The physiological value of the starches and sugars lies in the fact that they are oxidized in the body, and a certain amount of energy is thereby liberated.

Quinine, C{20}H{24}N{2}O{2}, when carefully oxidized with chromic acid or potassium permanganate, yields a series of products.

When its alcoholic solution is treated with ferricyanide of potassium it is oxidized to dipyridine, C{10}H{10}N{2}.

To allay alarm in the minds of those who fear they might swallow pellets of solder, I may add that Pereira cites Proust for the assurance that an alloy of tin and lead is less easily oxidized than pure lead.