CONTRIBUTIONS FROM THE CHEMICAL LABORATORY OF 

 CASE SCHOOL OF APPLIED SCIENCE. — XLII. 



AN APPARATUS FOR CONTINUOUS VACUUM 

 DISTILLATION.* 



By Charles F. Mabkry. 



Received May 13, 1902. 



The occasional contributions to methods for vacuum distillation seem 

 to indicate that a method is still wanting that shall combine convenience 

 and efficiency. It is quite true that the various attachments that have 

 been suggested and that are described in dealers' catalogues fall short of 

 efficiency in essential details. In the great amount of vacuum distillation 

 carried on in this laboratory during the last fifteen years, probably much 

 exceeding what has been done elsewhere in a single line of work, a durable 

 apparatus has been gradually evolved in which this work can be carried 

 on as expeditiously as distillations under ordinary pressures. 



One of the most essential features is a regulator to maintain a constant 

 tension, and the stopcock G with lever attachment formerly described t 

 and constantly in use is very satisfactory. 



The chief features to be provided for in a convenient apparatus are the 

 following : 



1. Exclusion of air from hot oil in still during chancre of receiver. 



2. Admission of distillates into still without interruption. 



3. Admission of air into receiver-before removal of each fraction. 



4. Exhaustion of receiver for new fraction without connection with 

 still. 



The complete apparatus in the form used at present is shown in the 

 following figure : — 



* This method is a part of the work that is carried on in this laboratory with aid 

 granted by the Academy from the C. M. Warren fund for chemical research, 

 t These Proceedings, XXXI. p. 10. 



