SUNSHINE ON THE FAEM. 379 



and yet we know we do not utilize more than eighty per 

 cent, of the energy which is liberated. In man, the heat and 

 nervous force which comes from the sohir ray, is largely dis- 

 sipated through the functions of the skin and lungs ; and in 

 burning fuel the great mass of the heat is lost through flues 

 and imperfect combustion. Chemical change which results 

 in unlocking the energies of the sunshine may proceed so 

 slowly as to be insensible in its effects upon man, as in the 

 rusting of metals, or in the slow decay of wood ; or it may 

 be so rapid as to utterly escape control. The stored sun- 

 shine in our barns, in the form of hay and grain, is in its 

 utilization attended by losses corresponding with those con- 

 nected with change in other forms of organized material. 

 In modern barns, properly constructed, we are astonished to 

 find how comfortable the temperature is when we enter them 

 on the cold mornings of winter. It may be difficult for 

 many farmers to realize that this warmth all comes from the 

 contents of their hay-mows and grain-bins, — from actual 

 burning or combustion of these nutrient materials. The 

 long rows of cows and oxen in the stalls may be properly 

 likened to an arrangement of little stoves, in which the pro- 

 ducts of the summer fields are burned ; each animal repre- 

 senting a stove of greater or less capacity, according to the 

 size. This burning is not spoken of in an ideal or poetical 

 sense : it is actual, positive. Every load of hay which the 

 husbandman takes to his barn from his fields in July or 

 August is to be burned up in winter ; and the exact amount 

 of heat which would be afforded by its active combustion in 

 the field is to be gradually eliminated from his animals in 

 cold weather. And furtJier : the amount of heat liberated 

 must represent in its energizing capabilities the solar energy 

 consumed in the growth of the grass or grain. In other 

 words, the number of increments of heat made sensible in 

 the organization of a cow by the consumption of one hun- 

 dred pounds of hay, exactly represents the number of incre- 

 ments of heat in the sunshine which produced that quantity 

 of forage. The food energies of a cow are not all expended 

 in producing animal warmth. A considerable portion goes 

 toward the milk-pail ; and all the sunshine of our fields that 



