Chap. 5 . ] Nutriment al Part of Flour. 5 7 



lation with a naked fire, it affords an acid water of a 

 brown colour, and a very thick oil towards the end of 

 the prccefs. Its coal is eafily reduced to alhes, which 

 contain fixed alkali. 



The fubftance which was mentioned as being dif- 

 folv^d in the water in which flour is walhed, does not 

 effentially differ from other faccharine mucilages. By 

 evaporating the water in which it is contained, M. 

 Poulletier obtained a vifcous, glutinous fubftance, of 

 a brownifh yellow colour, and (lightly faccharine tafte. 

 This fubftance, called by its difcoverer the mucofo- 

 faccharine matter, exhibited all the phenomena of 

 fugar in its combuftion and diftillation. It is this which 

 excites the acid fermentation in the water which floats 

 above ftarch ; for, as Macquer well obferves, the latter 

 is not at all foluble in cold water. The mucofo-fac- 

 charine matter exifts in a very fmall proportion in 

 wheat-flour. M. Fourcroy, however, is of opinion, 

 notwithftanding the fmall quantity of it, that it is the 

 part principally concerned in the fermentation by which 

 bread is leavened. 



With refpect to what is the ntitrimental part of flour, 

 all the fubftances into which it is refolved, by wafhing 

 it in water, fee m well adapted to this purpofe; but as 

 the amylaceous matter is the moft abundant, fo it is 

 probably the moft important ingredient. The amyla- 

 ceous matter in wheat is to the glutinous in the pro- 

 portion of about three to two. 



Bread is the farina of grain, made into a pafte with 

 water, and baked. Unleavened bread, or bifcuit, keeps 

 longeft without Ipoiling, and is therefore ufed at fea, 

 where baking would be extremely inconvenient. Bread 

 ufed on more is in general leavened, and for this pur- 

 pole a quantity of yeaft is added to it, while in the 

 itate of dough ; in cpnfequence of this, and of being 



kept 



