84 MASSACHUSETTS HORTICULTURAL SOCIETY. 



heat ; and phosphates, potash, starch or carbo-hydrates, the correla- 

 tives of animal fat, and of bone and sinew, — when absorbed in the 

 human system. 



The inherent fertility' of the soil may support plants for a little 

 while without well-balanced sustenance. The i)lant may derive a 

 part of its sustenance from other sources than the soil ; but with 

 few exceptions the sustenance of the plant is held in correlation 

 to the sustenance of the soil by bonds which cannot be severed. 

 In a similar way the animal may live a little while on its own fat, 

 if it shall have secured a supply* somehow and somewhere ; but it 

 also must be rightly sustained, if life is to be prolonged. 



The man must have a suitable proportion of each of these ingre- 

 dients in order to attain full and mature development ; the soil 

 must be supplied with the same ingredients according to its wants ; 

 the beast, again, must be fed in the due proportion. All organic 

 / life seems to be capable of being put into a chemical formula, 



varying in proportion but not in its constituent terms. Each and 

 all are sustained by much the same chemical elements, — each of 

 course in different measure and in different proportions. Is not 

 our problem that of balancing the forces without waste, alike with 

 respect to soil, beast, and man? 



If, then, the scientist can tell the man what proportion of 

 animal or vegetable food will suffice to sustain him in full vigor 

 and strength, according to the proportion of nutrients, and can 

 direct him in what proportions, and of what kind of food 

 he shall partake, it may happen that ere long he may tell each of 

 you exactly what ingredients to buy and to put into the laboratory 

 of your gardens in order to support each kind of plant in full 

 vigor at the lowest cost ; he may first ascertain exactly what you 

 have in the soil or in the air which rests upon it, or in the water 

 which permeates it ; and next what 3'ou must add for its deficien- 

 cies, or in order to make the ingredients already present fully 

 effective. lias this j'ct been accomplished? Have you not as yet 

 more confidence in your own empirical method — j'our observation 

 and the results of your own practice, than you have in agricultural 

 theory? Yet we know how much human food men waste — may 

 you not be wasting plant food also? 



It appears that if the man is fed only with starch and fat he will 



y become feeble or starve, even if these are furnished in apparently 



ample measure. It also appears that if he is fed oply with the 



