74 



GLANDS AND 



Sect, VI. 3. z 



boiled potatoes, as good bread may be made as from the beft wheat 



r ; as is affirmed by Monf. Parmentier. From this it appears. 



flou 



that the quantity of flarch in potatoes and in wheat produces the prin- 

 cipal difference of their refpeflive flours. See Zoonomia, P. III. Ar- 



I. 2. 3. 4 



/ 



I 



2. There is reafon to believe that the mucilage during the growth 

 of the plant is converted into ftarch ; and that this procefs continues 

 in grain fome time after it is carried into the barn or granary, which 

 occafions old wheat to produce better flour for the baker ; and old 

 oats and old beans are univerfally believed to give more nourifhment 

 to horfes. I fhall here add a conjedure, that I fuppofe the ufe of alum 

 in making bread confifts in its coagulating the mucilage, and perhaps 

 thus contributing to convert it into flarch ; for the bakers mix it 



daffi 



that it makes the flour of 



principally with new wheat ; ai 

 new wheat equal to old. 



Where much alum is mixed with bread, it may be diflinguifhed by 

 the eye by a curious circumftance, which is, that where two loaves 

 have ftuck together in the oven, they break from each other with a 



much fmoother furface, where they had adhered, than thofe 

 do which do not contain alum. 



Add to this, that alum is alfo ufed by the London bakers 



e 



;rs for th 

 purpofe of clearing the river water, with which they are fupplied 

 which is frequently muddy ; and alfo for inftantaneoufly defl:royin 

 the volatile alkali, which is faid to exifl: in fome London wells owin 



, Thefe purpofes it probably fulfils by 

 which may occafionally be mixed with 



the vicinity of dungh 



is 

 or 



coagulating the m 



o 



the water and fupport the mud 



by uniting with the calca 



tb, or with the volatile alkali which it may contain, and de 



pofiting the new-formed g 



ypfum 



own argillaceous bafe, th 



defcent of which may carry down other impuriti 



along with 



it, 



the fame manner as fome muddy wines have been rendered fi 



not by filtering them through fand, as then the mud retained on the 



furface 



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1 



