CANE SUGAR. 



quickly enough through the perforations, it can obtain a passage through the 

 valves dd\ the steam in its passage through the wash deprives it of its 

 alcohol, and a mixed vapour of alcohol, water and other volatile constituents 

 passes out of the analyser by the pipe //, and is led into the bottom of the 

 rectifier ; as the vapour meets the cold wash in the continuous pipe a a, it is 

 condensed and at the same time heats the wash ; the water vapour and bodies 

 of high boiling point, as well as some alcohol, are condensed in the lower part 

 of the still and fall dawn to the bottom and are continually taken away by the 

 pipe h, called the hot feints pipe. The alcohol in great part condenses in the 

 upper five chambers and falling down on the plate n n, is received in the 

 receptacle o and taken away by the pipe m ; this pipe leads to a refrigerator 

 and thence to the spirit store. A pipe g leads from the top of the rectifier 

 and takes away the uncondensed vapour ; this pipe too passes through a refri- 

 gerator, and the condensed vapours are collected and form the cold feints ; 1 1 

 is a water coil, by means of which the amount of cold feints allowed to be 

 formed can be regulated. The hot feints can either be allowed to mix with 

 the wash or they may be passed through a condenser and pumped to the top of 

 the analyser. The cold feints are collected separately, and when sufficient 

 have accumulated, they are mixed with the wash and redistilled ; if pumped 

 directly to the analyser, owing to their low boiling point they volatilize with 

 explosive violence. 



The wash leaves the rectifier at a temperature of about 190 F. and is 

 completely exhausted of spirit in its passage down the diaphragms of the 

 analyser, the expelled vapour passing through the pipe //being at a tempera- 

 ture of about 205 F. to 210 F. The upper coil in the pipe a a is at the 

 temperature of the wash, and the temperature increases regularly on passing 

 down; the strength of spirit condensed in the upper five chambers can be 

 regulated by controlling the temperature. A high temperature causes alcohol 

 to pass off in the cold feint pipes, and at the same time diminishes the con- 

 densation of watery vapour so that a weak spirit results ; a low temperature 

 makes alcohol condense below the spirit plate, increasing the quantity of hot 

 feints. To obtain the best results the temperature of condensed spirit in the 

 spirit plate should lie between 176 F. and 180 F. The control of the still 

 is effected either by regulating the supply of wash or of steam ; valves are 

 iitted, of course, on both the wash pipe and steam pipe. To enable the 

 attendant to know the strength of the spirit at any moment, a small pipe 

 passing through a supplementary refrigerator takes a sample of spirit from 

 the spirit plate, and conducts it to a locked test case ; if spirit 45 O.P. is 

 required, three glass bubbles, one which floats in 42 O.P., one in 45 O.P. and 

 one in 48 O.P., are placed in the vessel receiving the spirit; as soon as all 

 three bubbles rise the attendant knows his spirit is too weak, and when two 

 sink that it is too strong. As a further guide thermometers are placed in 



532 



