boys’ department. 
131 
Bop’ department. 
AGRICULTURAL CHEMISTRY.—No. 12. 
In my last letter, I gave you a description of the 
most important^ organs belonging to plants, ex¬ 
plained their texture and functions, described the 
flow of the sap, and told you that, in its descent, 
(after being submitted in the leaves to the action 
of the air,) it was fitted for the production of the 
various portions belonging to the vegetable growth. 
Let us now examine the vegetable fabric more 
closely, and take a view of those compounds called 
proximate principles. In speaking of the con¬ 
stituents of plants, the terms proximate and ulti¬ 
mate, are frequently used by writers on this sub¬ 
ject— tho former denoting their compound, the 
latter their elementary constituents. Every prox¬ 
imate principle must, therefore, be composed of 
two or more ultimate principles. There are a 
reat number of compound substances found in 
ifferent plants, and almost every species contain¬ 
ing one or more, which is not found in any other, 
though but a few of these are of much con¬ 
sequence to the agriculturist. The following 
group of twelve, which I will describe separately, 
comprises the most common and interesting among 
them :—Sugar, starch, gum, woody fibre, gluten, 
vegetable albumen, diastase, and acetic, tartaric, 
oxalic, citric, and malic acids. 
Now, if a person should tell you that he could 
take three ingredients, and from them form a num¬ 
ber of compounds, differing as widely from one 
another as sugar, starch, and woody fibre, you 
would be likely to doubt the possibility of such a 
fact; and, if he should say he would not only use 
the same three ingredients in each of his com¬ 
pounds, but, in each case, would mix them in 
precisely the same proportions, you would either 
pronounce it an impossibility, or you would sup¬ 
pose he was going to deceive your senses by jug¬ 
glery. But Nature is no juggler—neither does 
she perform impossibilities; yet she does accom¬ 
plish, in the composition of almost every vege¬ 
table that grows, precisely the operation above- 
mentioned. Out of carbon, hydrogen, and oxygen, 
she forms sugar, starch, and woody fibre ; and in 
each of these substances, the three ingredients of 
which they are formed , exist in exactly the same 
'proportions. 
This is truly a wonderful operation, and beauti¬ 
fully illustrates the economy, so to speak, which 
seems a governing principle in all of Nature’s do¬ 
ings. Instead of multiplying elements to an inde¬ 
finite extent, she contrives to economize a few, in 
such a way, as to make them answer the desired 
end. How strange, that any person, who has ever 
contemplated the wonders of creation, as displayed 
in animal or vegetable life, can doubt, for a mo¬ 
ment, the existence of a Supreme and All-Control- 
ing Power ! Although we can analyze vegetable 
compounds, and separate, examine, and weigh their 
elementary ingredients, yet we cannot reunite 
them so as to produce the same substance which 
Nature formed from them in the living plant; 
neither can we say, with any certainty, how 
nature forms such different substances, by combin¬ 
ing the same elements in the same proportions. 
In reading the works of Johnston, Leibig, and 
other authors, who treat extensively on these sub¬ 
jects, you will find plausible theories and conjec¬ 
tures to explain the process by which one com¬ 
pound is converted into another in the living 
plant. Although such speculations and investi¬ 
gations are interesting and useful, they would 
occupy too much space, were I to attempt to place 
them before you. My highest aim in writing these 
letters, will be accomplished, if I can awaken in 
you a spirit of inquiry, and prepare your minds for 
the comprehension and reception of truths more 
wonderful and grand, than any I shall attempt to 
unfold. In my next letter, I propose to treat of the 
twelve substances named above, under separate 
heads. J. McKinstry. 
Greenport, N. Y., March 1st, 1849. 
UTILITY OF FROGS. 
I remember somewhere of reading that, many 
and many years ago, a number of frolicsome boys 
were one day watching frogs, at the side of a pond, 
and that, as any of them put their heads above the 
water, they pelted them down again with stones. 
One of the frogs appealing to the humanity of the 
boys, made this striking observation: “ Children 
you do not consider, that though this may be sport 
to you, it is death to us.” It is to be feared that 
the same propensity to maim and torture these poor, 
innocent reptiles prevails to some extent with the 
youth at the present day. But this is cruel— 
wicked—wrong; for the usefulness of frogs about 
our gardens and fields can scarcely be too highly 
estimated, as their food consists almost exclusively 
of worms, slugs, insects, and other small living 
things, which they seek among the plants and 
grass on the land. 
Frogs, like the toad, it is well known, are hatched 
from eggs, laid early in the spring in shallow pools 
or near the edges of sluggish streams, which, when 
taken together, are called u spawn,” and often re¬ 
semble a mass of boiled sago, sprinkled with a large 
number of small black dots. The young tadpole, 
which is hatched from them, passes through several 
metamorphoses, and at the end of some weeks, be¬ 
comes a “ gaping, wide-mouthed, waddling frog.” 
If you examine his tongue, you will observe that, 
instead of being rooted at the throat, as in other 
animals, it is fastened to his under lip, with its 
point directed towards the stomach. Nevertheless, 
this singular arrangement is well suited to his pur¬ 
poses, for his tongue, as an organ of prehension, is 
very effective, being flat, soft, and long, and cov¬ 
ered with a viscous fluid, which enables him more 
readily to catch and secure his prey. When he 
wishes to use it, he lowers his under jaw, ejects 
and retracts it with the rapidity of light. 
Instead of torturing these poor reptiles, it is re¬ 
commended that every lad in the country, give 
place in some snug corner in the garden for a ves¬ 
sel holding a few gallons of water, buried nearly 
level with the surface of the ground, in which may 
be put one or more frogs, to be petted and cherished 
like any other domestic animal, and where its cu¬ 
rious and interesting habits may be studied at 
leisure. Rana. 
