CHEMISTRY. 430 



verse is true. On moistening' i1h> i»(>w(1«ms tlicy yield small anioiuitsof 

 ealciiim and aliimiimm in s(»l(d)le form. After l)read-makinf];^ Mio i)o\v- 

 ders eontaininj;" acid ealeiiim pliospliate leave most of their aluminum 

 behind as plu)si)luite, but when alum alone has been used the i)hosphate 

 is rephu'ed by liydroxide. In baking", tlie inferior of the loaf does not 

 exceed a temperature of 100° C, at which temperature neither the 

 •aluminum phosphate nor the liydroxide is completely d'jhydrated. Both 

 of these compounds in doses not much exceeding the quantities found ia 

 bread produce an inhibitory etiect upon indigestion, this point having 

 been determined by i)ersonal exj)eriments. That effect is probably due 

 to the fact that a part of the alumina unites with the acid of the gas- 

 tric juice and is taken into solution, while the remainder of the hydrox- 

 ide or i)hosi)hate preci[>itates the peptic ferment in insoluble form. 

 Partial precipitation of some of the organic matter of food may also be 

 brought about by the aluminum compounds in qijestion. From all the 

 evidence Mallet concludes that not only alum itself, but also the resi- 

 dues which it leaves in bread, are unwholesome. (Uhem. News, LViii, 

 270, 284.) 



Alaminum hi plant h. — It is commonly believed and asserted that flow- 

 ering [)lants do not contain aluminum as a normal constituent, although 

 one or two exceptions have been admitted. I>ut Yoshida, on examin- 

 ing carefully selected atul washed seeds of the pea, beau, lice, wheat, 

 barley, millet, and buckwheat, finds alumina present in the ash in every 

 case. The quantities found range from 0.053 i)er cent, in the ash of the 

 ])ea, ^oja hispida, up to 0.272 ]>er cent, in the ash of millet, Panicum 

 italicum. In the pea the cotyledons (!ontain no alumina, while the ash 

 of the hull or skin contains 0.208 per cent. The figure given above re- 

 lates to the whole pea. (Journ. Chem. Soc, Li, 748.) 



Silicon in iron and steel. — Thomas Turner, after a long and laborious 

 investigation, announces the following conclusions as to the influence 

 of silicon upon the iM()[)erties of iron and steel : 



Ingot iron containing silu;on in all proportions up to 0.5 per cent, 

 rolls well and does not show any signs of red-shortness; it welds per- 

 fectly with all proportions of silicon, and, with the somewhat doubtful 

 exception of the 0.5 per cent, specimen, it is not brittle when cold. 

 With less than about 0.15 per cent, of silicon, the limit of elasticity, the 

 breaking load, the extension, and the reduction of area are but little, if 

 at all, attected by the proportion of silicon present. With over 0.15 per 

 cent, the limit of elasticity and breaking load are increased, though the 

 effect of silicon in this respect is not nearly so marked as that of car- 

 bon. But the ductility is distinctly reduiied and rendered more irregu- 

 lar by the presence of much silicon. The fracture is also rendered more 

 granular or crystalline, and is less regular in character. (.lourn. Chem. 

 Soc, Liii, 824; continued from lt, 129.) 



The chemical structure of the natural .nlicates. — Under this heading 

 Clarke has summarized his views upon silicate structure, which vary 



