Miscellaneous Intelligence. 297 
generated in the respiratory process of animals, viz. carbonic acid and 
water. The solid pasteies of carbon which they deposit in the interior 
of the flame, and w are the source of light, are entirely consumed 
on arriving at its iia boundary ; their use as sources of artificial light 
under proper regulations is therefore quite compatible with the most 
stringent sanator nee 
In the usual proc s of gas manufacture there are generated in addi- 
jess to these oninatiog b hydrocarbons two other classes of gaseous 
nstituents, viz. impurities and diluents. With the exception of bisul- 
these compounds, .as it will probably be found impossible to remove 
them from the gas when once they have been forme 
addition to traces of thes Soy pus Lmmocata: ‘purified coal gas 
Citdnins only the following guint 
Formula. 
Olefiant gas, - - - C2He 
Illuminating Ac bites ? - - : - CsHs 
constituents. ) Butylen - - CsHe 
Other nT - - unknown. 
Light carburetted hy aroaee - CH2* 
Diluents. | Hydrogen, - : H 
The light emitted during the combustion of ical gas is due entirely 
to the first or illuminating class of Se which yield an amount 
of light proportional to the quantity of carbon contained in a given vol- 
the pala of smoke attendant on imperfect soa ilu- 
ting material is therefore necessary to give the flame a sufficient vol- 
ume, so as to separate the particles of —— reese asunder, and thus 
diminish the risk of their imperfect combus 
All the three diluents above mentioned ae rm this office equally 
well; but if we study their behavior during combustion we shall find 
that in a sanatory point of view, hydrogen is greatly to be preferred. 
The two —— most frequently ian against the use of gas in 
— ta been described as possessing a certain am of illu 
ting power, but a specimen of it brought from the coal strata ~antae Chat Mosk 
Lancashire’ rosa that it zee fe eee more light than hydrogen or carbonic o oxyd 
consumed from 
Szconp Szams, Vol set i ape 1854. 38 
