186 PROCEEDINGS OF THE CHEMICAL DEPARTMENT. 



changes take place in the distribution of the substances through 

 their different organs. These points are made more obvious by 

 the following table, which gives in lbs. the total quantities of the 

 different substances contained in the entire bean plants without 

 roots, at the six stages into which their growth was divided :— 



1st Stage. 2nd Stage. 3rd Stage. 4th Stage. 5th Stage. 6th Stage. 



Water . 807-19 5,650-37 21,714-85 33,870-29 29,227-33 12,813-86 



Albuminous compounds, 34-74 254-17 886-77 1, 235-99 1,044-17 819-19 



Other organic matters, 67-98 475-07 1,841-47 3,954-24 4,358-34 3,833-45 



Peroxide of Iron, . 049 2-92 24*92 10'93 13-00 4-99 



Lime . . . 392 16 06 43-61 58*97 51*03 2P18 



Ma-nesia, . . 050 3'95 12 87 1145 11-30 10 02 



Chloride of Sodium, . 132 10 95 3358 28 63 39 33 2286 



Soda . . 22 9-40 3972 43 86 3081 3P73 



Potash, . . . 62 7 71 20 09 22-15 35 45 2304 



Sulphuric arid. . . 0*98 5 08 15 61 1620 16*55 14 74 



Phosphoric acid . 95 1066 33-09 4006 33-77 29*75 



Silicic acid, . . 102 4 31 6'26 7-2 6 6*28 4 21 



91993 6,450-65 24,672-84 39,300-03 34,977-39 17,6i9-0J 

 Nitrogen, . . . 5 56 40 70 14210 19778 167-18 13112 



From this table it appears that while a single bean plant 

 exclusive of roots weighed after a month's growth only 72-65 

 grains, which may be described as its increase in weight in the 

 first month of its existence, it gained during the month of July no 

 less than 1260 grains, or more than 17 times as much, while in the 

 months of August each plant gained 1022 grains, or 14 times as 

 much as it did in the first month. It was, therefore, within 

 these two months that the active growth of the plants was con- 

 lined. After that time the quantity of valuable matters absorbed 

 was trifling, and owing to loss of water, the plants actually 

 diminished in weight. The leaves also began to decay and fall, 

 a change which, however, took place slowly during September 

 and chiefly towards its close, but was so active during October 

 that they had almost disappeared when the plants were ripe. 



The practical conclusions to be drawn from these experi- 

 ments are very obvious. They teach us that, as the great part 

 of the constituents of the bean crop are removed from the soil 

 within the space of two months, it must be of the greatest mo- 

 ment to use manures capable of yielding up their valuable 

 matters within a short period. If they are of a kind which do 

 not become available till late in the season they are practically 

 lost, so far as the crop to which they are applied is concerned, 

 although, of course, they remain for future years. 



Important also is it to notice how large is the quantity of 

 mineral matters contained in the crop, in which respect it greatly 

 exceeds wheat or any other cereal. An average crop of wheat 

 contains about 148 lbs. of mineral matters, of which almost exactly 

 half is silica, leaving about 74 lbs. for all the other substances, 

 while the bean crop in its state of greatest development, in its 

 5th stage contained no less than 23774 lbs. per acre, of which 



