NEW THERMOMETERS FOR MELTING POINT 

 DETERMINATION.* 



Uniformity in practise in making melting point determina- 

 tions would be very desirable, for even to-day there are too many 

 cases where different observers disagree. The failure to agree 

 is not always due to the quality of the material if we may have 

 confidence in the analytical data given. Many forms of appara- 

 tus are in use as well as various kinds of thermometers. Other 

 factors also enter in. The practise of reporting the corrected 

 reading is a step in the right direction and its extension should 

 be constantly urged. 



In order to avoid the necessity of making corrections for the 

 exposure of the mercury column I have devised a thermometer 

 with a short scale, so that it may be completely immersed in 

 the bath. The method of construction may be readily seen from 

 the accompanying sketch. Owing to the compact form of the 

 scale it was necessary to construct a set of seven thermometers, 

 each with a milk glass scale of 50*^ with divisions in degrees. 

 The length of the scale is 35 mm. The thermometer jacket is 

 lengthened so that the total length is 20 cm. This permits of its 

 suspension by means of a cork as in the Thiele apparatus which 

 is a particularly good form to be used with this thermometer. 

 The mercury bulb is small and compact and above it is a con- 

 striction to enable one to attach the capillary tube if that is 

 desired. For the protection of the manufacture of the thermom- 

 eters patent No. 507,320 has been entered in the German Patent 

 Office. The thermometers may be obtained from C. Richter, 30 

 Lehrterstrasse, Berlin, N. W. 5. 



Alvin S. Wheeler. 



University of North Carolina. 



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* Reprinted from The Journal of the American Chemical Society, Vol. XXXIV, 

 No. 9, September, 1912. 



