And the “ Great Carolina Marl Bed.” 65 
our children; we have been familiar with it since 
1839, have a large collection of specimens at the Col- 
lege of Charleston, and would be glad to submit them 
to him for examination. To this the Doctor readily 
assented, and we repaired immediately to the Col- 
lege. 
On examination, (there were fifty or sixty speci- 
mens in the closet,) he said: “I think you are mis- 
taken, zzese are not the same kind of rock as that in 
in my hand.” We rejoined, there is no doubt on our 
mind about it, but feel confident they are the same, and 
suggested that a quantity should be ground up finely, 
so as to obtain a fair sample for analysis. Dr. Pratt 
took, accordingly, several pounds, enquiring at the 
same time as to its chemical composition; we replied: 
Professor Tuomey made a crude analysis of it some 
years ago, his notes of the result were burnt with 
our library ; but we well remember that the amount 
of Phosphate of Lime, 16 per cent., was considered 
too small, and the Carbonate of Lime, Iron and Sand, 
too great to admit of its being used advantageously 
for Agricultural purposes. 
At that time patent fertilizers and fashionable su- 
perphosphates were unknown; in fact, Guanos in this 
country had been used but a short time, hence the 
anxiety of scientific men to develop the great masses 
of Marls which were found on the banks of rivers in 
South Carolina. 
We well remember relating, too, an incident which 
occurred some years ago regarding these rocks. A 
5 
