47 



regarding its application to all species individually and to furnish 

 such evidence to any Committee that might be appointed. 



An interesting discussion followed and finally Mr. Dorph- 

 Petersen intimated that he considered it desirable that on Thursday 

 afternoon the Congress should appoint a Committee to consider 

 Mr. Anderson's proposal and the views expressed by the various 

 delegates. He thought that it was not essential that aU the 

 members of the Committee should meet together, as they might 

 carry out the work by correspondence. 



The Congress accepted Mr. Dorph- Petersen's suggestion and 

 proceeded to the next business. 



Dr. JBuchholz then read the following paper : — 



The Determination of Moisture in Seeds. 



BY 



I>B. YNGVE BUCHHOLZ, Chbistiania. 



The determination of moisture in seeds often has great value both in 

 order to gain knowledge of the water content in the sample, and also 

 with regard to the " 1,000 grain " weight of the dry seed. 



The determination of moistiu:e — as is probably known — is carried out by 

 estimating the loss of weight in a known quantity of the substance through 

 heating to a certain temperature for a fixed time. Purely technically, 

 this analysis is so simple that it is commonly one of the first tests a beginner 

 is given to carry out in the chemical laboratory. 



In practice, however, it is anything but easy to determine the actual 

 moistiu'e content in organic substances, e.g., seeds, because the result 

 is largely dependent upon the conditions under which the analysis is carried 

 out. This is accounted for by the fact that it is not easy to remove all 

 water through heating without other processes taking place simultaneotisly,. 

 both those causing a loss of weight and also those causing an increase in 

 weight (e.g., certain processes of oxidation). The first will lead to too 

 high and the latter to too low analysis figures for the moisture. 



Purely theoretically we may say that in an analysis of the loss of weight 

 it is impossible to decide the moisture content absolutely correctly, and 

 the raethods that satisfy the purely theoretical claims more closely are so 

 difficult that to tackle this problem must be excluded from practical seed 

 testing. 



The only way would be to work so that the effect of the extraneous 

 processes is made as small as possible, provided that, at the same time, one 

 takes care to expel all water as quantitatively as possible. The conditions 

 that have a special influence here are : — ■ 



(1) The preparation of the sample (the degree of grinding). 



(2) The temperature at which the estimation takes place. 



(3) The time, i.e., the duration of the drying process. 



These conditions must be chosen so that one gets — as far as possible^ — ■ 

 corresponding results through parallel determinations, whilst permitting 

 the easiest possible methods of working. 



At the seed-testing stations of Scandinavia, and probably also in most 

 other countries, the preparation for this estimation is simple ; large-seeded 

 samples (such as cereals, etc.) are coarsely ground, and all small-seeded 

 samples are used whole. 2^ gr. of the coarsely ground, or 1 gr. of the whole 

 small seed is used. 



The material is heated for 5 hours at about 98° C. (steam drying oven). 



