Ch. IX.] ON THE GROWTH OF CORN.^ 137 



Taking these tilings into consideration, it seems the most priment plan 

 to have the corn cut before it is fully ripe : but in this a medium course 

 should be adopted ; for although grain, if allowed to become too ripe, 

 assumes a dull dusky hue in the sample, yet, if not ripened enough, it 

 shrivels in the drying. Under both circumstances, it is found to want that 

 brightness of colour and plumpness of kernel which constitute its beautv, 

 and are characteristic of its value ; nor, in either state, does it contain that 

 quantity of meal which it is capable of yielding when reaped at a proper 

 state of ripeness. The subject, however, chiefly applies to wheat. 



The corn, of each species, produces, when rijie, nearly the following 

 quantities of meal, or household flour, and bread, per bushel : namely, — • 

 Wheat, if v/eigliing fiOlbs., of Flour 481bs. of Bread C41bs. 

 Rye, do. 54 do. 42 do. 50 



Barley, do. 48 do. 37^ do. 50 



Oats, do. 40 do. 22i do. 30 



DISEASES. 



Much lias been written, to very little purpose, regarding the diseases of 

 corn. F'armers have generally not suflicient science, and men of science 

 not sufiicient practical experience of the phenomena presented in tlie various 

 stages of growth, to enable them to judge accurately of the causes, or the 

 means of cure. Thus they reason upon circumstances, assumed as matter 

 of fact, which have no real existence; palpably contradict each other; and 

 advance such conflicting opinions, tliat the subject apj)ears wrapped in 

 greater mystery than when first investigated. This is particularly the case 

 with regard to wheat ; which, although well known to be subject to 

 maladies that indiscriminately attack and spare land of the same nature 

 and in the same or different states of preparation, have been attributed by 

 men of the highest eminence as chemists, botanists, and naturalists, to a 

 variety of causes, each of which has been in turn refuted. Thus 



Jetliro TuU ascribes s?nut to moisture. 



Duhaniel says it is an infectious powder. ^ 



Dr. Hales deemed it to be occasioned by bruises ; and, on further expe- 

 riment, by damp weather during the flowering. 



Spallanzani asserts that it is occasioned by the want of due impregnation ; 

 and his opinion is supported by the memoirs of the Bath A'^ricultural 

 Society, as uell as by Dr. Darwin. 



Linnijeus, Walker, Somerville, and many other naturalists, suppose it to be 

 occasioned by the inoculation of an insect. 



Sir Humphry Davy conceives that it is produced by a fungous excres- 

 cence in the grain ; but this is contradicted by Bauer, who has ascertained 

 it to be a morbid swelling of the ear, not at all connected with the Growth 

 of a fungus. 



Dr. Home, in his principles of vegetation, imagines it to arise from an 

 over-abundance of juices ; and Chalmers ascribes it, in his Cyclopiedia, to 

 fatness in the soil : but Lisle attributes it, in his observations upon hus- 

 bandry, to a total want of sap in the plant. 



Prevost, Jussieu, and many others, presume it to arise from infection: 

 in which Vauquelin and Fourcroy partly agree, although their analysis does 

 not prove it. 



Bradley, and the author of ihe New Farmer's Calendar, call it blight ; 

 and several other writers confound it with mildew. 



We abstain, therefore, from all comment on so perplexing a subjrct, and 

 shall confine our observations to those brief notices which will be found under 

 the separate heads of the different species. 



