4 
cent, of phosphate of lime. As the deposit will probably 
extend the whole length of the fen, and has been proved to 
be not less than a quarter of a mile in width, and averages 
from one hundred and fifty to two hundred tons per acre, 
some idea may be formed of the almost national importance 
of the discovery ; as to its local value, probably the fee 
simple of the land previous to the deposit being known would 
not have averaged twenty pounds per acre, now at least one 
hundred pounds per acre will be netted by the diggings, and 
the land after this operation, by having the clay and marl 
brought up to the surface to mix with the peat, will become 
of at least double its original value, 
A paper was read by Mr. R. W. Pearson, “ On some 
Applications of the Chromates of Potash in Metrical 
Analysis.” The object of the communication was — First, 
to place on a surer basis modes of estimating lead and 
baryta by metre, which the author had previously indicated 
in “ The Chemist.” Secondly, to suggest some new appli- 
cations of the principles involved, for the indirect determina- 
tion of other substances. And lastly, to describe a process 
whereby chromium in its compounds may be metrically 
estimated. The manipulative part may be learnt by reference 
to a paper, by the author, on the Determination of Bismuth, 
in the Philosophical Magazine for March, 1856. The first 
section related to the determination of lead. After a critical 
examination of the methods now in vogue, the author gave a 
decided preference, both for celerity and accuracy, to the 
method based upon the use of bichromate of potash. For 
metre analysis, lead salts may be divided into two classes, 
according to the nature of their solution. 
If clear and transparent, the estimation is exceeding simple, 
the result being known by the precipitate and the color ot 
the supernatant fluid. In colored liquids, the formation ot a 
yellow color is partially or altogether concealed. In this 
