1. The Second Book of Moses, Exodus, Chapter 15, Verse 25.
2. The Works of Aristotle, Meteorologica II. 3, 359a (B. C. 330).
3. H. S. Thompson, J. Roy. Agric. Soc., 1850, 11, 68.
4. J. T. Way, J. Roy. Agric. Soc., 1850. 11, 313; 1852, 13, 123.
5. H. Eichorn, Pogg. Ann. Phys. Chem., 1858, 105, 126.