CULTIVATION OP PLANTS. 91 



produced by causes somewhat similar to those which occasion 

 blight, though at a more advanced period of the season. It 

 usually first attacks the leaf, and then the straw, just at the time 

 the grain is blooming; and when it comes on immediately after 

 the first appearance of the ear, the straw will also be affected; 

 but if the grain be fully formed, then it is but slightly dis- 

 coloured. 



There are many causes which probably contribute to the 

 production of this disease, and also to prevent the grain coming 

 to maturity. It is most likely induced by the peculiar state of 

 the atmosphere, during the periods of flowering and ripening; 

 or the absence of some indispensable ingredient in the soil. 

 This opinion appears to be correct, so far as we are yet able to 

 judge of the peculiar cause. 



It is doubtless the lack of some necessary ingredient of the soil which pre- 

 vents the wheat from coming to maturity. It has been suggested by men of 

 science, that lime is a very important ingredient for the growing of wheat. It 

 has also been ascertained by analysis that the lower soil contains double the 

 quantity of lime of the upper soil. When wheat is sown on land exhausted by 

 frequent shoal ploughing, it will produce smut, or the straw will rust, and the 

 kernel blight. I have noticed, and more particularly last summer, that where 

 wheat was sown on land cultivated under the usual practice of shoal plough in ir, 

 it was very smutty; and that when it was sown on land where the usual prac- 

 tice was deep ploughing, the wheat was free from smut. It this should be the 

 case on further observation, it would be evident that lime is a great preventive 

 against smut; for by deep ploughing it turns up the lower or sub-soil, which 

 contains the greatest quantity of lime, and gives a, greater facility to the growth 

 and brings it to perfection. But when the land is ploughed shoal the lime lies 

 inactive'. I have given these hints, that some scientific growers of wheat 

 might make the same observations and give us the result of their research. 

 Dr. HOLMES, Editor of the Maine Farmer. 



The Rev. HENRY COLMAN, an eminent agriculturist, and a 

 careful observer of all things connected with agriculture, and 

 those branches of science to which it is allied, has furnished 

 the public, through some of the early volumes of the New 

 England Farmer, with a number of able and highly instructive 

 essays on the culture of wheat; and after many experiments, 

 and careful and patient observation, he came to the conclusion, 

 (without, however, assuming to decide the question,) that the 

 disease was "atmospheric occurring at a particular state of the 

 plant, which rendered it peculiarly liable to blight or mildew." 



One experiment detailed by Mr. COLMAN, and which, no 

 doubt, had considerable weight in bringing him to the conclusion 

 to which he arrived, that the cause was, most probably, atmo- 

 spheric, is too interesting to be passed over. The following 

 is his account, as published at the time. 



"Three acres of wheat were sown on some of the best land 

 in the Deerfield, Massachusetts, meadows. The greensward 

 was turned up in the fall, rolled and harrowed; seed well soaked 



