SOILS FERTILIZERS. 421 



injured by the treatment, but the iteptoiiizini; orjianisuis, esitecinlly the BuHUiix 

 inycoidrs group, were less affected. Especially resistant were all sitore forms. 



The action of the carbon bisulphid was more marked in the pots than in the 

 field. The spore count was 1.8 to 3.8 per cent of the total count in the case of 

 the field soil after treatment, but 77 per cent in the case of the pot soil. The 

 bactei'ial flora of the two were very different after treatment. 



In a study of the i-esistance to carbon bisulphid (1.7 parts per 1,000 of water) 

 of various nonspore- forming bacteria in pure cultures, it was found that the 

 different kinds of bacteria showed great variation in resistance. The tubercle 

 bacteria of peas, BaciUus ruber-purpnrcus, B. stutzcri. Vibrio hcrnlinensis, and 

 T'. phospJioresccns were quickly killed, generally within 24 hours. On tho 

 other hand, the tubercle bacteria of Robinia, Bacillus prcepollcns, B. prodigi- 

 osus, B. pyocyaneus. Bacterium coli commune. Micrococcus urea:, and Proteun 

 vulgaris survived the treatment for as much as 4 hours. The staphylococci 

 were very resistant, surviving the treatment for as much as 48 hours. Azoto- 

 hactcr chroococcum in pure cultures and in soil extracts was killed in 24 hours 

 by 1.7 parts of carbon bisnli)hid per 1,000 of water at 20° C. In moist soils 

 impregnated with the fumes of carbon bisu]i)hid it survived 48 hours. The 

 results show in general that the vegetable forms of bacteria are, as a rule, 

 destroyed in 24 hours by carbon bisulphid of the strength given. 



In similar studies with the mixed bacterial flora of soils the effect of the car- 

 bon bisulphid was at its height at the end of 24 hours, little but the spore forms 

 remaining at the end of this period. At the end of 17 days, however, the bac- 

 terial count was nearly the same as before treatment, and in from 17 to 30 

 days there was an increase. 



The effect of desiccation on root tubercle bacteria, F. D. Chestkr (Dela- 

 irarr fita'. Bui. 7'N. pp. 15). — The results of previous investigations bearing upon 

 the effect of desiccation upon different kinds of bacteria are stated to be very 

 variable and confusing. The results of the author's experiments with cultures 

 of Pseudomonas radicicola freshly prepared from- root tubercles and dried on 

 cotton or in dishes, and with cultures obtaiiied from the Bureau of Plant 

 Industry of this Department lead to the following conclusions : 

 . "(1) P. radicicola has little power to withstand drying, and its preservation 

 in the dry state on cotton is inadvisable. 



"(2) Fresh cultures, by containing a larger number of active organisms, are 

 better for inoculating cotton thaii old cultures. 



"(3) Cultures drietl on cotton and exi)osed to atmospheric influences die very 

 rapidly, the great majority of the bacteria perishing during and up to the point 

 of complete desiccation, a few more resistant individuals surviving, and these 

 only for a very limited time. 



"(4) With the use of fresh, vigorous cultures, dried quickly on cotton, and 

 kept in sealed bottles, P. radicicola will survive for a longer time with certain 

 strains and for only a short period with others: but even this method of 

 preparation, which offers the l)est conditions for preservation, is uncertain. 



"(5) /'. radicicola when dried in thin films on glass perish very rapidly. 



" (0) The latter is also true of P. radicicola when dried on seed." 



On the action of barnyard manure, J. Stoklasa {Zischr. Landiv. Vcrsuchsio. 

 Ostcrr., 10 (1907), No. //, pp. .'i.'i0-.',71 ; FiUiling's Landw. Ztg., 50 {W07), No. 12, 

 pp. ',09-1,33; al)s. in Chem. Zenthl., 1907, I, No. 2',, p. 1702).— The author sum- 

 marizes and discusses the results of his numerous experiments on the im- 

 portance of manure as a means of increasing the bacteria content of soils, in 

 increasing the activity of the soil bacteria, and on the influence of this bacterial 

 activity on the plant food and properties of soils. 



