49 



also with all samples) — must be forwarded in an air-tight glass container 

 or in a close fitting tin box. The sample selected must be a good average 

 sample and must weigh at least 100 gr. for large seeds and 50 gr. for small 

 seeds. The sample must be well mixed before grinding and before weighing 

 off for analysis. When using 103° C. instead of 98° C, it must be 

 remembered that the moisture content obtained at 103° C. will be from 

 J per cent, to 1 per cent, higher than that obtained at the lower temperature. 



Mr. Devoto stated that the paper would be of great interest to 

 farmers in the Argentine who lose a large sum of money annually 

 because of the moisture content of maize. The Brown-Duval 

 apparatus for the estimation of moisture was introduced into his 

 country five years ago. The machine saved time but the results 

 obtained were not very exact. Mr. Brown stated that this 

 apparatus (which bears his name) was first developed with the view 

 of its application to the grain trade, especially corn. The apparatus 

 was simple and the test took only 15 minutes. It was necessary 

 to vary the times and temperatures according to the different 

 seeds to be tested, and provided this was done the results obtained 

 were satisfactory and tallied with those obtained by chemical 

 methods. He claimed that in using the machine errors of grinding 

 and weighing were eliminated. 



Professor Voigt said that in Germany two different methods 

 were employed — ^for certain seeds a temperature of 98° C. was 

 used, and for others 103° C. The seeds were put in a cold oven 

 and heated to the required temperature. The period of heating 

 was counted from the time that temperature was reached. 



Dr. Volkart stated that at the Ziirich Station they refused to 

 make determinations of moisture unless the samples were sent in 

 air-tight containers. Mr. Dorph-Petersen intimated that the same 

 condition applied in Denmark. The method used at his station 

 was to dry the samples in a copper apparatus surrounded by water 

 jackets containing water kept at boiling point. The temperature 

 in the apparatus was then about 98° C. Investigations showed 

 that the moisture content of samples stored in heated rooms 

 decreased. 



Further discussion followed regarding the different degrees of 

 temperature employed in the determination of the moisture 

 content of various seeds and the danger of oxidation during the 

 process. The Argentine Delegate laid stress on the necessity for 

 tests to be made from the commercial as well as the scientific 

 standpoint. 



(It will be observed from the report of the session on Thursday 

 afternoon that a Committee was appointed to deal with the 

 question of moisture content.) 



Afternoon Session. 



The Congress resumed at 2 p.m. 



Professor Bussard read a paper on the subject of weed seeds, 

 a summary of which is given on page 52. 



