Scientific American Supplement, No. 385, May 19, 1883

V >> Various >> Scientific American Supplement, No. 385, May 19, 1883

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DETECTION OF MAGENTA, ARCHIL, AND CUDBEAR IN WINE.

These colors are not suitable for converting white wine into red, but
they can be used for giving wines a faint red tint, for darkening pale
red wines, and in making up a factitious bouquet essence, which is added
to red wines. The most suitable methods for the detection of magenta are
those given by Romei and Falieres-Ritter. If a wine colored with archil
and one colored with cudbear are treated treated according to Romei's
method, the former gives, with basic lead acetate, a blue, and the
latter a fine violet precipitate. The filtrate, if shaken up with amylic
alcohol, gives it in either case a red color. A knowledge of this fact
is important, or it may be mistaken for magenta. The behavior of the
amylic alcohol, thus colored red, with hydrochloric acid and ammonia is
characteristic. If the red color is due to magenta, it is destroyed by
both these reagents, while hydrocholoric acid does not decolorize the
solutions of archil and cudbear, and ammonia turns their red color to a
purple violet. If the wine is examined according to the Falieres-Ritter
method in presence of magenta, ether, when shaken up with the wine,
previously rendered ammoniacal, remains colorless, while if archil
or cudbear is present the ether is colored red. Wartha has made a
convenient modification in the Falieres-Ritter method by adding ammonia
and ether to the concentrated wine while still warm. If the red color of
the wool is due to archil or cudbear, it is extracted by hydrochloric
acid, which is colored red. Ammonia turns the color to a purple violet.
Koenig mixed 50 c.c. wine with ammonia in slight excess, and places in
the mixture about one-half grm. clean white woolen yarn. The whole is
then boiled in a flask until all the alcohol and the excess of ammonia
are driven off. The wool taken out of the liquid and purified by washing
in water and wringing is moistened in a test-tube with pure potassa
lye at 10 per cent. It is carefully heated till the wool is completely
dissolved, and the solution, when cold, is mixed first with half its
volume of pure alcohol, upon which is carefully poured the same volume
of ether, and the whole is shaken. The stratum of ether decanted off is
mixed in a test-tube with a drop of acetic acid. A red color appears if
the slightest trace of magenta is present. The shaking must not be too
violent, lest an emulsion should be formed. If the wine is colored with
archil, on prolonged heating, after the addition of ammonia, it is
decolorized. If it is then let cool and shaken a little, the red color
returns. If the wool is taken out of the hot liquid after the red color
has disappeared, and exposed to the air, it takes a red color. But if
it is quickly taken out of the liquid and at once washed, there remains
merely a trace of color in the wool. If these precautions are observed,
magenta can be distinguished from archil with certainty according to
Koenig's method. As the coloring-matter of archil is not precipitated
by baryta and magnesia, but changed to a purple, the baryta method,
recommended by Pasteur, Balard, and Wurtz, and the magnesia test, are
useless. Magenta may in course of time be removed by the precipitates
formed in the wine. It is therefore necessary to test not merely the
clear liquid, but the sediment, if any.--_Dr. B. Haas, in Budermann's
Centralblatt.--Analyst_.

* * * * *

PANAX VICTORIAE.

Panax Victoriae is a compact and charming plant, which sends up numbers
of stems from the bottom in place of continually growing upward and thus
becoming ungainly; it bears a profusion of elegantly curled, tasseled,
and variegated foliage, very catching to the eye, and unlike any of its
predecessors. The other, P. dumosum, is of similar habit, the foliage
being crested and fringed after the manner of some of our rare crested
ferns.--_The Gardeners' Chronicle_.

[Illustration: PANAX VICTORIAE.]

* * * * *

A NOTE ON SAP.

[Footnote: Read at an evening meeting of the Pharmaceutical Society,
London, April 4, 1883.]

By Professor ATTFIELD, F.R.S.

Beneath a white birch tree growing in my garden I noticed, yesterday
evening, a very wet place on the gravel path, the water of which was
obviously being fed by the cut extremity of a branch of the birch about
an inch in diameter and some ten feet from the ground. I afterward found
that exactly fifteen days ago circumstances rendered necessary the
removal of the portion of the branch which hung over the path, 4 or 5
feet being still left on the tree. The water or sap was dropping fast
from the branch, at the rate of sixteen large drops per minute, each
drop twice or thrice the size of a "minim," and neither catkins nor
leaves had yet expanded. I decided that some interest would attach to a
determination both of the rate of flow of the fluid and of its chemical
composition, especially at such a stage of the tree's life.

A bottle was at once so suspended beneath the wound as to catch the
whole of the exuding sap. It caught nearly 5 fluid ounces between eight
and nine o'clock. During the succeeding eleven hours of the night 44
fluid ounces were collected, an average of 4 ounces per hour. From 8:15
to 9:15 this morning, very nearly 7 ounces were obtained. From 9:15
to 10:15, with bright sunshine, 8 ounces. From 10:15 until 8:15 this
evening the hourly record kept by my son Harvey shows that the amount
during that time has slowly diminished from 8 to a little below 7 ounces
per hour. Apparently the flow is faster in sunshine than in shade, and
by day than by night.

It would seem, therefore, that this slender tree, with a stem which at
the ground is only 7 inches in diameter, having a height of 39 feet,
and before it has any expanded leaves from whose united surfaces large
amounts of water might evaporate, is able to draw from the ground about
4 liters, or seven-eighths of a gallon of fluid every twenty-four hours.
That at all events was the amount flowing from this open tap in its
water system. Even the topmost branches of the tree had not become,
during the fifteen days, abnormally flaccid, so that, apparently, no
drainage of fluid from the upper portion of the tree had been taking
place. For a fortnight the tree apparently had been drawing, pumping,
sucking--I know not what word to use--nearly a gallon of fluid daily
from the soil in the neigborhood of its roots. This soil had only an
ordinary degree of dampness. It was not wet, still less was there any
actually fluid water to be seen. Indeed, usually all the adjacent soil
is of a dry kind, for we are on the plateau of a hill 265 feet above the
sea, and the level of the local water reservoir into which our wells dip
is about 80 feet below the surface. My gardener tells me that the tree
has been "bleeding" at about the same rate for fourteen of the fifteen
days, the first day the branch becoming only somewhat damp. During the
earlier part of that time we had frosts at night, and sunshine, but with
extremely cold winds, during the days. At one time the exuding sap
gave, I am told by two different observers, icicles a foot long. A much
warmer, almost summer, temperature has prevailed during the past three
days, and no wind. This morning the temperature of the sap as it escaped
was constant at 52 deg. F., while that of the surrounding air was varying
considerably.

The collected sap was a clear, bright, water-like fluid. After a pint
had stood aside for twelve hours, there was the merest trace of a
sediment at the bottom of the vessel. The microscope showed this to
consist of parenchymatous cells, with here and there a group of
the wheel-like or radiating cells which botanists, I think, term
sphere-crystals. The sap was slightly heavier than water, in the
proportion of 1,005 to 1,000. It had a faintly sweet taste and a very
slight aromatic odor.

Chemical analysis showed that this sap consisted of 99 parts of pure
water with 1 part of dissolved solid matter. Eleven-twelfths of the
latter were sugar.

That the birch readily yields its sap when the wood is wounded is well
known. Philipps, quoted by Sowerby, says:

"Even afflictive birch,
Cursed by unlettered youth, distills,
A limpid current from her wounded bark,
Profuse of nursing sap."

And that birch sap contains sugar is known, the peasants of many
countries, especially Russia, being well acquainted with the art of
making birch wine by fermenting its saccharine juice.

But I find no hourly or daily record of the amount of sugar-bearing
sap which can be drawn from the birch, or from any tree, before it
has acquired its great digesting or rather developing and transpiring
apparatus--its leaf system. And I do not know of any extended chemical
analysis of sap either of the birch, or other tree.

Besides sugar, which is present in this sap to the extent of 616
grains--nearly an ounce and a half--per gallon, there are present a
mere trace of mucilage; no starch; no tannin; 31/2 grains per gallon
of ammoniacal salts yielding 10 per cent. of nitrogen; 3 grains of
albuminoid matter yielding 10 per cent. of nitrogen; a distinct trace of
nitrites; 7.4 grains of nitrates containing 17 per cent. of nitrogen; no
chlorides, or the merest trace; no sulphates; no sodium salts; a little
of potassium salts; much phosphate and organic salts of calcium; and
some similar magnesian compounds. These calcareous and magnesian
substances yield an ash when the sap is evaporated to dryness and the
sugar and other organic matter burnt away, the amount of this residual
matter being exactly 50 grains per gallon. The sap contained no peroxide
of hydrogen. It was faintly if at all acid. It held in solution a
ferment capable of converting starch into sugar. Exposed to the air it
soon swarmed with bacteria, its sugar being changed to alcohol.

A teaspoonful or two of, say, apple juice, and a tablespoonful of sugar
put into a gallon of such rather hard well-water as we have in our
chalky district, would very fairly represent this specimen of the sap of
the silver birch. Indeed, in the phraseology of a water-analyst, I may
say that the sap itself has 25 degrees of total, permanent hardness.

How long the tree would continue to yield such a flow of sap I cannot
say; probably until the store of sugar it manufactured last summer to
feed its young buds this spring was exhausted. Even within twenty-four
hours the sugar has slightly diminished in proportion in the fluid.

Whether or not this little note throws a single ray of light on the much
debated question of the cause of the rise of sap in plants I must leave
to botanists to decide. I cannot hope that it does, for Julius Sachs,
than whom no one appears to have more carefully considered the subject,
says, at page 677 of the recently published English translation of his
textbook of botany, that "although the movements of water in plants have
been copiously investigated and discussed for nearly two hundred years,
it is nevertheless still impossible to give a satisfactory and deductive
account of the mode of operation of these movements in detail." As
a chemist and physicist myself, knowing something about capillary
attraction, exosmose, endosmose, atmospheric pressure, and gravitation
generally, and the movements caused by chemical attraction, I am afraid
I must concur in the opinion that we do not yet know the real ultimate
cause or causes of the rise of sap in plants.

Ashlands, Watford, Herts.

* * * * *

THE CROW.

[Footnote: Abstract of a recent discussion before the Connecticut State
Board of Agriculture.]

Prof. W. A. Stearns, in a lecture upon the utility of birds in
agriculture, stated that the few facts we do know regarding the matter
have been obtained more through the direct experience of those who have
stumbled on the facts they relate than those who have made any special
study of the matter. One great difficulty has been that people looked
too far and studied too deeply for facts which were right before them.
For instance, people are well acquainted with the fact that hawks,
becoming bold, pounce down upon and carry off chickens from the
hen-yards and eat them. How many are acquainted with the fact that in
hard winters, when pressed for food, crows do this likewise? But
what does this signify? Simply that the crow regulates its food from
necessity, not from choice.

Now, carry this fact into operation in the spring into the cornfield. Do
you suppose that the crow, being hungry, and dropping into a field of
corn wherein is abundance to satisfy his desires, stops, as many affirm,
to pick out only those kernels which are affected with mildew, larva, or
weevil? Does he instinctively know what corns, when three or four inches
beneath the ground, are thus affected? Not a bit of it. To him, a
strictly grain-feeding and not an insect-eating bird, the necessity
takes the place of the choice. He is hungry; the means of satisfying his
hunger are at hand. He naturally drops down in the first cornfield
he sees, calls all his neighbors to the feast, and then roots up and
swallows all the kernels until he can hold no more. There is no doubt
the crow is a damage to the agriculturist. He preys upon the cornfield
and eats the corn indiscriminately, whether there are any insects or
not. That has been proved by dissection of stomach and crop.

If corn can be protected by tarring, so that the crows will not eat it,
they will prove a benefit by leaving the corn and picking up grubs in
the field. Where corn has been tarred, I have never known the crows to
touch it.

Mr. Sedgwick remarked that, in addition to destroying the corn crop, the
crow was also very destructive of the eggs of other birds. Last spring
I watched a pair of crows flying through an orchard, and in several
instances saw them fly into birds' nests, take out the eggs, and then go
on around the field.

In answer to Mr. Hubbard, who claimed the crow would eat animal food in
any form, and might not be rightly classified as a grain-eating bird,
Prof. Stearns said the crow was thus classified by reason of the
structure of its crop being similar to that of the finches, the
blackbird, the sparrows, and other seed-eating birds.

[Illustration: THE AMERICAN CROW.]

Mr. Wetherell said: Crows are greedy devourers of the white worm, which
sometimes destroys acres of grass. As a grub eater, the crow deserves
much praise. The crow is the scavenger of the bird family, eating
anything and everything, whether it is sweet or carrion. The only
quarrel I have with the crow is because it destroys the eggs and young
birds.

Mr. Lockwood described the experience of a neighbor who planted corn
after tarring it. This seemed to prevent the ravages of the crows until
the second hoeing, when the corn was up some eighteen inches, at which
time the crows came in and pulled nearly an acre clean.

Crows, said Dr. Riggs, have no crop, like a great many carnivorous
birds. The passage leading from the mouth goes directly to the gizzard,
something like the duck. The duck has no crop, yet the passage leading
from the mouth to the gizzard in the duck becomes considerably enlarged.
In the crow there is no enlargement of this passage, and everything
passes directly into the gizzard, where it is digested.

Dr. Riggs had raised corn and watched the operations of the crows. Going
upon the field in less than a minute after the crows had left it, he
found they had pulled the corn, hill after hill, marching from one hill
to the other. Not until the corn had become softened and had come up
would they molest it. In the fall they would come in droves on to a
field of corn, where it is in stacks, pick out the corn from the husks,
and put it into their gizzards. They raid robbins' nests and swallows'
nests, devouring eggs and young birds. Yet crows are great scavengers.
In the spring they get a great many insects and moths from the ground,
and do good work in picking up those large white grubs with red heads
that work such destruction in some of our mowing fields.

Mr. Pratt stated that he had used coal tar on his seed corn for five or
six years, and had never a spear pulled by the crows. Dr. Riggs never
had known a crow to touch corn after it got to the second tier of
leaves. Mr. Lockwood said crows would sample a whole field of corn to
find corn not tarred. Mr. Pratt recommended to pour boiling water on the
corn before applying the tar. A large tablespoonful of tar will color a
pail of water.

According to Dr. Riggs, the hot mixture with the corn must be stirred
continually; if not, the life of the corn will be killed and germination
prevented. It may be poured on very hot, if the stirring is kept up and
too much tar is not used. If the water is hot it will dissolve the tar,
and as it is poured on it will coat every kernel of corn. If the water
is allowed to stand upon the corn any great length of time, the chit of
the corn will be damaged. The liquid should be poured off and the corn
allowed to cool immediately after a good stirring.

Mr. Gold had known of crows pulling corn after the second hoeing, when
the scare-crows had been removed from the field. The corn thus pulled
had reached pretty good size. This pulling must have been done from
sheer malice on the part of the crows.

Mr. Ayer was inclined to befriend the crow. For five years he had
planted from eight to twelve acres of corn each year and had not lost
twenty hills by crows. He does not use tar, but does not allow himself
to go out of a newly-planted cornfield without first stretching a string
around it on high poles and also providing a wind-mill with a little
rattle box on it to make a noise. With him this practice keeps the crows
away.

Mr. Goodwin thought crows were scavengers of the forests and did good
service in destroying the worms, grubs, and insects that preyed upon
our trees. He had raised some forty crops of corn, and whenever he had
thoroughly twined it at the time of planting, crows did not pull it up.
In damp spots, during the wet time and after his twine was down, he had
known crows to pull up corn that was seven or eight inches high.

Respecting crows as insect eaters, Prof. Stearns admitted that they did
devour insects; he had seen them eat insects on pear trees. Tame crows
at his home had been watched while eating insects, yet a crow will
eat corn a great deal quicker than he will eat insects.--_Boston
Cultivator_.

* * * * *

THE PRAYING MANTIS AND ITS ALLIES.

On examining the strange forms shown in the accompanying engraving, many
persons would suppose they were looking at exotic insects. Although this
is true for many species of this group, which are indigenous to warm
countries, and reach at the most only the southern temperate zone, yet
there are certain of these insects that are beginning to be found in
France, to the south of the Loire, and that are always too rare, since,
being exclusively feeders on living prey, they prove useful aids to us.

These insects belong among the orthoptera--an order including species
whose transformations are less complete than in other groups, and whose
larval and pupal forms are very active, and closely resemble the imago.
Two pairs of large wings characterize the adult state, the first pair
of which are somewhat thickened to protect the broad, net-veined hinder
pair, which fold up like a fan upon the abdomen. The hind legs are large
and adapted for leaping.

The raptorial group called _Mantidae_, which forms the subject of this
article, includes species that maybe easily recognized by their large
size, their enormous, spinous fore legs, which are adapted for seizing
other insects, and from their devotional attitude when watching their
prey.

These insects exhibit in general the phenomenon of mimicry, or
adaptation for protection, through their color and form, some being
green, like the plants upon which they live, others yellowish or
grayish, and others brownish like dead leaves.

In the best known species, _Mantis religiosa_, the head is triangular,
the eyes large, the prothorax very long, and the body narrowed and
lengthened; the anterior feet are armed with hooks and spines, and the
shanks are capable of being doubled up on the under side of the thighs.
When at rest it sits upon the four posterior legs, with the head and
prothorax nearly erect, and the anterior feet folded backward. The
female insect attains a length of 54 millimeters, and the male only 40.

The color is of a handsome green, sometimes yellow, or of a yellowish
red. The insects are slow in their motions, waiting on the branches of
trees and shrubs for some other insect to pass within their reach, when
they seize and hold it with the anterior feet, and tear it to pieces.
They are very voracious, and sometimes prey upon each other. Their eggs
are deposited in two long rows, protected by a parchment-like envelope,
and attached to the stalk of a plant. The nymph is as voracious as the
perfect insect, from which it differs principally in the less developed
wings.

The devotional attitude of these insects when watching for their
prey--their fore legs being elevated and joined in a supplicating
manner--has given them in English the popular names of "soothsayer,"
"prophet," and "praying mantis," in French, "prie-Dieu," in Portuguese,
"louva-Deos," etc. According to Sparmann, the Nubians and Hottentots
regard mantides as tutelary divinities, and worship them as such. A
monkish legend tells us that Saint Francis Xavier, having perceived a
mantis holding its legs toward heaven, ordered it to sing the praises of
God, when immediately the insect struck up one of the most exemplary of
canticles! Pison, in his "Natural History of the East Indies," makes use
of the word _Vates_ (divine) to designate these insects, and speaks of
that superstition, common to both Christians and heathens, that assigns
to them the gifts of prophecy and divination. The habit that the mantis
has of first stretching out one fore leg, and then the other, and of
preserving such a position for some little time, has also led to the
belief among the illiterate that it is in the act, in such cases, of
pointing out the road to the passer by.

[Illustration: MANTIDES AND EMPUSAE]

The old naturalist, Moufet, in his _Theatrum Insectorum_ (London, 1634),
says of the praying mantis (_M. religiosa_) that it is reported so
divine that if a child asks his way of it, it will show him the right
road by stretching out its leg, and that it will rarely or never deceive
him.

This group of insects is most abundant in the tropical regions of
Africa, South America, and India, but some species are found in the
warmer parts of North America, Europe, and Australia. The American
species is the "race-horse" (_M. carolina_), and occurs in the Southern
and Western States. Burmeister says that _M. argentina_, of Buenos
Ayres, seizes and eats small birds.

The genera allied to _Mantis--Vates, Empusa, Harpax_, and
_Schizocephala_--occur in the tropics. The genus _Eremophila_ inhabits
the deserts of Northern Africa, where it resembles the sand in color.

The species shown in the engraving (which we borrow from _La Nature_)
inhabit France.

* * * * *

MAY-FLIES.

There are usually found in the month of June, especially near water,
certain insects that are called Ephemera, and which long ago acquired
true celebrity, and furnished material for comparison to poets and
philosophers. Indeed, in the adult state they live but one day, a fact
that has given them their name. They appear for a few hours, fluttering
about in the rays of a sun whose setting they are not to see, as they
live during the space of a single twilight only. These insects have
very short antennae, an imperfect mouth incapable of taking food, and
delicate, gauze like wings, the posterior ones of which are always
small, or even rudimentary or wanting. Their legs are very delicate--the
anterior ones very long--and their abdomen terminates in two or three
long articulated filaments. One character, which is unique among
insects, is peculiar to Ephemerids; the adults issuing from the pupal
envelope undergo still another moult in divesting themselves of a thin
pellicle that covers the body, wings, and other appendages. This is what
is called the _subimago_, and precedes the imago or perfect state of the
insect. The short life of adult May-flies is, with most of them, passed
in a continual state of agitation. They are seen rising vertically in
a straight line, their long fore-legs stretched out like antennae, and
serving to balance the posterior part of the body and the filaments
of the abdomen during flight. On reaching a certain height they allow
themselves to descend, stretching out while doing so their long wings
and tail, which then serve as a parachute. Then a rapid working of these
organs suddenly changes the direction of the motion, and they begin to
ascend again. Coupling takes place during these aerial dances. Soon
afterward the females approach the surface of the water and lay therein
their eggs, spreading them out the while with the caudal filaments, or
else depositing them all together in one mass that falls to the bottom.

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