16 THE PRINCIPLES OF ENGLISH AGRICULTURE. 



of foods ; the diseases of plants and of animals, form a very 

 important series of papers. The action of fertilizers, home 

 and foreign agriculture, the reports of the chemist, the 

 botanist, the veterinarian, papers on drainage, on land im- 

 provement, papers on statistics, on machinery, on rotations, 

 papers on dairying, on cottages, on buildings, all help to 

 show the vast variety belonging to agriculture as a subject, 

 and put to shame those who reduce what they call the 

 principles of agriculture to a few crude notions with reference 

 to the constituents of plant food, the action of lime, the 

 minute composition of milk, the process of germination of 

 seed, the changes which take place in the ripening of grass 

 or of straw, the action of lime upon the soil, and various 

 other similar topics, which, although they should be included 

 in a system of teaching, ought only to take their place as 

 very secondary when compared with the larger topics which 

 I have endeavoured to put before my readers. 



Lastly, I would say that the following chapters are 

 addressed in the first instance to those who have made 

 agriculture their subject as professors or teachers of the 

 same. I have not scrupled to point out generally the errors 

 into which examinees are apt to fall, and I have also en- 

 deavoured to keep up the idea of width or breadth as 

 peculiarly the attribute of the great art and science of agri- 

 culture. The syllabus of the Science and Art Department 

 is equally comprehensive, and requires a knowledge of all the 

 subjects which have been mentioned in the previous pages. 



