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Technical application of ethyl chloride
EASTMAN
514
KODAK
COMPANY
NOTES.
[J. F. I.
the action depends upon increased adsorption of the developing agent. The bearing of this view, including the possibility of a solid complex formatioa between developer and silver halide on the mechanism of development is discussed, the mo’dification consisting in rega,rding the photo-chemical action of light and development as a process of coupling typified by: Light
-----+absorption ---+-nucleation Silver Halide adsorption --+--intermediate Developer-complex
---.-rearrangement and ,reduction
In addition there is a fogging action elf dilute iodide s’olutions, on silver bromide emulsio8ns, which is ascribed to nucleus infection of the grain. Technical
Applications
of Ethyl
Chloride
are
described
by
ALBERT HENNING in Journal of the Society of Chemical Industry, Tramsactious, 1920, xxxix, 1-8. Commercial ethyl chloride has a
high state of purity, it is not poisonous, and is not more inflammable than methylated spirit or benzine. High pressure apparatus is not required in its use, since its gauge pressure is only Ethyl 12 pounds per square inch at a temperature of 30~ C. chloride is used as an ethylating agent in the manufacture of dyestuffs and pharmaceutical products, as a solvent, as a refrigerant, and as an anEsthetic, either local or general. On the basis of its ethyl content, ethyl chloride is the cheapest ethylating agent ; when used for such a purpose in an autoclave, the stuffingbox of the latter should be provided with asbestos packing imEthyl chloride is a good solvent for pregnated with glycerin. fats, oils, and simple organic compounds, and may be used for their extraction. Organic compounds which contain several hydroxyl groups are dissolved to but a slight extent, if at all. A solid is obtained in crystalline form from its solution by cooling that solution ; if the solvent be ethyl chloride, the crystals may be obtained by evaporation of the solvent under reduced pressure, for the temperature of the solution then falls to -15” or -zoo C. Ethyl chloride is the best refrigerant for household machines, since it may be used at a low pressure, not exceeding 15 pounds per square inch. It is also used for this purpose in large machines on both land and ships. In chemical manufacture, when refrigeration is required, ethyl chloride may be used as the refrigerant, since it may be circulated directly through the apparatus; and circulation of cooled brine is entirely eliminated. When a spray of ethyl chloride is directed on a small object, the temperature of the latter may be reduced as low as -30” C. J. S. H.
514
KODAK
COMPANY
NOTES.
[J. F. I.
the action depends upon increased adsorption of the developing agent. The bearing of this view, including the possibility of a solid complex formatioa between developer and silver halide on the mechanism of development is discussed, the mo’dification consisting in rega,rding the photo-chemical action of light and development as a process of coupling typified by: Light
-----+absorption ---+-nucleation Silver Halide adsorption --+--intermediate Developer-complex
---.-rearrangement and ,reduction
In addition there is a fogging action elf dilute iodide s’olutions, on silver bromide emulsio8ns, which is ascribed to nucleus infection of the grain. Technical
Applications
of Ethyl
Chloride
are
described
by
ALBERT HENNING in Journal of the Society of Chemical Industry, Tramsactious, 1920, xxxix, 1-8. Commercial ethyl chloride has a
high state of purity, it is not poisonous, and is not more inflammable than methylated spirit or benzine. High pressure apparatus is not required in its use, since its gauge pressure is only Ethyl 12 pounds per square inch at a temperature of 30~ C. chloride is used as an ethylating agent in the manufacture of dyestuffs and pharmaceutical products, as a solvent, as a refrigerant, and as an anEsthetic, either local or general. On the basis of its ethyl content, ethyl chloride is the cheapest ethylating agent ; when used for such a purpose in an autoclave, the stuffingbox of the latter should be provided with asbestos packing imEthyl chloride is a good solvent for pregnated with glycerin. fats, oils, and simple organic compounds, and may be used for their extraction. Organic compounds which contain several hydroxyl groups are dissolved to but a slight extent, if at all. A solid is obtained in crystalline form from its solution by cooling that solution ; if the solvent be ethyl chloride, the crystals may be obtained by evaporation of the solvent under reduced pressure, for the temperature of the solution then falls to -15” or -zoo C. Ethyl chloride is the best refrigerant for household machines, since it may be used at a low pressure, not exceeding 15 pounds per square inch. It is also used for this purpose in large machines on both land and ships. In chemical manufacture, when refrigeration is required, ethyl chloride may be used as the refrigerant, since it may be circulated directly through the apparatus; and circulation of cooled brine is entirely eliminated. When a spray of ethyl chloride is directed on a small object, the temperature of the latter may be reduced as low as -30” C. J. S. H.