THE TECHNOLOGIST. [April 1, 1865. 



422 CAMBRIDGE COPROLITES. 



ovules, nearly sessile on axile placentae in two rows ; style included, 

 club-shaped, 3 — 5-sulcate at the apex, and bearing 3 to 5 stigmas. 



Capsule (pod or boll) more or less ovate, 3-5-celled, broader and 

 more nearly approaching to globose when the cells are 4 or 5 than when 

 they are only 3, with a coriaceous or subligneous pericarp, when ripe 

 bursting from the apex with from 3 to 5 valves, which bear the dissepi- 

 ment on their axis. Seeds fig-shaped or pear-shaped, with a black, 

 rather spongy skin, beset with long slender filaments (the cotton), 

 which either separate entirely from the seed when a gentle force is 

 applied, and leave it naked, or break it off near the base, leaving the 

 seed covered with a greyish or greenish tomentum (called fuzz by the 

 North American planters). There is also sometimes, both on the naked 

 seeds and on the fuzzy seeds, a short white pencil of fibres at the base, 

 but its presence is inconsistent even on. seeds of the same plant. The 

 fuzz itself is very variable, for in a single capsule I have found seeds 

 quite naked, and others half-covered with fuzz, so that its presence or 

 absence can never serve as a specific distinction.* 



CAMBRIDGE COPROLITES.f 



BY GEORGE SANDYS. 



The coprolitej is a fossil remain, and until within the last few years 

 was considered of no commercial value ; but modern science has clearly 

 demonstrated that it is one of the finest manures that a farmer can 

 possibly use. 



These coprolites are found in several counties, but in none so plenti- 

 ful as in that of Cambridge. They run in veins, about from eight to ten 



* The above description of the cotton-plant was drawn up from a comparative 

 view of as many sorts of American cotton as I could get together in a fresh state. 

 It professes to contain nothing new, beyond noticing that the stamens are really 

 in five separate parcels united into one tube, and that both ovary and capsule are 

 far oftener 3- or 4-celled than 5-celled (as usually described), of which I have 

 satisfied myself by examining thousands of examples. 



t See an article " On Phosphate Nodules," vol. iv., page 111. 



t "The word coprolite is taken from two Greek words, tcdnpos, dung, and 

 Kl6os, a stone (kopros-lithos), or fossilled dung or excrement. The microscope 

 oftentimes detects membranous matter in these fossils. The coprolite is com- 

 posed of phosphate of lime ; that is to say, it contains lime, together with a salt, 

 which neutralises its power. The admixture with sulphuric acid causes it to heat, 

 and the affinity of the acid to salt being stronger, it is carried away with the 

 fumes, the lime remaining, which being mixed with ammonia, becomes super- 

 phosphate of lime. This is the sole food of plants. The coprolite belongs to a 

 Silurian age, supposed to have been buried long before the creation of man." 



