ITS SEED MIXED WITH AMERICAN OIL-CAKE. 307 



dark-coloured shales form stiff soils, which produce good 

 grass, but are difficult — naturally, or have become so hj 

 unskilful treatment — to retain profitably in arable cul- 

 ture. In Yates County, upon this formation, the pigeon- 

 weed has become in some places almost the lord of the 

 soil. It was unknown there, as 'elsewhere, thirty years 

 ago ; now " hundreds of bushels of the seed are pur- 

 chased at the Yates County oil-mill ; and if it were worth 

 8s., instead of Is. 6d. a bushel, these hundreds would be 

 thousands ! " 



The reader will observe. In the concluding words of 

 this quotation, how one evil leads to another. The pur- 

 chase of this seed at the oil-mills can only be for the 

 purpose of adulteration. I have examined samples of 

 American llnseed-cake In which seeds were to be recog- 

 nised which I could not name. They might, I then 

 supposed, be those of the dodder, a parasite which infests 

 the flax plant in some localities; but they might also be 

 other cheap seeds purposely mixed with the linseed. 

 Those who are in the habit of buying cheap American 

 cake may think this point deserving of their attention. 

 As oil-cakes are chiefly bought by farmers, perhaps it is 

 only a kind of retributive justice that a set of idle 

 farmers in one country should thus be the means of 

 punishing a less discerning set in another. 



One purpose for which I have dwelt upon this weed Is 

 to show that a knowledge of the habits, or physiologi- 

 cal history, of our common plants Is as necessary to the 

 improvement of the art of culture, of the condition of 

 those who practise It, and of the agricultural productive- 

 ness of a country, as almost any other kind of know- 

 ledge. No one will readily accuse me of a wish to 

 undervalue the usefulness of chemistry to agriculture, 

 and yet I have often had occasion to regret the evil 

 influence of opinions hastily expressed by ill-informed 

 persons — as if this were the only branch of knowledge 



