Descriplion of an improved Apparatus for distilling. 353 



the admission of the air when necessary, and both the receiver 

 and the stil! liave proper discharge cocks, and may have man- 

 holes or cap-screws in any convenient situation for cleansing 

 them, and anv otlier useful apjiurtenances. 



The construction is shown in Plate II. and will be easily un- 

 derstood from the following description : — A is the still; LL 

 the outer case attached to it ; B is the close condensing vessel; 

 C is the close receiver, having an air-pump E on its top, and 

 also a stop-cock D; H is the discharge cock of the receiver; I 

 the discharge cock of the still ; G is the stop-cock in the pipe 

 connecting the close condensing vessel and the receiver. The 

 condenser and receiver are also in cases, but surrounded with 

 cold water. 



In this improved apparatus, the produce in the receiver may 

 at any period of the distillation be examined v.'ithout interrupting 

 the progress of the operation; for by turning off the stop-cock 

 G, so as to close the communication between the close condenser 

 and the receiver, the latter may be opened, without suffering air 

 to get into the other vessels, so as to stop or impede the distil- 

 lation. The advantages presented by this invention are many 

 and important. By the removal of the pressure of the air from 

 the surface of the liquid in the still, a very moderate heat suffices 

 to effect distillation — far less than in the common process; and 

 a great saving of fuel is effected, which (for the colonies espe- 

 cially) is a consideration very important. 



To show the extent of this benefit, it may be stated, as the re- 

 sult of repeated experiments, that distillation in this improved 

 apparatus takes place at a temperature full 80" below the com- 

 mon boiling point of 212°. By the regular application of this 

 low degree of heat through the medium of the liquid in which 

 the still is immersed, any empyreuma is entirely prevented, and 

 the produce in the improved apparatus is rendered far superior 

 to the best produce of common distillation. No accidejit of 

 burning to the bottom can occur in this apparatus, nor can loss 

 by evaporation, inevitable at the worm's end in the common 

 mode, and sometimes great when too fierce a fire is kept up. 

 The durability of the vessels is also promoted by this new con- 

 struction and mode of operating ; and as less heat is required for 

 distillation with this apparatus, so less cold water is wanted for 

 condensation, which in several of the West India islands, that 

 have but a very scanty supply of that useful article, is a very desir- 

 able saving. These advantages have been proved by many decisive 

 experiments, and the quality of the spirit obtained by distillation 

 in this improved method has been pronounced unrivalled by 

 gentlemen eminently competent as judges on the svibject. Those 

 ' VoK5l. No. 241'. i\7fly 1818. Z who 



