It should be noticed, however, that these are analyses of samples selected in 
the first instance as containing sufTicient Sodium Nitrate to make them worth 
transport, and not average samples of llie clay beds. 
On 28"' May, 1 89/1, Mr. Floyer, in conjunction with Professor Sickenberger, 
presented a report to H. E. Nubar Pasha, President of the Council of Minis- 
ters on the same subject. In this report, it is stated by Professor Sicken- 
berger that the rrMarogii or Nitrate-bearing shale is a horizontal bed of blue 
or grey stratified marls 3o to 5o metres thick, certainly extending from Edfu 
to Kawi, north of Armant, and possibly having its northern limit between 
Luxor and Qcna. To the east, it extends to the Oasis of Farafra through Dakhla 
and Kharga, and also to the Dungul and Kurkur oases (these conclusions being 
based on the observations of Zittel, Schweinfurth, Willcocks and Sickenberger 
himself), and in all cases is covered by the hard limestones of the Lower 
Londinian (Lower Eocene). With regard to age, Sickenberger differs from 
Zittel, regarding it as Upper Suessonian, and not upper Cretaceous. (For 
discussion of this question, see later.) 
The natives depend on the taste of the shales in determining their nitrate- 
yielding value, and have found by experiment that while some spots furnish 
shale worth transporting, that of other parts is useless or even harmful. They 
also believe that unproductive spots may in time become nitrate-beai-ing, 
though up to the present this important point lacks confirmation by precise data. 
Capt. Lyons visited Mualla in i8()5, and collected samples from three 
points in the clifl", 5o kilos, of shale were taken from approximately one 
quarter, one half, three quarters down the cliiT face, and at the base of the 
cliff. Copy of the analyses as submitted are given in Table n° 3, p. 168. The 5o 
kilo samples were pounded up and well mixed, after which a 3 kilo sample 
was taken for analysis. The results were : 
Maximum 1.80/0 Sodium Milrale. 
Minimum o.4o/o - — 
Mean o . (S5 0/0 — — 
Capt. Lyons concluded that for Mualla clifl" this mean must be taken as a fair 
approximation of what would be obtained from working the clifl" in bulk. 
OJicial Journal, N" 71, 3o June, 1894. 
