6 POPULAR ILLUSTRATIONS OF 



It will be seen that to convert starch into sugar, it is only 

 necessary to add four atoms of hydrogen and four of oxygen. How 

 is this obtained ? Why, as I have before remarked, one of the 

 conditions of germination is the presence of moisture or water, 

 which is composed of hydrogen and oxygen. Under the influence, 

 then, of this vital force of that mysterious power we term " life " 

 this wonderful change is effected which enables the young plant 

 to feed. 



But what becomes of the gluten of the flour ? It is contained 

 therein in the variable proportions of 12 to 20 per cent., and may 

 easily be separated from the starch by making a portion of flour 

 into paste with pure water, and then carefully washing it out on a 

 fine cloth. The starch, as a milky solution, will pass through the 

 cloth, leaving a greyish, elastic, insoluble substance behind, called 

 gluten. Now, this "gluten" of wheat-flour is composed of a small 

 proportion of a peculiar matter, to which its sticky or adhesive 

 properties are due, called "gliadine," and a large proportion of a 

 substance called " vegetable fibrine," which is identical, in chemical 

 composition, with white of egg or " albumen," with the chief con- 

 stituent of flesh or " animal fibrine," and with the chief constituent 

 of milk or "caseine," all of which are essentially parts of animal 

 bodies. The great difference between gluten and starch is owing to 

 the presence in the former of rather more than one-sixth of its entire 

 bulk of nitrogen, or as it is sometimes called " azote." If we wish to 

 produce fermentation in the sweet, sugary wort of beer, we intro- 

 duce what is called a ferment viz., yeast. If we wish to convert 

 our milk into cheese, we do so by introducing into it a piece of 

 rennet, by which decomposition is effected. So, nature in the 

 germination of the seed produces a ferment, through whose agency 

 the starch is converted into sugar, and it is done in this wise. 

 The gluten is decomposed, and is converted into what is called 

 diastase, which acts in decomposing the starch just as the yeast does 

 the sweet wort, or rennet with the milk. Gluten deprived of its 

 gliadine is constituted in a hundred parts, as follows : 



Carbon. Hydrogen. Nitrogen. Oxygen. 



54-60 7-30 15-81 22-29 



And by an interchange of these elements diastase is formed. This 

 diastase alters the molecular arrangement of the starch, and changes 

 it first into gum or dextrine, and then into grape sugar ; during 

 which process there is an evolution of carbonic acid from the excess 

 of carbon and oxygen. 



Such is the process by which the embryonic plant is provided in 

 infancy with the means of subsistence. 



