Vol. XXV. No. 9.] 
POPULAE SCIENCE IsTEWS. 
131 
nen beneath the wings, which the creature lifts 
in order that the ant may get at its honeyed 
recompense. Such mutual services between creat- 
ures in no way allied is a most curious fact in the 
ianimal world. 
Leauville, Colorado, July 15, 1891. 
[American Microscopical Journal.] 
O.MMON OBJECTS AVAILABLE FOR EX- 
HIBITING THE POWER OF THE MICRO- 
SCOPE. 
BY F. BLANCHARD, M. D. 
To the amateur microscopist it must often occur 
.0 exhibit the-power of his instrument to friends 
who are not familiar with it. On such occasions 
the selection of unsatisfactory objects Is most dis- 
appointing. The foot of the common house-fly, 
altliough a wonderful structure, has been de- 
?crit)ed so often in juvenile literature that the 
ludience is apt to yawn over an explanation of 
olaws and suction disk. So with the circulation 
of blood in the frog's foot, the rabbit's ear, and 
ili« salamander's tail. So with the irrational mo- 
iis of amoebae in Potomac water. 
It is the unpretentious object of this item to 
■luimerate some other readily obtainable objects 
for extemporaneous use on such occasions. They 
reciuire no elaborate preparation and no reagents. 
Tlie feathery dust from the wing of the "dusty 
miller'" is, perhaps, too commonly used to need 
mention. The feet, eyes, antenutc, and wings of 
cockroaches, bees, wasps, mosquitoes, and butter- 
flies furnish a great variety of wonder-inspiring 
views. 
Often you will be compelled to disappoint some 
one who expects to see "lots of little bugs" in a 
drop of well-water, but a drop of slime from the 
under surface of a lily pad will fully meet such 
expectation. 
I'he tail of the newt still remains the most con- 
venient oliject for showing the circulation of the 
blood. In the same jar where the newts are kept 
a few sprigs of chara should be kept growing. 
The stem of chara shows cyclosis beautifully. 
Thin peelings from the bulb of the common onion 
also show sap circulation well. In cold weather 
the onion should be kept in a warm place a few 
hours to quicken the circulation of the sap. 
Cross sections of common woods make interest- 
ing specimens. They can be cut with a keen jack- 
knife, if one has the " knack." Cornus stolonifera, 
a shoot one-quarter inch in diameter, makes a 
good one to begin on, but any soft wood will 
answer. 
Stellate and glandular hairs of plants, the 
breatliing pores of such plants as the white lily, 
the translucent leaves of mosses, and the pollen 
of flowers should not be forgotten. 
Minute seeds, with their infinite variety of form 
and marking, are things of beauty and a joy for- 
ever, lliey require a condenser, but no cover 
glass. Try the seeds of Arenaria serpyllifoKa, and 
you will be encouraged to seek further. A most 
delightful series of objects can be easily made 
from the small seeds of Caryophyllacex. The ge- 
nus Euphorbia furnishes another fine series in 
which you can often determine the species by the 
seeds alone. Juncus gives us still another series. 
In .7. effusus and J. bufonius the ribs and cross 
lines of the seeds are delicate indeed. 
The pappus of many species of Compositce is a 
charming sight under the microscope, especially 
when the pappus is plumose, as in Kuhnia, the 
thistles, etc. 
^lost of the common grasses have plumose stig- 
mas, which, with their coloring of purple, show 
finely with objectives of moderate power. The 
hairy palets of grasses make first-class objects. 
Lycopodium, the powder which druggists use 
to keep pills, etc., from sticking together, will 
prove of interest and is easy to obtain. It con- 
sists of the spores of the common club moss, or 
evergreen. The spores move over each other so 
freely that the powder in bulk shakes like a liquid. 
To the touch it seems like an oily liquid. But 
under the microscope it appears as innumerable 
yellow globes, somewhat shrunken and irregular 
when dry. Any species of lycopodium will fur- 
nish a supply from xVugust to October. The 
spores of ferns and mosses are equally interest- 
ing. 
But if you wish to elicit from your audience ex- 
clamations of delight, put on the slide a freshly 
ruptured spore-case of one of the larger Hepaticeai. 
Marchantia, asterella, or conocephalus will an- 
swer. The lively way in which the spiral elaters 
toss the spores about is sure to "bring down the 
house." 
Diatoms you will find in abundance in the stom- 
ach of the oyster ; but a more convenient source 
is common polishing-powder, which consists 
largely of their remains. 
Raw silk, cotton, and wool, hair and feathers, 
are rich spoil for the amateur exhibitor of the 
microscope. Common drugs, like morphine, qui- 
nine, and strychnine, — you need not go far for 
ready-made ol)jects. 
INDUSTRIAL MEMORANDA. 
Fob a good cement that will stick muslin to 
bunting, boil together two parts shellac, one part 
borax, and sixteen parts of water. The surface 
must not be greasy. 
A good recipe for making waterproof cement, 
to be used in constructing aquariums, is to take 
twenty-flve parts gutta percha in shreds and melt 
it carefully. Add seventy-five parts ground pum- 
ice stone, and then mix in one hundred and fifty 
parts Burgundy pitch and melt well together. 
Hai>py Tuought. — One day, in 1830, when a 
working jeweller, Joseph Gillott, now the famous 
steel pen maker, accidentally split one of his fine 
steel tools, and being suddenly required to sign a 
receipt, not finding his quill pen at hand, he used 
the split tool as a ready substitute. l"he happy 
accident led to the idea of making pens of steel. 
Coppered Iron. — A process has been recently 
invented by which iron may be coppered by dip- 
ping it into melted copper, the surface of the iron 
being protected by a layer of melted cryolite and 
phosphoric acid. It has been found that if the 
article when immersed is connected with *he neg- 
ative pole of a battery the coppering is done more 
rapidly. 
Substitute for Leather. — A German inven- 
tor has devised a new material which is intended 
as a substitute for leather in many of its uses. 
This material consists of panels of wood with 
wire netting between, the whole being glued to- 
gether under heavy piessure. The sheets thus 
made are said to be very tough and pliable, 
and suited for making trunks and other uses that 
require strength. 
■Widening the Suez Canal. — The Suez Canal 
is being widened in some parts to the extent of 50 
ft. The widening had been completed at the close 
of 1889 for a distance of about 10 miles from Port 
Said. In the course of last year the widening 
was completed for a further distance of five miles. 
By the close of 1881 the widening works are ex- 
pected to reach a point twenty-two miles and 
one-quarter from Port Said. 
A Good Non-actinic Varnish, says the Moni- 
teur de la Photographie, is obtained by dissolving 
aurine cake in methylated spirit. Another var- 
nish of the same kind is got by dissolving gam- 
boge in a mixture of methylated spirit and ether. 
Leon Vidal uses a solution of bitumen in benzol 
for impregnating those parts of a proof it is de- 
sired to render non-actinic, and, when the varnish 
is dry, he plunges the plate into aniline yellow or 
magenta red, etc., in aqueous solution, and after- 
wards dissolves out the bitumen by means of ben- 
zol when the plate is dry. 
SCIENTIFIC BREVITIES. 
An Oxide of Gold. — Using a fine sheet of gold 
as positive electrode in sulphuric acid or nitric 
acid solution, W. Ilampe found that the same 
became colored brown, and finally a reddish- 
brown powder fell to the bottom of the electrolyz- 
ing dish. This was proved qualitatively to be a 
hydrate of gold formed by the oxidizin§|action of 
the electrolytically evolved oxygen. On drying 
over sulphuric acid, and then heating, it exploded 
violently. 
Definitions of the Sciences.— Lord Salis- 
bury is quite a distinguished savant as well as a 
renowned statesman. In a recent lecture before 
the Chemical Society of London, he said: "As 
tronomy is, in a great measure, the science of 
things as they probably are, geology is the science 
of things as they probably were, chemistry is the 
science of tilings as they are at present." To 
these adds the Electrical Engineer, " electricity is 
the science of things as they probably will be." 
Smoke Screen.— Tlirough experiments made 
by English military authorities it has been found 
that whenever the atmosphere is laden with 
smoke or mist the power of an electric light is 
greatly diminished by crossing the beam of light 
by that of another at a certam angle. At the 
point of intersection the illuminated space is 
practically made a screen. It is proposed to uti- 
lize this knowledge, since the electric beam can 
thus be made to serve as a screen, back of which 
tactical operations might be conducted in secret. 
Meteorite.— Prof. Foote of Philadelphia has 
collected some remarkable Meteorites, at Canon 
Diablo, Yavapai Co., Arizona. The largest mass 
weighs 250 lbs., and another 154 lbs. A specimen 
which he sent to Dr. Koenig was recently de- 
scribed by him before the Academy of Natural 
Sciences. Dr. Koenig's analysis gave 2 9-10 per 
cent, nickel, and in the only piece which has yet 
been cut a cavity was exposed containing small 
diamonds. As this is the first instance of the 
occurence of tliis gem in meteoric iron, the find 
will be of great interest to scientists. 
Purification of Chemicals by Cold.— Pictet 
who has taken out a patent for the process, has 
discovered that from the purest chloroform of 
commerce, if cooled down to about — 70°, there 
separates out a crystalline body, which is then 
drained from the part which remains liquid. 
This liquid portion is then exposed to a temper- 
ature below — lOO'^, when the chloroform itself 
crystallises out, and can be separated from an im- 
purity which remains liquid. Chloroform puri- 
fied m this manner is a colorless liquid, having 
at 15° tlie sp. gr. 1.51. It is indefinitely perma- 
nent on exposure to light. AVhilst the so-called 
pure chloroform of commerce takes a greenish 
color if shaken up with solution of potassium 
dichromate and sulphuric acid, if Pictet's chloro- 
form is similarly treated the chromic mixture 
retains its yellowish color. 
