asi e 
evaporating di 
TRANSACTIONS OF THE SECTIONS. 55 
water, or sewage, will assume a condition favourable for the young crops to imbibe 
what they require. 
On Coloured Confectionary. By Dr. M‘Namara. 
The author drew the attention of the Section to the large quantity of highly poisonous 
colouring matters employed in the manufacture of confectionary, He reterred to cases 
of deaths resulting from this practice. He alluded to the manner in which these sub- 
stances might be coloured by vegetable colouring materials of a harmless nature, and 
suggested that a list of such colours should be compiled by parties competent to the 
task, from which alone confectioners should be permitted to select their colours. He 
.gave a sketch of such a list, and exhibited some beautifully coloured confectionary, in 
which such colouring matter had been employed. These confections he had for some 
time in his possession, and their colours did not appear to have faded. In conclusion, 
he cautioned the public against buying any confectionary in which green or blue 
colours exist, as such colours are probably produced by poisonous agencies. 
On the Effects of Alum in Panification. By W. Ovuine, MB, FCS. 
The author maintained that during the process of making fermented bread, in 
addition to the fermentation of some of the sugar of the wheat into alcohol and car- 
bonic acid, another species of fermentation or change most frequently took place, which 
consisted in a transformation of the starch into dextrine or sugar, and occurred to the 
greatest extent in flour that had undergone a damp harvesting, in some cases even to 
such an extent as to prevent altogether the production of a presentable loaf, save by the 
use of alum or some such agent. It appeared that alum exerted very little effect upon 
the necessary fermentation of the sugar into carbonic acid and alcohol, but that it 
impeded very greatly, or altogether prevented, the conversion of the starch into sugar. 
It was found that dough having of itself a tendency to undergo this saccharine change, 
or having the tendency induced by means of an infusion of malt, yielded loaves that 
were dark-coloured, sodden, sticky, sweet, and uneatable; while the same dough, with 
the addition of alum, yielded loaves that were white, dry, crumbly, and unobjection- 
able both as to taste and appearance. 
On the Presence of Copper in the Tissues of Plants and Animals. 
By W. Oviine, M.B., F.C.S.; and A. Dupré, Ph.D. 
The authors had made more than 100 examinations by a great variety of processes, 
and had recognized the presence of copper in nearly every instance. In several 
specimens of wheat-grain and animal tissue the copper had been estimated. From 
100 grains of wheat-ash, the authors had obtained -023 grain, and from an entire 
sheep’s liver, *515 grain, of oxide of copper. The process used, was to precipitate 
the copper eletrolytically on a platinum wire, to dissolve the deposit in nitri¢ acid, 
and to ignite the residue of the evaporated solution. 
On a new Method of forming Ammonio-Iodides of Metals. 
By the Rev. J. B. Reape, M.A., F.R.S. 
It is only within the last few years that the attention of chemists has been directed 
to compounds of metals with iodine and ammonia. The 5th edition of Brande’s 
‘Chemistry,’ published in 1841, is silént on the subject. At the Oxford Meeting of 
the British Association in 1847, Mr. Reade exhibited the ammonio-iodide and per- 
iodide of gold, and he has since experimented with other metals. 
The common method of forming the ammonio-iodides, is by placing an iodide of the 
metal in liquor ammoniz, or in ammoniacal gas, with or without heat. The method 
which Mr. Reade adopts, is to place the pure metal in direct contact with iodine when 
dissolved in ammonia. 
Some caution is required in forming this solution, but with ordinary care to secure 
a large excess of iodine, which dissolves teriodide of nitrogen if formed, the explosion 
of this terrible compound may be avoided. 
Solution of Iodine in Ammonia,—Perhaps the best mode of dissolving iodine in am- 
monia for the mumpose in question, is to place about 50 or 60 grains of iodine in an 
sh, hold it over the spirit-lamp for a few seconds tillit is thoroughly warm 
