376 BURGESS AND WALTENBERG! MELTING POINTS 



the alumino-thermic method with calcium; it contains traces of 

 Ca, Al and Fe. Professor Wedekind of Strassburg also furnished us 

 with a sample of his 97 to 98 per cent vanadium. We have also 

 examined' two samples purchased from Kahlbaum at different 

 dates. None of the samples melts sharply, the substance being 

 viscous; all samples show evidences of incipient melting many 

 degrees below the temperature at which the melting is complete. 



With the Kahlbaum samples, evidences of melting were appar- 

 ent as low as 1500°; melting was complete at about 1720°, the 

 samples showing evidences of non-homogeneity of composition. 



With Dr. V. Wartenberg's and Professor Wedekind's vanadium 

 the following results were obtained: 



TABLE V 



Melting Point of 97 per cent Vanadium by Micropyrometer 



97 to 98 per cent V from Wedekind 1700°, 1757°, 1773°, 1717° 



97 per cent V from v. Wartenberg; 1680°, 1691°, 1691° (pieces of about 0.001 mg.), 

 1685°, 1699°, 1705° (medium sized pieces), 1725° (largest pieces). 



Evidences of incipient melting were apparent at about 1650° with 

 these materials. Other determinations of the vanadium melting 

 point range from 1680° to 1750°. We would place the vanadium 

 melting point at about 1720°, both from a consideration of our 

 own and of other determinations. 



Titanium. Prof. M. M. A. Hunter, of Rensselaer Polytechnic 

 Institute kindly placed at our disposal a sample of pure titanium, 

 which he had prepared from material furnished by the Titanium, 

 Alloy Manufacturing Company of Niagara Fails. This titanium, 

 analyzed by Professor Hunter, contains only a trace of iron and 

 no other detectable impurity. Professor Wedekind likewise kindly 

 sent us two samples prepared by him of 94 to 95 per cent purity 

 and one by Dr. v. Wartenberg. The colloid titanium of Wede- 

 kind melted at 1508° to 1451°, and his powdered titanium at 

 1452°. We also took observations on two samples from Kahl- 

 baum, which were evidently quite impure, showing evidences of 

 an extended melting range. For the Kahlbaum samples the fol- 

 lowing melting points were obtained: 1664°, 1724°, 1677°, 1737°, 

 1641°. The titanium of Hunter and of v. Wartenberg showed 



