410 



riiiKTiKTH Annual Kepoki 



sition for the three years since the completion of the ditch was as 



follows : 



1917 1918 1919 



Total solids 308 266 262 



Chlorides as NaCl 209 182 173 



Several times during the interval the character of the water has 



changed from black alkaline to gypsum (permanent hardness) and 



back to black alkaline. The monthly analyses for 1919 are recorded 



in Table IV. 



TABIvH IV. MONTHLY VARIATIONS IN COMPOSITION OI" WATER FROM TH B 



TEMPE DRAINAGE DITCH, 1919. PARTS PER 100,000 



Str. 

 Mod. Str. 

 Mod. Str. 

 Mod. Str. 



Str. 



Str. 



str. — Strong. Mod. Str. — Moderately strong. Mod. — Moderate. Neut. — NeutraL 



In the Twenty-eighth and Twenty-ninth Annual Reports there 

 were published analyses of Arizona feeding stuiTs, many of them 

 being materials concerning which little information is available. 

 Since data of this sort have considerable value to others and are not 

 likely to be recorded elsewhere, the list is extended here by the 

 addition of recent analyses in Table V. 



