MANUFACTURE OF COAL-GAS.

25

which occupies two volumes, or exactly one-half of the space occupied by the hydrogenbefore combination.

The following diagram represents the composition by volume of all the compound gasesand vapours which are of importance to the gas manufacturer. The column headed “ beforecombination ” represents the gaseous volume of the elements composing such gas or vapourbefore their chemical union ; and a comparison of this column with that headed “ after com-bination ” shows the amount of contraction which has occurred at the moment of combina-tion. The letters O, H, and C are employed to indicate respectively oxygen, hydrogen, andcarbon, O representing sixteen parts, by weight of oxygen, H one of hydrogen, and C twelveof carbon.

VOLUME BEFORE COMBINATION. VOLUME AFTER COMBINATION.

HI

Vapour of Water .

. |0

H

. |0 He

Carbonic Acid .|C

LightCarburetted Ilvdrogen... IC

0

1C

o

. |CO,|

H

H

|c

U

H

. \ciR

Olefiant Gas

IH HHill,

|C 2 HJ

Acetylene

CJH

C|H

|C 2 Ho|

Propylene

H HHH H H

|C a .IL i

Butylene

C C IIHHHC, C H H H H

|c,n 8 ;

Naphthaline Vapour

C H

H

C1 H

H

C

ClC

C H

H

c

c“c

C H

H

Turpentine Vapour

C

c

H

H

H

H

C

c

H

H

H

11

1C

c

c

H

H

H

H

C

c

c

11

H

II

H

IC 10 H 8 |

CinH

10 niel

E