324 EXPERIMENT STATION EECOED. 



.'/ (1905), No. 2, pp. 219-226). — A discussion of the importance of developing 

 methods of artificial preparation of nitrate of soda, especially by means of 

 intensive nitrification, to replace supplies derived from natural nitrate deposits 

 which are becoming exhausted or might he entirely cut off in time of war. 



On a nitrogen assimilating Clostridium, H. Pringsheim (Centhl. Bald. 

 {etc.\, 2. AM., 16 (1906), No. 25, pp. 795-800; ahs. in Cheiii. Ztg., 30 (1906), 

 No. 81, Repert. No. 35, p. 330). — The nitrogen assimilating capacity of a new 

 species of Clostridium isolated by the author and named Clostridiiiin aiiicri- 

 canuin is compared with that of C. pastciiriaiinm of Winogradski. It is 

 shown among other things that the new Clostridium is much slower in its 

 action than C. paxteiiriainiui. 



, The bacteria of the root tubercles of leguminous plants, K. F. Keller- 

 MANN and T. D. BECKwrni (Ccittbl. Bakt. [etv.\, 2. Abt., 16 (1906), No. 17-19, 

 p. 54O). — The behavior of the micro-organisms of the root tubercles of velvet 

 beans, soy beans, garden i)eas. and alfalfa on various culture media is briefly 

 described. 



The securing of a supply of nitrogen for agriculture in the twentieth 

 century, A. Stutzer {Dc'it. LuiuUr. Pie><S(', 33 (1906). No. 55, pp. 'i52. 'i'i3, 

 flijs. Jf). — This is a brief discussion of means of utilizing the nitrogen of the air 

 by means of leguminous plants and electrical processes. The utilization at 

 Notodden, Norway, of cheap water power for production of the electrical energy 

 used in oxidation of the nitrogen of the air is especially referred to. 



The apparatus devised for utilizing the nitrogen of the air, A. Neuburger 

 (Ztschr. Aitgeic. Chcm., 19 (1906), No. 22. pp. 977-985. flgs. 17). — The princi- 

 ples of construction and operation of the various forms of apparatus proposed 

 for this purpose are briefly discussed. 



The new Norwegian saltpeter industry (UgcsJcr. Laiuhit.. 1905, No. 52; 

 HedescWc. Tidsskr., 1906, No. 2. pp. 20-27/).— The manufacture of nitrates by 

 electrical processes at Notodden, Norway, is referred to. 



The occurrence of sodium salts in Egypt with special reference to nitrate 

 of soda, F. Hughes {Yearbook Khcdiv. A</r. Soc, Cairo. 19li5, pp. lJf.5-170, 

 fig. 1). — Lake and desert deposits are briefly referred to and the occurrence of 

 sodium salts, especially nitrates, in the soils and drainage waters and in the 

 natural manures known as koufri, marog, and tafla, is more fully discussed. 



The salts most frequently found in soils are chlorid, sulphate, carbonate, and 

 bicarbonate of sodium, the last two being much less abundant than the first two. 



The occurrence of a large alluvial ])lain at Kom Ombo in Upper Egypt, which 

 is impregnated with sodium chlorid, sul])hate, and nitrate, is described, the 

 nitrate occurring in suflicient amomit to make the soil, which is known under 

 the local name of marog. of value for fertilizing purposes. Analyses are re- 

 ported which show as high as 5.9 per cent of nitrate in this soil. The salts are 

 derived fi'om clay hills innnediately siirrounding the ])lain, 



Koiifri. the most important natural manure of Lower Egypt, consists of the 

 remains of old villages, which analysis shows to contain in some cases as high as 

 4.4 per cent of nitrate of soda besides various other salts. 



The Esna shales (known as tafla) of Upper Egypt, containing from 6 to 8 

 per cent of nitrate of soda, are said to be the most important salt deposits in the 

 coiuitry. A series of ex]ieriments in the extraction of this material, which gave 

 a iiroduct containing r»4 i^er cent of nitrate, is reported, and the economy of the 

 process with limited water and fuel su]iply is discussed. The origin of the tafla 

 salts is considered and the conclusion is reached that the nitrate which they 

 contain has been produced by the decomposition of organic matter. 



A bibliography of 25 references is given. 



