PRESERVATION BY DRYING. 239 
It is well to remember that drying and smoking do not kill the animal 
parasites that may be in the meat, like trichina or tape-worms. 
Fruit. The drying of apples, squashes, pumpkins, and other 
vegetables is a common process of farm life. In warmer regions of 
the earth the sun's rays are sufficient to dry many fruits for preserva- 
tion. Raisins and figs are thus prepared. In colder regions arti- 
ficial heat must be employed. By the use of artificial heat it has 
been found possible to preserve, by drying, a large number of fruits. 
Pears, prunes, plums, raspberries, blackberries, blueberries, and straw- 
berries represent some of the farm products which readily yield to 
this method of treatment. In fruit prepared in this way the water 
is not all removed, sometimes as much as 30 per cent, being left. 
In most cases there is considerable sugar in the dried product which 
aids in the preservation. In pears there is some 30 per cent, of 
sugar, while in raisins there is about 60 per cent. It must always 
be remembered that drying does not destroy the bacteria, but only 
checks their growth, and if the fruit has been exposed to a possible 
contamination of pathogenic bacteria, the drying does not remove 
the danger. This method of preserving fruits naturally affects their 
flavor and is frequently quite unsatisfactory for this reason, although 
it does not materially affect their nutritive value. In recent years 
hydraulic pressure has been used to extract the water with results, 
on the whole, superior to the extraction by simple drying. 
Hay. One of the most important applications of the drying 
process is in the preparation of hay. The fresh grass contains 
so much moisture that it could not be preserved in masses without 
undergoing extensive decomposition, and to obviate this the farmer 
resorts to the simple plan of drying out some of the water. But 
this phenomenon of drying is not always as simple as it looks, and 
sometimes a fermentation is certainly involved. Where the climate 
is moderately dry and the sun hot, the simple method of exposing 
the grass to the sun for a few hours is most widely adopted. But 
such a method is not possible in regions where there is likely to 
be a great deal of rain. 
Curing of Hay by Self -fermentation. In countries where rains 
are frequent and sunshine rare, the sun's rays cannot be depended 
