20 



INTKOnUCTION 



Work of 

 the Chemical 

 Laboratory 



Analyses 

 of Soils and 

 Subsoils 



The Poisonous 

 Ushar plant 



chemical hiboratory. Alt-liougli Dr. Beam lias certainly not received that outsiile aid 

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

 lew 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 

 proper scientific training, could not appreciate the necessity for scientific methods of 

 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 Gezira, 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 of 

 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 

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

 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 ti'eatment 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 resumeil with, it is thought, better chance of successful results. 

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

 his observations in England. Of special interest are his conclusions, based on Dr. Beam's 

 suggestions, as regards the role of ants in gum production, an interesting analogy, possibly, 

 between the transmission of diseases aifeeting animal and vegetable life respectively. 



Dr. Thompson, besides assisting in the work on soils, water, poisons, commercial 

 products and the various analyses which are always being conducted, took up as a line 

 of research the pharmacology of Calotropis procrra, the Ushar plant, with a view to 

 isolating the toxic principle or principles which, as previously explained, may occasion 

 poisoning by merissa, the national Sudanese drink, a kind of beer brewed from dura — ■ 



