All rights reserved
TO
PROFESSOR ANGELO MOSSO
OF TURIN
from whom both have received many kindnesses of a personal character, and to whom one of us is indebted for furtherance in scientific research, we offer our sincerest thanks, with the assurance that we have looked upon the translation of this splendid little work, as the fulfilment of an agreeable duty.
E. L. and F. K.
August 1895