BOOK II. 11. 19-21 



you try to put back and tread down in trenches the 

 earth that has been removed, if there is an excess 

 as by some sort of leavening, it Avill be a sure sign 

 that the soil is fat ; if it is insufficient, that it is poor ; 

 if it makes an even fill, that it is ordinary." And yet 

 the statements which I have just now made may seem 

 not so trustworthy in the case of blackish earth 

 (ptilla),^ which is better tested by its yield of crops. 

 We shall also make distinctions of taste as follows : 20 

 from that part of the field which displeases us most, 

 clods should be dug and soaked in an earthen vessel, 

 then thoroughly mixed with fresh water and, after 

 careful straining in the manner of dreggy wine, ex- 

 amined by tasting ; " for, whatever is the taste trans- 

 mitted from the clods to the water, such we shall 

 take to be the taste of that soil. But, apart from 

 this experiment, there are many signs which show that 

 ground is sweet and suitable for grain — for example, 

 the rush, the reed, grass, trefoil, the dwarf-elder, 

 bramble bushes, wild plums, and many other things 

 which are well known also to searchers for springs,** 

 and which are not nourished except by veins of sweet 

 water in the ground. And we should not be content 21 

 with the first appearance of surface soil, but should 

 take pains to investigate the character of what hes 

 beneath — whether it is earthy or not. It will be 

 satisfactory for grain, however, if the soil below is 

 equally good to a depth of two feet ; for trees, a 

 depth of four feet is sufficient.^ When we have 

 investigated these points as stated, we shall put our 



** For directions as to the ancient methods of locating 

 water, digging wells, and piping, see Vitruvius, De Arch. 

 VIII, Chaps. 1 and 5-6, and PaUadius, IX. 8-12. 



' Cf. PaUadius, I. 6. 11. 



121 



