Uses, tests for purity and preparation of chemical reagents : employed in qualitative, quantitative, volumetric, docimastic, microscopic and petrographic analysis, with a supplement on the use of the spectroscope

Front matter

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Preface

sions which may have occurred are certainly not intentional. Out of the vast amount of material before him he has selected what appeared to him most important, and in regard to critical sifting he has spared no effort. Many of the new reactions were thoroughly tested before admitting them, and hundreds of experiments were made to verify statements in regard to the reliability of new methods.

There being only metric weights and measures referred to in the volume, and therefore no possible chance of a mistake, the author may perhaps be pardoned the liberty of abbreviating gramme by gr.

As the spectroscope forms so valuable an adjunct to the means of analytical research, a short chapter has been added, describing the use of the simpler and inexpensive forms usually employed in the laboratory, with the aid of the accessories everywhere at hand. The descriptions of the spectra give the position of lines and bands aecurately by wavelengths, so that they may be conveniently mapped out on diagrams. A number of plates illustrate the text and afford aid in the identification of the spectra. As only a limited number could find a place in the short chapter, the author has selected of the emission spectra such as may be easily produced by the aid of a Bunsen gas burner, or a strong alcohol lamp, and of absorption spectra those of the coloring constituents of blood and such materials as might be most easily mistaken for them, some others referring to the detection of adulteration of red wine, or illustrating chemical reactions (e. g. furfurol-urea) or identifying color reagents used as indicators in volumetric work.

The author hopes that his colleagues of the craft may find his little volume of some use to them, and that they will pass a lenient judgment on its short-comings.

CHAS. O. CURTMAN.

St. Louris, Mo., March, 1890.