THE 
NITRATE SHALES OF EGYPT 
BY 
W. F. HUME, D. Sc., A. R. S. M., F. G. S. 
DIRECTOR GEOLOGICAL SURVEY OF EGYPT 
VICE-PRESIDENT OF THE EGYPTIAN INSTITUTE. 
(Plates IV-V.) 
The following remarks are a summary of the work undertaken in connexion 
with the Nitrate Shales of Egypt, the results hitherto oLtained being largely 
distributed in pamphlets or official records difficult of access. 
The subject will be considered under the following heads : 
I. Studies made on Percentages and Average Content of Nitrates in the Shales. 
II. Experiments in Methods of Enrichment in Nitrates. 
III. Distribution of Nitrate Shales in Egypt, 
IV. Theories as to Nitrate Formation. 
I 
STUDIES MADE ON PERCENTAGES AND AVERAGE CONTENT 
OF NITRATES IN THE SHALES. 
The Nitrate-bearing beds of Upper Egypt were first described from the 
point of view of their agricultural importance in January, 1896, when 
Mr. E. A. Floyer read a paper before the cclnstitut Egyptiemi on the 5*'' January 
entitled Note sur remploi d'une argile comme matière fertilisante dans la Haute- 
Egypte. He there called attention to the wide employment of the crTaflai) or 
Nitrate shale by cultivators between Edfu and Girga as a manure for their 
crops. He had also taken samples from the heaps of ccTaflai^ which had been 
brought down to the banks of the Nile, these being analysed by Dr. Mack- 
enzie at the Agricultural College. The results of six analyses showed a maximum 
Sodium Nitrate content of 1 8.53 0/0, minimum '2.56 0/0 , and mean 1 0.96 0/0. 
(See Analyses, Table n" 1, p. 168.) 
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