BULLETIN OF THE BUSSEY INSTITUTION. 353 
sea-water on soils, says: ‘‘ When earth that has been soaked with 
sea-water dries out thoroughly it effloresces, and the same appear- 
ances may be seen on walls which have been built or plastered 
with lime that contained common salt. This white ‘‘ growth” may 
often be seen on the sea-strand in dry summer weather, and it is 
apt to be at its best several days after an exceptionally high tide. 
I collected a quantity of this white substance from several spots on 
the strand, taking care to get it as pure as possible, and found that 
it consisted in part of carbonate of soda. Consequently carbonate 
of soda and chloride of calcium must have been formed from chlo- 
ride of sodium and carbonate of lime under these conditions.” 
Here in Massachusetts, as long ago as 1839, Dr. S. L. Dana,* 
of Lowell, labored assiduously to diffuse a knowledge of the fact 
that useful manure may be made by treating peat with alkalies. 
He insisted in particular on the advantages that may be obtained 
by making compost with a mixture of lime and salt, whereby peat 
may be ‘‘ cured” so that it can in some part replace dung; or as 
we now know, so that some of its nitrogenous constituents may be- 
come available food for plants. The efficacy of the methods pre- 
scribed by Dana manifestly depends on the presence of alkalies ; 
that is to say, in the case of the lime and salt, on the formation of 
small quantities of carbonate of soda, as has been explained al- 
ready. It should be said that the teachings of Dr. Dana have had 
no little influence in this country. The lime and salt mixture has 
been, at one time and another, freely used by American farmers in 
compost-making. <A good illustration of the estimation in which 
the mixture was held is afforded by the following citation from the 
‘¢ Sixteenth Report of the Secretary of the Massachusetts Board of 
Agriculture,” 1868, p. 286. The statement is there credited to 
Mr. E. L. Metcalf. ‘‘ We have used large quantities of wood- 
ashes —in fact all we can get — every year; we also use lime and 
salt, which we consider invaluable on certain soils. Properly pre- 
pared it is a powerful fertilizer and good for any crop. In gar- 
dens and fields too rich in humus . . . it appears to change the 
chemical condition of the soil and give new life to the inert ele- 
ments of fertility that are in the land.” The same writer speaks 
of using with advantage a mixture of leached ashes, salt, and plas- 
ter of Paris. 
Mayer himself speaks of the weak alkaline reaction which is ob- 
* See his ‘- Muck-Manual for Farmers,” Lowell, 1842, ch. VII. 
+ Compare this Bulletin, p. 392 of vol. I. 
