40 Prof. J. A. Ewing. [Nov. 22, 



The crystals of silicotetraphenylamide are perfectly colourless short 

 prisms of considerable size. They melt at 136 137 to a transparent 

 liquid, which can be heated to 210 without decomposition. On 

 cooling this liquid solidifies to a transparent glass which, like the 

 original crystals, can be easily decomposed by water. 



If silicotetraphenylamide be heated tinder diminished pressure 

 (about 80 mm.), it affords a distillate of aniline, and leaves a residue 

 which seems to be the silicon analogue of carbodiphenylimide ; but 

 the latter has not yet been completely analysed. 



The detailed investigation of the new substance and its derivatives 

 is in active progress, and promises to throw light on the hitherto 

 obscure relations of silicon and nitrogen. 



I have reason to believe that the homologues of aniline, and certain 

 other analogous nitrogen compounds, act like excess of aniline on the 

 silicon haloids, and produce substances similar to the subject of this 

 note. These reactions are also being investigated in my laboratory. 



IV. " On the Magnetisation of Iron and other Magnetic Metals 

 in very strong Fields." By J. A. EwiNG, B.Sc., F.R.S., 

 Professor of Engineering in University College, Dundee, 

 and WILLIAM Low. Received October 29, 1888. 

 (Abstract.) 



Early in 1887 the authors communicated to the Royal Society the 

 results of experiments made by subjecting iron to strong magnetic 

 force by placing the sample, in the form of a bobbin with a short 

 narrow neck and conical ends, between the pole-pieces of an electro- 

 magnet. The experiments have been continued and extended by 

 using much stronger magnetic forces and by testing samples of nickel, 

 cobalt, and various steels, as well as wrought iron and cast iron. The 

 large magnet of the Edinburgh University Laboratory, kindly lent 

 by Professor Tait, was used throughout the experiments, and allowed 

 the authors to effect a high concentration of the magnetic force by 

 using bobbins the necks of which had a cross-sectional area of (in some 

 cases) only y-gVo ^ the cross-sectional area of the magnet cores. By 

 this means the induction ^ was raised to the following extreme 

 values : 



In wrought iron 45,350 c.g.s. 



cast iron 31,760 



Bessemer steel 39,880 



Tickers' tool steel 35,820 



,, Hadfield's manganese steel. ... 14,790 ,, 



nickel 21,070 



cobalt , 30,210 



