CHLORINE.

217

Order IL—CHLORINE, AND ITS COMBINATIONS WITH OXYGEN.

CHLORIN'IUM.—CHLORINE.

History, Synonymes, and Etymology. —This gas was discovered by Scheelein 1774, who terraed it dephlogisticaled murialic ocid. Berthollet, in 1785,named it oxygenated murialic acid. Sir H. Davy called it chlorine (froraX**>Z°r, green.) on account of its colour.

Natural History. —It is found in both kingdoms of natnre.

*. In tue Inorgamzed Kingdom it exisls principally in combinalion vvith sndium,either dissolved in the water of the ocean or forming deposites of rock galt. Chlorinealso occurs in conibination with magnesium, calcium, lead, silver, &c. Free hydro-chloric acid is met with in the neighbourhood of volcanoes, and is probably produced bythe dccomposition of some Chloride.

ß. In the Organized Kinodom it is found, in combination, in both animals and vege-tables. Sprengel (De Candolle, Physiol. Vtg. tom. i. p. 220.) says, maritime plants ex-hale chlorine, principally during the night. Hydrochloric acid in the free State, exists,according to Dr. Prout, in the stomach of animals during the process of digestion.

Preparatton. —There are several methods of procuring chlorine gas:—

1. By adding Diluted Sulphuric Jlcid to a mixlure of Common Salt andJBinoxide of Manganese. —This is the cheapest and most usual method of pre-paring it. Mix intimately three parts of dried common salt with one part of thebinoxide of manganese, and introduce the mixture into a retort. Then add asmuch sulphuric acid, previously mixed with its own weight of water, as willform a mixture of the consistence of cream. (Brande directs 8 salt, 3 manga-nese, 4 water, and 5 acid;—Thenard, L| salt, 1 manganese, 2 acid, and 2 water;—Graham; 8 salt, 6 manganese, and dilule acid as much as contains 13 parts ofoil of vitriol.)

On the application of a gentle heat, the gas is copiously evolved, and may becollected over either warm or cold water. 1

In this process two equivalents or 80 parts of sulphuric acid reacton one equi-valent or 44 parts of the binoxide, and on one equivalent or 60 parts of chlorideof sodium, and yield one equivalent or 36 parts of chlorine, one equivalent or 76parts of the sulphate of the protoxide of manganese, and one equivalent or 72parts of the sulphate of soda.

MATERIALS.

leq. Chloride Sodium... CO

1 eq. Binoxide Manganese 44

2 eq. Sulphuric Acid..... 80

COMPOSITION.Chlorine ............ 36-

1 eq. ^^^^^^^^^^^^^^^^^^^^

1 eq. Sodium .............. 24^1

> 1 eq. Soda 32

( 1 eq Oxygen ............ 8 j

( leq. Protoxide Mang .....36>

: 1 eq Sulphuric Acid ..... 40

1 1 eq. Sulphuric Acid .....40

PRODUCTS.

—1 eq Chlorine.......... 36

1 eq. Sulphate Soda------

1 eq. Protosulphate \Manganese...%- \

. 76

2. By heating a mixture. of equal weights of common Hydrochloric Acid andBinoxide of Manganese in a glass retort over a lamp.

In this process two equivalents or 74 parts of hydrochloric acid react onone equivalent or 44 parts of the binoxide, and yield one equivalent or 36 partsof chlorine, two equivalents or 18 parts of water, and one equivalent or 64 partsof protochloride of manganese.

COMPOSITION. PRODUCTS.

MATERIALS.

3 eq. Hydrochl. Acid.... 74

1 eq. Binox. Mang.....44

118

1 eq Chlorine 36-

1 eq. Chlorine 36-

2 eq. Htjdrog. "

2 eq. Oxygen 161 eq. Mangan. 28-

118

-1 eq. Chlorine.

~2eq. Waler.................. 18

1 eq. Protochlo. Mang.........64

118

PivTnÄrinform.tion respecting tlrTc^ercial roode of preparing ehlorine, see Hypochlorit* tf Um,

Vol. I.— 28