Alkylation reaction cells layer

A complicating feature proved to be the fact that some alkyl radicals also induced the blue color, although it appeared possible to allow for this by varying the distance of the molybdenum oxide layer from the front face of the reaction cell. The silica surfaces were at first thought to be perfect reflectors for H atoms, but corrections were applied subsequently by Allen et al. (2) when this was found not to be strictly correct. 

---