1878 .] 
AMERICAN AGRICULTURIST. 
475 
of sugar and change it into 8 lbs. of charcoal and 11 lbs. 
of pure water, though he has not yet learned how to put 
the coal and the elements of the water together to pro¬ 
duce the sugar. That requires the action of the living 
plant....Our sugar comes mainly from the sugar cane 
grown in the Southern States (most from Louisiana), and 
from the West India Islands. The canes are somewhat 
like corn-stalks, but larger, taller, with narrower leaves. 
The sap or juice of the cane is pressed out between iron 
rollers, then boiled down to syrup, which crystallizes 
into sugar grains in large vats... .Most of the sugar used 
in Europe is from the juice of the sugar-beet. It is similar 
to our cane sugar ... The raw sugar is refined chiefly in 
Fig. 1. —HUNTERS* CAMP.—A NOVICE TRYING SNOW-SHOES. 
Northern cities, by dissolving it, straining it through 
cloth, and through burned bones, after which it is 
boiled down until thick enough to crystallize in grains. 
Tlie I>octoi*’s Correspondence. 
The letters accumulate, and I am surprised as 1 look 
back, to find how long it is since I answered any of them. 
Here is one from “ R. J. P.,” Mankato, Minn., enclosing a 
LEAP WITH BLACK SPOTS, 
and he wishes to know about them. I should have men¬ 
tioned this when speaking about the “ Cluster Cups ” last 
month. Those, you recollect, are Fungi , small plants liv¬ 
ing on the substance of the leaf; this which our Minne¬ 
sota friend sends is a fungus, but of another kind, and 
this is about all he can learn about itat present Some¬ 
times youngsters ask questions that are regular puzzles. 
To answer them one must go a long way back into first 
principles, and write a treatise on matters in general. 
One “ G.,” at Eureka, Mo., has given me several questions 
of this kind; of these I can try only one now. He asks: 
“what is air composed op? 
I think Oxygen, Hydrogen, and Nitrogen, but how much 
of each ? Is it not the Oxygen in the air which we breathe 
that keeps up the heat of our bodies ? Then if Oxygen is 
so hot, why is it that a fish which lives in among so mnch 
Oxygen, is so cold?”—This question, or rather series of 
questions, shows a desire to know about things, and 
that “ G.” thinks and reasons, but it also shows that he 
has either not had an opportunity of learning about 
the air, or that he has been imperfectly tanght. Let 
us see if we can help him in this case. Firstly, as to 
the composition op air. 
Air is essentially a mixture of Oxygen and Nitrogen, in 
the proportion of one measure of the first to four measures 
of the other. You will notice that I make two words 
prominent by putting them in Italics. Essentially , for there 
are other things found in the air: watery vapor or mois¬ 
ture, the amount varying with the temperature, and Car¬ 
bonic Acid, about one measure in every 2,500 measures 
of air. A very small proportion you will think, but small 
as it is, it is very important; I can not tell you more 
about this now, except to say that, it is very necessary to 
the growth of plants. Still smaller quantities—mere 
traces of other substances—are also found in the air, but 
we will not notice them. The other word that I marked 
is mixture. For I wish you to understand that air is 
a mixture and not a compound. 
Now how can I make “ G.” and the rest of you under¬ 
stand this ? Let us see. Certain substances are called 
simple bodies or elements. Oxygen is an element, so is 
Nitrogen—but you can not see these. Sulphur (or Brim¬ 
stone) is an clement, so is Quicksilver (or Mercury), so 
are Iron and Gold when pure. You all know how Sul¬ 
phur looks. Well, chemists, let them try their best can 
not separate it into any other substances—it is sulphur 
and nothing else. When a substance is found that con¬ 
tains only one kind of matter, and that no skill of the 
chemist will separate into two kinds, that is called an 
dement. Thus far there are about (13 elements. In the 
air Oxygen and Nitrogen are merely mixed , the Oxygen 
is just as much Oxygen, and the Nitrogen just as 
much Nitrogen as before.. But these elements unite 
to form compounds, and 
when they do this the 
compound is quite unlike 
either element in every 
respect. Sulphur and 
Quicksilver unite to form 
the beautiful red Vermil¬ 
lion, quite unlike either. 
Iron unites with Oxygen, 
and we have Iron Rust— 
quite different, from Iron— 
and finally Oxygen and Ni¬ 
trogen,which, when mixed 
in the air, are breathed, 
can be made to unite 
and form a most powerful 
acid—Nitric Acid (Aqua¬ 
fortis) — and so changed 
are they, so different 
the compound from the 
elements of which it is 
made, that the vapor suffo¬ 
cates at once, and the acid 
dropped on the flesh at 
once kills and destroys it. 
THIS BRIEF LESSON IN 
CHEMISTRY 
will give Master “ G.” 
and the rest of yon some¬ 
thing to think of. Now for 
the rest of the question. 
We may say that the Oxy¬ 
gen in the air we breathe 
does cause the heat of 
the body. He the* says “ if Oxygen is so hot, why is 
it that a-fish which lives in among so much Oxygen, is so 
cold ? He does not say so, but having heard that water 
is a large part Oxygen, he wonders why it is so cold. He 
starts with a wrong idea.—“ If Oxygen is so hot”—but it 
isn't hot, and the rest of his question goes for nothing. 
Still it allows me to say one more important thing. When 
these elements unite to form compounds, heat is usually 
given out, especially when one element is a gas, like 
Oxygen. Oxygen by itself is neither hot nor cold, 
BUT IT PRODUCES HEAT 
when it unites with other elements; when it unites 
with sulphur, heat ia 
given off, when it unites 
with coal (carbon) we 
have heat accompany¬ 
ing the change, when 
it unites with wood, (car¬ 
bon and hydrogen) there 
is heat. All our artificial 
heat comes from the 
union of oxygen with the 
fuel.But to go from 
heat to cold. Here is “S. 
C.,” of New Jersey, who 
has been reading about 
glaciers—those great fields 
of ice found in the Alps 
and other high mountain 
ranges, where there is per¬ 
petual snow. They are 
often several miles long, a 
half a mile and more wide, 
and occupying a valley, 
appear like a river of ico 
and—what is very wonder¬ 
ful—like a river, glaciers 
FLOW DOWNWARD. 
What troubles young S. 
C., is this, if glaciers are 
solid ice , how can they 
move or flow like a 
stream, for a book he has 
read, states that “a hut 
which Agassiz built on a Fig. 2.—winter 
glacier, moved 486 feet in two years.” The flow of the 
ice of glaciers has been carefully studied by several phi¬ 
losophers, and they differ as to the matter. The cause 
of the movement is pressure from above, but how solid 
ice can flow, and go down as it must, over steep places, 
and still remain solid has long been a puzzle. Discov¬ 
eries about ice made not many years ago, help explain 
the glacier movement. It has been found that when ice 
is under great pressure, it melts, and when this pressure 
is removed it becomes solid again: also that when two 
Experiment with ice. 
smooth surfaces of ice are brought together, they atone© 
freeze together and become solid. This property of ice 
IS CALLED REGELATION. 
The explanation given of this is hardly suited to 
youngsters, who must for the present accept the fact that 
it is so, and that it is so they can prove by a very pretty 
experiment. Support a block of ice by the ends, two 
chairs will do, as shown in the engraving; I had occa¬ 
sion to show it some time ago, and set the block upon 
the bars of a partly open clothes-horse. Pass a copper 
wire, the size of a knitting needle or finer, over the 
block, and suspend a weight to it; I used two big stone 
hammers as they were at hand, but a basket of stones or 
other weight will answer. The ice under the wire will 
melt, the wire sinks in, and as it does so, regelation takes 
place, the water above the wire will at once freeze, and 
in a few hours the wire will be half way through the ice, 
with the block just as solid as ever. I tried it on a warm 
Autumn day, with the thermometer about 70°—for no 
matter how familiar I may be with an experiment, when 
I tell yon about it, I always try it to see what difficulties 
you are likely to meet with when you undertake it. Now 
to apply this to the glacier; it is supposed that where 
the pressure is greatest, the ice melts, and parts of the 
mass can thus move and adjust themselves, and as soon 
as the pressure is relieved the ice becomes solid again— 
that the flow is a succession of meltings and freezings. 
Winter Ways and Sports. 
If one would see how the people of the far north live, 
and how they amuse themselves, they should visit them 
in winter. Those who travel for amusement go north in 
SPORTS—THE HUNTER ON SNOW-SHOES, 
summer, and to the far south in winter; this isa mistake, 
for they see neither part of the country at its best. In 
the far north, where winter is long and cold, the short 
summers are very hot. and those who go there in sum¬ 
mer, find the people engaged in trying to keep cool, and 
fail to see their proper home-life and amusements. As 
