THE QUALITY OF WHEAT 69 



factors; first, the percentage of dirt, weed seeds, and 

 other impurities ; secondly, the percentage of water in the 

 sample ; and, thirdly, a complex and somewhat ill-defined 

 character, commonly called "strength." 



(a) Impurities. The first factor is not very important 

 in New Zealand, for under the methods of growing, 

 cleaning, and threshing practised here, a practically 

 clean sample is produced. The threshing machine used 

 generally throughout the country separates the sheaf 

 into six parts, straw, short straw, chaff, dust and small 

 weeds, "seconds" or shrivelled and broken grain, and 

 finally "firsts" or clean wheat fit for milling. It will 

 be easily seen that this classification gives a good, clean 

 sample. In some foreign countries, however, this is far 

 from the actual state of affairs. Indian and Russian 

 wheats contain a great percentage of impurities, which 

 render them in this respect relatively inefficient from the 

 miller's point of view. 



(&) Percentage of Moisture. The percentage of 

 moisture, the natural moisture as it is usually called, 

 varies greatly in the different producing countries. 

 English wheats contain about 16 per cent, of moisture, 

 rising in wet seasons to 18 per cent. In Russia the per- 

 centage is about 12, which is the average for Canada, 

 United States, and Argentina ; while in Australia and on 

 the arid lands of the Pacific Coast of North America 10 

 per cent, is about the average. New Zealand wheats 

 contain relatively high moisture percentages. Pearl in 

 normal seasons has a moisture content of from 15 to 16 

 per cent., according to the tests made over a series of 

 years by a local miller; while Tuscan and Hunter's go 

 as high as 16 to 17 per cent. In wet seasons these per- 

 centages may be increased to 17 for Pearl, and 18 for 

 Tuscan and Hunter's, which is considerably higher than 

 the percentage for most of the exporting countries. 



The importance of the percentage of water arises from 



