INTRODUCTION 25 



quoted in all works on this subject, to the Sudan Plant Diseases Ordinance, which owes 

 its existence to his efforts, and to his notes on mosquitoes and mosquito-devouring fish, 

 to indicate what an essential factor this economic entomological worlc is in the well-beino' 

 and for the future of the Sudan. A most gratifying feature is the help rendered 

 Mr. King by well-nigh everyone, from Governors of Provinces downwards. 



One leaves the most important items to the end as a rule, working, as it were, 

 towards a climax, and hence it is only fitting that this place of honour, so far as 

 Volume B is concerned, should be devoted to a brief consideration of the work of the 

 chemical laboratory. Although Dr. Beam has certainly not received that outside aid 

 which should have been fully and cordially extended to him, yet, I think, there are now 

 few in the country who will deny how great a bearing his laborious and painstaking 

 investigations into Sudan products and soils have on the development of the country. 

 He has undoubtedly been hampered and hindered in his work by those who, without Work of 

 proper scientific training, could not appreciate the necessity for scientific methods of Laborato"^*^' 

 collection and procedure, and, I fear, resented advice on these essential points. I believe, 

 however, that the worst is past and that those responsible for the development of 

 commercial products are now likely to co-operate and to recognise how absolutely 

 essential it is to abandon slipshod measures and to proceed on sound scientific lines. 

 This is specially necessary in the case of soil investigations which now bulk so largely. 

 The locality which is being chiefly studied is the Gezu-a, that vast area lying between 

 the Blue and White Niles, which, if properly handled, may yet bear great crops of 

 wheat and of cotton. There is a scheme afoot to place it under perennial irrigation, 

 and, as the cost of the irrigation work will be very great, it is essential that a sound 

 knowledge of the character of the prevailing types of soil be secured before any reliable 

 opinion can be expressed as to the success or otherwise of such an undertaking. As 

 Dr. Beam says, " attention has been called to the paramount importance of a study oi' 

 the subsoil as well as of surface conditions, since the question of drainage, resistance to 

 drought and root penetration will depend essentially upon the nature of the substrata. 

 Mechanical analyses of these soils and their subsoils {i.e. the determinations of the 

 proportions of gravel, sand, silt and clay) are therefore being made in all cases, and 

 determinations of the proportion of the essential plant constituents, potash, phosphoric Analyses 

 acid and nitrogen as well. These results, taken in conjunction with the observations made subsoils^" 

 in the field, should yield sufficient 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." 



Soil samples are also being obtained from Dongola and other districts, so that a good 

 general idea may be obtained of the classes of soils met with in areas which are, or are 

 likely to be, cultivated; while the prospect of increasing the yield of certain crops by 

 scientific treatment is shown in a most interesting paper on " Gypsum as a Fertiliser 

 for Sudan Soils." Moreover, after a prolonged and careful study of the question 

 of soil examination. Dr. Beam has devised new, rapid and special methods, which not 

 only greatly facilitate his own work, but appear to place the physical examination of 

 arid soils on a sounder basis than it has hitherto occupied. These are fully described. 

 The gum work, which for reasons explained by Dr. Beam, had perforce been abandoned, 

 is shortly to be resumed \vith, it is thought, better chance of successful results. 

 Mr. Edie again contributes a paper on the subject, having kindly continued and 



