Rosearcli on 

 (•mil 



Toxicological 

 work 



Soil 

 examinations 



2-4 KEFOUT OF CHKMICM, LAUOKATOKV 



A very groat luiiount of time and labour was spent on {,'uai research, the earlier 

 results from which were most promising. It is all the more to be regretted, therefore, 

 that one is forced to record, as in previous years, the entire failure of the Woods and 

 Forests Department to effectively co-operate with us in this work. This Department 

 is, however, now in process of reorganisation, and it is expected that we may count 

 upon its aid in tlie future for the field work connected with research on forest products. 

 Fortunately, too, the laboratories were able to secure for a second year the services of 

 F. H. Edie, B.Sc, Carnegie Research Fellow, who sjieiit the w^inter of 1908-9 in the 

 forests near Taiara, Kordofan. Mr. Bdie's researches were chiefly bacteriological, and 

 his very interesting results appear to confirm those recorded by Greig Smith. The 

 writer was also able to spend a short time in tlie gum forests of the Blue Nile (Sennar 

 District), and a brief account of the observations there made will also be found below. 



In the con ISC of its work, the chemical laboratory has been confronted with two 

 very important i)roblems, namely, the discovei'V of reliable tests for hashish and for 

 " iishar " (('(ilotniiii.i procera) . The latter plant contains a milky juice which is extremely 

 poisonous, and there is considerable evidence to show that it is not infrequently used 

 by the native with criminal intent. It is gratifying to be able to record that what 

 appears to be a reliable test for the former has now been found. As regards " usiiar," 

 Dr. Thompson has conducted a research on the latex of the plant and brought forward 

 certain colour tests for it which may prove to be of value. 



As will be seen from the list of samples tested, a very considerable number of soil 

 examinations has been made in the past two years. At present the laboratories are 

 largely engaged in a study of that section of the Gezira district which it has been 

 proposed to put under perennial irrigation, when funds for the purpose become available. 

 The cost of such irrigation works will be very great, and it is obviously necessary that 

 some knowledge be secured of the character of the prevailing types of soil, before 

 embarking upon a venture of such magnitude. 



Attention has been called, by this section of the laboratories, to the paramount 

 importance of a study of the subsoil as well as the surface conditions, since the questions 

 of drainage, resistance to drought and root penetration will depend largely upon the 

 nature of the substrata. Mechanical analyses of these soils and their subsoils (i.e. the 

 determinations of the proportions of sands, silt and clay) are therefore being made, and 

 estimations of the proportions of essential plant constituents as well. These results, 

 taken in conjunction with the observations made in the field, should yield suflicient 

 evidence to enable one to form at least a reasonably accurate judgment as to the results 

 which may be expected from irrigation, if the cultivation is carried out on suitable lines. 



We have been fortunate in securing the aid of Mr. S. C. Dunn, Government 

 Geologist, for field work in connection with these investigations, and are greatly indebted 

 to him for the able manner in which he has carried it out in spite of climatic conditions 

 which nmst be experienced to be appreciated. The first series of 184 samples were 

 collected during the month of May with the thermometer ranging as high as 120' F. in 

 the shade, and almost daily sandstorms. 



