A Manual of the Chemistry of the Carbon Compounds

08 THE CHEMISTRY OF
It is a colourless gas possessing an ammoniacal smell, and condensing
at + 8° to a mobile liquid.
Trimethylamine CH, J-N boils at -f 9-3°, possesses a strong smell of
CH.J
ammonia and herrings brine, and is miscible with water. It occurs
in many plants, as in the flowers of the hawthorn and the pear-tree,
and in Chmopodiuvi mdvaria, as well as in different animal liquids.'
Very often it is met with as a product of the decomposition of nitrogenous
animal or vegetable compounds; thus herrings' brine contains
it in so large a quantity that it can be easily prepared from it by distillation
with alkalis.
When trimethylamine is mixed with methyl iodide, heat is evolved,
tetramethylammmium iodide "S(CB^tl being formed, a salt which
forms colourless crystals and is not decomposed by alkalis. Ou treating
its aqueous solution with freshly precipitated silver oxide, a
strongly alkaline solution of the hydroxide N(CHg)40H is obtained,
which by evaporation in, vacuo over sulphuric acid is left behiud as a
crystalline mass, which is as caustic ns caustic potash. When exposed
to the air it rapidly absorbs water and carbon dioxide.
PHOSPHORUS BASES OF METHYL.
MethylphospJdiu H >-P.—The hydriodide of this base is produced
H J
on heating a mixture of methyl iodide, phosphoninm iodide, and
zinc oxide in sealed tubes for four hours to 150 :—
2CH8I + 2PH4I +• ZnO = 2(P(CHS)HS!.HI) + Zur, + H8O
On adding water the hydriodide splits up into hydriodic acid and
methylphosphine, a colourless gas, having a most penetrating and
overpowering smell. By pressure or cold it is condensed to a light
liquid, which boils at — 14°. On mixing the gas with air it takes
oxygen up, forming white fumes, and when gently heated it takes
fire. With acids it readily combines, forming well-defined salts,
which are all decomposed by water. These salts possess the remarkable
property of bleaching vegetable colours, whilst the free base does
not act upon them. This can be easily shown by holding litmus
paper, which has been partly moistened with an acid and partly with
water, in the gaseous base, when only the portion moistened with the
acid will be bleached. Amongst the salts the most characteristic is
the hydriodide N(CHg)HsI, obtained In compact crystals by passing
the gaa into most concentrated hydriodio acid, whilst from hydriodic
acid diluted with ether it crystallizes in iridescent platea
On passing methylphosphine into fuming nitric acid it is oxidised