4)36 Remarks and Observations suggested 



The author of the treatise Botany in the Library of Useful KnoW' 

 ledge, and Mr. Ellis in his Enquiries into Vegetable Physiology, 

 seem to be of the same opinion. When we examine seeds in their 

 newly formed state, as oats and wheat in the ear, we find the 

 matter beginning to be deposited as the future food of the em- 

 bryo of a milky mucilaginous consistency called gum ; as it con- 

 tinues to ripen, more carbon is deposited, the food gets more 

 solid, and ultimately assumes the condition of flour or starch ; 

 which, if the weather has been sunny, gets nearly as hard as 

 wood. This is a wise provision of nature for the preservation 

 of the seed : in its recent or mucilaginous state, much less heat 

 and moisture would decompose it, and these unripe seeds would 

 not keep well ; but before the young embryo can receive nourish- 

 ment in the spring, from the food deposited for that purpose, it 

 must be again decomposed and made soluble. We thus see 

 how well-ripened seeds, which have their food highly fixed, by 

 the deposition of carbon, into the form af starch or flour, are so 

 much more easily preserved ; and how unripe seeds, provided 

 only, as Dr. Lindley says, their embryo be perfected, will germi- 

 nate more quickly than ripe seeds ; the starch of the ripe seed 

 must be again reduced to mucilage, before it can become soluble 

 food. M. Raspail, in examining the starch of plants, found the 

 ultimate particles to consist of a substance similar to gum or 

 sugar, but polarising light to the right, whereas the other did it 

 to the left; and he therefore called it dextrine : this dextrine is 

 soluble in water, but each of the particles he found to be sur- 

 rounded with a hard shell or skin which is very insoluble, and 

 requires a high heat to burst it, Mr. Ellis says 160° to 180°; 

 the author of Botany [Library of Usefd Kno'wledge) says nearly 

 a boiling heat ; and that, to produce the heat necessary, we 

 must, after all other sources, add the vital heat, when the embryo 

 is stimulated into life. M. DeCandolle suggests that tannin and 

 alkaline matters may help to rupture the shell of the starch. Mr. 

 Charles Maltuen found that seeds in germinating threw off acids, 

 and retained alkalies ; and that they germinated at the negative, 

 or alkaline, pole of the battery much sooner than at the positive, 

 or acid, pole ; and afterwards, by enclosing seeds in glass phials 

 filled with solutions of different kinds of acids and alkalies, he 

 found that the seeds germinated in the alkalies in a third part of 

 the time that they did in the acids. M. Payen [Journal de Cliimie 

 Medicate, Avril, 1834) tried seeds of wheat, rye, barley, oats, 

 and maize, in water, and in water mixed with different proportions 

 of soda, lime, and tannin ; and he found, from experiment, that 

 the seed in growing gave ofF acids ; that those in the alkaline 

 mixtures grew quickest ; and, as the acid given off increased, the 

 seeds in the alkaline mixtures grew still more perceptibly quicker; 

 and, when the alkali neutralised by the acid given off was replaced. 



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