152 



Here, then, upon the Coal series of Yorkshire, although 

 consistence of the soil, vegetation, and the geological rela- 

 tions of soils, have each their respective value as marks of 

 the value of land ; yet all these are modified and are sub- 

 ordinate to (in the western districts) the climate, aspect, &c., 

 of each particular farm. 



Such, then, is an outline of those indications which are 

 guides in judging of the fertility or barrenness of soils ; with 

 examples of their application through the whole of York- 

 shire ; any one of which is not to be used to the exclusion of 

 the other, whenever it is practicable to use them all. The 

 Royal Agricultural Society, however, gives preference to those 

 obvious ones which are called practical, for they say — " by 

 " these, farmers and surveyors give at once a practical 

 ** opinion upon the probable nature of land which they in- 



spect." I do, however, maintain that whenever a person 

 has a knowledge of all the signs, i.e., the chemical and the 

 geological, in addition to those more obvious ones mentioned, 

 and is capable of applying them, he will form a more correct 

 opinion than another who relies only upon those more simple ; 

 and he will find in innumerable cases that the geological 

 signs will explain why the chemical ones are exhibited ; while 

 both combined will again show why a diff'erence of colour or 

 consistence exists, which again will explain the difference of 

 vegetation upon various soils. 



The whole of this subject is well illustrated by what has 

 occurred in the practice of medicine. Thirty years ago, the 

 only signs of disease in the chest, were learned from states 

 of the pain, the skin, the tongue, the breathing, cough, and 

 the sputum. It is now, however, well known that in inflam- 

 mation of the substance of the lungs, (pneumonia) one-tenth 

 of the cases are entirely free from pain — that one-seventh 

 show nothing abnormal in the breathing — and in one-sixth 

 the cough and expectoration are simply catarrhal ; so that a 



