44 



AGRICULTURAL TEXT-BOOK. 



(J. T. Plummet;) but it would have been more perfect if the tempera 

 ture of the soil had also been recorded: 



It is stated that at Albany, N. Y., of Indian corn planted 

 when the temperature of the soil was but 45 in the spring, 

 the seed all rotted; but when planted, when the temperature 

 was about 60 , it vegetated. 



This subject is one of great importance to the farmer ; large 

 quantities of seed and labor are annually lost in consequence of 

 inattention to such particulars ; and there is yet much to learn 

 that is valuable in this regard. The proper time for seed-sowing 

 may be accurately ascertained by means of experiment ; and by 

 the use of the thermometer and meteorological tables. 



134. As is well known, a ray of the sun s light, consists of 

 seven rays of different colors, which, uniting, form the ordinary 

 white light But, besides this, the sun s rays contain three dif 

 ferent kinds of rays: (a,) a ray of light; (b,) of heat; (c,) of 

 chemical agency. The effect of these on vegetation is essen- 



