Mb. J. Napieb on Incrustations in Steam Boilers. 191 



yellowish colour, resembling an alloy of gold and silver. They are 

 all rapidly oxidized in the air. 



Glucinium has been obtained by the action of Sodium upon its chloride, 

 and Magnesium by a similar process. They are both quite permanent in 

 the air, and can be drawn into wires and otherwise worked. Many of 

 the other metals have been recently obtained by improved processes, but 

 their properties are less remarkable than those already mentioned. 



Although the progress which has recently been made in the separation 

 of the metals from their compounds is great, much still remains to be 

 accompUshed, and the greater number of them are still scarce and can 

 be obtained only with great difficulty. 



Mr. Kennedy exhibited a collection of Crustaceans from the Shores 

 of Millport. 



February 10, 1858. — The Peesident in the Chair. 



Professor WilUam Thomson gave an account of experiments on the 

 Elasticity of Metals. 



Professor Allen Thomson exhibited and described several skulls from 

 ancient burial places, — viz. :— 1. Two skulls fi-om catacombs near the 

 Great Pyramid in Lower Egypt, — one of them apparently Pelasgic, the 

 other Egyptian ; 2. A skull from an ancient tomb in Malta, probably 

 Phoenician ; 3. A skull from the excavations at Kertch, very regularly 

 formed, and fully developed; 4. A skull from an old burial place in 

 New Zealand. Professor Thomson compared the forms of these skulls 

 with those of more modern races of mankind. 



Professor William Thomson showed an improved Apparatus for Test- 

 ing the Electric Conductivity of Metallic Wires. 



February 24, 1858. — Me. Beyce, Vice-President, in the Chair. 

 Mr. James Napier read a paper " On Incrustations upon Steam 

 Boilers." 



On Incrustations in Steam Boilers. By Me. James Napiee. 



Inceustatiok upon steam boilers is an effect so universal, that it seems 

 to be considered a necessary consequence connected with all steam 

 boilers, and therefore borne with as an incurable evil ; and it is only 

 when the evil is very great, and as a matter of sheer desperation, reme- 



