Egypt is nothing more than the deposit left by the Nile in flood. The water is most heavily charged with detritus in August, less in September, and still less in October. Many analyses have been made of Nile water. Following M. Barois, I place side by side the analysis of Dr. Letheby of 1874⁄75 and Dr. Mackenzie of 1896/97/98. The year 1874 was an extraordinarily high flood. =========+============================== Month. | PARTS IN 100,000 OF WATER +----------+--------+---------- | Dr. | Dr. |The Mean |Mackenzie.|Letheby.|of the two ---------+----------+--------+---------- January | 31·0 | 16·7 | 27·4 February | 25·3 | 12·6 | 22·1 March | 12·7 | 5·3 | 10·9 April | 15·8 | 6·6 | 13·5 May | 14·7 | 4·8 | 12·2 June | 14·1 | 6·9 | 12·3 July | 13·9 | 17·8 | 14·8 August | 159·0 | 149·2 | 156·6 September| 156·1 | 53·3 | 130·4 October | 110·0 | 37·8 | 92·8 November | 70·8 | 34·4 | 61·7 December | 47·0 | 28·9 | 42·4 ---------+----------+--------+---------- Mean | 56·0 | 31·3 | 49·8 =========+==========+========+========== From this last column M. Barois concludes that in high floods 100,000,000 tons of solid matter pass Assuân, and 88,000,000 in mean floods. It is unfortunate that we have no analyses of low floods like 1877, 88, 99, 1902 and 1904 which were extraordinarily muddy. The water had little sand but much mud. The sand is scoured out of the bed of the river itself in high floods. After Dr. Letheby the composition of Nile deposit is as follows:-- =========================+=========+============== |In flood.|In low supply. +---------+-------------- Organic matter | 15·02 | 10·37 Phosphoric acid | 1·78 | ·57 Lime | 2·06 | 3·18 Magnesia | 1·12 | ·99 Potash | 1·82 | 1·06 Soda | ·91 | ·62 Alumina and oxide of iron| 20·92 | 23·55 Silica | 55·09 | 58·22 Carbonic acid and loss | 1·28 | 1·44 -------------------------+---------+-------------- Total | 100·00 | 100·00 =========================+=========+============== Comparative analyses of subsoil water in Egypt and Nile water in time of low supply are given below.