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but capable of being hermetically closed. From near the top a 

 large diameter bamboo 5 feet to 7 feet long passes to the con- 

 densing boxes of wood placed in a suitable tank and connected 

 with short lengths of similar bamboo. The still has a perforated 

 bottom and stands over an iron basin built into a small stone 

 or brick furnace. The basin about 2 feet 6 inches to 3 feet in 

 diameter is fitted with a supply tube for adding water as required 

 and an overflow pipe closed with a plug during distillations. The 

 condensing boxes consist of bottomless boxes of suitable size 

 having three or more partitions in each with communications at 

 opposite ends of each division to insure thorough circulation of 

 the camphor and water vapours. The tops of the boxes are 

 hermetically closed about 1 inch below the upper edges and the 

 boxes are stood in the tank as mentioned above being connected 

 by short bamboo lengths. Cold water from a stream flows from a 

 pipe or bamboo on the top of each box and then overflows into 

 the tank which has an outlet pipe 2 inches to 3 inches from the 

 bottom. By this means a water seal 3 inches deep is kept round 

 the bottom of the boxes. The mixture of camphor vapour and 

 steam from the still enters the first box just above the water level, 

 circulates round the various partitions, and so passes from box to 

 box, the camphor being condensed in pure white crystals on the 

 walls and partitions as it cools down. The last box is fitted with 

 an outlet of bamboo, which can be kept closely plugged with 

 straw. This acts as a safety valve and enables one to ascertain 

 whether condensation is perfect, as there should be little or no 

 smell of camphor observable. In working, the still is loosely 

 filled with the fresh prunings as brought in, the top put on and 

 well luted with clay, water poured into the basin, and a fire lit to 

 bring it rapidly to 'the boil. As soon as this occurs and a slight 

 smell of camphor or eucalyptus can be smelt at the escape tube on 

 the last box, the fire is reduced and the water merely kept hot for 

 several hours. A good plan is to have a glass let into the cover of 

 the first (or all) of the condensing boxes and as soon as vapour 

 begins to condense on it to immediately reduce the fire to a 

 minimum, as the object to be gained is to drive off all the 

 camphor with as little steam as possible. A small wooden spigot 

 in the top of the still makes it possible to ascertain when all smell 

 of camphor has disappeared, but care must be taken when opening 

 it not to become scalded. When completed, probably in 6 to 

 4 hours, the door at the bottom of the still is opened, the prunings 

 removed and the still recharged from the top. All water in the 

 pan which contains much tannin, &c, in solution is changed by 

 opening the overflow plug and pouring in a fresh quantity 

 through the supply tube. During distillation it is necessary to 

 occasionally add some water to the pan to maintain a constant 

 level and prevent burning. To save time it would be best to 

 have two stills connected with the condensers as with many 

 citronella grass stills, since the one could be filled, while the other 

 distillation was proceeding ; the latter could then be allowed to 

 cool down before opening without a loss of time. To preserve the 

 heat in the top of the still and ensure the camphor passing away 

 readily, the still should be thickly coated with clay or other non- 

 conducting material, the Japanese method being to surround the 

 still with cane work and ram clay into the space between. 

 27432 B 



