ON THE COMPOSITIOIf OF VVHEATEN FLOUR. 501 



COMPOSITION OF THE FLOUR OP 



French Wheat. Odessa Wheat. 



100-5 100 100 98-8 98-4 100-3 



§ 9. Of the influence of soil and climate on the composition of 

 wheaten flour. 



1°. The nature of the soil has a sensible influence upon the composi- 

 tion of the grain that is reaped from it. The proportion of gluten, for 

 example, is said to be generally greater in grain which is reaped from 

 calcareous soils, or from such as abound in organic matter. In the north 

 of Ireland, this fact has been observed in regard to the wheat grown in 

 the limestone districts ; and the millers of the midland counties of Eng- 

 land (on the new red sandstone) are accustomed to mix, with their native 

 corn, that of the chalk districts to the east and south, for the purpose of 

 giving additional strength to their flour. 



Climate. — The wheat of warm climates also is supposed usually to 

 contain more gluten. Thus flour, prepared from some Eastern wheats, 

 compared with that from others of French growth, was found to contain 

 water and dry gluten in the following proportions : 



Water, Gluten, 



per cent. per cent. 



. 15-1 12-7 



. 12-9 11-2 



French, Saissette 

 Roche! le 

 Brie . 

 Tuzelle 



Odessa 

 Taganrog* 



The quantity of gluten contained 



. 13-5 10-7 



. 13-0 8-3 



. 13-0 15.0 



. 12-6 22-7 

 n English flour has generally been 



stated much too high. Thus, Sir Humphrey Davyf says that he ob- 

 tained from the flour of — 



Gluten, Gluten, 



per cent. per cent. 



English winter wheat 19 Barbary wheat 23 



' English spring wheat 24 Sicilian wheat 21 



— and others have given numbers nearly as high. But the gluten is 

 very difficult to dry, and I believe that the large per-centage of this sub- 

 stance assigned by previous experimenters has arisen from the water not 

 being sufficiently expelled from it by prolonged heating to 220° F. I 

 select the following from a greater number of determinations, carefully 

 made in my laboratory : — 



• Taganrog, at the head of the sea of Asoph, exports the produce of the banks of the 

 Don. 



• Agricultural Chemistry, Lecture III. 



