92 PROCEEDINGS OP THE AMERICAN ACADEMY 



found it advisable to keep the elevated condenser at as low a tem- 

 perature as would permit the vapor of the most volatile liquid to 

 pass through it; for in proportion as its temperature is higher 

 than this, the product will contain a larger quantity of the less 

 volatile constituents ; and if the temperature he allowed to equal 

 that of the retort, the conditions of the experiment would not 

 differ essentially from ordinary distillation, except that friction, 

 from contact of the vapor with the sides of the worm during its 

 passage through the elevated condenser, might give it some slight 

 advantage. Between these two extremes of temperature for the 

 elevated condenser, therefore, it may he adjusted suitably for any 

 unstable liquid requiring and admitting purification by distilla- 

 tion, since the time required to distil a given quantity of liquid 

 by this process may be shortened, other things equal, in propor- 

 tion as the temj)erature of the elevated condenser is raised nearer 

 to that of the retort; and by shortening the time, other condi- 

 tions the same, decomposition, as said before, is proportionately 

 lessened. 



I might give the details of many experiments to prove the supe- 

 riority above claimed for my apparatus, for it has given me reliable 

 results under the most varied conditions; but this does not seem to 

 be required. I trust that the foregoing remarks will be sufficient 

 to lead any one who may have questioned the adaptability of my 

 apparatus for the class of substances now under discussion to view 

 it in a different light. 



