CHEMISTRY. 439 



verse is true. On moisteuing tlie i)()\v(lers they yield small junoiuits of 

 calcium and aluinimiin iu soluble Ibrm. After bread-making the i)OW- 

 ders coutaiuiug acid calcium phosphate leave most of their aluminum 

 behind as i)hosphate, but when alum alone has been used the phosphate 

 is replaced by hydroxide. In bakiny;, the inferior of the loaf does not 

 exceed a temperature of lOO"^ C, at which temi>erature neither the 

 aluminum phosphate uor the hydroxide is completely dehydrated. Both 

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

 bread produce an inhibitory effect upon indigestion, this point having 

 been determined by personal experiments. 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 phosphate precipitates 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 question. From all the 

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

 dues which it leaves iu bread, are unwholesome. (Uhem. ]S"ews, lviii, 

 276, 284.) 



Aluminum iti plants.— It is commonly believed and asserted that flow- 

 ering plants do not contain aluminum as a normal constituent, although 

 one or two exceptions have been admitted. But Yoshida, on examin- 

 ing carefully selected and washed seeds of the pea, bean, rice, wheat, 

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

 case. The quantities found range from 0.053 per cent, in the ash of the 

 l)ea, Soja hisjuda, up to 0.272 ]>er cent, in the ash of millet, Panicum 

 italioum. In the pea the cotyledons contain no alumina, while the ash 

 of the hull or skin contains 0.2G8 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 intluence 

 of silicon upon the i)roperties of iron and steel : 



Ingot iron containing sili(;on in all ])roportions 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, affected 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 reduced 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. (Journ. Chem. 

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



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

 Clarke has suramarized his views upon silicate structure, which vary 



