Acids as 
Preservatives 
Essential 
Oils 
Salt 
72 HOUSEHOLD BACTERIOLOGY 
a condition is not one of sterility—are so many that 
the cold place adds the antiseptic “ounce of preven¬ 
tion.” So far as the bacteria are concerned, in the 
sunshine would be the best place to keep such stores. 
This, however, would in time fade the food and under 
some conditions would help to dry it, or crystallize the 
sugar. Here, as elsewhere, there must often be a 
choice among unfavorable conditions. 
Some food supplies, like rhubarb, are so strongly 
acid that bacteria will not grow in them. This is some¬ 
times canned in cold water with no cooking. Toma¬ 
toes and cranberries are sometimes canned in this way. 
Bacteria do not like strong acids, so the housewife 
saves her cucumbers, tomatoes, etc., by making them 
into pickles. These, however, will mold. 
The essential oils, as clove, cinnamon, mustard, etc., 
are antiseptic in their effects. They possibly lend their 
aid in the preservation of the fruit as well as in adding 
flavor. Mustard, especially, has strong disinfecting 
properties. Perhaps this is its greatest value as a con¬ 
diment, for it may act upon the bacteria liable to cause 
fermentation in the digestive tract. 
Strong solutions of salt prevent the growth of bac¬ 
teria. Common salt, both in brine and as powder, 
is perhaps the oldest preservative, and although it 
makes most food stuffs less digestible it is probably 
the least harmful of any antiseptic substances. This 
cannot be said of borax, boracic acid, salicylic acid, 
the sulphites and formaldehyde (formalin) ; all of 
