CHEMICAL SCIENCE. 231 



most distinguished chemists of Germany. They were made accord- 

 ing to a prescribed scheme, and, that there should be no reason to 

 slight the work, the labor was paid for. It is true that analytical 

 chemistry was not so advanced in 1846 as now. It is true that the 

 methods then practised for estimating phosphoric acid and some 

 other substances were not as perfect as they now are ; but for the 

 most part the analyses then made are as accurate as they could be 

 executed to-day. It cannot be supposed for a moment that analysts 

 like Rammelsberg, Genth, Knop, Varrentrap, etc. etc., would by- 

 fault of method or by carelessness return anything but results that 

 were accurate, as far as it was possible to make them such. 



A tabulation of the results, however, shows that the different deter- 

 minations disagree to such an extent as to make it the sheerest folly 

 to base any calculation of the value of the soil upon analysis. Some 

 of the analyses agree sufficiently to show that accordant results are 

 possible if uniform material be taken ; but the grand result of the 

 investigation is that the difficulties of getting a uniform material are 

 exceedingly great. Again, we must remember that in the investiga- 

 tions in question, the three examinations of each soil were made 

 upon portions of one carefully mixed sample. What would have 

 been the result had each chemist received a sample collected sepa- 

 rately from all the others, and from different parts of the field ! 



Again, the chemical analysis of soil reveals nothing as to its te- 

 nacity or lightness, its porosity or retentiveness for water, yet these 

 physical and mechanical conditions, more than anything else, deter- 

 mine the adaptation of a soil for any particular crop. The best grass 

 lauds are not the best wheat lands ; and although it would scarcely 

 be questioned that wheat requires a richer soil than grass in order to 

 produce an average crop, and although, as we know, it often hap- 

 pens that many successive hay crops may be removed from a meadow 

 without sensible diminution of the yield, while uninterrupted crop- 

 ping with wheat nearly always reduces the capacity of the soil in a 

 very few years below a profitable point ; yet each average hay crop 

 removes from a field more of every ingredient of vegetation than the 

 grain and straw together of an average harvest of wheat. Such at 

 least is the testimony borne by the most recent and trustworthy data. 



Twelve or thirteen years ago, Dr. Anderson, in his capacity of 

 chemist to the Highland and Agricultural Society of Scotland, had 

 occasion to investigate two soils which had become " clover-sick," 

 and he caused them, together with similar adjacent soils which still 

 produced clover, to be most minutely analyzed. Without repro- 

 ducing his figures, which may be found in the Trans, of the High- 

 land and Ag. Soc. for 1849-51, p. 204, we will merely quote some 

 of the remarks which accompany the analyses : " The results of these 

 analyses are certainly of an unexpected character, and appear to me 

 to indicate that, in this instance, the failure of the clover cannot have 

 been dependent upon the chemical constitution of the soil. In both 

 cases the results of the analyses of each pair do not present a greater 

 difference than would be obtained from the analyses of two portions 

 of soil from different parts of any field." 



Very recently, M. Stoeckhardt has published an account of several 

 " clover-sick " soils from Schlanstaedt, which reveal to analysis a 



