570 



Tr ansae tions. — Physics . 



corresponded with the first, although the decomposition in 

 this case is not so great. In the third series the temperature 

 was lower and the operation conducted more slowly. Further, 

 the charge, though medium, was somewhat softer, containing 

 less stearic acid and more palmitic and oleic acid. 



Thrrz- 



X 



From a consideration of the three series of experiments the 

 following conclusions can be drawn : In the case of the run- 

 nings from the first coil the freezing-point first falls a little 

 and then rises more and more rapidly until it reaches a maxi- 

 mum just before the end of the operation. After that there is 

 a very rapid fall, followed by an even more rapid rise. This 

 final rise, however, is not noticeable in the third series of 

 experiments, but in this case the charge was softer and the 

 temperature was not allowed to rise so high. 



During the early stages of distillation the freezing-poims 

 of the produce that condenses in the second coil are slightly 

 higher than those of the runnings througli the first coil. How- 

 ever, the curves soon cross, and then keep parallel for most 

 of their length; but whereas the first curve falls rapidly, the 

 second suffers only a slight decrease, crossing the first as it 

 is falling and again during its rise (fig. 2). The third curve 

 commences higher than the second, but falls below it just as 

 the second gradually drops below the first. 



A complete investigation of this nature does not appear to 

 have been previously made, and the exact nature of the 

 changes have not been studied. By testing with his thumb 



