190 THE DESICCATION OF AFRICA. 



7,000 cubic feet per second for each thousand square miles of 

 surface. The gaug-in^s of the Zambesi above the Falls are given 

 in a very recent Rhodesian Report as 11,750 cubic ieet per 

 second for the seven winter months of 1905, and although the 

 summer flow would be enormous, yet these figures should prevent 

 one ifrom too readily assuming that a basin of the size advocated 

 could be kept filled during normal years. Moreover, such a body 

 would bring abotit the extension of the present fever-stricken 

 swamps, and would, through periodical floodings, give rise to 

 marginal barren salt-flats, while the effects upon the climate of 

 any re-condensation of the moisture evaporated, upon which the 

 success O'f the whole scheme depends, would be more or less 

 problematical. 



Uses of Mirabilis JalAPA.— F. Mancada Guignones 

 gives an account in La Rivista Agricola'^' of a long study of the 

 plant commonly known as Marvel of Peru (Mirabilis jalapa). 

 When grown in gardens it flowers abundantly, but jjroduces 

 small seeds. Imt if grown under arid conditions, and i)articularly 

 if fertilised with ashes, it flowers less, but produces seeds which 

 are much larger and richer in starch. This starch is of very 

 good quality, and produces an excellent floitr capable of being 

 used for bread, biscuits, etc. The seeds also contain a sugar, 

 and can be subjected to alcoholic fermentation. The stamens, 

 jjistils and perianth (which dries up without separating from 

 the seed) yield a fast purple, which can be used for dyeing silk. 

 The flowers open towards evening (hence another common 

 name for the plant in SoiUh Africa is " Vier-uur bloem " or 

 " Four o'clock ") and exhale a strong odour during the night 

 which is said to stupify or drive away mosquitoes. In such a 

 case it might be advantageously cultivated in malarious areas. 

 It grows in a semi-wild condition in several parts of South 

 Africa — for instance, near Idutywa in the Transkei, and on the 

 Rhodesian veld. 



RoYAii Society of South Africa.— At the annual 

 meeting of the Royal Society of South Africa, held on the 25th 

 September. 1918, the following were elected Fellows of the 

 Societv: Prof. A. Brown, M.A., B.Sc. F.R.S.E. ; Miss E. M. 

 Doidge. M.A., D.Sc, F.L.S. ; S. H. Haughton, B.A. F.G.S. ; 

 Prof. H. B. Fantham, M.A., D.Sc, A.R.C.S., F.Z.S. : and Prof. 

 A. Yoimg, M.A.. D.Sc, F.G.S., F.G.S. 



'-• 14 ( igi8), 142, 143. 



