248 



1HK ALUMNI JOURNAL. 



cesses of the plant. The recent investi- 

 gations of Rayleigh and Ramsay have 

 shown how the physicist and chemist 

 are able to carry on their investigations 

 to an almost incredible degree of exact- 

 ness. Thus far the botanist, however, 

 has tried in vain to produce any device 

 whereby such accurate quantative results 

 might be obtained. The reason for this 

 this difficulty is apparent because of the 

 marked difference between the sciences, 

 for in the work of the botanist there is 

 the factor of " vital force" which pro- 

 duces changing conditions, new and 

 different products resulting while the 

 experimenter is at work. 



There is another school, a small one, it 

 is true, but one which is likened to the 

 " thunder of the gods " — it is the school 

 of Schwendener. He and his disciples 

 claim that our knowledge, at best, is but 

 meagre, and that our means of acquiring 

 more information are still too inadequate 

 to warrant the hope that we can obtain 

 any final or even satisfactory answers to 

 questions in which plant life is con- 

 cerned. 



'The analyses of plants show that their 

 proximate principles consist of inorganic 

 constituents as well as carbon com- 

 pounds. The number of inorganic com- 

 pounds is limited, whereas the number of 

 organic compounds is exceedingly great, 

 and, furthermore, the quantity of the 

 latter would in all cases (with few ex- 

 ceptions), far exceed the mineral matter. 

 The quantity of ash remaining from the 

 incinerated plant varies from 1.5 or 2.0 

 per cent, (as in wheat flour) to 18 or even 

 28 per cent, (in tobacco), and in rare 

 cases like Chara fcetida it attains 70 per 

 cent. The leaves contain more inorganic 

 matter than stems, the rind contains 

 more than the wood, and the epidermis 

 of stems and leaves contains more than 

 the internal tissue. We find, however, 

 that there is inorganic matter in every 



plant, in every organ, and indeed in 

 every cell. The following salts are nec- 

 essary to the life of the plant: KN0 3 , 

 Ca 3 (P0 4 ) 2 , MgS0 4 , CaS0 4 and FeS0 4 (in 

 green plants). In a large number of 

 plants there is also Si0 2 , Na and CI, 

 while in still others there are Mn, I, Br> 

 Fl, Li, Sr, Ba, Rb, Al, Cu, Pb, Ag, As, 

 Zn, Ni and Co. Some of these elements 

 are combined with carbon compounds 

 forming double compounds, as in the 

 aleurone grain and others are present in 

 inorganic combinations. 



The carbon compounds upon elemen- 

 tary analysis are found to consist of but 

 very few elements; viz.; — C, H, O, N, 

 P and S. These elements are, however, 

 so combined in the plant, forming the 

 tissues and food, that in many cases the 

 molecules exhibit an exceedingly com- 

 plex arrangement. They are combined 

 in the plant forming the following classes 

 of compounds; I. P. 'astids, consisting of 



(1) Chloroplastids, as the chlorophyll 

 grains in green plants; (2) Leucoplastids, 

 or starch generators, found in rhizomes 

 and (3) Chromoplastids, or the color 

 granules of fruits and flowers. II. Car- 

 bohydrates which include: (1) Monosac- 

 charides or gly coses, as dextrose (C 6 H 10 O 5 ); 



(2) Disaccharides or saccharoses, as cane 

 sugar (C 12 H 2 ,0„); (3) Polysaccharides, 

 being (a) crystallizable as rafhnose 

 C 36 H 64 32 +io H 2 0) and (b) uncrystalliz- 

 able or colloidal and of the general for- 

 mula (C 6 H 10 O 6 ) n ± (H 2 0) w . To this lat- 

 ter group belongs starch, lichenin, inulin, 

 the sacchorocolloids like gum arabic,. 

 cerasin, bassorin, cellulose and also the 

 vegetable jellies (pectin bodies). (4) A 

 group of bodies related to the glycoses, 

 as arabinose (C 6 H 10 O B ), quercin (C 6 H 12 6 ), 

 quercite (C 6 H 12 5 ), mannite (C 6 H 14 6 ). 



III. Protoplasm, which consists of a 

 mixture of substances called proteids. 



IV. Proteids, which consist of (1) Plastin 

 (C, H, O, N, S, P.), being considered 



