he 
BULLETIN OF THE BUSSEY INSTITUTION. 349 
fibres ; the texture is coarser.” Good crops were obtained in my 
own field-experiments from heavy dressings of carbonate of potash 
(pearl-ash) used upon rutabagas, beans, and barley, and it has 
occasionally been used * in field-practice in this country — notably 
as an application for potatoes. The results were favorable when the 
dressing of potashes was not too heavy. Mayer tells of a number 
of good results that have been obtained abroad by the use of car- 
bonate of potash with beets, potatoes, and tobacco, though reports 
adverse to its use are not wanting; so that from a comparison of 
many European trials he concludes that it is a highly capricious 
manure. It will be noticed that this conclusion plainly supports 
the argument that carbonate of potash should not be regarded 
merely as a direct source of plant-food, and that care must be 
taken to apply it only to soils which are fit to profit by it. 
As regards the action on humus, it appears that carbonate of 
soda behaves very much like carbonate of potash; and it is of in- 
terest to recall the fact that nearly fifty years ago it was proposed 
here in Massachusetts to make composts of peat and soda-ash.f 
There is of course, however, always an important advantage to be 
credited to wood-ashes and potashes, as compared with any sodium 
compound, in that the potash of the ashes is a true food of plants 
while soda is not. Mayer has seen tobacco-plants grow with no- 
ticeable luxuriance when manured with carbonate of soda. He 
found also that carbonate of soda and chloride of potassium used 
together were favorable for the growth of tobacco, and that millet 
grew decidedly better when the sodium carbonate was used than 
when it was not. Professor Johnson’s experiments on the improve- 
ment of soil-nitrogen by alkalies have been cited in vol. I. of this 
Bulletin, p. 265. Compare also Bobierre’s statement -on p. 271. 
It is worthy of remark that the observation of Angus Smith,{ to 
the effect that putrefaction is apt to set in when a soil rich in or- 
ganic matter is wet with an alkaline solution and kept warm, is 
plainly in full accord with the more recent observations of mycolo- 
gists who find that while the development of the bacteria which 
are concerned in putrefactive processes is hindered by acids, their 
growth is rapid in liquids that are slightly alkaline. 
The significance of this first decay of organic matter, such as 
* See ‘*Nineteenth Report of the Secretary of Massachusetts Board of 
Agriculture,” 1871, pp. 101, 103. 
+ S. L. Dana, ‘‘ A Muck-Manual for Farmers,” pp. 184-189. 
t Cited in vol. I. p. 387, of this Bulletin. 
