PROCEEDINGS OF THE CHEMICAL DEPARTMENT. 171 



It is to be particularly noticed that the total quantity of ash 

 here given does not correspond with that got by adding together 

 the amounts given under the separate parts of the plants; and 

 the reason for this is that the latter include the sand adhering 

 mechanically to the surface, which is excluded from the former, 

 as it is intended to embrace only those substances which really 

 form a part of the tissues of the plant. The point most worthy 

 of observation is the comparatively small quantity of mineral 

 matter which the bean contains at this stage of its existence. It 

 amounts, exclusive of roots, to only 10 lbs., and of this, less 

 than one pound consists of phosphoric acid, and about two-thirds 

 of a pound of potash. Lime, however, is comparatively abund- 

 ant, amounting to 4 lbs., so that even at this period the bean has 

 acquired the right to be distinguished as a lime plant. It is pro- 

 bable that at this early stage of its existence the bean has drawn 

 little, if at all, on the resources of the soil, for the seed must have 

 contained a sufficiency of mineral matters to supply most of that 

 the produce contained. Unfortunately, I am not in a condition 

 to offer any decided proof of this, from not having had an oppor- 

 tunity of analysing the beans used for seed, no sample of them 

 having been preserved. We may, however, form an approxima- 

 tive estimate from the known composition of beans. A bean 

 weighs on the average from nine to ten grains, so that the 

 100,000 beans whie> germinated must have weighed about 

 950,000 grains, or 130 lbs., and have contained about 4"5 lbs. of 

 mineral matter, nearly half of which must have consisted of 

 potash and a fourth of phosphoric acid. The produce, therefore, 

 actually contains less of these particular elements than the seed 

 did ; and as far as they are concerned the plant may be said to 

 have been independent of the soil. It is otherwise, however, 

 with lime, of which the seeds could not have contained more 

 than 1 or 1*5 lbs., so that a very large proportion of that con- 

 tained in the produce must have been derived from the soil. 

 And in this we find an illustration of that remarkable provision 

 of nature, by which, whatever may be the nature of the con- 

 stituents of the growing plant, potash and phosphoric acid are 

 those most abundantly stored up in the seed, aud this is, no 

 doubt, because these substances are intimately bound up with 

 the first changes occurring in the germinating plant, while lime 

 is of secondary importance, and not required, or, at least, not in 

 large quantity, until the leaves and stems in which it is most 

 abundant, begin to be developed. 



2nd Stage, 1st July, 1864 



During the month of June the plants made steady, but not 

 rapid, progress, and by the 1st of July had attained an average 

 height of 18 inches. The leaves, of course, had greatly increased 



