No. 4.] U.S. DEPARTMENT OF AGRICULTURE. 199 



There are generally several materials available in ever}' lo- 

 calit}^ and the difficulty of selecting the most suitable is 

 evident. The only proper way in which a selection can be 

 made is by means of physical and chemical laboratory' tests. 



Important investigations looking to improving the quan- 

 tity and (juality of table syrups have been made in the sugar 

 laboratory, and critical studios have been undertaken to 

 determine the influences that tend to produce the maximum 

 content of sugar in beets, melons and other sugar-producing 

 plants. 



Studies of various insecticides in common use in agricul- 

 ture have been conducted, in order to determine whether the 

 poisons employed in such insecticides are found in the food 

 products derived from the plants thus treated. 



The stud}^ of the character of waters used in irrigation, 

 especially in the growing of rice, have been begun, in order 

 to determine the quantity of injm'ious salts which these 

 waters may contain, and the quantities thereof that ma}' be 

 safely used upon the fields. 



New laboratories have been established to study the effects 

 of preservatives and other added substances upon the health 

 of the consumer, with the view of determining the character 

 and amount of such substances which may be safely used in 

 such foods without iujur}^ to public health. 



A drug laboratory has been established, to study the 

 character, standard and adulteration of drug products. The 

 larger portion of the drugs in commerce are of agricultural 

 and horticultural origin, and the necessity of securing purity 

 and conformity to standards in articles of this kind is evi- 

 dent. Dangerous narcotics and poisonous substances should 

 not be indiscriminately sold, and drugs intended for ordinary 

 therapeutical purposes should conform to the standards laid 

 down by competent authorities. 



The Bureau of Chemistrj^ is constantly increasing the ser- 

 vices rendered to other departments of the government in 

 many different ways ; as, for instance, the study of the 

 character of cancelling inks used by the Post-office Depart- 

 ment, and the colors and inks used for printing bank notes, 

 bonds and other government securities. 



