Jan. 6, 1871.] 3 [ Wood. 
The Publication Committee reported upon the subject of 
the publication of Dr. H. C. Wood's Memoir of the Fresh 
Water Aleve of the United States. 
The Report of the Finance Committee, postponed from the 
last meeting, was read by its Chairman, Mr. Fraley; and the 
sums recommended by the Committee were, on motion, ap- 
propriated for the expenses of the ensuing year. A. further 
recommendation to increase the insurance on the Hall, was 
on motion adopted; and the meeting was adjourned. 
RevIVAL oF Fruit TREES prematurely ceasing to bear fruit, or prema- 
turely decaying, by Guo. B. Woop, M. D. 
Communicated to the American Philosophical Society, January 6, 1871. 
Ys y > 
It is well known that most fruit trees, especially the peach and apple 
trees, in sites where they have been long cultivated, often cease to bear 
fruit, and even perish, long before their natural period. Thus the peach, 
which has a normal life of 50 or 60 years, or longer, and grows under fa- 
vourable circumstances to the size of a considerable tree, generally, in this 
part of the United States, ceases to bear fruit after two or three years of 
productiveness, and soon after begins to decay, seldom living beyond 15 
or 20 years. The apple tree also, long before it has attained its normal 
length of life, often ceases to yield fruit, cither for a time or permanently, 
without apparent cause; and trees, planted on the site of an old orchard 
which has been removed, not unfrequently refuse to bear at all, or at least 
to a profitable extent. 
Tt is obviously of great importance to discover the cause or causes of 
such failures, and, if possible, to apply a remedy or preventive. Unless 
I greatly deceive myself, I have succeeded in showing that the evil gen- 
erally has its source in a deficiency of the salts of potassa in the soil, and 
may be corrected by supplying that deficiency. 
The alkali potassa, in combination generally with one or another of 
the vegetable acids, is an essential ingredient in all plants, excepting 
the sea plants, in which its place is supplied by soda. In living vegeta- 
bles it is contained dissolved in the juice, and is consequently most abun- 
dant in the most succulent parts; and, when the plants are burned, the al- 
kaliis left behind in the ashes, of which it constitutes an exceedingly vari- 
able proportion, according to the peculiar plant or part of the plant burned. 
Thus, while the ashes of oak wood contain only about 3 parts in 1000, 
those of the common poke, the growing wheat stalk, and the potato 
stems, contain 48 or 50 parts or more. The greater portion by far of the 
alkali is in the state of carbonate, with a little in the caustic state, and 
being, inthese conditions, very soluble in water, is extracted by lixiviation 
