4 U. S. BUREAU OF FISHERIES. 
chloride and 95.3 parts of pure salt required five days to penetrate 
fish to the extent that pure salt did in three days; and the same salt 
required nine days to penetrate as far as pure salt did in four and 
one-half days. It was found that salt apphed dry to fish penetrated 
fish as deeply in five days as saturated brine did in eight days. It 
was found that blood spoiled at a lower temperature than fish flesh, 
and that fish containing blood, roe, and milt spoiled at about 65° F., 
while thoroughly cleaned fish could be salted successfully at 90° or 
even 100° F. It remained, therefore, only to take advantage of these 
principles and to apply certain facts already known from other 
sources to hasten penetration of salt and retard decomposition of 
fish until they are preserved. 
PRINCIPLES OF IMPROVED PROCESS. 
The principles will now be taken up and discussed in such a way 
that by following in detail the method outlined it is believed any 
person can carry them successfully into practice. The principles 
are: 
1. Careful handling of fish before salting. 
2. Thorough cleaning, especially removal of all blood. 
3. Use of salt of a high degree of purity. 
4. Application of salt in the dry condition. 
To these should be added—if the fish are to be stored for any 
considerable length of time—storage of fish in brine. (There is 
considerable doubt of the feasibility of storing salt fish in very warm 
climates; until this subject is investigated it seems advisable to hold 
only in cool storage.) 
These principles are known, at least in part, to many experienced 
salters of fish, yet the combination of them all is rarely or never fol- 
lowed. The great difference that is made in the quality of salt fish 
by following them will be readily observed upon comparing the 
product with that of ordinary processes. 
1. CAREFUL HANDLING OF FISH BEFORE SALTING.—Two precautions 
are particularly important under this head, namely, to avoid bruises 
and to avoid warmth. Bruises promote decomposition of fish in the 
same way that they cause fruits to rot. Therefore, fish should not 
be forked, walked on, squeezed when taken from nets, nor packed deep 
in boats, boxes, or barrels, and care should be exercised to see that 
they are not crushed or bruised by large chunks of ice. Warmth, as 
every fisherman knows, hastens decomposition. It is best to put the 
fish in finely crushed ice immediately after capture, but if not so 
treated they should be kept as cool as possible and should be salted 
with the least possible delay. It is well to remember that fish are of 
about the same temperature as that of the water from which they 
come, and therefore fish taken from warm water should be handled 
more expeditiously than those from cold water. Fish should be 
shielded from direct sunlight and should not be allowed to dry, 
as the skin shrinks and loses its luster if dried. 
2. THOROUGH CLEANING, ESPECIALLY REMOVAL OF ALL BLoop.—It has 
been found in the case of river herring that blood spoils at a much 
lower temperature than flesh. These fish can be salted at from 90° to 
100° F. or higher if the blood is all removed, while those containing 
