MR. HORNER ON THE ALLUVIAL LAND OF EGYPT. 
125 
of solid matter held in suspension in the water of the Rhine, and requested that a 
similar process should be followed*. Dr. Abbott’s account of his experiment, con- 
tained in a letter to me dated Cairo the 12th of December 1850, is as follows: — “ I 
beg-an your experiment on the 1st of October, and on that day took an imperial 
gallon of water from the Nile at the depth of 20 feet, and at that part of the river 
opposite the Transit Wharf at Boulac. The current is there very strong, and the 
water is not likely to have any of the dirt or filth that might possibly be mixed with 
it lower down, where a large number of boats are collected. I took one gallon of 
water daily for ten days, which I put into an earthen filter, and left covered, until 
it became perfectly dry ; and then put it into a paper and kept it until a M^eek ago, 
when I weighed it and found the quantity to be 18|^ drachms apothecaries weight 
(1110 grains). I am now endeavouring to dry it in a cake, or rather to bake it in 
the form of a small brick to send to you.” 
I weighed the little brick sent to me accurately on the 1 1th of May 1851, and found 
it to be 1106 grains, so that the solid matter held in suspension is llO’G grains in an 
imperial gallon. An analysis of this solid matter was made at the Royal College of 
Chemistry in London, by Mr. Brazier, under the superintendence of Dr. HofmannT? 
and yielded the following results : — 
Silica 53-04 
Sesquioxide of iron 18-43 
Sesquioxide of alumina 8-76 
Carbonate of lime 4-19 
Sulphate of lime 0-75 
Lime 2-25 
Magnesia 0-66 
Potassa 0*69 
Soda 2-1 6 
Chloride of sodium 0-04 
Organic matter 9-03 
100-00 
This hardened mass, when moistened, kneaded into a clay. 
In future references to this specimen I distinguish it by the letter A. 
B. A specimen of Nile sediment from the lower part of the Delta, sent to me hi/ 
Mr. Murray. — It was collected at Damanhour, about six miles and a half from the 
left bank of the Rosetta branch, from a branch canal which connects the Nile with 
the Mahmudieh Canal near Bastie, and was a part of the sediment deposited by the 
inundation of 1849. This deposit is carefully collected on account of its ferti- 
* Edinburgh New Philosophical Journal, January 1835. 
t That the accuracy of the analyses might be relied on, I requested and obtained the aid of my distinguished 
friend Dr. Hofmann, who kindly undertook the superintendence of this and of the other analyses hereafter 
mentioned. 
