June 28, 1918] 



SCIENCE 



647 



yielded an extract of practically the same con- 

 ductivity as 1 hour's extraction. 



The method adopted in testing the series 

 of flour samples was essentially as follows: 10 

 grams of flour were shaken up with 100 c.c. of 

 carefully prepared conductivity water in a 

 Jena glass flask, and the mixture maintained 

 in an ice bath at 0° for one hour. During 

 this time the flask was shaken vigorously every 

 10 minutes. The contents of the flask were 

 then placed in a tube and whirled for about 5 

 minutes in a large centrifuge. The superna- 

 tant liquid was filtered, returning through the 

 filter until clear, and clear filtrate placed at 

 once in the conductivity cell. The latter was 

 immersed in a water thermostat at 30° and 

 brought to temperature. The conductivity 

 was determined in the conventional manner, 

 the usual and necessary precautions being 

 taken to insure accurate results. 



The series of conductivity measurements 

 shown in the following table were made with 

 the collaboration of Mr. E. H. Doherty. The 

 samples have been classified by groups as they 

 are known to the miller. If these are rear- 

 ranged in order of their ash content it will be 

 found that with the exception of one group, 

 and a single member of another group, the 

 conductivity parallels the ash content. The 

 group which presents the exception is the 

 break flours, four of the five having lower con- 

 ductivity values than would be expected from 

 their ash content. The large proportion of 

 variation in this group of flours suggests the 

 operation of some factor in the break flours 

 which does not appear in the other flours. 

 The only other variation from the otherwise 

 uniform parallelism between the percentage of 

 ash and conductivity of the water extract is 

 found in the third low grade. The conduc- 

 tivity here is lower than would be computed 

 from the ash content. The data at hand do 

 not indicate the exact reason for these rela- 

 tively small deviations. 



The possible value of this test of flour grade 

 is indicated by this preliminary investigation. 

 The determinations can be made with ease and 

 speed when the equipment is assembled, and 

 the technique acquired. We propose to carry 



SPECIFIC coNDUCTivrrT or ploub extracts at 30° 



Conductivity Atb, 



Grade of Flour «X10-> Percent. 



First break 6.15 0.41 



Second break 5.69 .34 



Third break 5.78 .34 



Fourth break 6.83 .91 



Fifth break 9.56 1.50 



First sizings 5.25 .53 



Second sizings 5.49 .58 



Third sizings 6.91 .71 



First middlings 4.61 .38 



Second middlings 4.51 .39 



Third middlings 4.50 .38 



Fourth middlings 5.18 .44 



Fifth middlings 5.25 .53 



Sixth middlings 6.11 .62 



Seventh middlings 6.30 .67 



First tailings 7.71 .97 



Second tailings 9.18 1.27 



First low grade 6.72 .79 



Second low grade .... 7.59 .93 



Third low grade 7.53 1.07 



Patent 5.21 .45 



Clear 7.71 .90 



Heddog 14.98 2.53 



the study farther when research of this char- 

 acter can properly be resumed. In the in- 

 terval it seemed advisable to present these 

 findings, that they may be applied if the 

 method proves to be as well suited to this pur- 

 IX)se as appears at this time. 



C. H. Bailet 

 Division op Agricultukal Biochemistry, 

 UxrvzRsiTT Fabm, St. Paul, Minn. 



THE NORTH CAROLINA ACADEMY OF 

 SCIENCE 



The North Carolina Academy of Science held its 

 seventeenth annual meeting at the State Normal 

 College, Greensboro, on Friday and Saturday, 

 April 26 and 27, 1918. The executive committee 

 met at 2:10 p.m. on Friday and passed on the 

 business matters of the academy. The reading of 

 papers was begun at 2:45 p.m. and continued 

 until 5 p.m., when adjournment was had. At night 

 owing to the absence of President W. A. Withers, 

 due to serious illness in his family, the presidential 

 address on "Gossypol" had to be omitted. How- 



