A FORTNIGHTLY REVIEW 



LIBRARY 

 NEW YORK 



IMPERIAL DEPARTMENT OF AGRICULTURE FOR THE WEST INDIES, '^rden.*' 



OF THK 



Vol. IX. No. 203. 



BARBADOS, FEBKL'AUV 5, 1910. 



Prick Id. 



CONTENTS. 



Page. 



in tlK- Soil Xi 



39 



< Obtained 

 3C 



Page. 



Balance of Life- 

 Book Shelf ... 

 Cacao, Product 



from 



Ca';ao Land, Draining of 36 

 Cay-cay of .\nnaiii. The ... 41 

 Change of Habits l>y Birds 41 

 Characteristics (jf Manicol>a 



Ruhher Trees .. ... 40 



Cotton Notes : — 



Cotton-(i rowing in China 38 

 38 

 40 

 45 



West Indian Cotton ... 

 Cotton Waste, Uses of ... 

 Department News 



Euphorbia Latex for Pre- 

 venting Corrosion ... 



Fungus Notes : — 



Cacao Diseases in Suri- 

 nam 



Gleanings 



Oreen Dressings in Antigua 

 and Dominica 



41 



Insect Notes ; — 



The Sweet Potato Weevil 

 I'ganda Insect Pests ... 

 Implemental Tillage in 



St. Vincent 



Market Reports 



Notes and Counnents ... 

 Orange (Ml, Sweet, in Italy 

 Phosphates, Loss of from 



•Soils 



Poultry Notes:— 



Rheumatic Troubles of 



Poultry 



Sporobolus Indicus 



Students' Corner 



Sugar Industry : — 



Seedling Canes in Porto 



Rici 



Tapioca, Manufacture of in 



Malay States 



Tick and Disease. The . 

 West Indian Products ... 

 Wild Ii)ecacuanlia. The 



42 

 42 



3.5 

 48 

 40 

 41 



43 



43 

 4t) 

 45 



35 



40 

 47 

 47 



38 



The Balance of Life in the Soil. 



11. THE KKFECT8 OK STEKlLI/CATlo.V. 



l[j iTfSjvHE general considerations which were given 

 »^j i^^Jiin the last number of the AgricuUviral News 

 A-.J'rH lin relation to the state of the soil, and to the 

 changes which may constantly take place in it, led to 

 a discussion of the effects that are obtained when the 

 soil is subjected to inHnences which interfere with the 

 balance between the different forms of living matter 

 by which it is inhabited. The work of various investi- 

 gators was shortly mentioned, including that of Russell 

 and Hutchinson, the latest experimenters on the sub- 



ject, the consideration of whose labours, in view of their 

 importance, was reserved for this number. 



In these experiments, the soil was treated in four 

 ways, all of which resulted in partial or complete 

 sterilization. In the first two, partial sterilization was 

 effected by heating the soil to a temperature of 98° C, 

 or by adding 4 per cent, of toluene, which was allowed 

 to escape at the end of three days by spreading out the 

 soil in a thin layer. According to the third method, 

 the toluene was allowed to remain in the soil during 

 the whole of the experimental period. As a fourth 

 variation, a few experiments were made with soils that 

 had been completely sterilized by being heated to 

 a temperature of 12.5° C. A control was supplied by 

 a fifth series of experiments, in which the soil w;is not 

 treated. The soils, after treatment, were moistened and 

 kept for definite periods in bottles closed by cotton 

 wool, at the temperature of the laboratory. It nuiy be 

 mentioned that the sterilizing agent employed in two 

 of the series of experiments — toluene — is a liquid 

 hydrocarbon, very similar to benzene in its constitution 

 and properties, which exists in light coal-tar oil, and is 

 obtained when balsam of tolu, wood, and some other 

 organic bodies are distilled. Like many similar substan- 

 ces it is very destructive to life of every kind. 



The first result obtained in the experiments was 

 that 'the increased productiveness of partially sterilized 

 soils is due to an increase in the amount of .^mmonia 

 present'. Considering the partially sterilized soils, it 

 was found that, at the end of twenty-four days, the 

 soil that had been heated to 98° C. showed the greatest 

 increase in the amount of ammonia present; the 

 soil that had been treated with toluene, which had 

 subsequently been allowed to evaporate, came next; then 

 the soil from which it had not been allowed to escape; 

 while in the case of the untreated soil, the increase in 



