580 



though many of his experiments have no direct reference to the far- 

 mer, in the growth of his crops or the tillage of his land, yet they are 

 becoming more and more the basis upon which the correct principles of 

 agriculture are founded. He tells you, reasoning from his analysis, that 

 the leguminous plants must have a good supply of lime from which to 

 extract the substances that form their vegetable matter; that the cereal 

 plants must have the phosphates and silicates in the soil where their 

 roots can reach them, if we would have them come to perfection, and 

 that if we expect to raise lai'ge root crops, such as turnips, carrots, and 

 vegetables of a like nature, potash and its compounds are needed in the 

 soil to bring them to perfection. 



You prefer the very common timothy grass for your hay ; the chem- 

 ist analyzes that grass, and shows you that there is a good reason for 

 your preference. He tells you that timothy grass, taken from the field 

 when nearly ripe, contains but 57.21 of watei, while of flesh-forming 

 matter there are 4.86, of fatty matter 1.50, of heat producing matter 

 22.85, and of woody fibre 11.52, exceeding in all these particulars 35 

 other kinds, both natural and cultivated, which were at the same time 

 submitted to the same tests. Among these was the common red clover, 

 100 parts of which was found to contain 81. of water, 4.27 of flesh- 

 forming matter, 0.69 of fatty substances, 8.45 of heat producing prin- 

 ciples, and 3.76 of woody fibre, exceeding in these matters many other 

 well known grasses. 



While the chemist aids you in this way, by analyzing and identifying 

 the principles of which the various plants are composed, explaining to 

 you their wants and properties, another class of students, the physiolo- 

 gist^ informs you to what extent these principles contribute to the nutri- 

 tion of animals, how from one substance is formed the fat, from another 

 the flesh and muscle, while others go to support respiration and ani- 

 mal heat. 



The agricultural chemist again, conjointly with the geologist, describes 

 the soils, their formation, their qualities, and the properties they possess 

 of nourishing various kinds of plants. The botanist, also, is examining 

 the vegetable kingdom with a view to pointing out the relations of 

 plants to each other, and their uses, and of adding new varieties to those 

 already naturalized and made fruitful, beautiful or profitable to man. 

 In short, all the several departments of human art and learning are at 



