346 



Annual Report Agricultural Experiment Station 



grams of the material were dissolved in boiling sulphuric acid till 

 almost colorless, the acid diluted and decanted from any residue 

 remaining undissolved. All the corn meals left small residues of 

 easily identified minerals, such as quartz and garnet, but no glass. 

 One sack of meal contained several large fragments of glass which 

 could not have been eaten and evidently were intended to create 

 prejudice rather than to do injury. No fine glass was found in 

 any of the samples, but the millers in all cases were cautioned to 

 clean their corn so that no adhering soil would be carried into the 

 meal, causing grit that might be mistaken for glass. One sample 

 of cocoa was found to contain a few very minute fragments of 

 glass-like material which may have been chipped off the porcelain 

 lining of some machinery used in its preparation. One sample of 

 bran that was reported to have killed a calf was found to contain 

 cyanide. 



THE TEMPE DRAINAGE DITCH 



In continuation of the work reported in the Twenty-seventh 

 and Twenty-eighth Annual Reports occasional analyses of the dis- 

 charge of the Tempe drainage ditch have been made. The results 

 for the year 1918 are detailed in Table XXI which should be studied 

 in connection with previous results given in the Twenty-eighth An- 

 nual Report on page 475. 



TABLE XXI. monthly VARIATION IN COMPOSITION OF WATER FROM THE 



TEMPE DRAINAGE DITCH, PARTS PER 100,000 BY C. N, CATLIN 



Date 



1918 

 Jan. 10 

 Feb. 10 

 Mar. 10 

 Apr. 10 

 May 11 

 June 5 

 July 8 

 Aug. 1 

 Sept. 

 Oct. 10 

 Nov. 3 

 Dec. 12 



Hardness 

 (perma- 

 nent) 

 CaSOi 



1.1 

 11.5 



78.5 



11.9 

 6.5 

 1.1 



Hardness 

 (temporary) 

 Ca(HC03)2 



2.2 



127.5 

 130.0 

 127.2 

 112.6 

 128.4 

 118.3 

 113.8 



69.5 

 No Sample 



93.5 



87.4 

 127.5 



Alka- 

 linity 

 NaoCOa 



1.7 



2.5 



5.9 

 5.9 



Qualitative 



ALKALI STUDIES 



The research w^ork of the department conducted under the 

 Adams Fund has been limited to alkali problems. During the past 

 year the Chemists have studied the influence of various chemicals in 

 different amounts on the rate of percolation and on the composition 



