I. AGRICULTURE AND RURAL ECONOMY. 377 







until the whole mass is saturated with the liquid, this, on emer- 

 ging from the lower opening, will appear colorless and odor- 

 less, the peculiarities of the water being entirely changed. It 

 is certain that this property, possessed by soils, of attracting 

 soluble substances from their solutions, has a very important 

 influence upon the practice of agriculture, although much 

 remains to be done in order to utilize it. This much is cer- 

 tain, that the finer constituents of the soil, especially the clay 

 and humus, possess the property, partly by capillary attrac- 

 tion and partly by chemical transmission and exchange, of at- 

 tracting definite quantities of soluble plant-nutrients, espe- 

 cially ammonia, potash, phosphoric acid, and sulphuric acid, 

 and other salts, and from dilute watery solutions to make 

 them so much less soluble that they can only be extracted 

 again, very slowly, by the long-continued action of water. It 

 is to this that we owe the fact that the substances most im- 

 portant for the nutrition of plants are not continually re- 

 moved from the soil by the rain, and that putrescent or offen- 

 sive liquids undergo a purification by striking through the 

 earth ; that, with insufficient manuring, clay soils lose their 

 fertility more slowly than sandy soils, etc. 



The absorbing power of the soil appears to be in direct pro- 

 portion to its adhesiveness ; and as sandy soils possess this 

 peculiarity in a less degree, the manures applied to them pass 

 off more readily, to the injury of vegetation. This fact has 

 been acted upon for a long time, since it is the practice to 

 apply a slight but oft-repeated manuring to sandy soils, while 

 with the heavier soils the reverse may be the case. Mitt/i. 

 Landwirth. Central-Verein, JCassel, 1871, xn., 114. 



Packard's report on Massachusetts ixsects for 1871. 



Dr. Packard presents his annual report (for 1871) upon the 

 beneficial and injurious insects of the state to the Alassachu- 

 setts Board of Agriculture, under whose auspices he has been 

 engaged, and remarks that the past year has been made note- 

 worthy by the unusual abundance of two insects, compara- 

 tively strangers in the state, and which have made their ap- 

 pearance in sufficient numbers to produce very serious injury 

 to crops. These are the onion thrips and the cabbage-web 

 moth, which, with other species, are described at length in 

 the pamphlet. 



