14 



To deal with the figures in detail, it will be seen that one minute's 

 immersion in water at 70 C. has no effect on the germination whatever, 

 while even at 75 C. it is highly doubtful whether any damage is done, 

 the germination actually found being the same as that found at 55 C. 

 when obviously the seed was not damaged. 



Hot-water treatment for five minutes shows a distinct loss in 

 germination at 65 C., which is increased at 70 C. At 60 C., however, 

 the damage is at most slight and in all probability non-existent. 



In the Domains' machine three and a half minutes' treatment 

 shows what appears to be the beginning of a drop at 60 C., but owing 

 to the paucity of the figures it is difficult to be certain. Six and a 

 quarter minutes' treatment, however, causes severe damage to the seed 

 at a temperature as low as 53 C., while with ten and a half minutes 

 the seed is damaged at 47 C. and loses its germinating powers 

 practically completely at 55 C. In view of the results obtained with 

 the other machines, it seems quite certain that the seed was actually 

 raised in these cases to temperatures much higher than those 

 recorded. The figures are therefore only significant in connection 

 with this particular machine. 



In the Ministry's machine, in which, as already explained, the 

 recorded temperature is also too low, seed with a seven minutes' 

 treatment is undamaged at 57 C., but is undoubtedly damaged at 

 60 C., while seed with a nine minutes' treatment seems to be damaged 

 at as low a temperature as 53 C. With the five minutes' treatment 

 a big gap occurs in the figures available at the critical point, but 

 the drop in germination probably begins about the same point as 

 with the seven minutes' treatment. 



The germination figures from tests with Simon's machine have 

 all been added together, since in no case has any loss in germination 

 been found at any temperature used. No trials have been made 

 with temperatures over 65 C., partly because all the trials were made 

 with a view to testing the machine from the practical point of view 

 and not with a view to finding theoretical figures for the effect of 

 heat on cotton seed, and partly because it is difficult to obtain a 

 temperature over 65 C. without exceeding the steam-pressure for 

 which the machine is guaranteed. 



Other machines working on principles similar to those of Simon's 

 machine have given generally similar results, except where, owing 



