APPENDIX. 



231 



The preceding numbers express the unequal weight of mineral nutritive 

 substances taken up from the sand and artificial soil by equal weights 

 of the different plants mentioned. The absolute and not the relative 

 weight of the component parts of the ashes is given. For example, the 

 live tobacco plants grown in sand gave 0*506 gr. in ashes, whilst the 

 three which grew in the artificial soil gave 3*923 ; five would, therefore, 

 have given 6*525 gr. The proportion of the mineral ingredients taken 

 up by five tobacco plants from the sand, and that taken up from the arti- 

 ficial soil by an equal number of plants, is as 10 : 120. In an equal 

 space of time, those whicii grew in the artificial soil absorbed nearly 

 thirteen times more of inorganic ingredients than those in the sand, and 

 the whole development of the plant was exactly in proportion to the 

 supply of food. Wiegmann and Polstorf subtracted the ashes of the 

 seed used from the numbers in the last line, which show the amount of 

 ashes in a given weight of the grown plantj but this has caused a small 

 error in the numbers, as all the plants grown in the sand were reduced 

 to ashes, and a corresponding amount only of those grown in the arti- 

 ficial soil. The weight of the seed of every plant grown was 3 grammes 

 if we except the tobacco, which was not weighed. 



TABLE 



Mowing the Amount of Moisture in the Vegetable Substances analysed 

 in the Experiments of Boussingault. 



COMPOSITION OF MANURE DRIED IN VACUO AT 110° C 



