CYANAMID — MANUFACTURE, CHEMISTRY AND USES 55 



To determine the effect of varying quantities of iron 

 hydroxide gel, the precipitated undried hydroxide was mixed 

 with glass sand in different proportions, and treated as above 

 with the following results : 



Cyanamide Glass-sand plus iron hydroxide gel containing 



nitrogen in , » . 



milligrams 2.6 ji FegOa i-3 5^ FesOa 0.65^ FcgOa 0.26 ?i Fe2 O3 



Applied 33.00 33.00 33.00 33.00 



After I day 0.00 4.31 12.32 23.11 



" 2 days — 0.00 3.69 13.55 



'* 3 " •••• — — trace 9.85 



" 4 " — — 0.00 8.00 



" 5 " •••• — — — 5-37 



The amount of conversion, therefore, varies with the amount 

 of iron oxide present. 



The same iron hydroxide gel was treated in different ways 

 to see what effect would be obtained by changing the form of 

 the material : 



Precipitated iron hydroxide 



Cyanamide Dried Heated in 



nitrogen in 5 hrs. at steam for Ignited 



milligrams Untreated io5°C 2j^ hrs. for % hrs. 



Applied 33.00 33.00 33.00 33.00 



After >^ day — 4.31 12.32 — 



After I day 0.00 0.00 6.46 14-47 



" 2 days — — 1.57 6.16 



*' 3 ** — — 0.00 4.00 



•* 4 '• _ _ _ 1.84 



" 5 " — — — o-oo 



The untreated iron hydroxide has the most activity, which is 

 decreased somewhat by steaming and greatly decreased by 

 ignition. 



To determine the effect of iron oxide in the condition of a 

 hydrosol, 250 cc. of iron oxide sol containing 0.8 per cent, iron 

 oxide was treated with 1.25 grams cyanamide. The solution 

 remained clear and fluid during the course of the experiment. 

 For the determinatiou of cyanamide, 10 cc. of the clear solu- 

 tion was pipetted off, flocculated with ammonium nitrate and 

 after dilution and filtration, treated in the usual manner. The 

 following results were obtained: 

 5 



