244 BOARD OF AGRICULTURE. 



of its essential associated constituents in the ocean, besides 

 an unusually large percentage of phosphoric acid. The latter 

 appeared to be present mainl}^ as a phosphate of proto-ses- 

 quioxide of iron. 



A few subsequent analytical statements may convey some 

 definite idea regarding that surftice mass, which in most 

 instances is of bluish-green color, and only here and there 

 yellowish red, in consequence of a large excess of hydrated 

 sesquioxide of iron ; it appeared usually in form of scales 

 separated from the underlying mass. 



I. One hundred parts of the air-dry 



mass lost, at 100°-110 C, . . 10 per cent, of moisture. 



One hundred parts of the same sam- 

 ple, left by calcination, . . 39.5 parts of ash constituents. 



One hundred parts of the air-dry 



mass contained .... 0.5630 jier cent, of phosphoric acid. 



II. One hundred parts of an air-dry 

 sample, taken from a different 

 locality, contained . . . 0.8510 per cent, of sulphuric acid. 



The quantity of phosphoric acid noticed in these two 

 instances is very large, and exceeds in the second case — in 

 percentage, twice the amount of that acid — found in the ash 

 constituents of the entire organic and inorganic soil mass of 

 the central portion of the marshes (see Secretary's report for 

 1874, page 339). 



As the main portion of the phosphoric acid had been left 

 behind by the evaporation of the surface-soil water, it becomes 

 quite evident, that the latter is unusually rich in one of the 

 most valuable soil constituents ; but we are told, also, in an 

 unmistakable manner, how essential it is for future agricult- 

 ural success, as far as time is concerned, that the drainage of 

 the marshes should be attended to without delay, and, at the 

 same time, with a view to a system which would bring the 

 discharge of the drainage water as far as practicable under a 

 satisfactory control. 



It is a well-known fact, that both carbonic acid and chloride 

 of sodium (common salt) favor in a remarkable degree — 

 accompanied with water — the solubility of neutral phosphate 

 of lime. One per cent, of salt secures its full reaction. The 



