THE FARMER'S MAGAZINE. 



475 



OBSERVATIONS 



ON THE PLANTS WHICH FORM THE BOGS 

 IN IRELAND. 



BY D. MOORE. 



[Read before the British Association at Dublin, August, 1857.] 



On reading the different reports of the Commis- 

 sioners who were appointed to examine into and 

 report on the nature and capabilities of the bogs 

 of Ireland, the idea will occur to those acquainted 

 with the matter, that ampler details of the plants 

 whose growth and decomposition constitute the 

 various kinds of bog therein mentioned would have 

 rendered those able reports more interesting, par- 

 ticularly in a natural-history point of view. But 

 surveyors are not often botanists, and probably do 

 not consider it any part of their duty to enter into 

 such minutiae. Besides, a good deal has since been 

 written at various times on the subject of Irish peat 

 bogs, without anyone having filled up the hiatus I 

 have alluded to, so far as I am aware. The case is 

 different in Dr. MacCulloch's report on the peat 

 bogs of Scotland, who has paid particular attention 

 to the plants which form the different kinds of turf 

 enumerated by him, and has based some of his 

 principal reasonings on the formation of peat from 

 his knowledge of the slow or quick growth of these 

 plants. It therefore occurred to me, that in a 

 country like this, which has so large a portion of 

 its surface covered with bogs, and where bog 

 labour is a very considerable source of productive 

 economy, a short paper on the plants which enter 

 principally into the formation of our peat bogs 

 might prove an appropriate subject for being dis- 

 cussed at this meeting of the British Association. 

 The different varieties of bog which have been 

 chiefly distinguished by writers on the subject in 

 this country are red bog, brown bog, and black 

 bog, which, although not very scientific, yet being 

 the names by which they are best known, I shall 

 adhere to, in the following details ; and first as to 



Red Bog. — The differences of colour and con- 

 sistencies of matter, of which the substances are 

 composed, depend chiefly on the localities where 

 they are produced, according as they vary in differ- 

 ent degrees of moisture, temperature, and altitude, 

 whereby the growth and decomposing of vegetables 

 are affected. No doubt that iron and some other 

 mineral substances which are generally found in 

 peat bogs affect the colouring to a small extent, 

 but the former combination of causes produces the 

 effect principally. 



By far the greater portion of our extensive bogs 



belong to this variety, which is the least valuable 

 for fuel, and generally varies in depth from 10 to 

 35 or even 40 feet. Those immense deposits of 

 vegetable matter appear to have been accumulating 

 during many ages in the same positions and under 

 nearly similar circumstances as we find them at the 

 present time. It may very fairly be inferred that 

 the processes of growth and decomposition of 

 plants are now much slower than they formerly 

 were, owing to the greater elevations the surfaces 

 of the bogs have attained above the levels of the 

 drainage rivers, and the more general drainage of 

 the surrounding districts ; but in the absence of all 

 trustworthy experiments on the growth of bog in 

 Ireland this only amounts to conjecture. When 

 passing over bogs I have frequently inquired of 

 turf cutters when the turf was cut out of holes I 

 saw partially filled with soft vegetable substance ; 

 and if some of their statements can be depended 

 on, that soft half- decomposed matter will accumu- 

 late to the depth of one foot in five years, which we 

 may suppose will ultimately be compressed to at 

 least one-fourth part of that bulk. 



Wherever those bogs are of any considerable 

 extent, and remain in nearly their natural state, 

 without deep cuttings having been made through 

 them to drain off thg surface water, a series of 

 depressions will invariably be found on their sur- 

 face, though not perceptible to the eye when look- 

 ing over the apparent level expanse of wild waste 

 they form. It is only when one enters on them 

 this is found out, by sinking deeper, and perceiving 

 the whole surface shake for many yards around. 

 When covered over with vegetation the soft parts 

 are called flows or quagmires; but those depressions 

 frequently consist of a series of deep water holes, 

 which are probably for the most part remaining 

 portions of large lakes yet in process of being filled 

 in with vegetable debris. These quagmires may, 

 and no doubt often do, result from springs, as they . 

 frequently occur at nearly the culminating points of 

 the bog. 



Taking those flows and partially-fiUed-up water- 

 holes into consideration, with the elevated surround- 

 ing districts which generally prevail in the neigh- 

 bourhood of large bogs, the conclusion that has 

 been mostly come to is, that those great natural 



