' 270 . Use of Sulphate of Copper, &c. in Bread. 
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The author divides his essay into two parts; in the first he treats 
of the origin of the use of those ‘materials which are employed in 
adulterations, of the proportions of them which have been adopted 
by bakers, of the effects they produce, and of the methods he has 
found miost effectual for detecting their presence, even in minimum 
quantities ;—in the second, he determines the action which these dif — 
ferent substances exert upon the quality of bread. ‘This was effected 
by. baking a very gréat number of loaves with variable proportions 
_ the adulterating materials. 
“PART FIRST. | 
a The north of France and Belgium has been for. some time past 
the principal theatre of frauds committed by bakers, by the mixing 
of sulphate of copper with their bread. .The practice appears t0 
have commenced about 1816 and 1817, in which years the grain 
was generally of a bad quality. 'To obviate this inconvenience, they 
mixed with the wheat flour, the flour of dry beans and ot -sub- 
stances, and at length made.use of blue vitriol, finding that it¢ niti- 4 
buted to hasten the fermentation, to cause the dough to retain more 
water, to diminish the labor of kneading, and produce a lighter and 
finer looking bread from the defective or the mixed. flour.*, The 
abuse was afterwards carried to such an extent, that in some ‘of the 
towns, commissioners were chosen to have the permanent supervision 
of the bread made and sold by bakers. ' — 4 
If the detection and punishment of so serious a crime as the por 
soning of bread is.a matter of importance to the public welfare, 1's 
also very necessary to be able clearly to demonstrate the presence of 
the poisonous material. ~The detection of copper in bread woul 
seem to present no difficulty, as this metal’ manifests its presence by 
decisive chemical characters. The contact of sulphuretted, hydro, 
sen, hydro-ferrocyanate of potash, or ammoniacal was, may remove 
all uncertainty ; but when it is considered in how small a proportion 
this poisonous salt is employed, these experiments demand the most 
careful attention. Prussiate of potash indeed will indicate the pres 
ence of one part of sulphate in nine thousand parts of white bread, by 
the production of a rose color in the containing fluid. ‘The author 
obtained the following results, =~ > é | 
ects mig ae I ES gk i eee 
* Thirteen bakers were condemned on the 27th of January, 1829, by the ‘cor- 
rectional tribunal of Brussels, for mixing sulphate of copper with their bread. 
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