his
conceptions, Pasteur tried, in fact, to combine with
active malic acid and its compounds, the right- and left-
handed tartaric acids and their compounds, asparagin
with the two tartaric acids, etc. Between the different
substances thus produced he actually determined some
differences greater than those existing between the
corresponding substances formed by means of inactive
bodies. But the results are clearer when one combines
the tartaric acids with the organic alkalies of plants,
quinine, cinchonine, brucine, strychnine, etc., endowed
also with the rotary power. The identity of the chem-
ical properties which existed in the tartrates with
mineral bases disappears. The right- and left-handed
tartrates of the organic alkalies are no longer either equally
soluble or equally hydrated. They bear very unequally
the action of heat, and they lose more or less easily their
water of crystallization. If by chance their chemical
formula is the same their crystalline forms are different
and incompatible. Finally, sometimes, with aspara-
gin, for example, combination is possible with the right-
handed body, impossible with the left. As for their
rotary powers, instead of being equal and opposite, as in
the case of the combinations of the tartaric acids with
mineral bases, there may be either addition or subtrac-
tion, and the resultant deviation is very different in the

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