226 ANNUAL EErOPiTS OF DEPARTMENT OF AGEICULTURE. 



forcnces Avore foniid in the baking qualities of such mixtures, ir- 

 revSpective of the fineness of the rice flour used. As was to be ex- 

 pected, the color of the bread Avas influenced by the degree to which 

 the rice had been polished. 



Much attention has been given to the study of the spoilage of corn 

 meal, with a view to determining the most suitable conditions for its 

 storage. The spoilage produced by ditferent organisms and the 

 effect of tlie growth of such organisms on the composition of thy 

 meal, especially with relation to acidity and ranciclity, liaA'e been 

 investigated, in the hope that a sound basis may be found to esti- 

 mate the degree of spoilage of corn meal and its fitness for food. 



GRAIN MILL, ELEVATOR, AND COTTON GIN EXPLOSIONS AND 



FIRES. 



The emergency demonstration campaign, conducted in cooperation 

 with the Bureau of Markets, to conserve grain and flour by prevent- 

 ,ing explosions and fires Avas carried out in the manner described in the 

 Report of the Chemist for 1918. Five thousand six hundred plants 

 were visited and OA'er 30,000 pledge cards signed by the owners, 

 operators, and employees. A number of reconnnendations suggested 

 to the companies as possible precautions against dust explosions were 

 cheerfully adopted, and it is belicA-ed that these slight changes have 

 assisted in reducing the loss in this countr}^ due to explosions and 

 fires in mills and elevators. Not a serious explosion occurred in such 

 a plant during the year. A ver}' disastrous explosion did occur iu 

 a different type of plant, a starch Avorks, 43 persons being killed and 

 a number injured. This demonstrates clearly that the work should 

 be extended to other dusty industries. As no funds Avere available 

 to proceed Avith the Avork after the close of the fiscal year, and as 

 the U. S. Grain Corporation desired that it be continued as a form 

 of insurance for its own operations, arrangements were made to 

 transfer the force engaged upon this campaign to the rolls of the 

 Grain Corporation. The Vxork Avill be continued by that corporation, 

 the Bureau of Chemistry collaborating by furnishing general super- 

 A'ision. 



The campaign to prevent explosions and fires in thrashing ma- 

 chines has been continued and extended to cover other sections than 

 Oregon, Idaho, and Washington, to which it had hitherto been lim- 

 ited. In cooperation with the Bureau of Plant Industry and the 

 Bureau' of ISlarkets, special attention Avas given to the deA'clopment 

 of the suction-fan installation to remoA-e dust from thrashing ma- 

 chines, and an effort was made to determine the effect of its opera- 

 tion on grain cleaning and on the possibility of snuit-spore collection 

 and disposal in order to prevent the dissemination of the spores over 

 surrounding land. Plant pathologists haA-e expressed themselves as 

 quite hopeful that the devices for the disposal of spores which have 

 been designed and tested may proA'e of great service in the control 

 of the smut of Avheat. 



The discovery that many of the fires in the cotton gins of the 

 SoutliAvest are due to static electricity reported last year was con- 

 firmed this year. The limited funds available made it necessaiy to 

 confine this Avork, which was done in cooperation Avith the Bureau of 

 Markets and the various State and insurance agencies, almost en- 



