214 



Spring application gave better results than fall application. Ap- 

 parently the best results can be expected from 2 applications in 

 the spring, one just at the beginning of growth and the second 

 about 3 weeks later. The soils should in all cases be supplied 

 with an abundance of lime. 



GEORGE LUNGE. Coal Tar and Ammonia. (Gurney and Jackson. 

 London, 1909); Abs. Nature, August n, 1910, vol. 84, p. 166. 



The volume on coal-tar and ammonia is now in its fourth 

 edition. What enormous changes have come over the industry of 

 tar production, and of the extraction and utilisation of the innu- 

 merable substances which enter into its composition, will be evident 

 from even the most superficial examination of the several issues. 

 The rate of progress, indeed, transcends anything to be observed 

 in any other branch of manufacture. Only nine years have elapsed 

 since the third edition made its appearance, but such has been 

 the accumulation of new material in that interval that practically 

 the whole of the chapters eleven in number dealing with coal-tar 

 and its products have had to be revised and in great part re- 

 written. In this section of the work Dr. Lunge has had the assis- 

 tance of Dr. Kraemer, of Berlin, an acknowledged authority in 

 this branch of chemical technology. 



England is still the great tar-producing country of the world, 

 but her supremacy in this respect is threatened by the United 

 States. Tar is mainly obtained from gas-works, from blast furnaces, 

 and from coke-ovens. In the United Kingdom the annual pro- 

 duction at the present time approaches a million tons obtained by 

 the destructive distillation of about seventeen or eighteen million 

 tons of coal an amount exceeding that of the whole of Europe 

 put together and probably more than twice the aggregate yield o 

 Germany and France. 



J. AUGUSTUS VOELCKER. Experiments at Woburn with nitro- 

 genous top dressings 1909. Journal of the R. Agric. Soc. 

 of England, Vol. 70, 1909, pp. 381-387. 



In 1908 experiments with calcium cyanamide (" nitrolin ") were 

 conducted at the Woburn Farm Experimental station of the Royal 

 Agric. Soc. of England with barley, mangolds and potatoes. In 1909 



