IN NATURE of February 21 (p. 390) appears a letter from Prof. Wyndham R. Dunstan in which he represents me as having concluded “that carbonic acid is essential to the rusting of iron ...

To connect worlds, one had to protect them. The Han emperors understood this, and the Great Wall was built over 11,000 ...

Sulfur, in the form of iron sulfide, can cause steel to be too porous and prone to cracking. Atomic number 16, atomic weight 32.064. Silicon (Si): Silicon is the second most abundant element in ...