SALTIXG UlYER HEEEIl^G. 5 



blood will sour if salted at 65° F. In cool climates the blood may be 

 left in the fish if desired, as it imparts a distinct flavor, for example, 

 in the Scotch method of curing herring. But in warm climates, 

 where conditions are unfavorable at best, there is no choice but to 

 remove every trace of blood as well as all entrails and roe and the 

 head. To do this it is necessar}- to behead the fish, take out entrails, 

 scrape the kidney out (the bloody strip lying under the backbone), 

 and wash the fish thoroughly. (A 20-penny wire nail, the head of 

 which has been sharpened with a file, makes a convenient instrument 

 for scraping out the kidney.) Large fish may be split through the 

 back and laid open. The washing should preferabl}'^ be done b^' 

 rousing the fish in brine of about the strength of sea water, but it 

 may be done in cold fresh water. In the case of alewives or river 

 herring, the washing operation should also serve to remove scales by 

 vigorous rousing. It may seem that if the blood spoils at 65° F. 

 the meat of the fish would not necessarih' be ruined. But the taint 

 of spoiled blood is sufficient to make the entire fish unfit for food. It 

 is also probable that the presence of blood may initiate a kind of 

 decomposition of the flesh. 



3. Use of salt of a hkjii degree or purity. — This is tlie most im- 

 portant factor in salting fish in warm climates; yet some people are 

 inclined to (juestion the truth of this statement. Fishermen gen- 

 erally have no first-hand way of knowing whether or not any par- 

 ticular lot of salt is pure, as neither the looks of salt nor the claims 

 of advertising matter are always reliable indications of i)urity. By 

 purity is meant not cleanness but the scarcity of foreign sulDstance 

 in the salt. Salt may be highly impure j^et perfectly white and very 

 fine and clean, for the two most objectionable impurities, lime and 

 magnesium salts, are white, like salt. On the other hand, salt may 

 be dirty or colored, and yet if lime and magnesium salts are absent 

 may penetrate and preserve the fish. 



It is therefore necessary to have a salt of a A-ery high degree of 

 purity; that is, with less than 1 per cent total impurity. Tliere are 

 grades of salt on the market containing a total of less than one- 

 tenth of 1 per cent impurity.^ These salts are especially suitable for 

 salting fish by this method. Chemical analysis is the only reliable 

 guide to purity; most reliable dealers are able to give the correct 

 analyses of their brands of salt, and these figures should be required 

 before purchase. The figures for sodium chloride (pure salt) should 

 1)6 09 per cent or over — the higher the better. 09.96 per cent some- 

 times appearing. The figures for calcium (lime) and magnesium 

 salts should l)e as low as ])ossible. It makes little difference whether 

 they are sulphates or chlorides, any salt in which calcium and mag- 

 nesium taken together are more than 1 per cent should be looked 

 upon with suspicion for salting fish in warm climates. 



The presence of moisture does not cause the salt to be unsuitable. 

 If moisture is present, as it usually is, allowance should be made for 

 it; pure salt (sodium chloride) and moisKire added together should 



' NairuM of inanwfnrtiirorH of sntlsfactory brands of saU will bo suppllod on nppllratlon 

 to tliiK I'.iircan ; aiKo if aiiiilysis of a (-alt in furnished, the Bureau will, upon rtquest, give 

 opinion as to its suitability for curing flsh. 



