DEVICE FOR THE SIMULTANEOUS OBSERVATION OF MELTING

VOL.9, NO. 11

MELTING POINT AND TEMPERATURE

1975

DEVICE FOR THE SIMULTANEOUS OBSERVATION OF MELTING POINT AND TEMPERATURE EUGENE W. BLANK,241 N. N m m STREET, ALLENTOWN, PENNSYLVANIA The advantage of using a microscope for the simultaneous determination of melting point and temperature by means of a hot stage and camera lucida' can be obtained when using a Thiele tube by utilizing two right-angled prisms, Details of the arrangement of the apparatus are shown in Figure 1. The device should work admirably on an electrically heated melting-point tube,: although the writer has used it only with a flame-heated tube. The upper prism is turned 45' in respect to the lower one. The prisms are mounted in clips made from sheet brass and the upper prism is so arranged as to be capable of sliding up or down the thermometer to which it is clipped. By using this device no observational error is introduced into a determination due to the time required for the eye to leave the meltingpoint tube and pick up the temperature reading on the thermometer. For this reason it is possible to raise the temperature of the bath more rapidly and materially reduce the time required for a determination.

4 ,

f

!I I

i

I? I

: ' !

I

+I-

CHAMOT AND MASON."Handbook of ChemiFIG- 1 cal Microscopy." Vol. 1. John Wiley & Sans. Inc., A strong beam of light left New Ymk City, 1930, p. 202. oblique to the page is directed 'SANW, I d . E w . Chem.. Anal. Ed., 3, 65 the thermometer and the (1931). melting-point tube.