506 



to deal with a reasonable amount of seed in a limited amount of 

 time. With shorter periods the temperature is too high to be controlled 

 with ease and certainty. The importance of thoroughly testing every 

 single machine cannot be too strongly emphasised. Another set of 

 experiments tested the effect of varying the amount of seed passed 

 through the machine. The results are tabulated and show that in 

 no single case were all the caterpillars killed, although when a thin layer 

 was exposed to exactly similar conditions not a single larva survived. 

 This emphasises the fact that it is not the temperature recorded by 

 the thermometer which matters, but the actual temperature reached 

 by each individual seed. The disadvantage of a machine of this type 

 from the commercial point of view is the enormous size which will be 

 necessary if it is to deal with seed at the rate at which it comes from 

 the gins. The above machine had an internal capacity of over 40 cubic 

 feet and was only able to deal with 1 ardeb [5-447 bushels] in about 

 5 hours, an alarmingly slow rate. An apparatus for the fumigation 

 of cotton seed has been built by Messrs. Thos. Cook & Son at their 

 Bulak workshops on the lines indicated previously. Six vats, each 

 with a capacity of about 40 cubic feet (i.e., about 27 bushels of cotton 

 seed), form the body of the plant, and the rest of the apparatus consists 

 of the system of tubes, the pump and the carburetter in which carbon 

 bisulphide is evaporated. Fumigation was effected by pumping the 

 gas into the first vat filled with seed ; after half an hour the gas was 

 transferred from the first vat to the second vat. Whilst it was acting 

 here, the seed was emptied from the first vat. In not a single case was 

 a larva found to have survived the fumigation. The results are shown 

 in a table, which also gives the corresponding data in the controls. 

 With certain improvements, outlined in this paper, the machine could 

 be regularly used in ginneries, the only objection being the use of 

 gases which are either poisonous or inflammable. Provided proper 

 precautions are taken, the danger is almost negligible. The original 

 cost of a machine for dealing with 162 bushels an hour would be 

 between £E.300 to £E.400. The cost of the chemicals may be 

 put at about 2|fZ. per 5*447 bushels of seed. A mechanical cleaning 

 apparatus, built by Messrs. Wm. E. Dell & Son, of Mark Lane, London, 

 has been erected on the State Domains estate at Sakha. In the first 

 part of this machine an inner cone revolves within an outer one and 

 separates the seed from adhering lint ; in the second part the seeds 

 are subjected to a wind which carries away lint, dust, light seeds, etc. 

 In the original trials in London, the treated seed had an increased 

 germination of 17 per cent., a large quantity of bad seed being removed 

 without any damage being done to the remaining seed. When 

 re-erected in Egypt, it gave fairly good results in throwing out the 

 majority of seeds infested by pink boll worm and killing most- of the 

 remaining larvae, but the seeds were at first found to be injured by 

 the process. Trials were made to find the best adjustment of the 

 machine, but so far as germination was concerned, results as good as 

 those recorded in London were never obtained. This machine is not 

 to be recommended for Taqaivi seed, but ought to be found very useful 

 for treating bad seed from third, fourth and fifth pickings. Seed from 

 the last pickings of badly infested crops is practically unsaleable. 

 From such samples this machine will rescue a large proportion of the 

 good seed which would obtain a ready sale for crushing. 



