report of the secretary of agriculture. lxxix 

 Investigations in the Sugar Laboratory. 



Important investigations looking to improving the quantity and 

 quality of table sirups have been made in the sugar laboratory, and 

 critical studies have been undertaken of the influences tending to pro- 

 duce the maximum content of sugar in beets, melons, and other sugar- 

 producing plants. 



Studies of Insecticides. 



Studies of the various insecticides in common use in agriculture 

 have been conducted with the object of determining the value of their 

 constituents. Since arsenious acid is one of the most common con- 

 stituents of insecticides, an investigation has been commenced to 

 determine the effect of this body upon the foliage of plants and to 

 ascertain whether any of the arsenic thus applied for insecticidal pur- 

 poses is found in the food products derived from the plants which 

 have been thus treated. 



Study of Environment of Chemical Composition of Cereals. 



Extensive collaborative work has been instituted with many of the 

 agricultural experiment stations for the stud}- of the effect of environ- 

 ment on chemical composition of wheat and other cereals and to ascer- 

 tain the most reliable methods for judging the quality of the soils 

 from their chemical constitution. 



Study of Waters used in Irrigation. 



The stud}- of the character of waters used in irrigation, especially 

 in the growing of rice, has been begun, to determine the quantit}" of 

 injurious salts which these waters may contain and the quantities 

 of this water which may be safely used upon the fields. 



Establishment of New- Laboratories. 



New laboratories have been established to study the effects of pre- 

 servatives and other added substances upon the health of the consumer, 

 with the view of determining the character and amount of such sub- 

 stances which may be safely used in such foods without injury to 

 public health. 



A contract laboratoiy has also been established for the purpose of 

 ascertaining the quality and quantity of materials purchased for the 

 Department of Agriculture and other Departments of the Govern- 

 ment, and to establish specifications for such supplies, based on phys- 

 ical and chemical properties. 



A drug laboratory has been established also 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 



