IV 
THEORIES AS ÏO NITRATE FORMATION. 
It is obvions from the above remarks that no theory of a local character is 
acceptable. M. Pluvinage in his cc Industrie et Commerce des Engrais r, p. i8('', 
has mentioned the suggestions already made as to the origin of the nitrates 
in VAïûi. 
1. The views of Ochsenius and Thierceling as to their origin from guano 
are entirely inapplicable to the Egyptian deposits. 
2. An electrical theory has been put forward, according to which the nitrogen 
of the air under electric discharge forms nitrate of ammonia, which then 
reacts with common salt to form nitrate of soda. This also finds no support 
from the facts. 
3. The theory of origin from sea-weed, as propounded by Noellners and 
Sieveking also affords little help, as traces of vegetable matter are not common 
and iodine has not been noted. On the other hand, as already stated, in parts 
there is some evidence of abundant animal life. 
/i. Dr. Newton (Society of Chemical Industry, 1900) quoted by Mr. Hughes 
(/oc. cit., p. 166) held that the nitrate of Chili might be the concentrated fer- 
tility of the thousands of square miles of land between the watershed of the 
Cordillera and the coast line of hills. It is along the line at the foot of these 
hills that the nitrate grounds are situated. Their situation, always on the land- 
ward side, is an indication that the cc caliche ii is derived from the land. In 
Chili the nitrate deposits form definite beds overlying others of varied nature, 
in Egypt they appear to be restricted to shale of definite geological age, so 
that comparison as regards origin seems excluded. 
5. Messrs. Barron and Beadnell have connected the existence of the nitrates 
with the abundance of fossil remains, without discussing the nature of the 
chemical changes to which their origin might be due. Miintz and Plagemann 
have submitted the view that organic nitrogenous materials, transformed by 
I am inilel)le(l to M. Mosseri, who called niy alleiition to this work. 
