504 EFFECTS OF GERMINATION M ND BAKING 



manures is very striking, if the determinations are really to be depended 

 upon. They are certainly interesting in a theoretical point of view, and 

 are deserving of careful repetition. In reference to their bearing upon 

 practical farming, however, it must not be forgotten, that the results of 

 small experiments are never fully bonie out when they are repeated on 

 the large scale — that the relative value of different animal manures is 

 materially affected by the kind of food on which the animal has lived^ — 

 that independent of manures, there are circumstances not yet made out 

 which materially affect the produce of single patches* — and that it will 

 rarely be in the power of the practical farmer to apply at pleasure to his 

 fields the relative proportions of the several manures used by Hermb- 

 stadt. Thus, if instead of 20 tons of farm-yard manure he wished to 

 try blood or urine alone, he must apply 24 tons of the former, and 70 

 tons of the latter — quantities which it might be both difficult to procure 

 and inconvenient to apply. 



The most practically useful results yet published in regard to the ac- 

 tion of the different manures upon the weight of the crop, the proportion 

 of flour yielded by it, and of gluten in the flour, are those of Mr. Burnet, 

 to which I have already had occasion to draw your attention. f These 

 results were as follow : — 



KINI,OKM.K.KB. ^f^l 



Nothing 31 i bshls. 



Sulphated urine and wood ashes. 40 " 



Do. and sulphate of soda. 49 " 



Do. and common salt. .49 " 



Do. and nitrate of soda, .. 48| " 



We perceive here a slight increase in the per-centage of gluten when 



the manures were applied, but nothing which at all resembles the great 



differences given by Hermbsatdt, or which renders it probable that by 



skilful management, as some have supposed, we may hereafter be 



able to raise in our fields whole crops of corn which shall yield a flour 



containing 20 or 30 per cent, of gluten. 



§11. Of the effects of germination, and of baking, upon the flour of wheat. 



The effects of germination and of baking upon the flour of wheat are 

 very analogous to each other. In both cases, a portion of the starch is 

 changed into gum and sugar. 



1°. Germination. — I have already described to you (p. 118), the very 

 beautiful change which takes place di ring the sprouting of the seeds of 

 plants — how a portion of their gluten s changed into diastase, and how, 

 by the agency of this diastase, the starcli of the seed is changed into gum 

 and sugar. In an experiment made by De Saussure, 100 parts of the 

 farina of wheat had by germination lost 6 parts of starch, and in their 

 stead had acquired Sif of gum and 2i of sugar. The eflTect of this 

 change — which proceeds as the plant continues to grow — is to make the 

 starch soluble, and thus capable of entering into the circulation of the 

 young plant. 



2°. Baking. — It is the larger proportion of gluten usually contained 

 in the flour of wheat that renders it so much better fitted for the bakin? of 



" See Appendix, pp. 59 and 79. T See p. 362 and Appendix pp. 49 and 71. 



