506 EXPERIMENT STATION EECOKD. 



The method consists of ijlacing the substances under examination in a 300 cc. Er- 

 lenmeyer flask containing 150 cc. of a mixture consisting of one-third toluol and 

 two-thirds xylol. Paraffin having a boiling point higher than 100° C. can also 

 be employed, but it has no advantages over the substances mentioned. The 

 mixture is distilled into a 10 cc. graduated collection tube provided with a fun- 

 nel having a glass stopcock ground in. The amount of water present in the 

 tube is read off, and after applying certain corrections the percentage is com- 

 puted. Several optional forms of the collecting device are also described. 



The results of tests of the method with honey, butter, and milk showed that 

 it gives good results. 



A special flask for the rapid determination of water in flour and meal, 

 J. H. Cox (U. 8. Dept. Agr. Bid. 56 (1914), PP- 7, figs. 7).— A description is 

 given of a special flask, to be used in connection with the Brown-Duvel moisture- 

 determining apparatus (E. S. R., 24, p. 215), and designed for commercial work. 



The flask may be constructed of either copper or glass. It is double walled 

 and has an inner capacity of about 900 cc, A single-walled flask is not suited 

 for testing finely ground substances and the meal under test very frequently 

 burns badly at the bottom. The method is deemed rapid and accurate. 



A detailed description of the entire Brown-Duvel apparatus and method is 

 given, with a special form of graduate for collecting the water distilled from 

 the grain. 



Determination of moisture in maize for export, H. J. Yipond (Undon So. 

 Africa Dept. Agr. Rpt. 1910-11, pp. 395-397). — A series of tests w^ere carried 

 out to determine the reliability of results obtained by the Brown-Duvel method 

 (E. S. R., 18, p. 1122). 



In all cases the temperature was allowed to reach 190° C. before the burner 

 was removed. The time required to reach 190° varied from 14 to 20 minutes; 

 the highest temperature obtained after removing the flame was 196°. 



The results obtained were compared with check determinations made with 

 ground material and drying in a steam oven. In the case of the ordinary 

 steam oven method there was a slight gain in weight after the material had 

 been dried for 3* hours, presumably due to an oxidation of the oil present in 

 the cereal. 



The results with the Brown-Duvel apparatus were about 2 per cent too high. 

 " The net conclusion is that the Brown-Duvel tester gives very reliable results 

 when worked under uniform conditions, but the figures are rather high under 

 those prescribed by the originators of the method. This can easily be remedied 

 either by deducting say 1 per cent from the readings thus obtained, or by 

 adopting a slightly lower temperature for working. The grain after testing 

 invariably shows a certain amount of blackening, principally in the embryo, 

 indicating the destruction of organic matter. 



" Similar tests with soy beans (taking the temperature up to 190° in 20 

 minutes in such a way that the final temperature reached after removing the 

 flame does not exceed 192°) gave readings about 3 per cent higher than those 

 obtained by the ordinary (steam oven) method." 



A few tests were made also to determine the total loss of weight in grind- 

 ing. The amount of grain weighed off was 48.649 gm. and the amount obtained 

 after grinding w^as 48.524 gm. " This loss probably includes some of the meal, 

 150 that it represents the maximum loss which can be attributed to evaporation 

 of water from the grain during grinding." 



Contribution to the study of flour, E. Gury (Mitt. Lehensm. Unterstwh. u. 

 H]ig., ScJncciz. Gsndhtsamt., J^ (1913), Yo. 3. pp. 113-121, fig. 1).— This is a study 

 of the methods for determining the moisture content of flour, and was made 



