MANURES AND MANURING 1 5 99 



tngms. of iodine 



per 1000 gms. 



of substance 



Sylvinc colourless, crystalline 0.0 



hyaline crystals • , 0.0 



colourless crj^stals 23.7 



crystalline light yellowish red 13.7 



" " yello\nsh red 73-1 



" colourless cn,'stals 0.0 



Carnallitc crj^stalline yellowish 5.0 



grey 4-5 



red 0.0 



" " pink 0.0 



colourless crystals 0.0 



None of the samples analysed contained potassium iodate. In syl- 

 vine, the iodine was present as potassium iodine and in carnallite it was 

 probably in the form of KI.Mg.l2-6H20. Crude bromine was also tested 

 for iodine, with negative results. 



1 168 - Effect of Vaxying Amounts of Admixed Water upon the Decomposition of Crude 

 Calcium Cyanamide and the Formation of Dicyanamide. — hager G.and kern j , 



in Zeitschrift tiir angcwandtt' Chcinie, Vol. XXIX, pp. 221-223, 1916 ; abstract in Joiitnal 

 of the Society of Chemical Irdustry, Vol. XXXV, No. 15, pp. 856-857. lyondon, August 25, 

 1916. 



Quantities of crude calcium cyanamide of 100 gms. each were 

 treated separately with 5, 10, 15, 25, and 50 gms. of water and enclosed 

 in air-tight glass vessels. After 5 or 7 months the material was analysed 

 by Caro' s metliod. The fertiliser used contained : total nitrogen 18.62 

 per cent, of which 17.73 was water soluble, cyanamide nitrogen 16.75 per 

 cent, nitrogen as dicyanamide 0.50 per cent, as ammonia 0.24 per cent, and 

 as "urea" nitrogen {i. e. the element left in the filtrate after precipitation 

 of the dicyanamide) 0.48 per cent. 



Seven raonths storage without water caused no perceptible change : 

 with 5 and 10 gms. of water, the changes were very small, the dicyanamide 

 nitrogen rising to 0.61 and 0.87 per cent respectively. The presence of 

 15 gms of water produced more change : the dicyanamide nitrogen rose 

 to 1. 13 per cent, the urea nitrogen to 0.71 per cent the cyanamide 

 nitrogen fell to 13.61 per cent, and the ammonia nitrogen to 0.14 percent. 

 Very little change took place in the first ten days when 25 gms. of water 

 was added but after 7 months, 2.58 per cent of dicyanamide was found. 

 With 50 gms. of water profound changes took place and the material 

 set to a hard stone like mass; after 2 14 months and 7 months, the di- 

 cyanamide nitrogen rose to 7.51 and 9.17 per cent respectively, the cya- 

 namide nitrogen falling to 2.81 and 0.28 per cent respectively in the same 

 periods. Calcium cynamide shoirld not be stored after it has become wet 

 but it may be used immediately ; the use of water to produce it in a gra- 

 nulated form is not likely to succeed. 



