FOR the analysis of the nitrate content of sea water, and for certain tests on alkaloids, it is necessary to have sulphuric acid free from all but the most minute amounts of nitric acid. After testing ...

If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the ...

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 ...