Diazomethane is a yellow inodorous gas, very poisonous and corrosive.
A typical resin is a transparent or translucent mass, with a vitreous fracture and a faintly yellow or brown colour, inodorous or having only a slight turpentine odour and taste.
It is also advisable to wash all woodwork and gangways annually with a weak solution of formalin, or other inodorous germicide.
The waters are tasteless and inodorous, and contain calcium and magnesium bicarbonates, combinations of hydrogen and silicon, and of iodides, bromides and lithium.
A few do not exist ready formed in the plants, but result from chemical change of inodorous substances; as for instance, bitter almonds and essential oil of mustard.