PRESERVATION OF FISHERY PRODUCTS FOR FOOD. 
519 
in tliis way, but the extra cost of packages and the increased facilities for handling 
opened oysters in larger packages have almost entirely done away with the shipment 
in cans. It is yet ijracticed along the Gulf of Mexico, especially on the Texas coast, 
and at a few points along the Atlantic coast and in the interior of the United States. 
CANNING SOFT CLAMS. 
The soft clams arenaria) of the New England coast have been canned in 
quantities of greater or less extent for thirty years or more, principally by establish- 
ments ill Maine as a minor jiart of their output. There are also a few canneries of 
which the xRdncipal output consists of clams. The first clam cannery in this country 
was established at Pine Point, Me., 8 miles west of Portland, by Messrs. Burnham & 
Morrill. 
The process of canning in general use is as follows: First the siphon or “snout” 
is cut olf, the thin skin or film covering removed, and the clams cleaned in the same 
manner as when jirepared for the table. They are then placed in tin cans, holding 
from G^- to 12 ounces, after which the cans are nearly filled with the liquid, diluted 
with either fresh, salt, or sea water, and the covers soldered on. The cans are next 
placed in crates and the contents are cooked in a tank of boiling water, the time of 
boiling depending on the freshness of the clams, usually continuing about 2 hours 
when the clams are fresh, and a trifie longer if they have been out of water several 
days. Th^ cans are at once vented and again sealed and boiled about 1.1 hours, when 
they are ready for labeling and boxing. 
In some establishments a lining of white pajjer is jdaced on the bottom, around 
the sides, and at the toj) of the can, to prevent the contact of the contents with the 
tiu, which sometimes results in the clams turning dark. 
The xmoduct of canned clams in the United States at present amounts to about 
40,000 cases annually, valued at $2.50 to $3.50 per case. 
CANNING MACKEREL. 
There are three distinctive varieties of canned mackerel xmepared in this country, 
differing entirely in tlie methods of i)rei)aration and alike only in that they are sealed 
in tin cans: (1) fresh mackerel cooked in the manner usually ai)plied to salmon — the 
oldest and most extensively used process; (2) broiled mackerel; (3) brine-salted mack- 
erel, which are placed in tin cans sinqdy for convenience in marketing.. 
MACKEREL PLAIN-CANNED. 
The iireparation of the first variety of canned mackerel was begun in this country 
in 1843 by Messrs. Treat, Noble & Holliday, of Eastport, Me., and was carried on 
by tliem incidentally with the canning of lobsters. During several years following 
1843 the output was very small, averaging about 5,000 1 -pound cans per year, the 
public being somewhat slow to fully appreciate the qualities of the ])roduct, but from 
that date to the present time the business has been continued on the Maine and 
Massachusetts coasts in counection with lobster and otlier canneries, and the extent of 
the product has fluctuated from year to year according to the abundance of mackerel 
on the coast. 
In canning fresh mackerel it is ipiite essential that the lish be prepared as soon 
as practicable after being removed from the water. In dressing them the heads, tails. 
