160 



the sulphide is let fall on this alloy a deep red spot is produced, 

 and this quickly changes to a perfect black stain. 



When larger proportions than 10 per cent, of aluminium are 

 melted with copper, the alloys become hard, and ultimately, by 

 increasing the proportion of aluminium, the alloy is made brittle. 



The alloy of 10 per cent, of aluminium and 90 of copper is 

 malleable, ductile, and has a golden color, but it is not capable of 

 withstanding the action of acids or of sulphide of ammonium. 



An alloy of 10 parts of aluminium and 90 of zinc is malleable, 

 and takes a very brilliant polish with the lustre and color of 

 highly-polished steel. 



Dr. Jackson remarked that we know, as yet, but little of the 

 uses of aluminium and of its alloys, and that the introduction of 

 the new metal, at moderate cost, into the workshops of our me- 

 chanics and artisans, is likely to open a new field for enterprise in 

 metallurgy. 



Numerous experiments are required, and larger quantities of 

 the alloys should be made, so as to test their properties and value 

 in a practical way, and the sacrifice of some hundreds of pounds 

 of aluminium could well be afforded in view of the useful results 

 that would be obtained by experiments with its numerous alloys. 



Were aluminium works erected in this country, it is prob- 

 able that the first few years' production from them would be 

 consumed in experiments by our practical artisans, or be sold for 

 specimens to schools and colleges, or to private gentlemen. By 

 manufacturing this metal on a large scale, the cost of its production 

 can undoubtedly be made quite moderate. It is stated that it can 

 now be made in Paris at a cost of nine dollars a pound. This 

 is a considerable reduction from the former prices, for the speci- 

 mens now before the Society cost one hundred and sixty doUai's 

 per pound. 



The following paper was read at the meeting of Octo- 

 ber 1st, 1856, by Dr. David Weinland. 



A PSYCHOLOGICAL VIEW OF THE MOTIONS OF ANIMALS, BY 

 DR. DAVID "WEINLAND. 



There is hardly any part of the science of natural history 

 which has been so little studied as the psychology of animals. 



