274 CHEMICAL MANUEES. 



The air is burnt in an electrical oven having the form of a drum. 

 This furnace was modified and improved by Samuel Eyde. In 

 this drum the air is submitted to a temperature of 3000° C. By 

 rapid cooling the nitrous oxide (NO) formed in the electric flame 

 is retained almost entirely, whilst in former processes it was in 

 great part lost. The nitrous oxide issuing from the furnace at a 

 temperature of 600° to 700° C. (1112° to 1292° F.) combines with 

 the oxygen to form NO.^, which is passed through a series of towers. 

 It finally yields nitric acid of 50 per cent strength, which is satur- 

 ated with lime. The mass is then heated to 450° C. (842° ¥.), which 

 is its melting-point, then poured into cast-iron cylinders, where it 

 solidifies slowly. In the beginning, crystallized nitrate of lime was 

 nianufactured which was difficult to use owing to its hygroscopic 

 properties. This product melted between the fingers and could 

 thus only be used mixed with peat dust. That was why they 

 afterwards set themselves to make basic nitrate of lime ; but this 

 product only contains 11*7 per cent of nitrogen, which rendered 

 its freight charges heavy, and formed an obstacle to its sale. 

 Lately, the partially dehydrated salt tested 13 per cent of nitrogen. 

 The first manufactory of any importance of this product was built 

 at Notodden in Norway. The experience acquired in that factory 

 has induced the management of the company to increase the plant, 

 so as to make 8000 to 10,000 tons per annum. This factory is main- 

 tained by the Badische Anilin und Sodafabrik. The unit of nitrogen 

 in nitrate of lime is sold at the same rate as the nitrogen in nitrate 

 of soda. 



Agricultural Experiments loitli Cyanamide. — Calcium cyana- 

 mide has of late years been the subject of numerous agricultural 

 experiments by P. Strohmer, O. Botticher, Otto A. Stutzer and E. 

 Wein. 



It must be observed in a general way that calcium cyanamide 

 neither suits humic acid soils (? peaty soils) nor light sandy soils. 

 On the other hand, it may be used in all loamy soils of average 

 fertility. Owing to the formation of dicyanamide, this manure 

 aught to be spread at least eight days before sowing and covered in 

 afterwards in not too superficial a manner. The action of cyanamide 

 is weaker than nitrate of soda, it is also slower than the latter. 

 But as the unit of nitrogen is supplied cheaper by the new manure 

 a greater amount can be used to restore the balance. Without 

 doubt cyanamide deserves attention. According to the experiments 

 of Remy, this manure succeeds very well on clay soils, less so in 

 sandy soils. F. Loehnis has observed that the conversion of 

 cyanamide into ammonia in the soil is effected by bacteria, for ex- 

 ample by the B. Megatheriuvi, the mycoid and other species in part 

 new. We know that the conversion of ammonia into nitrate is like- 

 wise effected by bacteria, and according to the researches of G. 



