NOTES AND ABSTRACTS. 469 



I Nitrogrenous Manures, Crops as Affected by. By B. L. 



Hartwell, H. J. Wheeler, and F. E. Pember {U.S.A. Exp. Stn., Rhode 

 Island, Bull. 143, June 1910). — Tliis bulletin deals with the results of 

 ten years' pot experiments conducted with the object of ascertaining 

 the value of various materials as sources of nitrogen. Galvanized-iron 

 ash-cans, 26 inches deep and 18 inches in diameter, served as pots, and 

 these were sunk in the ground and well drained, 100. lb. of subsoil being 

 placed at the bottom of each pot, and over it 123 lb. of surface soil 

 (p. 292). Certain conditions which would have a very important 

 influence upon the results were controlled as far a? possible, among 

 them being the amount of water, potassium, and phosphorus, as well 

 as a reaction of the soil suitable to the plant and to the putrefaction and 

 nitrification of the organic materials used, namely, dried blood, star 

 fish, ground bone, hoof meal, tankage, ground fish, horn meal, and hen 

 manure. Nitrate of soda was also used, and about 50 per cent, of the 

 nitrogen applied in that form was recovered in the crops, which was a 

 larger percentage than was recovered from the nitrogen applied in any 

 organic form (p. 300). The conclusion is arrived at that, taking the 

 entire ten-year period, all of the sources of organic nitrogen, including 

 the dried blood, proved to have about the same degree of availability 

 (p. 305). Although the crops from nitrate of soda frequently contained 

 larger percentages of nitrogen they were not much heavier than those 

 from the organic manures, the favourable action of the latter being 

 probably due in part to the fact that a neutral reaction of the soil was 

 practically maintained so that putrefaction and nitrification were 

 favoured. — A. P. 



Oils and Perfumery Plants in the United States, Produc- 

 tion of Volatile. By Frank Eabak (U.S.A. Dep. Agr., Bur. PI. Ind., 

 Bull. 195, Dec. 9, 1910; figs.). — Statistics are given showing what 

 a large and active market there is in the United States for the products 

 -of the volatile oils derived from plants, to be used either as flavourings 

 or in the manufacture of perfumes. It is pointed out that many of the 

 plants from which volatile oils are obtained could profitably be grown 

 in N. America or are already found there. The chemical and structural 

 composition of aroma-bearing plants is described, the fact being made 

 clear that not all volatile oils pre-exist in plants. Some of our most 

 valuable oils are obtained from plants which, though not possessing 

 the oil already formed in their tissues, do possess certain basal con- 

 stituents from which volatile oils can be formed. 



The m.ethods of extraction and producing such oils are described, 

 illustrations are given of the necessary apparatus, and instructions are 

 added in the cultivation and harvesting of perfume-bearing plants. 



M. L. H. 



Oncidia, Regrular flowering of. By F. Ledien {Orchis, vol. V. 

 pt. 2, pp. 26-27). — The Oncidia flower more regularly when grown 

 in pots or saucers, and annually transplanted, using a mixture of 



