THE ALUMNI JOURNAL. 



271 



exists in the form of an organic com- 

 pound in the plant. A plant that loses 

 its green color through lack of iron is 

 said to be chlorotic. This condition is 

 sometimes confounded with etiolation, 

 which means lack of green color through 

 deprivation of light. 



XI. There are some elements that 

 would seem not to be essential to plant 

 economy ; yet it is well known that they 

 are absorbed und utilized by some 

 plants. Among this class may be men- 

 tioned Si, Na and CI. 



(1) Silicium enters the plant in the 

 form of soluble silicates and possibly as 

 silicic acid. It occurs principally in the 

 cell wall. There are few plants (if any) 

 that will not show the presence of Si in 

 their ash. It was formerly thought that 

 Si was necessary, especially to cereals. 

 Sachs, however, showed that the amount 

 of Si0 2 could be reduced from 1 8 per 

 cent, to 0.7 per cent without injuring the 

 plant. The breaking down of Si0 2 was 

 supposed to be due to lack of Si0 2 in the 

 soil (Davy), but it is now known to be 

 due to etiolation. The leaves of cereals 

 contain more Si0 2 than the stems. It is 

 supposed that Si0 2 is useful to many 

 lower forms of plant life (diatoms) in 

 preventing the entrance of the germinat- 

 ing tubes of fungus spores. 



(2) Sodium is always present, even 

 though in but minute quantities, in the 

 ashes of plants. It is present in marine 

 plants in considerable quantity at times 

 — perhaps from adhering salts. A very 

 small quantity is absorbed by the plant 

 and its usefulness is questioned. 



(3) Chlorine is supposed to be required 

 by some plants in the transportation of 

 the carbohydrates. In some experiments 

 made upon buckwheat plants that were 

 raised in a solution without chlorides, 

 the chlorophyll corpuscles became over- 

 charged with starch grains, owing to the 



fact that the starch was not carried out 

 rapidly enough. This condition was 

 remedied by the addition of KC1. It is, 

 however, observed, that maize plants 

 will grow well in solutions without 

 chlorides and that the accumulation of 

 starch in the chlorophyll-corpuscles may 

 be induced by various abnormal ex- 

 ternal conditions. 



(4) A few other constituents are found 

 in some other plants in noticeable quan- 

 tities as, (a) Iodine and bromine in 

 marine plants, (b) Aluminum in the 

 spores of Lyeopodium. (c) Manganese 

 in some Cupidiferce . (d) Rubidium in 

 the beet-root, (e) Fluorine in Lycopo- 

 dium clavatum. (f ) Zinc in some species 

 of Viola and Silene growing on zinc soil. 



In subsequent papers the localization 

 and chemistry of the various constituents 

 will be considered, with tests for these 

 principles, and their service in the plant 

 economy where it may be possible to in- 

 dicate it. 



The yellow coloration of milk on exposure to 

 heat is due, according to M. Cazeneuve and M. 

 Haddon, to the oxidation of the lactose in 

 presence of the alkaline salts of the milk. Lac- 

 tose during this oxidation yields acids, especial- 

 ly formic acid, easily detected, the presence of 

 which suffices to explain the coagulation of the 

 milk as it ensues with any acid. — The Popular 

 Science Monthly. 



Saccharin as an Antiseptic. — Burkart and 

 Seifert have undertaken a series of experiments 

 on the relative antiseptic value of pure sac- 

 charine. They find that it has only one-fifth of 

 the antiseptic value of salicylic acid, if pure 

 saccharin be used. Ordinary saccharine, con- 

 taining 60 per cent, of pure benzoyl-sulphonic 

 imide and 40 per cent, of para sulphamido- 

 benzoic acid, is only one-eighth as powerful as 

 salicylic acid, which fact points to the para acid 

 being without any antiseptic value at all. The 

 preservative action of saccharine depends, fur- 

 ther, on the fact that it replaces, in the product 

 in which it is used, substances of a highly fer- 

 mentable nature. — Annates de Pharmacie. 



