ON THE CHEMICAL COMPOSITION OF GUANO. 135 
desiccation in an oven, it will gradually lose its weight until 
it contains only 30 per cent, of water ; then calcination alone 
can make it lose more. — Ibid from Journ. de Pharm. 
ART. XXXVIL— ON THE CHEMICAL COMPOSITION OF GUANO. 
ExtrdHt of a letter from M. E. Marchand ; of Fecamp, to M. Boul- 
lay. 
Being entrusted with the revision, for a local journal, of 
an article on guano, and on its value as a manure, I ex- 
amined this curious product myself, and I found, by analy- 
sis, that it is composed of — 
Hippurate - "*) 
Urate - - | 
Phosphate - - y of ammonia. 
Oxalate - - 
Hydro-chlorate - J 
Chloride of sodium. 
Carbonate (?) - ~] 
Oxalate - - j> of lime. 
Phosphate - j 
Ammoniaco-magnesian phosphate. 
Alumina, oxide of iron, and silica. 
Indeterminate organic matter. 
The existence of hippuric acid in this product is very 
remarkable ; for, if guano be regarded, with M. Girardin, 
as coprolithes arising from antediluvian birds, or, with M. 
de Humboldt, as excrements and altered remains of birds 
which have inhabited, and still inhabit, the islands of the 
coast of Africa, it is no less true that the origin of hippuric 
acid, in this product, is difficult to be conceived, since none 
of the analyses of the excrements of birds which have hith- 
erto been made and published have noticed this principle 
among its constituents. 
