THE VEGETABLE GARDEN 239 



the requisite degree of cleanliness is not observed in their packing. 

 Happily, however, such carelessness is not general. 



Every housewife may run a miniature canning factory in her 

 own kitchen, and on the farm this is especially economical and 

 desirable, the economy being less pronounced in the case of city 

 dwellers, who must buy their fruits and vegetables. Enough vege- 

 tables annually go to waste from the average farm garden to supply 

 the table during the entire winter. But usually the farmer's wife 

 cans her tomatoes, preserves her fruits, and leaves her most whole- 

 some and nutritious vegetables to decay in the field, under the 

 impression that it is impossible to keep them. This is a great mis- 

 take. It is just as easy to keep corn or string beans as it is to keep 

 tomatoes, if you know how. 



Sterilization. The great secret of canning or preserving lies 

 in complete sterilization. The air we breathe, the water we drink, 

 all fruits and vegetables, are teeming with minute forms of life which 

 we call bacteria, or molds, or germs. These germs are practically 

 the sole cause of decomposition or rotting. The exclusion of air 

 from canned articles, which was formerly supposed to be so impor- 

 tant, is unnecessary provided the air is sterile or free from germs. 

 The exclusion of air is necessary only because in excluding it we 

 exclude the germ. In other words, air which has been sterilized 

 or freed from germs by heat or mechanical means can be passed 

 continuously over canned articles without affecting them in the 

 least. If a glass bottle is filled with some vegetable which ordinarily 

 spoils very rapidly for instance, string beans and, instead of a 

 cork, it is stoppered with a thick plug of raw cotton and heated 

 until all germ life is destroyed, the beans will keep indefinitely. The 

 air can readily pass in and out of the bottle through the plug of 

 cotton, while the germs from the outside air cannot pass through, 

 but are caught and held in its meshes. This shows that the germs 

 and their spores or seeds are the only causes of spoilage that we 

 have to deal with in canning. 



Germs which cause -decay may be divided into three classes 

 yeasts, molds and bacteria. All three of these are themselves plants 

 of a very low order, and all attack other plants of a higher order 

 in somewhat the same way. Every housewife is familiar with the 

 yeast plant and its habits. It thrives in substances containing sugar, 

 which it decomposes or breaks up into carbonic acid and alcohol. 

 This fact is made use of in breadmaking, as well as in the manu- 

 facture of distilled spirits. Yeasts are easily killed, so they can be 

 left out of consideration in canning vegetables. Molds, like yeasts, 

 thrive in mixtures containing sugar, as well as in acid vegetables, 

 such as the tomato, where neither yeasts nor bacteria readily grow. 

 Although more resistant to heatLthan yeasts, they are usually killed 

 at the temperature of boiling water. As a general rule, molds are 

 likely to attack jellies and preserves and are not concerned with the 

 spoiling of canned vegetables. The spoiling of vegetables is due 

 primarily to bacteria. 



The reproduction of bacteria is brought about by one of two 



