trees, 

 nd 



XVI. 74. 



BOOK XVII. 11. 24-111. 27 



that we liave specified like shade and even cold. 

 Consequently the best course is to rely on experiment. 



III. It comes next after the heavens to give an soiu favcnir- 

 account of the earth, a subject no easier to deal with, "^lfYj^and 

 inasmuch as the same land is not as a rule suited for cTCf:' 

 trees and for crops, and the black earth of the kind 

 that exists in Campania is not the best soil for vines 

 evervwhere, nor is a soil that emits thin clouds of 

 vapour, nor the red earth that many writers have 

 praised. The chalky soil in the territory of Alba 

 Pompeia and a clay soil are preferred to all the other 

 kinds for vines, although they are very rich,a quality 

 to which exception is made in the case of that class of 

 plants. Conversely the white sand in the Ticino dis- 

 trict, and the black sand found in many places, and 

 likewise red sand, even when intermingled with rich 

 soil, are unproductive. The signs adduced in judging 

 soil are often misleading. A soil in which lofty trees 

 do brilUantly is not invariably favourable except for 

 those trees : for what grows higher than a silver fir ? 

 yet what other tree could have lived in the same 

 place ? Nor do luxuriant pastures always indicate a 

 rich soil : for what is more famous than the pastures of 

 Germany ? but immediately underneath a very thin 

 skin of turf there is sand. And land where plants grow 

 high is not always damp, any more, I protest, than 

 soil that sticks to the fingers is always rich — a fact that 

 is proved in the case of clay soils. In point of fact no 

 soil when put back into the holes out of which it is dug 

 completely fills them, so as to make it possible to 

 detect a close soil and a loose soil in this manner; 

 and all soil covers iron with rust." Nor can a heavy 



the land will be suitable for grazing and for vineyards, but 

 if it raore than GIls it the soil will do for heavy arable land. 



19 



