there appears within five minutes a distinct violet tinge. The presence
of essential oils gives rise to a partial reduction of the permanganate
without affecting the conversion of alcohol into aldehyd.

* * * * *




ON THE CALORIFIC POWER OF FUEL, AND ON THOMPSON'S CALORIMETER.

By J.W. THOMAS, F.C.S., F.I.C.


A simple experiment, capable of yielding results which shall be at least
comparative, has long been sought after by large consumers of coal and
artificial fuel abroad in order to ascertain the relative calorific
power possessed by each description, as it is well known that the
proportion of mineral matter and the chemical composition of coal differ
widely. The determination of the ash in coal is not a highly scientific
operation; hence it is not surprising that foreign merchants should
have become alive to the importance of estimating its quantity. While,
however, the nature and quantity of the ash can be determined without
much difficulty, the determination of the chemical composition of
coal entails considerable labor and skill; hence a method giving the
calorific power of any fuel in an exact and reliable manner by a simple
experiment is a great desideratum. This will become more obvious when
one takes into consideration the many qualities and variable characters
of the coals yielded by the South Wales and North of England coal
fields. Bituminous coals--giving some 65 per cent, of coke--are