SEVERAL circulars recently received from the Bureau of Standards of the Department of Corn- merce, Washington, well illustrate the untiring in- dustry to be found in the American public offices.

Founded in 1780, the American Academy of Arts and Sciences is an international learned society whose members are the world's leading scientists, scholars, artists, business people, and public leaders.

OSMIUM tetroxide at 18s. a gram is the most expensive substance used in biological research. It is principally used in the Kolatchew and Weigl methods for the Golgi apparatus, and in the F. W. A. and ...

Scientific American is part of Springer Nature, which owns or has commercial relations with thousands of scientific publications (many of them can be found at www ...