P/ios/)hatin Materials listed for Af/riailtiiral Purposes. 353 
men renders available for the use of" farmers the discoveries of 
phosphatic deposits in Norway, Spain, America, and other 
coiuitries. The composition of most of the })hosphatic materials 
which are used at the present time by manure-manufacturers in 
England has been carefully ascertained ; but many of the analyses 
are scattered in scientific journals, and not readily accessible to 
the a<?riculturist or manufacturer. Several phosphatic materials 
ag-ain have only recently been imported into I'higland, and of 
these no trustworthy analyses have been as yet published. Of 
others we possess careful analyses made from picked specimens, 
but no published account of the composition of the materials in 
the state in which they actually occur in commerce. I propose, 
therefore, to give an account of all the more important phos- 
phatic materials now in use, and briefly to describe their general 
appearance and more characteristic physical properties, stating 
the localities wliere they are found, their composition as ascer- 
tained by me, and some particulars which may be of interest or 
practical importance either to the farmer or to the maker of 
artificial manures. The following is a list of the substances of 
which I shall treat : — 
1. Norwegian apatite. 
2. Spanish phosphorite. 
3. Cambridgeshire coprolites. 
4. Suffolk coprolites. 
5. American phosphate (!Maracaibo guano). 
6. Sombrero, or Crust-guano. 
7. Kooria Mooria guano. 
8. Other phosphatic guanos. 
9. South- American bone-ash. 
10. Animal-black, or bone-charcoal. 
11. Bones. 
There are a few other phosphatic materials which now and 
then find their way into commerce, but to these 1 shall either not 
refer at all or only incidentally. 
1. Norwegian Apatite. 
Apatite, a hard and often Avell-crystallised mineral, chiefly 
composed of phosphoric acid and lime, is found in this countrv 
in Devonshire, Cornwall, and Scotland, but not as yet in sufficient 
quantity to allow of its being collected for technical purposes. 
In America it is found imbedded in granite at Baltimore, in 
gneiss at Germantown, in mica-slate in West Greenland ; in 
granite at Milford Mills, near Newhaven, Connecticut ; at 
Topsham, in Maine, in granite, and in various other localities 
mentioned in detail in Dana's ' Mineralogie.' On the Continent 
