II 15 THE BOOK OF GARDENING. 



Thus we see that the dry substance of vegetables, that is to 

 say, the organic portion, varies from 3.7 per cent, in the fruit 

 of the Cucumber, to 25 per cent, in the tuber of the Potato. 

 The nitrogen varies from 0.16 per cent, in the vine of the 

 Cucumber, to 0.51 per cent, in the leaves of the Carrot. The 

 ash or mineral portion varies from 0.61 per cent, in the vine of 

 the Cucumber, to 2.39 per cent, in the leaves of the Carrot. 



Looking at the ash constituents in the different vegetables, it 

 is seen that these ingredients vary in quantity even more than 

 do the organic constituents. Thus, potash varies from 12 per 

 cent, in the leaves of the Carrot, to 61 per cent, in the tubers 

 of the Potato. Phosphoric acid varies from 4 per cent, in the 

 leaves of the Carrot, to 19 per cent, in the vines of the Cucumber. 

 Lime varies from 3 per cent, in the tubers of the Potato, to 33 

 per cent, in the leaves of the Carrot. Soda ranges from 2 per 

 cent, in the haulm of the Potato, to 20 per cent, in the roots of 

 the Carrot. The data further shows that in most cases the refuse 

 portion of vegetables — the stems and haulms — abstract from the 

 soil a very much larger amount of plant food constituents, weight 

 for weight, than do the marketable portions, teaching the gardener 

 the advisability of returning to the soil all the unsaleable products. 



Well-made farmyard manure is very rich in available potash 

 and phosphoric acid, which is doubtless one reason of its 

 immense value and general application to all garden vegetables, 

 containing, as the foregoing data shows that they do, so large a 

 proportion of these ingredients. 



COMPOSITION OF FRUITS, IN 1001b. OF EACH. 



Selected Constituents in the Ash, Per Cent. 



Potash 



Phosphoric Acid 



Lime 



Soda 



46.2 



10. g 



4.9 



14.0 



S'-9 

 16.0 



7-5 

 2.2 



