348 BULLETIN OF THE BUSSEY INSTITUTION. 
so fully in an earlier number of the Bussey Bulletin * that it would 
be mere repetition to dwell upon the subject here. It will be suffi- 
cient for my present purpose to say that wood-ashes have long been 
used in this country for composting peat, and that it is reasonable 
to suppose that if the potash carbonate can act so powerfully in the 
compost-heap to change the nitrogen of humus, it will have a some- 
what similar action upon the humus in a soil when it is merely 
spread upon the land. This. effect was noticed by Lorain in con- 
nection with his observations on the cementing action of wood- 
ashes mentioned above on p. 346. He says: ‘*I was not a little 
surprised when I first removed to the backwoods to find that veg- 
etation, in place of being destroyed by the very large quantity of 
ashes lying within the compass of the spot where a log-heap had 
been burned, was commonly much more luxuriant than on any 
other part of the ground, unless the soil was in general rich enough 
to produce luxuriantly.” And again he says: ‘‘If the crop hap- 
pens to be wheat or other small grain it often falls or lodges where 
the heaps of logs were burned, but is less likely to be injured by 
superabundant luxuriance where brush or brambles were con- 
sumed.” 
In some of my own field-experiments this property of carbonate 
of potash was particularly noticeable. Thus on the plot that was 
heavily dressed with wood-ashes — mentioned on the previous page 
as an instance where a soil was firmly compacted by the alkali — 
the plants grew almost as rank and succulent as if they had been 
manured with dung.t So too when ashes are spread as a top- 
dressing on grass-land, the improved color of the grass shows 
clearly that it has access to nitrogenous food. Ihave been as- 
sured by Mr. J. H. Adams, a gentleman familiar with the cultiva- 
tion of tobacco, that there is a practical objection to the use of 
wood-ashes as a manure for this crop, at least as regards the bet- 
ter kinds of tobacco, in that it makes the plants grow coarse — 
doubtless because of nitrogen from humus which the alkali brings 
out. It is interesting to note that the same word is used by other 
tobacco-growers in cases where the influences which promote the 
rank growth are unmistakably nitrogenous. Thus it has been 
written: ‘* Blood-fertilizers and cotton-seed meal tend to make 
tobacco coarser. . . . On new land tobacco has larger stems and 
* Vol. I. pp. 270, 387 et seq. 
+ Compare Bussey Bulletin, I. pp. 127, 270, 314, and the tables which in- 
clude plot ‘‘ BB. 4.” 
