I 



On Chalk Marl. 545 



I am quite willing to admit that the analysis of soils is not at 

 present what the friends of aj^ricultural chemistry might wish. 

 We have much yet to learn before we shall be enabled con- 

 fidently to point out the relation existing between the chemical 

 composition and agricultural capabilities of a soil ; but that such 

 a connection does exist we cannot for a moment doubt, and we 

 must regard the present unsatisfactory state of our knowledge on 

 this subject as a defect inseparable from the early stages of any 

 and every branch of human knowledge. Our true wisdom is, to 

 wait patiently whilst we work manfully, assured that success can- 

 not fail ultimately to reward the earnest and persevering search 

 after truth. As effect follows cause, so must the agricultural 

 capabilities of a soil, under given conditions of climate, culture, 

 and mechanical structure, be in precise relation to its chemical 

 composition. I fully anticipate, therefore, that practical agri- 

 culture will one day derive immense benefit from this depart- 

 ment of applied chemistry. 



In the meanwhile no fact that can be added to our present 

 knowledge will be without its share in contributing to the ultimate 

 result. It is true that it may be left for others to incorporate 

 these isolated observations, and to give them a connected and 

 rational form ; but because the building of the house is necessa- 

 rily delayed, it does not follow that the stones should be left 

 unshaped in the quarry. It is a mistake to speak of barren facts : 

 there are no such things ; facts are the indispensable materials of 

 philosophical generalization, and their acquisition must in all cases 

 precede a knowledge of the principles upon which they depend. 



It is hardly necessary that I should mention that the practical 

 observations and descriptions of the different strata are those of 

 Mr. Paine, to whose kindness I also owe the collection of the 

 specimens for analysis. Whilst Mr. Paine's local knowledge of 

 the strata of the chalk in his district is a sufficient guarantee of 

 the identity of the samples with the members of the series which 

 they profess to represent, the ample experience which he has 

 gained in his own operations, as well as in the careful observation 

 of those of others, enable him to speak to the value of the re- 

 spective soils as manure. I consider myself particularly fortunate 

 in having induced him a second time to join me in these investi- 

 gations. ' J. T. Way. 



The following specimens of chalk and chalk-marl subsoils, 

 comprising the whole series of the distinctive strata of the chalk 

 formation from the gault clay to the upper chalk, in ascending 

 order, were taken in a sectional hne, over a distance of about four 

 miles, from south-east to north-west, at right angles with the 

 upthrow of the strata in the extreme west corner of Surrey and 



VOL. XII. 2 N 



