This little book is a handy volume that may be carried in the pocket. That its teachings are sound is evident from the fact that it has passed through twelve editions. In the present edition, "the part relating to the compounds of oxygen has been in great part re-written and re-arranged to keep pace with the advances in organic chemistry so far as is possible in a work of this character." The orthography adopted by the American Association for the Advancement of Science has been adopted, and it looks a little queer to read of "sulfur" and the like, but as we have already become accustomed to "fluorin," "chlorin," " bromin " and "iodin," the shock is not great. This intensely practical age has little time to waste in writing and printing superfluous letters from mere etymologic reasons.