PRESERVATION OF FISHERY PRODUCTS FOR FOOD. 
561 
Hydrocarbon gas. — This is substituted for the air which occupies the space in and 
around the substance to be preserved, subjecting the same to a temperature of about 
300 p, 'I'he gas is let into the package through a hole in the top and the air escapes 
through a hole in the bottom, and both holes are then closed. (Letters Patent No. 
45765, dated January 3, 1865.) 
Sulphides of carbon. — Fish are placed in a receiver and the air exhausted. Gase- 
ous bisulphide, protosulphide, or other sulphide of carbon is then let into the receiver 
under pressure and permeates the flesh. In combination with the sulphide is used 
phenic acid, methyl or other product of the destructive distillation of wood. (Letters 
Patent No. 85184, dated December 22, 1868.) 
Gelatin, lime, glycerin, etc. — Put the fish in an air-tight compartment and exhaust 
the air with a vacuum pump, then by means of a force pump introduce a solution of 
gelatin and bisulphite of lime. When completely saturated remove the fish and dip 
them in a concentrated solution of gelatin containing bisulphite of lime, glycerin, 
sugar, and gum. (Letters Patent No. 90944, dated June 8, 1869.) 
Glycerin. — Eemove from the fish all the refuse matter, such as skin, bones, etc., 
and then grind the residue and compress from it the watery portions, blood, and oily 
matter to whatever extent may be desirable, and then treat it with glycerin, regrinding 
the material during this process. The fish is then pressed into a compact mass and 
placed in any suitable wrapper of tin foil or other material, or boxed, (Letters Pat- 
ent No. 87986, March 16, 1869.) 
Glycerin and antiseptic salts. — Oysters, fish, and meats may be preserved by use 
of a mixture of glycerin with phosphate of soda, or other antiseptic salt in connec- 
tion with aldehyde, formic ether, or acid in a solution of carbonic acid, water, glycerin, 
etc., and the preserved substance is then covered with i>arafin or stearin. (Letters 
Patent No. 93183, dated August 3, 1869.) 
Saltpeter and alum. — The fish, either after or before they have been salted, are 
placed for 4 hours in a solution of saltpeter and alum, made in proportion of 5 pounds 
of saltpeter and 4 ounces of alum to 60 gallons of sea water. They are then dried either 
in the sun or by artificial means. If they are to be smoked, 2 hours in the solution 
is said to be sufficient. It is claimed that this process removes all tendency to sweat 
or decay. (Letters Patent No. 95179, dated September 28, 1869.) 
Soda and carbolic acid. — After being cleaned the fish are dipped in a solution in 
proportion of 5 gallons of water, 2 pounds of sulphite or bisulphite of soda, and 2 ounces 
of carbolic acid in crystals. • Oysters, clams, etc., may be dipjied in a solution of their 
own liquor and the chemicals. (Letters Patent No. 86040, January 19, 1869.) 
Thymol or thymate salts. — Place the fish, oysters, meats, or other animal substances 
to be preserved in solutions of thymol, thymic acid, or any of the thymate salts and 
water, alcohol, or glycerin, etc. (Letters Patent No. 108983, dated November 8, 1870.) 
Chloroform and ether, etc. — The meat or fish is placed in air-tight packages, into 
which is poured a small quantity of chloroform, which becomes vaporized and sur. 
rounds the substance with an atmosphere of vapor which acts as a preservative. The 
cans are then sealed and are ready for shipment. When needed for use the chloroform 
is removed by means of an air-pump. (Letters Patent No. 128371, dated June 25, 1872.) 
Borax, saltpeter, etc. — By the Herzen preserving process, meat is soaked from 
24 to 36 hours in a solution of 3 jiarts borax, 2 boracic acid, 3 saltpeter, and 1 salt, in 
100 parts water, then packed in some of the solution. Before use the meat must be 
soaked 24 hours in fresh water. 
