126 MASSACHUSETTS AGRICULTURE. 



4. It must be kept from too great a degree of heat, for 

 this is a most powerful agent in promoting fermentation. 



5. The proper temperature being ascertained, it must be 

 kept uniform. The expansion and condensation of the juices 

 by variations of temperature hasten their fermentation, instead 

 of permitting it to take place slowly and gradually, as desired. 

 But though it is well known that apples and pears may be 

 exposed to a temperature a few degrees less than 32° for a short 

 time without material injury, it is found that when kept long 

 at a temperature but little above freezing, the ripening process 

 is checked to such a degree that it is never perfectly resumed ; 

 and experience has shown that a uniform temperature of 40° is 

 as low as is advisable. Fruit may safely be exposed to still air 

 of less than 32°, when it would be injured in currents of the 

 same temperature. It seems hardly necessary to say that a 

 thermometer is indispensable in a fruit room. 



6. Light is one of the strongest stimulants of vegetable 

 growth. Its effect on the skin of the fruit continues, though in 

 a less degree, after it is separated from the tree, and therefore 

 the fruit should be kept as far as is possible in total darkness. 

 Not only does it keep better, but the flavor and color, both of 

 summer and winter fruit, is better when the light is excluded. 



7. The atmosphere should be uniformly dry, for moisture 

 is not only necessary to fermentation, but, by being condensed 

 on the skin, tends to decompose it, and thus render its protec- 

 tion less effectual. This happens to a greater extent in apples 

 and pears with smooth and glossy skins, than on those russeted 

 varieties, whose thick, rough skins arc less perfect conductors of 

 heat, which may account for the well-known long-keeping of the 

 russet apples. The moisture produced by condensation from the 

 air must not be confounded with that caused by sweating when 

 the j-uit is placed in large Inasses soon after being gathered. 

 When the air becomes colder than the fruit, evaporation takes 

 place, and the surface becomes dry ; and these alternations of 

 moisture and dryness, like those of heat and cold, arc injurious. 



Having determined the conditions necessary to the ripening 

 and preservation of fruit, we have now to apply these principles 

 to the construction of a fruit house. Passing by the costly 

 patented methods which have been tried and condemned, or 

 which, though correct in principle, are not yet practically tested 



