24 - GEOLOGICAL MEMOIRS. 
On the Formation of Minrrau Puospuates (Ueber die Bildung 
_ phosphorsaurer Mineralien). By Prof. G. Biscuor of Bonn. 
[Verhandlung. der Niederrhein. Geselsch. zu Bonn vom 15 Dez. 1846. 
From an abstract in L. and B.’s Neues Jahrbuch, 1847, p. 367.] 
APATITE, the most widely distributed of the minerals containing phos- 
phoric acid, is very probably the source whence not only the greater 
number of other similar minerals, as for instance the phosphate of 
copper, the green phosphate of lead, &c., have been produced as 
secondary formations, but also from which the phosphoric acid so very 
generally diffused in the vegetable and animal kingdoms has been and 
still continues to be obtained. Prof. Bischof found that the apatite is 
soluble in water containmg carbonic acid, although requiring a larger 
quantity of it than the phosphate of lime prepared as an artificial 
salt, or even than the bones. The apatite is extracted from mountain 
rocks by water of this nature, and such very weak solutions either 
produce new mineral phosphates, or are imbibed by plants and the acid 
thus conveyed to the animal kmgdom. M. Bischof mentions the oe- 
currence of vivianite in the bones of the human skeleton. When this 
substance is once received into the realm of organic nature, an unin- 
terrupted circulation takes place; the decaymg animal restores its 
phosphate of lime to the vegetable world, and the animals again receive 
it in their food. Its solubility in water, even when this contains only a 
small proportion of carbonic acid, explains why animal bones, when 
exposed to moisture, in the course of time altogether disappear, whilst 
those in dry situations may endure for thousands of years, as the 
Egyptian mummies and the bones of extinct animals buried mm beds im- 
pervious to water clearly show. He then refers to the experiments 
recently made by many chemists, which establish that phosphoric acid 
is far more widely diffused in the mineral kingdom than was formerly 
suspected. Traces of it have been found in various crystalline rocks, 
for instance in granite, gneiss, mica-slate, and basalt ; and also in the 
lava from Niedermendig. The occurrence of this acid in sedimentary 
formations will appear less remarkable, when it is remembered, that 
most of them contain more or less abundant remains of organic bodies, 
from which water may have conyeyed phosphate of lime into the rock. 
The importance of phosphoric acid to the vegetable kingdom has been 
long known, and also that manures owe no small part, burnt bones the 
whole, of their value to the presence of this acid. The more gene- 
rally therefore it is found in the mmeral kingdom, the more easily 
explicable does its wide diffusion in the organic world become, and 
the more means are presented for improving cultivation and increasing 
the fertility of the soil. The contmual decomposition of mountain 
rocks constantly renews the supply of phosphoric acid to the vegetable 
kingdom. This fact must also throw still more into the background 
the opinion, long ago regarded at the tribunal of chemistry as without 
foundation, that organic nature could produce phosphoric acid or phos- 
phorus, or any other elementary body. In conclusion Prof. Bischof — 
calls attention to the frequent conjunction of the phosphoric and fluoric 
acids, which may be followed from the mineral even ito the animal 
