PRELIMINARY REPORT ON PEAT.

izontal intergradation is found wherever a swamp or marsh is bordered by a hammock or a wooded slope. Peat can also be more or less completely transformed into humus by taking it out of the water (or draining the water away from it) and stirring, pulverizing, composting or cultivating it so as to aerate it thoroughly, until finally-after a few years perhaps enough of the carbon oxidizes away, and the acids disappear, for it to be called humus.
CONDITIONS NECESSARY FOR PEAT FORMATION.
True peat requires for its formation either a permanent body of water or a soil which is saturated with water most of the time, especially in warm weather. The water must not be too deepfor very few plants are able to grow in deep water-or too much agitated by currents, waves or tides, it must not fluctuate in level much, and it must not contain too much salt, mud, or other mineral substances.
The most familiar example of permanent water is the ocean; but in its deeper parts there is no vegetation except a few microscopic forms, and on all unprotected shores the waves effectually prevent the accumulation of peat. Extensive marshes form in sheltered bays, lagoons, etc., connected with the ocean, but salt marsh peat, for various reasons, one of which is the large amount of sediment-constantly brought down by rivers, generally contains too much mineral matter to be of much value.
Permanent water is also furnished by most rivers, but many of these are too swift or too muddy, or vary too much in level, for the formation of good peat. Conditions are somewhat better in the estuaries at the mouths of rivers-especially those rivers which are not muddy near enough to the sea to have little current and to be little affected by floods and droughts, and far enough from it to have hardly any tide or salt water.
Large lakes are often too deep in the middle, and their margins too much disturbed by waves, like the ocean; and shallow ponds usually dry tip at some season of the year and allow the yegetable debris which may accumulate in them in the wet season to oxidize; but between these extremes is the happy mean. Small lakes, or shallow bays or coves of larger ones; permanent ponds, and shaded springy places, such as the swamps at the heads of streams, offer some of the best conditions for peat.
It goes without saying that peat formation also demands certain climatic conditions. The climate must of course not be so cold that no vegetation will grow, or so dry that there are no per-

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