208 OPEN AIR GKAPE CULTUEE. 



" Of these substances, tlie three first are of the 

 utmost importance, on account of their entering so 

 largely into the indispensable constituents of the food 

 bj which vegetable life is sustained. The quantity 

 of ammonia thus ascertained to exist, is about what i,< 

 expected in two hundred weight of Peruvian guano ; 

 and bountiful nature gives us, moreover, nearly ona 

 hundred and fifty pounds of nitrogenous mattei' 

 equally suited to the nutrition of our crops." 



But although nature is thus liberal in supplying the 

 necessary wants of her children, man desires returns 

 rather more extensive than is merely necessary for 

 the good of the plant. He therefore adds directly to 

 the soil those matters which contain proper nutriment 

 for the vine. In doing this, however, it is not neces 

 sary to follow very accurately any recipe founded upon 

 the analysis of the vine, provided we obtain sufficient 

 of those elements w^hich are most wanted. If we only 

 spread a liberal table, the vine will select its own 

 food. 



Of all applications to the soil, none deserve more 

 confidence than well rotted barnyard manure ; from 

 time immemorial it has been the staple reliance of 

 the gardener and farmer and few are the instances in 

 which its judicious application has been known to 

 fail. 



That it may do good and not harm, however, whe% 



