ies in ee ea ae | 
- & ete a 
On Fossil Plants from Washington Territory. 85 
muck) from the neighborhood of New Haven, (containing when 
fully dry 68 per cent of organic matter) which is. highly pri 
as a means of improving the porous hungry soils in this vicinity, 
and which when drained grows excellent crops, is capable o 
_ absorbing 1°3 per cent of ammonia, while ordinary soil absorbs 
but 05 to ‘1 per cent. 
The great beneficent law regulating these absorptions appears 
to admit of the following expression: those bodies which are most. 
rare and precious to the growing plant are by the soil converted into, 
and retained in, a condition not of absolute, but of relative insolu- 
bility, and are kept available to the plant by the continual circulation 
tn the soil of the more abundant saline matters. 
he soil (speaking in the widest sense) is then not only the 
ultimate exhaustless source of mineral (fixed) food, to vegeta- 
tion, but it is the storehouse and conservatory of this food, pro- 
tecting its own resources from waste and from too rapid use, and 
converting the highly soluble matters of animal exuvie as well 
as of artificial refuse (manures) into permanent supplies. 
Yale Analytical Laboratory, May 15th, 1859. 
Art. X.—On Fossil Plants collected by Dr. John Evans at Van- 
couver Island and at Bellingham Bay, Washington Territory.—In 
from L. LesquerEvx to J. D. Dana, dated Columbus, 
a letter 
Ohio, May 12, 1859. 
_ Dear Sir,—Supposing that Prof. Heer who is now engaged in 
publishing a magnificent Fossil Flora of the Tertiary of rin 
would be much interested in the examination of the plants of 
Dr. John Evans’ survey, of which a short description is pub- 
lished in the last number of your Journal, I sent him a sketch 
of the drawings prepared for Dr. Evans’ report. I have just 
received an answer to the communication, and as it fixes the 
value of my species and gives some opinions which are of great 
interest to American geology, I take the ery of translating 
ication. 
_ apart of his letter and sending it to you for pu 
Prof. Heer says: “I have hailed with the greatest delight the 
_ news which you give me in your letter of 2lst March. They are 
_ the first rays of light penetrating the dark night which until now 
__ has covered the tertiary flora of America, and the day is close at 
_ hand, when the fog which still darkens the wonderful flora of 
_ those times will be uplifted, and the New World open to us its 
_ treasures. They will prove of the greatest interest for the natu- 
_ ral philosophy of the earth, and give us most important infor- 
_ mation as to the relation of climate at the tertiary epoch, and to 
_ the secular progression or distribution of temperature over the 
whole earth. But it is also of the greatest importance for the 
