DISCOVERY OF AN IMMENSE VEIN OF PHOSPHATE OF LIME. 
81 
And again, if wheat is too thick and luxuriant 
in spring time, so as to hinder the light from 
getting in upon its stems, those stems will be 
unable to decompose the carbonic acid of the 
air; they will be unable to procure charcoal to 
make them hard and woody; they will be 
white and succulent, without strength, and lia¬ 
ble to be laid by the rain; but mow those top 
leaves off, or let a lot of sheep bite them off, and 
you let the light in upon those stems, and they 
will regain the power they have lost, and they 
will strengthen and harden in consequence of 
able to procure their woody sub¬ 
stance from the air. D U L lliu. fc—tWj Jooojm, 
pose the carbonic acid of the air, and, retaining 
its charcoal, give off the pure healthy oxy¬ 
gen, can be proved. I have taken a number 
of cabbages, one after another, on successive 
days, cutting them about mid day, when they 
might be supposed to be full of the gas, if 
ever they took any at all, and exposed them 
under water to the sun. Very soon, bubbles of 
gas collected in the top of the glass, and on 
examination it was proved, by their ability 
to burn things brilliantly, that they were pure 
oxygen. Those cabbages had been collecting 
the deadly gas as I and you were breathing it 
out, and as every chimney over a fire was send¬ 
ing it into the air, and they were decomposing 
it and sending the healthful part of it back to 
the air and keeping the charcoal to themselves. 
See, then, how important the air is to plants, as 
well as to us; it provides them with all the woody 
part of their substance ; it provides us with the 
breath we live upon, and the fires that warm 
us. See how important the process of combus¬ 
tion, whether slow as in the case of ordinary 
decomposition, or more rapid as in the case of 
respiration and ordinary burning, is to plants. 
Unless, in this manner, the air was continually 
supplied with this poisonous gas, plants might 
exhaust it of all the materials on which they 
feed and live. See how important plants are 
to us; they keep the air healthy for us, deprive 
it of those noxious gases which would other¬ 
wise soon collect and destroy us, forming their 
own substance at the expense of our enemy; 
so that the very thing which would destroy us 
is made to provide us with food and with fuel 
through their means. See, too, how admirably 
the growth of evil, in the natural as v/ell as in 
the moral world, is checked and made produc¬ 
tive of good in the end, by the overruling hand 
of God’s Providence. 
Thus much, then, we have learned regarding 
the air in connection with agriculture; it pro¬ 
vides the plant with its woody substance; it 
keeps up the warmth of the living animal by 
burning a portion of its food in its lungs.-^. o a z 
LARG-E WHEELS ON ROUGH ROADS. 
The advantages of large wheels on rough 
roads are strikingly exemplified in the quitrin 
and volante , vehicles in common use in Havana 
and other parts of the island of Cuba. 
Quitrin.— Fig. 14. 
The wheels are some ten feet in diameter, 
and to the axletrees, elastic tongues, or shafts, 
some 15 or 20 feet in length, are attatched, and 
over the axles, a top or covered body, is mount¬ 
ed, resembling the top of our New-England 
chaise. From the rough state of the roads on 
the island, these vehicles have been used for a 
great number of years, for which they serve an 
admirable purpose. By the large size of the 
wheels, an increased leverage is obtained, and 
they more readily overcome the obstructions 
they meet with in the form of gulleys, stumps, 
and stones. From the great length, also, of the 
shafts, they are quite elastic, and impart an 
easy motion to the carriage on level roads as 
well as those that are rough. 
~ — - — -©♦-- 
DISCOVERY OF AN IMMENSE VEIN OF PHOS¬ 
PHATE OF LIME. 
This locality of phosphate of lime, I discov¬ 
ered, at Crown Point, in 1847, and published an , 
account of it in my report, under the name of 
eupyrchroite, regarding it as a new kind of 
mineral. Since that time, I have also made 
reference to this mineral, and particularly in the 
agricultural journal which I conducted at one 
time; and I often expressed the wish that some 
one would open the vein and determine its value 
and extent. But no one seemed to regard it in 
a favorable light. I was instrumental, last fall, 
in opening this mine. It turns out to be a solid 
vein of phosphate of lime, eight feet thick, at 
least, and has been traced a long distance from 
northwest to southeast. It is known to con¬ 
tain 92 per cent, of phosphate of lime, with 
fluorine and chlorine, iron, or a sulphuret of iron 
and copper, in small proportions, furnishing 
