130 Moneij-value of Night-Soil and other Manures. 
Another material point in these valuations is the difference of 
the value put on phosphate, according as it is classed as soluble 
or insoluble. It may be inferred from Dr. Voelcker's paper in 
this numljer of the Journal, that our authorities will reconsider 
this point, though it may not be easy to readjust it. 
It seems to be now recognised that before becoming: food for 
plants the phosphate resumes an insoluble form. 
The value of phosphatic manures depends, then, not on the 
transient solubility, but on the fineness of the powder perma- 
nently produced, it being easy of assimilation in proportion to 
that fineness. If this be so, those particles which have recently 
been subjected to the influence of vital action, vegetable or 
animal, will be more available than such as have been turned 
into stone by Nature's alchemy ; and yet these two classes of 
substances have of late been indiscriminately set at a lower value, 
as insoluble phosphates. 
This mistake, if mistake it be, has also bred some practical 
harm, phosphatic guanos, Avhen imported, not having met with 
the encouragement which they deserved, or having been treated 
with sulphuric acid at much cost, not so much to increase their 
value, as to adapt them to our market and our defective scale of 
valuation. 
But if decomposition, not transformation or solution, be hence- 
forth our object in dealing with phosphate, the important point 
to ascertain will be the origin, be it mineral or organic, ol the 
material employed, and home manufacture may again be resorted 
to as tlae best guarantee that the materials are organic. The use 
of a small proportion of sulphuric acid may revive, in spite of 
great difticulty of transport, and even the warning that about the 
first 10 lbs. if used with 100 lbs. of bones only form gypsum, 
not superphosphate, may not be heeded, if a violent action can 
onlv be generated which shall result in reducing the mass to 
fine powder. The classification and pricing of phosphate, seems, 
therefore, to call for some revision. 
I am not disposed to quarrel with the customary valuation for 
organic matter, of 1/. per ton. This is so moderate that it may, 
perhaps, hardly meet the approval of those who sympathize with 
a late influential eff'ort to resuscitate Old King Humus, who had 
gradually sunk into oblivion since the younger powers of earth — 
the children of Priestly, Cavendish, Davy, tScc. — had torn the 
veil of mystery from that awful brow, and divided his substance. 
But it rests with his advocates to plead his cause. 
Whatever, then, be the value of the excreta of the average man 
potash at 20^ per ton, stated tliat from kelp it could be procured at 15/. per ton, 
together with other fertilizers worth -Zl. 
