Entered, according to Act of Congress, in the year 1874, by

D. VAN NOSTRAND,

In the Office of the Librarian of Congress, at Washington, D. C.

PREFACE.

THIS little work has been prepared more especially for the use of a class of chemical students who devote a semester to the analysis of vegetable products and other organic mixtures, taking previously at least two semesters in qualitative and quantitative analysis. After working with this class for several years, without other aid than a manuscript digest of directions and references, the author is convinced that a compilation in this subject is desirable-not alone for students in special applications of chemistry, but for the convenience of every general analyst.

Proximate organic analysis is not altogether impracticable, and organic chemistry is not solely a science of synthetical operations even at present. It is true, as the chief analytical chemists have repeatedly pointed out, that in the rapid accumulation of organic compounds the means of their identification and separation have been

left in comparative neglect. It is true, also, that the field is limitless; but this is not a reason for doing nothing in it. Fifty years ago, the workers in inorganic analysis were unprovided with a comprehensive system, but they went on exploring the mineral kingdom and using their scanty means to gain valuable results.

That this compilation is a fragmentary and very brief exponent of this part of analytical science as it exists at present, the author is fully aware, but he hopes that, as a beginning, it may prove to be worth enough to afford an opportunity for its improvement hereafter.

UNIVERSITY OF MICHIGAN, September, 1874.