304 FLORIDA GEOLOGICAL SURVEY-THIRD ANNUAL REPORT.
7. Mangrove peat from along east side of Snake Creek, which is the channel between Windly's Island and Plantation Key (or Long Island), Monroe County, near 437 mile-post on Florida East Coast Ry. Taken from about 3 feet below the surface, in mangrove swamp, whose vegetation is mostly Rhizophora Mangle (red mangrove). Peat reddish brown, very coarse and fibrous. Collected in September, 19io, under direction of W. J. Krome, Constructing Engineer of the F. E. C. Ry. Extension, at our request. Analysis by E. Peck Greene, assistant state chemist.
Moisture ABSOLUTELY DRY PEAT,
No. in airdry peat Ash Fixed VolatileS Fuel vale
carbon matter Sulphur Nitrogen (B. T. U.)
1 17.2 8.3 30.1 61.6 .59 2.89 10082 2 ........... 14.7 30.7 54.6 4.08 1.93 8816
3 ..........18.0 29.9 52.0 3.94 1.97 8586
4 ........ 25.7 25.9 48.4 3.64 1.66 7783
5 ......... 16.6 30.8 52.6 4.13 1.94 8705
6 10.0 11.0 26.1 62.8 .39 2.74 (9877)
7 16.0 15.2. ........................... 2.36
NOTES ON THE SIGNIFICANCE OF SOME OF THE ANALYSES.
It would seem from the figures given that most of our peat contains only about half as much water when air-dry as does the better known material from the glaciated region of Europe and the northern parts of this continent. Too much stress should not be laid on this, however, for the water-content shown probably depends nearly as much on the condition of the air at Pittsburgh at the time the analyses were being made as it does on the nature of the peat itself. (All the samples which show more than io% of water were collected in April, May or June, and analyzed a month or two later, when the air of the room in which the tests were made was presumably more humid than in winter, on account of artificial heat not being used.) Nevertheless, it is probably safe to say that the Florida peat dries out as well as that from any other part of the world, if not better.
The purest peat is No. 29.11, which has only I.5% of ash. Other samples with less than 5% are Nos. 13.11, 15.11, 29.12, 37.11, 41.11 and 42.11, all of which are from peat prairies or similar situations. (Locality No. 37 I have called a tyty bay, but it is treeless in the middle, and therefore has the characters of a peat prairie).
The proportion of volatile matter to fixed carbon, is nearly 3 to t in No. 19.11, a coarse saw-grass peat. In nearly every case