350 



Criticisms of apparatus : ( 1 ) The chief disadvantage 

 of a metal (iron) condenser is the discolouration of the 

 camphor by iron rust. If the condenser were entirely of 

 copper there would be little or no colouration. 



(2) Since practically all the camphor condenses in the 

 condenser tubes and only the oil and water pass into the 

 receiver, a tube condenser has the disadvantage that the 

 tubes would soon get blocked. Apart from this the layer 

 of camphor on the tube would form a nonconducting 

 medium and lessen the effeciency of the condenser. 



(3) It is difficult to clean out a tube condenser, and 

 easily remove the camphor, though this could easily be done 

 by a special scraper fitting the condenser tubes. 



(4) The chief disadvantage of the particular still 

 described is the time wasted in discharging and recharging. 



The discharging could be hastened by having a lateral 

 opening above the perforated plate, and made air tight by 

 an asbestos sheet. 



(5) In a large still the weight of the leaves or wood, 

 especially when wet, would tend to create pressure inside, 

 by blocking the passage of steam. This could be remedied 

 by using a series of perforated plates, a definite quantity 

 of material (wood or leaves) resting on each. 



A better plan and one which would simplify discharg- 

 ing and charging would perhaps be a metal cage which could 

 be lifted bodily out of the still by means of a crane or other 

 mechanical device and easily emptied by inversion and re- 

 placed when discharged. This would also allow steam to 

 enter the material from all sides. 



Yields. 



In the first experiment with this apparatus, a whole 

 tree, including roots, was received from the Batu Tiga 

 Experimental Plantations and consisted of: — 



Leaves weighing 12^ lbs. = 7*5 per cent. 



Twigs less than \ inch diameter weighing 30 lbs. = 18*2 

 per cent. 



Twigs and wood over I inch diameter 93 lbs. = 56*3 per 

 cent. 



Roots 29-5 lbs. = 18-0. 



Separate distillations were made of the leaves, twigs 

 under | inch diameter, wood, and root with the following 

 results. 



12^ lbs. of leaves yielded 2 ozs. of camphor and oil 

 = 1-0 per cent. 



