S82 



THE FARMER'S MAGAZINE. 



Ihe baker to oppose the glucogenesis as much as possi- 

 ble. Hciico, in making bread from certain kinds of 

 flour, he finds it necessary to add alum, or lime, or 

 bean-meal, or some corrective substance which, from 

 experience, lie knows will cause the flour to yield a 

 loaf presentable to the ejc and agreeable to the 

 palate." 



Tliis has long been the popular, and, as it would ap- 

 pear, not erroneous opinion. It receives more confir- 

 mation a little further ou : — " One very important use 

 of alum is to prevent any undue deterioration of the 

 starch during the process of raising and baking. If we 

 mix a solution of starch with infusion of malt, in the 

 course of a few minutes only the starch can be no 

 longer detected, being completely converted into dex- 

 trine and sugar; but the addition of a very small quan- 

 tity of alum either prevents altogether, or greatly 

 retards, the transformation. The action of diastase 

 upon undissolved starch is very gradual, but here also 

 the interference of the alum is easily recognizable. 

 Bread made with infusion of bran or infusion of malt is 

 very sweet, sodden, brown- coloured, and so sticky as 

 almost to bind the jaws together during its mastication. 

 But the addition of alum to the dough causes the loaves 

 to be white, dry, elastic, crumbly, and unobjectionable, 

 both as to taste and appearance. I have found that 

 flour, which of itself was so glucogenic as to yield bread 

 undistiuguishablefrom that made with infusion of malt, 

 could, by the addition of alum, be made to furnish a 

 white, dry, crumbly, eatable loaf." 



The testimony of Liebig and Payen are both quoted 

 to warrant the use of alum ; and Dr. Odling thus sums 

 up in favour of the practice : — " In the absence of any 

 evidence, either from fair inference or direct observa- 

 tion, that the introduction of small quantities of alum 

 into bread is prejudicial to health, it seems that the 

 practice is not so reprehensible as is usually maintained. 

 It certainly improves greatly the quality of bread made 

 from inferior flour, and, in a politico-economical point 

 of view, is important, inasmuch as it renders a large 

 quantity of flour suitable for human food in the form 

 of bread, which flour would otherwise have to be de- 

 voted to less important uses." 



Still the doctor had it by no means all his own way. 

 He rather takes it for granted that we really know of 

 no ill effects arising from the use of alum. Dr. Snow, 

 on the contrary, " had many years ago come to the 

 conclusion that the practice of putting alum into 

 bread was a fruitful source of rickets amongst children. 

 It appeared toliirathat rickets were more prevalent 

 among£t children in London and the south of England 

 than was the case in the North or in Wales, where the 

 children were just as overcrowded and as deficiently 

 supplied with milk as in London. He believed that 

 for grown people the admixture of a little alum was 

 not very injurious, though for children it was so." 



Then again, Mr. Pittard, " And many other medical 

 practitioners had a settled belief that alum in bread was 

 injurious to mankind. Sickly children had been found 

 to improve marvellously upon baked flour, whilst they 

 pined away upon soaked bread. The chemists spoke 

 slightingly of the medical men because they did not 

 pretend to know the chemistry of the question, and said 

 that they were ignorant that the alum was decomposed 

 in the making of bread. Even if that were so, it did 

 not prove that the alum was rendered innocuous ; if 

 alum was resolved into alumina and sulphuric acid, he 

 did not know whether alumina might not be injurious 

 in the body. It was a fact worthy of note that, al- 

 though alumina was one of the most plentiful substances 

 on the earth, yet it did not enter into the compo- 

 sition of any organic bodies whatever, whether 

 animal or vegetable. This alone was reason against 



the introduction of alum into food. With salt it 

 was very different. They might be told that the 

 chemical effects of alum on the animal system 

 were not extraordinary, but there were chemical 

 effects to be considered." Dr. Normanby, Mr. Varley, 

 Mr. Johnstone, and Mr. Malone also spoke to the 

 injury arising from the constant use of alum. But Dr. 

 Gilbert " suspected the truth lay somewhere between 

 the two extremes. Ho was not disposed to think that 

 alum could be, with advantage to the consumer, added 

 to really good flour, for the purpose of bread-making. 

 On a large class of constitutions he thought there was 

 medical testimony enough to show that alum, or 

 alumina, in bread acted injuriously. With such it 

 induced constipation, and this was a fruitful source of 

 more serious disease. On the other hand, it was to be 

 remembered, that owing to the seasons, which we could 

 not control, a considerable jiortion of the flour, which 

 must be consumed by somebody, was not in a perfect 

 condition to yield a bread of good texture and 

 other requisite characters without the aid of some 

 extraneous matter; and if the bread were not of 

 suitable texture and condition, its digestion would be 

 imperfect, and if digestion, then assimilation also. 

 The question was then, so far as related to alum, 

 whether or not the benefits which it undoubtedly pro- 

 duced, so far as the physical and some otlier characters 

 of the bread were concerned, were greater or less than 

 the evils he believed it in many cases induced. The 

 subject required much careful consideration ; and if a 

 substance or method that would have the same effects 

 in retarding the chemical changes to be avoided in 

 flour and bread, and which at the same time was un- 

 doubtedly innocuous, could be generally adopted, few 

 would then uphold the use of alum. The suggestion 

 of Dr. Odling to use lime-water, as recommended by 

 Baron Liebig, w'as deserving the serious attention both 

 of bakers and medical men." Mr. Dugald Campbell 

 went more decidedly with the baker, and was "pre- 

 pared to say that such a quantity of alum as would do an 

 injury would render the bread unsaleable." And Mr. 

 Callard, himself a baker, confirmed this : — " Dr. Snow 

 had mentioned a quantity of alum as having been found 

 in bread that he (Mr. Callard) could not suppose to be 

 possible. Such bread could not possibly be eaten." 



We regard the points of this discussion as not with- 

 out interest, and we present them accordingly to our 

 readers. The conclusion would seem to be that the 

 evil has been greatly over-rated. It is very certain 

 that some of the much- noised alum discoveries have 

 been made upon tests anything but reliable. Dr. 

 Odling charactei'ized the means often employed as a 

 disgrace to chemistry, and in showing up " the loose 

 speculation," and " groundless defamation" of gentle- 

 men " gasping for notoriety," had throughout the best 

 of the argument. Still the use of alum in any degree 

 is but at present a necessary evil. Mr. Callard, the 

 baker, in admitting it was extensively used, said the 

 trade would be glad if scientific men could point to 

 some less objectionable substance, and the public will 

 readily echo this request. We gather from what we 

 heard, that on the whole the common opinion as to 

 alum is a very correct one. It is injurious, and is 

 mostly to be found in the best-loolung bread. Dr. 

 Snow has detected much less in the bread supplied to 

 the lower classes, though he had expected that what 

 were called cheap bakers used more than those who 

 supplied May-fau", but such was not in reality tho 

 case. 



It is a question, then, that concerns us all, and one 

 that we trust such men as Dr. Gilbert and Dr. Odling 

 have as yet by no means done with. They may " reform 

 it altogether," 



