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Full text of "Electrical experiments; illustrating the theory, practice and application of the science of free or frictional electricity"

LIBRARY OF 
WELLESLEY COLLEGE 




PRESENTED BY 

Edith Milwood Perrin '10 



N 



ELECTRICAL 

EXPEEIMENTS; 



ILLUSTRATING 



THE THEORY, PRACTICE, AND APPLICATION OF THE SCIENCE 



PEEE OE EEICTIONAL ELECTEICITY : 

CONTAINING THE 

METHODS OF MAKING AND MANAGING ELECTRICAL APPARATUS 
OF EVERY DESCRIPTION, 



jfumBrntis SllttHtrEtinB cgHgraiimgs, 



G. FRANCIS, F.LS. 

AUTHOR OF THE DICTIONARY OF ARTS AND SCIENCES ; CHEMICAL EXPERIMENTS ; THE DICTIONARY 

OF PRACTICAL RECEIPTS ; THE DICTIONARY OF TRA.DE COMMERCE, AND NAVIGATION 

THE ART OF MODELLING WAXEN FRUIT AND FLOWERS ; MANUAL OF 

LEVELLING ; LITTLE ENGLISH FLORA ; FAVORITES OF THE 

FLOWER GARDEN ; GRAMMAR OF BOTANY 

ETC. ETC. ETC. 



FIFTH EDITION. 



D. FRANCIS, 21,. MILE END ROAD, & G. BERGER, HOLYWELL STREET, 

STRAND. 

1850. 






D. PEANCIS, PRINTER, MILE END ROAD. 



PREFACE. 



A WORK entitled ** Electrical Experiments" must necessarily be in some degret 
copied from former treatises ; the more especially as the best experiments 
and it may be said the best-constructed apparatus, with but few exceptions, 
are the result of the ingenuity or the reflection of those who studied the 
subject half a century ago, when electricity was all in all with lecturers as 
well a» with philosophers ; and when the discoveries in it rapidly succeeded 
one another, each more curious, beautiful, or important than its predecessors. 

At this earher period, namely, from about 1 740 to the beginning of the 
present century, philosophers were learning the facts of the science by long 
series of experiments ; lecturers were teaching these facts and giving them 
popularity by the invention of ingenious apparatus, and showy illustrations, 
and authors were careful to embody these interesting particulars in their 
various' ^treatises ; hence the works of Priestley, Adams, Cavallo, Ferguson, 
Hawkesbee, Singer, and others, abound with experimental interest. This time 
has now past ; the experiments proved the facts, the facts suggested the laws 
of the science, and these becoming known, the learned with few exceptions 
turned their attention to other matters. If they have condescended to write 
upon the subject of frictional electricity, they have in all the latter treatises 
given merely a dry explanation of facts and laws, apparently regarding the 
detail of experiments as beneath their notice, and forgetting that tyros in 
science must have their senses gratified as well as their minds enlightened » 
and equally oblivious of the truth, that a fact illustrated by a pleasing popular 



PREFACE. 

experiment often fixes itself upon the memory, which without that experi- 
m-ent, would fail to he remembered, or even regarded. 

The Author of this little work impressed, as he has ever been, with the 
opinion that the more interesting and amusing a science may be made, the 
more it will be studied, has endeavoured to collect all the good experiments 
he has met with elsewhere, and has invented many, as further illustrations 
of certain parts of the subject. He has been accustomed to make all his 
own apparatus, and to lecture on natural philosophy for many years. The 
remarks appended therefore to numerous experiments may be considered 
practical, and the descriptions also of all the apparatus are original, and it is 
hoped as plain as they could be made. In speaking hov/ever of the originality 
of the descriptions, it is to be remarked, that some portions of the present 
work were written by the Author for the " Magazine of Science," of which 
he was the Editor. 

This treatise contains more experiments and illustrations than any other 
work upon the subject, and all the facts that are known with certainty relative 
to frictional electricity, although some disputed matters, such as the origin of 
electricity, and whether there be one fluid or two, are very briefly discussed, 
they being matters of mere conjecture, and in whichever way they may oe 
decided, will make no difference whatever in the practical and populai 
development of the science, at least according to our present applications 
of it. 

G. FRANCIS, F.L.S. 




Electricity teaches the laws and effects of a peculiar substance or influence 
called the electric fluid, and derives its name from the Greek word electron, 
amber ; the first electrical effects having been observed in that substance. 

Daily observations on recurrent phenomena, as well as direct experi- 
ments, prove that the whole earth and atmosphere, below, upon, and above 
the surface, is pervaded by this highly-elastic and subtle fluid, sometimes in a 
disturbed state, producing then the most stupendous phenomena ; at other 
times in a latent condition, and although then imperceptible, yet not on that 
account less abundant. If it be not the very essence of life and existence, 
it acts a very important part in the animal and vegetable economy. Over 
chemical and meteorological change its power is no less extraordinary. It is 
easily proved identical with the vivid and withering lightning, the streaming 
aurora, the rapid whirlwind, the terrific waterspout, the rolling pillars of 
sand of the desert, and in all probability produces the falling meteor, and the 
devastating earthquake. 

These are some of the more obvious efi'ects of the electric fluid 
when in that free condition in which it is produced by mechanical means ; 
without considering the modifications of it which accompany chemical action, 
called galvanic ; or it might be described not merely as regulating solitary 
phenomena, but as occasioning all the multitudinous effects of chemical 
composition and decomposition ; of crystallization ; perhaps of hght, heat 
and combustion ; and as analogous to magnetism and gravitation. Although 
the earth and atmosphere are alone subject to our experimental researches, 
yet there is just reason to conclude that it abounds throughout the universe 
as the elemental fire which fills all space, and that it is the mighty power 
that is employed by the Great Creator, to move, restrain, and regulate the 
millions of worlds with which it has pleased him to fill the vast and brilliant 
firmament. 



Besides the value of electricity in teaching us the laws and effects of 
the fluid we have been describing, in thus explaining so many of the grandei 
phenomena of nature, and directing us to guard our persons and property in 
some degree against their destructive effects — the science has other claims 
to our notice. Its application has been found efficacious in curing some of 
the most hngering and painful diseases ; the general laws to be remembered 
are few ; all the apparatus necessary may be made either by ourselves or by 
ordinary workmen at little expense ; the experiments require for their suc- 
cess only common care and attention, and yet are so brilliant, so varied, and 
so surprising, as to be a never-failing source of wonder and delight. 

It is surprising that a fluid thus universally distributed, and which is capable 
of such extensive application, should have remained almost unknown until very 
modern times. Although Theophrastus, who lived more than 2400 years ago, 
writes that amber, and another body which he called Lyncurium, when rubbed, 
were capable of attracting towards them light substances, yet this solitary ex- 
periment, not explained till so many centuries afterwards, was the whole 
knowledge the ancients had of electricity; and it was not till the latter part of the 
sixteenth century, when Dr. Gilbert, by discovering that other bodies had similar 
properties, drew in some degree the attention of philosophers to the subject. 
Still there was so little to engage pubhc attention, that seventy years elapsed 
before the electric light was seen. This was discovered by Mr. Boyle, and 
was enough to stamp with the dignity of a science, what had before been 
considered as but trivial and unimportant experiments. Attempts were now 
made to construct a machine by which the fluid should be accumulated in 
greater abundance. In this Otto Guericke, the celebrated inventor of the air 
pump was successful, and still more so Mr. Hawkesbee, whose treatise, pub- 
lished in 1 709, was the first upon the subject, and the discoveries he made with 
this improved machine, which was the first one made of glass, far exceeded 
those of his predecessors. The science was from this stationary for thirty 
years, when a Mr. Gray directed his attention to it, and arranged bodies into 
two classes ; the first electrics, or those which like amber were capable of 
being excited, and conductors, or those which not capable of excitation them- 
selves, that is, thought at that time not to be so, yet allowed the fluid to pass 
along them. Not long subsequent to this, M. du Fay, discovered the dif- 
ference between what were then called vitreous and resinous electricity. He 
taught that the phenomena of attraction and repulsion were occasioned by 
two fluids distinct from and mutually opposed to each other. From this time 
electricity became more studied, though not popular till the discovery of the 
Leyden phial in 1746, when it spread rapidly over Europe, engaging equally 
the attention of all classes of people. Dr. Franklin explained the mode of 



3 

acticn of the phial, and pubHshed his celebrated theory of there being but 
one fluid, the diminution or redundancy of which he supposed to be the 
cause of all electrical action. Soon the identity of the fluid with lightning 
was boldly asserted and proved both by Dr. Franklin and L'abbe Nollet at 
about the same period, the former venturing to bring down hghtning from 
the clouds, and to perform with it all the experiments then known, thus 
boldly setting the question at rest for ever. Lightning being thus satisfac- 
torily accounted for, the transition to other meteoric phenomena was easy, 
and in a very brief period the powerful agency of electricity in modifying the 
surface of the earth, and the atmosphere around it, was firmly established. 
Mechanical electricity, free electricity, the electricity of friction, the electricity 
of tension, for by all these names this particular part of the subject is called, 
could go no further ; but the wonderful discoveries made during the present 
century of the intimate connexion between this science, galvanism and 
magnetism, not only confirm our previous views, but induce us to attribute 
the facts of all these difi'erent departments, as arising from one common 
cause, and producing effects only so far varied as might be expected from 
altered circumstances, and the difi'erent materials subjected to experiment. 
The history of -this connexion or identity will lead us almost too far from our 
immediate object ; we shall only observe that at the present time so much do 
these subjects engage the attention of the scientific world, and so numerous 
and unexpected are the discoveries made in them, that each year opens a 
still wider field for electrical research, and the laws which regulate the 
material world. 



CHAP. I. 

ELECTRICAL ACTION, EXCITATION, AND DIFFERENT STATES OF THE 

ELECTRIC FLUID. 

The electric fluid, though existing in every object around us, is, while in its natural state 
of rest, not pei'ceptible to our senses ; but as soon as by any cause it is disturbed, that 
which was before latent becomes free, and v/e are immediately sensible of its presence. 
If violently agitated, the fluid itself becomes apparent ; if less moved, we are only con- 
scious of the disturbance by the effects it produces in attracting towards it the light 
substances around, and repelling them when by contact the fluid in those bodies also is 
disturbed. The laws of this attraction and repulsion must form the subject of a futuio 
consideration ; at present it will be more convenient to consider the nature of electrical 
action, and call attention to a few of those common experiments, which show the uni- 
versality of the electric fluid, and the numerous yet simple operations by which bodies 
may be artificially excited, or thrown into a state of electrical action. However diversified 
experiments on excitation may be, yet friction will be found to attend the whole of them, 



and the more attentively the various phenomena are noted, the better founded must be the 
conviction that this alone causes electrical disturbance. The eflfect will be in a great 
measure accordant with the degree of friction employed, and with the dissimilarity of the 
bodies acted upon ; and although it will be seen from some of the illustrations, that 
evaporation and change of temperature of certain substances causes them to appear 
electrical, yet each of these operations is attended by a motion of the particles among 
themselves and against the containing vessel ; thus here, as in more obvious instances, 
friction is produced, though by natural means, rather than by that mechanical rubbing 
which we are accustomed to employ. The conclusion to which we must come, that friction 
is the ultimate cause of excitation, is impressed the more strongly upon us by the circum- 
stance that all those bodies which become electrical by heating, cooling, crystallization, or 
other change of form or temperature, are still more easily and more powerfully excited by 
the rubbing which effects other bodies. 

In performing electrical experiments of any kind it must always be borne in mind 
that the earth is the grand reservoir of the electric fluid ; from the earth it must at all 
times be taken, and to be retahied even for a single moment it must be prevented 
returning to the earth again ; this is easily accomplished by the application of the different 
properties of electrics and conductors. The first of these classes of bodies may be excited 
readily, but will not suffer the fluid to pass along them ; the conductors on the contrary 
are excited with difficulty, but suffer the fluid to escape over their surfaces with great 
rapidity of motion. Be it observed also, that the electric fluid takes every opportunity to 
return to a state of rest and quietude, and to keep it disturbed, the body in which it is 
excited must be insulated, or supported by electrics, and no conducting substance brought 
within its sphere of attraction. In some of the following experiments, indeed in most 
of them, we witness an electrical action only in one of the bodies subjected to friction, 
while the rubber or other body is not considered. This however is equally acted upon, 
and if we take proper means for detecting the electricity of both the rubber and substance 
rubbed, we shall find that the action is the same in amount in both, but the nature of the 
action is contrary in the rubber to what it is in the substance rubbed — one exhibiting what 
is called a redundancy, and which is therefore said to be electrified plus or positively/ ; 
the other having a proportionate deficiency, or is said to be electrified minus or negatively. 
These two degrees or contrarieties of effect neutralize each other, and thus when two bodies 
are rubbed together while they remain in contact with each other, no action is apparent ; 
but when that contact is separated, visible effects take i)lace. Tliese preliminary remarks 
will render plainer the annexed experiments. 



Ex. 1. Attraction of amber. — Take a 
piece of yellow amber, warm it, rub it briskly 
on the coat sleeve, and hold it towards some 
scraps of bran, filaments of feathers, or other 
light bodies lying upon a book or a smooth 
table. The amber being excited by the fric- 
tion will attract the particles of bran, &c., 
and hold them suspended. This is the first 
electrical experiment recorded. The workers 
in amber are so annoyed by its strong at- 
tractive, and easily excitable nature, as to 
have the tips of their fingers often very greatly 
affected by it. 



2. Attraction of sealing wax. — A simi- 
lar effect takes place when a stick of sealing 
wax is rubbed and presented to any light 
matters ; they will as before rise up and cling 
to it. If either the sealing wax or the amber 
be held towards the bran, &c , before it 4S 
rubbed, it will have no effect upon them. 

Any thing dry and covered with sealing wax 
answers the same purpose as sealing wax. 
The best thing to use is the glass tube men- 
tioned in Ex. 9, one half of it in length being 
heated, and red sealing wax then rubbed on 
it ; this will adhere and form a resinous tube. 



3. Attraction of rubbed paper. — Take 
two pieces of white paper, warm them at the 
fire, place them upon each other on a table 
or book, and rub strongly the upper paper 
with a piece of India rubber ; the papers will 
now be found strongly electrical, so as to ad- 
here together with such force that it requires 
some trouble to separate them, and when 
separated and then made to appi'oach each 
other again, they will immediately rush to- 
gether a second time. 

4. Adhesion of brown paper to a wall. 
— Take a piece of common brown paper 
about the size of an octavo book, hold it 
before the fire till quite dry and hot, draw it 
briskly between the side of the coat and the 
sleeve several times, so as to rub it on both 
sides at once by the woollen. The paper will 
now be found so powerfully electrical, that if 
placed against a wainscot, or the papered wall 
of a room, it will remain there for some 
minutes without falling. 

5. Adhesion of a feather to excited paper. 
— If while the paper remain fixed to the wall 
a light fleecy feather be placed against it, it 
will adhere to the paper in the same way as 
the paper adheres to the wall. 

6. Glass plate excited. — Support a pane 
of glass, (first warmed) upon two books, one 
at each end — place some bran underneath it, 
and rub the upper side with a warm black silk 
handkerchief or a piece of flannel — the bran 
will now fly and dance up and down with 
much rapidity. 

This experiment is the only contribution 
that Sir I. Newton made to electricity, but 
it was important, inasmuch as it proved what 
was unknown before, that glass showed elec- 
trical effects on the side contrary to that which 
was excited. The account was read to the 
Royal Society in 1675. It is very interesting. 
" Having laid upon the table a round piece 
of glass, about 2 inches broad, in a brass 
ring, so that the glass might be i of an inch 
from the table, and then rubbing the glass 
briskly with the corner of his silk cloak, little 
fragments of paper laid on the table under the 
glass began to be attracted, and move nimbly 
to and fro ; after he had done rubbing the 
glass the papers would continue a consider- 
able time in various motions ; sometimes 
leaping up to the glass, and resting there 
awhile ; then leaping down and resting there ; 
then leaping up and down again ; and this 
sometimes in lines seemingly perpendicular to 
the table ; sometimes in oblique ones ; some- 
times also leaping up in one arch, and leaping 
down in another, divers times together, with- 
out sensibly resting between; sometimes skip- 
ping in a bow from one part of the glass to 
another, without touching the tabl ; and 
sometimes hanging by a corner, and turning 



often about very nimbly as if they had been 
carried about in the midst of a whirlwind, 
and being otherwise variously moved, every 
paper with a different motion. Upon his 
sliding his finger on the upper side of 
the glass, though neither the glass nor the 
inclosed air below were moved, yet he ob- 
served that the papers, as they hung under 
the glass, would receive some new motion, 
inclining this way or that, according as 
he moved his finger.'' This is done much 
better by a glass, 6 or 8 inches over, at the 
distance of an inch from the table. 

7. Coffee excited. — In grinding coffee, 
particularly if it be fresh burnt, it will be 
seen to cling around the lower part of the 
mill, and also around the cup or basin held 
to catch it — sometimes so strongly as to cover 
the sides 2 inches or more above the general 
surface. 

These experiments are all examples of elec- 
trical attraction, and some of them may be 
made much more conspicuous to a public 
audience, if the light matters to be attracted 
are suspended in some manner, as for ex- 
ample in the following instrument, which is 



called a balance electroscope. Fix a glass 
rod, a common phial, a stick of sealing wax, 
or a slip of window glass upright upon a foot 
or board, cement a needle point upwards upon 
the top of this ; and upon the needle point 
suspend an equally-balanced slip of very dry 
wood cut as thin as possible, made perfectly 
smooth, and about 8 inches long. At each 
end of the wire fix a scrap of paper, or a 
small ball made of cork, or the pith of elder. 
To make one of these electroscopes or 
electrical indicators, in the best manner, the 
foot and supporter should be of brass, and 
the balance of a fine glass thread ; the balls 
being of pith, and covered with gold leaf. 

Ex. 8. Attraction of electroscopes. — 
Hold the excited sealing wax, amber, paper , 
ribbon or glass of these experiments towards 
one of the balls of the balance electroscope, 
the suspended filament of wood will turn 
round on the pivot, so that the ball will follow 
the excited matter held to it. 




A. more delicate, and perhaps more con- 
venient electroscope is 
made as follows: — The 
foot is of wood, the up- 
right is a stout wire, 
bent towards the top 
as shown in the figure. 
Upon the hook of this 
are suspended two 
pieces of sewing silk, 
about 6 inches long 
each, and which have 
either small disks of 
white paper, two pith 
balls, or two feathers 
tied at the ends. This 
is called \X\e pendulum 
electroscope. For the 

above experiments one thread and feather is 

sufficient. 

9. Glass tube excited. — This is shown 
much more conspicuously by using, instead 
of the sealing wax, a glas-s tube about 2 feet 
long, and an inch in diameter ; make this 
perfectly dry and warm at the fire, then rub it 
briskly with an old black silk handkerchief, 
made warm. The glass will be powerfully 
excited, and of course attract with great force 
the suspended feather. 

10. Desaguliers gives the following curious 
experiments. He says, that when an excited 
tube has repelled a feather, it will attract it 
again, after being suddenly dipped into water, 
in fair weather it will not attract it, unless it 
hath been dipped pretty deep into the water, 
a foot of its length in at least ; whereas in 
moist weather an inch or two will suffice. 
—Philos. Trans. Abr., vol. 8, p. 429. 

11. The attraction of water by an excited 
tube is shown by bringuig the tube to a stream 
issuing from a condensing fountain, which 
thereupon is evidently attracted to it. — 
Desaguliers. 

12. Recession of charged objects. — Hold 
the glass tube in contact with the suspended 
feather for a short time, the feather which at 
first was attracted will soon become what is 
called charged, that is filled with electrical 
fluid. It will in this state become fleecy, the 
filaments will diverge from each other, and 
the feather j/?y away from the glass tube, and 
most likely adhere to the wire support of the 
electroscope. Sometimes if the tube be power- 
fully excited, the feather will fly backwards 
and forwards, giving a good example of elec- 
trical attraction and repulsion. 

Note. — It is here to be observed, that we 
use the terms repelled, charged, filled with 
electrical fluid, &c. in their popular sense 
only, so also until we can consider more fully 
the nature, effects and laws of electricity, 
cannot enter into a discussion, whether there , 



be in reality no repulsion at all, or if there 
be one electric fluid or two. 

13. Repulsion of electrified feathers. — 
Let there be two feathers suspended upon the 
electroscope by different silk threads, they 
will both adhere at first to the glass, and then 
recede from it, and also from each other. If 
there be three or more feathers, the same 
effect will be exhibited. 

14. Feather driven about the room. — If, 
while still excited, a light fleecy feather be 
brmgl t near, it will at first cling to the glass 
rod, and afterwards fly away from it, and 
may be driven about a room, by holding the 
glass between it and any surrounding object. 
If it should touch any thing not electrified, 
it will fly back to the glass again. It will be 
observed, that the same side of the feather 
is always presented to the excited tube. 

15. Electrified hair. — Another instance 
of electric repulsion is seen when a bunch of 
long hair is combed before a fire, '* each par- 
ticular hair will stand on end," and get as 
far as possible from its neighbour. 

The above experiments show the electric 
disturbance of various bodies, so as to inform 
us that some power exists which is called into 
action by friction, assisted by perfect dryness 
of the materials employed, but they do not 
communicate any intelligence of what this 
power really is ; yet a very trifling increase of 
the intensity of any of the foregoing will 
render the fluid itself perceptible to our cor- 
poreal senses, sight, hearing, feeling, smelling, 
and as we shall show hereafter taste also, 
though we believe this cannot be made per- 
ceptible by the simple means we are now 
employing. 

The ancients were quite unacquainted with 
any other electric effect of amber, but that 
recorded in the first experiment. Dr. Hall 
discovered many other electric properties of 
it, as recorded in Philo. Trans. Abr. ,Yo\.2, 
He says — 

16. "I found by gently i-ubbing a well 
polished piece of amber with my hand in the 
dark, that it produced a light ; whereupon I 
got a pretty large piece of amber, which I 
caused to be made long and taper, and drawing 
it gently through my hand it afforded a con- 
siderable light. I then used many kinds of 
soft animal substances, and found that none 
did so well as wool. And now new pheno- 
mena presented themselves, for upon drawing 
the piece of amber through the woollen cloth, 
and squeezing it pretty hard with my hand, 
a prodigious number of little cracklings were 
heard, and every one of these produced a 
little flash of light ; but when the amber was 
drawn gently and lightly through the cloth, 
it only produced a light, but no cracklings ; 
but by holditig one's finger at a little distance 



from the amber, a large crackling is produced 
with a great flash of light, and what to me is 
very surprising is, that upon its eruption it 
striker, the finger very sensibly, wheresoever 
applied, with a push or puflf like wind. The 
crackling is full as loud as charcoal on fire, 
and five or six cracklings or more, according 
to the quickness of placing the finger, have 
been produced from one single friction, light 
always succeeding each of them. Now I make 
no question, but upon using a longer and 
larger piece of amber, both the cracklings 
and light would be much greater, because I 
never yet found any crackling from the head 
of my cane, though it is a pretty large one. 
This light and crackling seem in some degree 
to resemble thunder and lightning." Dr. Hall 
also states that light can be produced from 
jet, sealing wax and the diamond. 

17. Break a large lump of loaf sugar in the 
dark, or pound it in a mortar, when it will 
appear covered with a beautiful lambent blue 
flame. When grocers are sawing up loaves 
of sugar as samples, the dust is most lumi- 
nous and beautiful. 

18. The electric light and snapping ob- 
tained from paper. — Excite a piece of brown 
paper, after having made it quite hot before 
the fire, as in Ea;. 4 ; make it adhere to the 
wall in a dark room, and immediately tear it 
from the wall, a light attended by a faint 
snapping noise will arise. This is the elec- 
tric spark. 

19. '1 he same is very perceptible, if the two 
pieces of white paper, excited as in Ea^.3, are 
taken and torn asunder in the dark. 

20. Electric light and odour obtained 
from' quartz. — Rub or grate together two 

round uncut stones of quartz, calcedony, 
cornelian, &c., and a strong phosphoric light 
and odour will be produced, showing another 
peculiarity: viz., that the electric fluid is 
perceptible to our sense of smelling. 

21. The spark felt. — Support a round 
plate of metal upon the top of a very dry wine 
glass. Excite the brown paper as in Ea;. 4, 
and place it on the metal plate ; if now you 
hold your knuckle quickly to the metal plate, 
a small but very perceptible spark will pass 
from the metal to the hand, showing the fluid 
is perceptible to the touch, and also that it 
will pass from one body to another, for it is 
the fluid from the excited paper, which passing 
throagh the metal is felt by the hand. 

22. Sensation of cobwebs. — Hold the ex- 
cited glass tube close to the face, a sensation 
like that of cobwebs spread over the face will 
be immediately apparent, and the hair will be 
sensibly moved at the near approach of the 
tube. 

23. Shock from a cat. — Take up in the 



lap a black cat which has been lying for some 
time before the fire ; hold it by one hand under 
the throat, and with the other hand rub the 
cat several times along the back. The hair 
will soon become so excited, and overcharged 
with the electric fluid, that a complete shock 
may sometimes be felt, and generally a suc- 
cession of small sparks. We need scarcely 
observe, that Miss Pussey must be a con- 
senting party. This experiment, as indeed 
do all of an electrical nature, succeeds best 
in frosty weather. 

24. Metallic ball electrified. — Suspend 
from the ceiling a metallic ball by a silk cord, 
and touch it with the excited glass tube. This 
(Dall will now attract the feathers or the balls 
of the common electroscope in the same 
manner as the glass rod itself does. This 
shows that electricity is communicated fr(Mn 
one body to another, as it is very evident that 
the metallic ball became electrical by contact 
with the tube. 

The above experiments, and which show 
the various effects of the electrical fluid, are 
made with somewhat brisk and continued 
friction, and therefore produce effects of suf- 
ficient plainness and strength to be perceptible 
to us without any instrument of superior de- 
licacy. It will naturally be concluded, that 
a less degree of friction will still produce 
similar eff"ects, although they will be propor- 
tionably less in amount. Indeed we shall 
soon have occasion to show that the most 
trivial actions we do, and the most casual 
operations of nature, require only favorable 
circumstances to make their electrical cha- 
racter apparent. Among these circumstances, 
the most important is, that we should perform 
the expei'iments with care, and the second, that 
the instruments we use to detect the disturb- 
ance of the fluid should be of extreme deli- 
cacy. These instruments are called electro- 
scopes and electrometers. The first indicates 
an apparatus which shows that a disturbance 
has taken place in the fluid of an excited body, 
as is the case with the pendulum and balance 
electroscopes we have described, and the 
other, (the electrometer) is capable of measur- 
ing the exact amount of this disturbance. It 
is necessary to describe one of each of these, 
that we may see the efl'ects produced by other, 
and less obvious, or at least less powerful 
modes of excitation. 

THE GOLD LEAF ELECTROSCOPE. 

The gold leaf electrometer is made of two 
forms, as shown in the following cut. In that 
marked 1, and which is called from iti in- 
ventor, Bennett's gold leaf electroscope con- 
sists of a wooden foot, which supports a glass 
tube about 2^ inches wide, and 5 long. This 
has two slips of tin foil pasted i,a the opposite 
sides as represented. The cyli ider is closed 



8 



at top by a brass cap, which fits tight round 
the sides, but takes off and on, in order that 
if the two slips of gold leaf which hang from 
the middle of the cap in the inside should 
become broken, tbey may be repaired. The 
cap should not in any other case be removed. 
The gold leaves are about 3i inches long, and 
^ an inch wide ; they are best fastened on by 
a little piece of flatted brass, soldered to the 
inner side of the cap, and the leaves, attached 
by gum water, gold size, paste, or any thing 
similar. They should hang so as to touch each 
other when not in an electrified state, and 
when divergent, as shown in the cut, they 
should approach to the slips of tin foil on the 
glass. The cap has occasionally a point which 
screws upon it, as shown ; this however is 
never used, except in trying experiments 
upon the electricity of the atmosphere. 




Sausseur's gold leaf electroscope, which is 
represented in fig. 2 of the above cut, differs 
from the former in the manner in which the 
gold leaves are insulated. The cap is a flat 
plate, with a wire soldered beneath. The 
gold leaves are soldered at the lower end of 
the wire, and the whole wire is inclosed in a 
glass tu.ie. The outer surface of this tube 
is best covered with sealing wax, as the in- 
sulation of resinous substances is much better 
in damp weather than that of glass, which 
rapidly attracts the moisture of the breath, or 
of the apartment. The diameter of the glass 
may be 4 inches, the height of it 8 inches. 
The size of the plate at top from 2 to 4 inches, 
as most convenient. The cap which incloses 
the top of the glass, and into which the glass 
tube is cemented, may be of wood or metal ; 
the former is preferable. 

A cheap and good substitute for the above 
may be made of a common six-ounce phial, 
a wire passing through the cork of it, having 
the gold leaves within the phial, and a brass 
ball or a bullet above. A lamp glass, also, 
with a cork above and below, (ball and gold 
leaves similarly arranged,) answers every 



purpose, the bit of card also is of little 
consequence ; and let it be remarked, once 
for all, that whenever glass apparatus is em- 
ployed, it must be kept perfectly dry, slightly 
warm, and free from dust. Of so much con- 
sequence is this, that should there have been 
a failure in any of the simple experiments, it 
most probably has arisen from neglect of this 
precaution. There are numerous variations 
of this instrument, according to the purposes 
for which they are required. One of extreme 
delicacy, though not so much so as that with 
gold leaves, is made with two fine strips of 
straw, suspended on little wire loops. Ano- 
ther is furnished with two extremely delicate 
silver wires, with small pith balls attached : 
this is used chiefly for experiments upon the 
electrical state of the atmosphere. This with 
numerous other electroscopes wil be de- 
scribed hereafter. 

Note. — We would remind the young elec- 
trician that the tvhole of his apparatus may 
be made by himself with ordinary care, and 
that he may do so with greater facility, we 
will fully describe the various parts of each 
instrument. Let him at all times remember 
to round off all sharp edges and corners, and 
to make the wood work smooth. Every thing 
in glass, except plates, whether cylinders, 
tubes, rods or handles, he may purchase at 
per lb., at the glass works, Holland Street, 
Blackfriars. Tinfoil may be cheapest bought 
at a pewterer's. A maker of it lives in Brown's 
Lane, Spitalfields, London. A roll 5 feet long, 
and 10 inches wide, costs bd, or a smaller 
roll 3^d. Tinfoil for electrical purposes may 
be as thin as possible ; it is best put on to 
wood or glass with common paste. When 
silk is used, let it be always black, except 
when otherwise specified. The best varnish 
for electrical apparatus is copal varnish or shell 
lac varnish ; and if they are required to be 
ornamented with a colored varnish, let it be 
by two or three coats of sealing wax dissolved 
in spirits of wine, laid on with a small brush. 
Both the shell lac varnish and the sealing wax 
varnish are easily made by breaking the lac 
or the wax in small pieces, putting it in a 
phial with spirits of wine, brandy or whiskey, 
enough to cover it, and then placing the phial 
on the hob till the resinous substance is dis- 
solved. These varnisljes dry in a few minutes, 
but copal varnish tnkes two days. The mode 
of action and degree of susceptibility of these 
electrometers are shown by the following series 
of experiments: — 

25. Take tie paper which was before 
experimented with, and after again exciting 
it well, lay it upon a plate of tin, supported 
by a dry wine glass. Immediately and sud- 
denly apply the knuckle to the under surface 
of the tin, and a spark will be felt. A better 
substance than tin would be a round piece uf 



9 



wood 6 or 8 inches in diameter, ^ an inch 
thick, rounded at the edges, and covered 
neatly with tin foil, as by this means sharp 
edges are avoided. 

26. Suspend a pair of pith balls to the 
under surface of the plate of tin or wood ; 
place the excited paper upon it as before, 
and observe that the pith balls will recede 
from each other, or show electrical repulsion. 
This then explains the mode of action of the 
electroscope, and the appearance it presents. 
In this experiment the disturbed fluid of the 
paper acts upon the fluid of the metal plate, 
and that upon the fluid in the pith balls. In 
gold leaf electroscopes the fluid is in like man- 
ner disturbed, and of course according to its 
amount or degree of disturbance so will be 
the greater or less divergence of the gold 
leaves. 

27. Hold near the above instrument any 
of the excited bodies used before — such as the 
paper, or the glass rod, and the nold leaves 
will diverge to a considerable distance from 
each other, and remain so for some time. A 
well-excited glass tube will stimulate it at a 
distance of 2 or 3 feet, and must not be brought 
too rapidly close to it, or the gold leaves will 
be rent to atoms by the violence of the action. 

28. Brush the cap of the electroscope with 
the feathery part of a quill, and the gold 
leaves will instantly diverge. 

29. Give the cap a blow or two with the 
corner of a black silk handkerchief, previously 
warmed, and the friction, small as it is, will 
be found to have the same effect as before. 

30. Take a knife, fvith a glass or ivory 
handle, and cut some small pieces off a slip 
of deal, so that they shall fall upon the cap 
as before. Each piece carrying down with 
it a portion of the fluid disturbed, will, in a 
similar manner, aff'ect the instrument. 

31. After playing a tune upon a violin 
with a well- rosined bow, hold the bow towards 
the cap of the electroscope, the gold leaves 
will immediately diverge. 

32. Sift some steel, brass, or other metal- 
lic filings, upon the cap of the electroscope, 
from out of a metallic sieve. The&e tilings 
become electrical by the friction merely of 
passing through the holes of the sieve, and 
will consequently affect the gold leaves. The 
same may be done with charcoal, putty pow- 
der, black-lead, lime, and numeroas other 
bo lies. 

33. Let the metallic sieve out of which 
they are sifted be held by a sealing wr-x or 
dry glass handle. Sift some metallic powder 
through it, but at a distance from the elec- 
troscope ; then hold the sieve to the electro- 
scope, that will be found to be excited ; and 
if the means be taken which are explained 



in the after-part of this chapter to ascertain 
the nature of the exciteqaent, it will be found 
that the sieve is in a contrary state to that of 
the powder. 

34. Bombazine excited hy rending. — 
Warm a piece of this stuff" at the fire, or 
any other kind of material formed of two 
substances, such as woollen and silk, silk 
and cotton, silk and hair, &c. ; when warm 
and dry, draw out the various threads, of one 
of the substances, and put them on the cap 
of the electroscope; it will immediately be- 
come aff"ected. The weavers of bombazine 
are well aware of these electrical properties. 

35. Melt some chocolate in an iron cup, 
adding a few drops of olive oil ; place the cup 
upon the top of the electroscope to cool, as 
it cools, it will become electric, and show this 
by the divergence of the gold leaves. 

36. Clean a piece of dry glass with whiting, 
and let the particles fall upon the top of the 
electroscope, they will sensibly affect it. Dust 
brushed off" a coat will generally aifect it in 
like manner. 

37. Break a stick of sealing wax in half, 
and hold one of the broken ends towards the 
cap, and the gold leaves will diverge. 

38. Varnish a piece of glass ; when the 
varnish is dry, scrape some of it off, letting 
it fall upon the electroscope ; this also will 
show a sensible eff'ect. 

The student will perhaps desire to vary 
these experiments, and being observant will 
soon ascertain that there are apparent ano- 
malies in the mode of action, or in the eff'ect 
produced, for which he will, until such are 
explained, be unable to account for. 

39. For example, let him liold the glass 
tube to the gold leaf electroscope, so as to 
make the leaves diverge, but so as not to 
touch it ; he will observe that immediately 
he removes the exciting cause, the effect will 
cease ; as the glass is withdrawn, the leaves 
will collapse. Now let him touch the cap 
with the excited glass, and then withdraw it. 
The gold leaves will now continue to diverge, 
and not collapse as before. 

40. While they are thus divergent, let the 
glass still excited be made to approach a 
second time, the leaves will recede still farther 
from each other than before. 

In the former of these experiments the elec- 
tricity is induced; that is, no electricity is 
really communicated to the leaves, but the 
approach of the excited electric has had suf- 
ficient power to disturb the fluid of the whole 
apparatus, and to drive it to the extremity 
of the gold leaves ; they being both electrified 
repel each other, but the effect is transient 
only, and when the exciting cause is removed, 
of course the effect ceases. In the latter 



10 



experiment, in which the exciter touches the 
apparatus, it positively charges it with some 
of its own fluid, and therefore it is in this 
case not merely the extremity of the gold 
leaves which become electric, but the whole 
apparatus, and they being the only delicate 
parts of it, show that it is so ; this then is an 
instance of accumulated or communicated, 
and not induced electricity. The next two 
or three experiments open to us a new field 
of inquiry. 

41. Roll up a band of flannel, warm one 
end of it at the fire, and hold it by the other. 
Excite the sealing wax by the warmed end, 
hold the excited wax to the gold leaf electro- 
scope, and it will show the usual signs. Next 
remove the wax and hold the flannel ; this 
will also show that it is excited. Next hold 
them both together towards the instrument, 
and no effect will be apparent. 

It is then evident that in every instance of 
friction, as there must be two bodies rubbed 
together, so both of them become equally 
excited. In the one body the fluid accumu- 
lates, and that body becomes positively elec- 
trified ; the other is to an exactly equal degree 
deprived of its fluid by the first, and it be- 
comes electrified negatively, and these two 
degrees of disturbance are such as exactly at 
all times to destroy each other, as was proved 
in one instance in the last experiment, where 
the wax and flannel being held together pro- 
duced no effect. Yet although this is known 
to be the case, the general result of the 
operation of presenting the flannel and the 
wax is the same, the gold leaves were diver- 
gent in both instances ; this is because two 
bodies electrified, whether negatively or posi- 
tively, repel each other. When the wax was 
presented, as wax when rubbed by flannel 
becomes negative, it attracts to itself the fluid 
of the apparatus. This is collected near to 
Uie wax, and the opposite end is consequently 
deficient ; when the flannel is presented, as 
that is positive, it drives the fluid of the ap- 
paratus to as great a distance as it can, and 
the gold leaves are consequently divergent 
from excess of fluid. These eff"ects, though 
apparently the same, may be proved to be 
contrary to each other, as follows : — 

42. Touch the cap with the excited wax, 
so that the gold leaves are affected by com- 
municated electricity, then bring the wax near 
them a second time, and they will diverge 
still npore, but bring instead of this the ex- 
cited flannel towards them, and they will 
collapse ; in fact, the fluid in the flannel being 
of a contrary character has annulled the 
effect of the wax. 

43. Next, while the leaves are divergent 
with negative electricity by the wax having 
touched them, excite a glass tube and hold 



it towards the instrument. The leaves will 
collapse as in the last instance, showing that 
the effect of the flannel in the last experi- 
ment, is the same as that of the glass in this, 
or that they are both electrified positively by 
the friction that has been used. 

44. Suppose that the glass tube in the last 
experiment be rubbed by flannel, instead of 
the silk handkerchief recommended in Ex. 9, 
the effect would be the same, as may be tried ; 
if so, the flannel with which it is rubbed must 
be negative ; whereas, in the last experiment 
the flannel was positive ; thus the same sub- 
stance may be positively or negatively elec- 
trified, according to circumstances. 

45. Try an experiment similar to Ex. 44 
with a glass tube, rubbed with a black cat's 
skin, and the glass is then negative, and the 
skin positive. 

46. Roughen the glass, and rub it with 
silk, and the rough glass is then negative, 
and the silk positive. 

47. Rub the sealing wax with a piece of 
tinfoil held tightly in the hand, and upon 
trying the effect, the wax will now be found 
positive, although in all our former experi- 
ments it has been negative. 

It is important then to observe, that 
no body has any peculiar character of fluid 
inherent in it. Glass and sealing wax only 
show their ordinary effect under ordinary 
circumstances, each as we have seen takes the 
place of the other occasionally ; this however 
was not suspected at first. M. Du Fay, 
who ascertained the negative character of the 
latter, and the positive character of the glass, 
imagined that these effects were constant, so 
much so as to designate the two states of 
negative and positive, by the terms resinous 
and vitreous ; supposing, and in which he 
has had many followers in our day, that there 
were two distinct fluids, the disturbance of 
which was at all times simultaneous and equal. 
It was not till the experiments of Mr. Canton 
in the latter part of the year 1753, and of 
Mr. Wilson soon afterwards, that showed the 
impropriety of the terms vitreous and re- 
sinous, though they were not able to affect 
the question of whether there is one fluid or 
two. 

These experiments may be varied without 
end, and we have by them a ready means of 
ascertaining at all times the electric properties 
of all substances which will admit of friction ; 
for we have only to electrify any electroscope 
with one substance, the effects of which we 
are certain, and we can by that test all others. 

48. Excite a glass tube, let it touch an 
insulated body, for example, the balls of the 
pendulum electroscope, and then hold the 
body to be tested close to it, if the bali» 



n 



recede still more when electrified by this body, 
it is electrified positively, and if they col- 
lapse, it is electrified negatively. The two 
states of the fluid may also be shown, as 
follows : — 

49. Excite a rod of sealing wax, and ano- 
ther of glass, both by flannel. Hold them one 
on each side of a pith ball suspended by silk, 
the ball will vibrate backwards and forwards 
from one to the other. The moving body 
may be made in the shape of a fly or spider. 

In all the above experiments it must be 
observed, that the excited body to be tested 
must be held towards the same part of the 
apparatus as the test object was, or the result 
will be indecisive, and may even appear con- 
trary to what it is in reality. As before ob- 
served, when an excited glass tube is held to 
the electroscope, if it do not touch it, it 
drives the fluid to the farther extremity, 
which extremity is the part that shows the 
positive effect. If it be held towards that 
extremity, immediately the eff"ect may cease, 
because it drives that redundancy to the other 
end. This curious effect may be tried thus : — 

50. Make a pendulum electroscope with a 
glass support, and linen threads instead of 
silk ones, or what will do as well, damp the 
silk threads with the mouth, touch the top of 
the strings with the excited tube, and the balls 
will diverge, the fluid being driven to them ; 
then present the tube a second time also at 
the top, and they will diverge still more ; 
hold it sideways towards them, and although 
they will approach the tube, their divergence 
will be but little altered. Hold the tube 
beneath them, and they will collapse. The 
effect of the induction now produced by the 
tube being to repel the fluid towards the top, 
and consequently away from where it shows 
itself. 

5 1 . Try the same experiment with an elec- 
troscope made of the following shape ; the 




cross arm being a metallic wire, the support 
being glHSs. The excited glass tube being 
»lli)we ! to touch the end A, and then being 
withdrawn, both pairs of pith balls will show 
signs of divergence. Hold the glass tube a 
second time to the end A, but without touch- 
ing it, the pair at A will partly collapse, while 



that at B will diverge still more. Rcrcrse 
the experiment by holding the excited glass 
to B, and the balls at B will collapse, while 
those at A will increase their divergence. 

Instead of giving other experiments to this, 
which necessarily have a great sameness in 
their result, we have appended the following 
table, taken from Cavallo^s Electricity, and 
by the inspection of which the positive or 
negative result of the friction of all ordinary 
substances may be at once ascertained. 

Cat Skin is rendered positive by friction 
with every substance with which it has 
hitherto been tried. 

Smooth Glass is positive with every sub- 
stance, except cat skin. (We believe 
that this will hold good with several 
other furs ; for example, that of a 
black rabbit.) 

Rough Glass '\s positiveviiih dry oiled silk, 
sulphur and metals ; negative with 
woollen cloth, quills, wood, paper, 
sealing wax, white wax, and the human 
hand. 

Tourmalin is positive with amber, and 
the blast of air from bellows ; negative 
with diamonds and the human hand. 

Hare's Skin is positive with metals, silk, 
loadstone, leather, the hand, paper, 
and baked wood ; negative with other 
finer furs. 

White Silk is positive with black silk, 
metals, black cloth; negative with 
the hand, paper, hair, and weasel's 
skin. 

Black Silk is positive with sealing wax ; 
negative with hare's, weasel's, and 
ferret's skin, the hand, brass, silver, 
iron, and white silk. 

Sealing Wax ispositive with some metals ; 
negative with hare's, weasel's, and 
ferret's skin, the hand, silk, leather, 
woollen cloth, paper, and some metals. 

Baked Wood is positive with silk ; negative 
with flannel. 

Mr.Singer justly remarks, that " the result 
of experiments of this kind is much influenced 
by the state of the bodies employed, and the 
manner in which friction is applied to them. 
In general, strong electric signs can only be 
produced by the friction of dissimilar sub- 
stances, but similar substances, when rubbed 
together, so that the motion they individually 
experience is unequal, are sometimes electri- 
fied, and in such cases, the substance whose 
friction is limited to the least extent of surface 
is usually negntive ; thus the violin bow of 
Ejc. 31, was positivo, while if the strings 
had been alao tried, thev would have beeu 



12 



found negative." Another remarkable cir- 
cumstance is that color makes a considerable 
difference, black and white having in many 
cases a contrary effect. The following curious 
experiments on ribbons, stockings, &c., will 
illustrate many of these effects ; — 

52. Adhesive Ribbons. — Take two silk rib- 
bons, one black, the other white, each about 
3 feet long ; warm them at the fire, holding 
them up flat against each otherwith one hand, 
draw the thumb and fingers of the other hand 
briskly over them several times ; they will 
thus become powerfully excited, and although 
the upper ends of the ribbons be forcibly 
separated to the distance of a foot or more, 
the lower ends will still cling together. The 
black will be negative. 

53. Instead of a black and white ribbon, 
use two that are white, or two that are black ; 
excite them in the same way, and they will 
become repellant of each other, both being 
positive if white, and negative if black. 

54. Take a single ribbon, either white or 
black, warm it, hold it by one end, while 
another person holds the other end ; draw 
backwards and forwards over it briskly any 
negative electric, such as amber, sealing wax 
or rosin. The ribbon will be excited posi- 
tively, whether white or black. If instead of 
being held at each end, it be laid upon a quire 
of smooth dry paper, and then rubbed, the 
effect will be the same. If positive electrics 
be drawn over the ribbons, they will be ex- 
cited negatively. 

55. A strip of flannel and black ribbon 
will excite, and show the same effect as two 
differently colored ribbons. 

56. Dry two white silk ribbons at the fire, 
extend them on any smooth plane, draw the 
edge of a short ivory rule over them several 
times. While they continue on the plane, 
they do not seem to have acquired any elec- 
tricity ; yet, when taken up separately, they 
are observed to be negatively electrified, and 
repel each other. When they are separated 
from each other, electric sparks may be some- 
times perceived between them ; but when 
they are again put on the plane, no electrical 
appearances are seen without a second friction. 

57. Place the ribbons on a 'rough con- 
ducting substance, rub them as before, and 
they will, on their separation, show contrary 
electricities, which will also disappear when 
they are joined together. The upper ribbon 
is negative, the lower positive. 

58. Place the white ribbons which have 
been rubbed upon the rough surface, upon 
that surface again after they have been se- 
parated from it, and suffering them to remain 
there a few minutes, they will then upon being 
separated be found to attract each other ; tlie 



uppermost being positivoly, the lowermost 
negatively electrified. 

59. When two ribbons are made to repel 
each other, draw the point of a needle length- 
ways down one of them, and they will rush 
together. 

60. Bring an electrified ribbon near a 
small insulated metallic plate — it will be 
attracted but feebly. Bring a finger near the 
plate, a spark will be observed between them, 
though both together show no signs of elec- 
tricity ; on the separation of the ribbon they 
again appear to be electrified, and a spark is 
perceived between the plate and finger. 

61. Lay a number of ribbons of the same 
color upon a smooth conducting substance, 
draw the ivory rule or paper knife over them, 
take them up singly, and each will give a 
spark where it is separated from the other. 
The last will do the same with the conductor, 
and they are all negatively electrified. Take 
them from the plate together, and they will 
all endeavour to recede from each other. 

62. Let them be placed on a rough con- 
ducting substance, and then be separated 
singly, beginning with the lowermost, sparks 
appear as before ; but all the ribbons will be 
electrified positively, except the uppermost, 
or that upon which the ivory knife has acted. 
If they receive the friction upon the rough 
conductor, and are all taken up at once, all 
the intermediate ribbons acquire the elec- 
tricity of the highest or lowest, according as 
the separation is begun with the highest or 
lowest. 

63. If we take two ribbons of white silk, 
cut from the same piece, and make them rub 
against each other, while they cross at right 
angles, the piece which crosses the other 
transversely assumes negative electricity, and 
the other becomes positive, 

64. The same effect is sometimes produced 
by rubbing two sticks of sealing wax, placed 
at right angles with each other. It would 
appear from these, and other experiments, 
that the substance which is subjected to the 
greatest friction becomes negative, and the 
other positive. 

Mr. Symmer, an electrician of the last 
century, made some very curious observations 
and experiments on silk stockings. He was 
accustomed to wear two pair at the same 
time, and from the refitiarks he made upo;i 
taking them off and putting them on, th,5 
following experiments are deduced : — 

65. Electrified stockings. — Put upon the 
same leg a worsted stocking, and over this a 
silk one. Warm the leg at the fire, and rub 
the hand over the stockings. This done, slip 
off the siik stocking suddenly, and the two 
sides of it will recede from each other, and 



13 



the whole retain the same shape as if the leg 
still remained in it. 

66. If the stockings are both of silk, the 
one white and the other black, and they be 
warmed, rubbed, and then pulled off toge- 
ther, they will show no sign of electricity ; 
but on pulling off the black one from the 
white a crackling of sparks may be heard, 
and a light may be perceived upon their 
separation, if performed in the dark. 

67. When the stockings are separated, 
and held at a distance from each other, both 
of them appear to be highly excited — the 
white stocking positively, the black nega- 
tively ; and while separated they are both 
inflated, as in Ea;. 65. 

68. If the stockings be of different colors 
they will attract each other ; if of the same 
color they will repel, in the same way as the 
ribbons of former experiments. 

69. Let the stockings thus inflated by 
different electricities be suffered to meet ; 
the inflation immediately subsides, and they 
stick together with considerable force, each 
becoming quite flat. If they be again se- 
parated they will be inflated almost as 
strongly as at first. 



70. Take a ribbon of hot paper, and draw 
it backwards and forwards upon a dry linen 
cloth, laid on the knee, and the paper will 
always be negative. 

71. If rubbed against a metal it will be- 
come negative, unless the latter has received 
a high degree of polish, when it will some- 
times become positive. 

72. "When paper is rubbed against white 
silk it is generally negative, unless the silk 
be very hot, when the paper often becomes 
positive. With black silk it always becomes 
positive, except the silk be worn thin, when 
the paper is generally negative. 

73. Draw a black or white silk ribbon 
backwards and forwards over a piece of 
metal, and it becomes negative, whether the 
metal be polished or not. 

74. Take a piece of silk cloth, and swing 
it backwards and forwards in the air of a 
dry room, and it will show signs of negative 
electricity when held to the electrometer. 

75. A ribbon of silk, paper, or linen, 
rubbed against the skin of an animal still 
covered with hair, will always become very 
strongly and negatively excited. 



CHAP. 11. 

ELECTROMETERS. EXCITATION BY HEAT, PRESSURE, CONTACT, 
CLEAVAGE, CHEMICAL ACTION, AND EVAPORATION. 



It has been already observed, that friction is the cause of electrical disturbance, and that 
its extent agrees mainly with the degree of friction employed ; thus there are many 
operations in which friction is produced in a very small degree — these are, no less than 
more obvious examples, proportionably productive of electrical appearances. The mere 
contact of substances, the separation of two bodies which are united, heating, cooling, 
evaporation, impulse of steam, chemical actions, animal muscular motion, even the slow 
vegetation of plants and seeds give out certain electrical signs ; nay, it is probable that 
there is not an action we can do, or a change cf motion in an inanimate object we can 
occasion, which does not in a greater or less degree disturb the electrical fluid, sometimes 
exhibiting it in one character, and sometimes in another. Thus clouds drifting through the 
atmosphere, the wind impinging upon the earth's surface, the rolling of the ocean upon the 
shore, the rise and fall of dew, the occurrence of rain, hail, snow, and numerous other 
phenomena of daily occurrence do, in their immensity, produce often well-known effects. 
These are apparent to us when insulated as in our ordinary experiments ; in othci* cases 



14 

though equally produced, yet not observable, because of the want of those circum- 
stances, which would have prevented these sudden effects from being as suddenly dissolved. 
We can however show by our contrivances, that these electrical disturbances must take 
place in all cases, even where the most minute substances are concerned, and where the 
degree of friction is so small that it can scarcely be estimated. 

The experiments of Coulomb, and others of later date, upon this electricity of 
pressure, contact, &c., are very interesting and varied; many of these can be well shown 
by the foregoing electroscopes ; but there are others of them of too delicate a nature to 
show their effects to even the most susceptible of the instruments we have hitherto de- 
scribed ; indeed, many of them would never have been witnessed at all, unless Coulomb 
had contrived an electrometer which could be acted upon by less powerful impulses than 
those we have hitherto found it necessary to depict or describe. The following is the most 
delicate instrument of the kind : — It is called 




COULOMB S TORTION ELECTROMETER. 

It consists of a glass vessel, about the 
diameter of a common tumbler, and 6 or 8 
inches high ; such glasses 
are made for the use of the 
confectioners. We have 
represented it as made of 
a common pint decanter, 
as that will answer the 
purpose well, as would 
also a wine bottle, or large 
phial. Through the top 
passes an untwisted raw 
silk thread, 4 inches long. 
The glass decanter is gra- 
duated at the top by a 
piece of card fastened on to a cork ; the card 
is graduated to 360°, and the cork which fits 
the decanter has a hole cut through it suffi- 
ciently large for the silk thread to pass 
through it, and to have, at all times, sufficient 
room to vi^ork without touching the sides of 
the hole. There is a little hand on the upper 
end of the filament of silk, and at the lower 
end a very fine gum lac or red sealing wax 
thread, having at each extremity a small knob. 
This lac needle and its knobs weighs only i 
grain. A small hole is drilled in the side of 
the vessel at A, through which passes a fine 
wire, terminated at both ends with small balls. 
It is cemented in the side of the glass by 
sealing wax. When an excited body is made 
to touch the knob at A, the knob at the other 
extremity will acquire the same electricity as 
the excited body. This electricity it will com- 
municate to the knob of the lac needle, sus- 
pended by the silk thread, which was previ- 
ously almost in contact, and the two knobs 
will repel each other. The moveable knob 
will therefore be repelled from that which is 
fixed, and the quantity of electricity will be 
proportionate to the distance to which it is 
duiven. By means of the micrometer at top, 
It may be set at atiy position, so as in other 



cases to show the degree of attractive force. 
The following instrument, called Coulomb's 
electrical balance, is made upon precisely 
the same principle, and is of great delicacy. 

coulomb's electrical balance. 

A is a glass vessel, fitted into a stand at 
the foot, and having a circular portion of its 
circumference graduated. 
Upon A is fixed a long 
glass tube B, at the top of 
which is a circular scale of 
ivory C, with a small hand 
moveable around the cen- 
tre. Upon the centre of 
motion of this hand is sus- 
pended a single untwisted 
fibre of silk, which passes 
down the tube B, and into 
the vessel A, where it is 
terminated by a small piece 
of straw D, across which 
passes a wire and light ball 
E, forming a balance ; also 
through the top of A passes 
th'j wire F, which has a ball 
at each end ; one then of 
course will be without the 
vessel A, and the other within it, and exactly 
opposite to the ball E. When the upper ball 
F is electrified, it acts upon the ball E, 
repelling this to a certain distance, which 
distance, and consequently the degree of elec- 
trization, is indicated by the graduated scale 
on the side of A. 

These instruments are superior for delicate 
experiments to those electroscopes formerly 
described, because the degree of tortion which 
they undergo is a true criterion of the power 
exhibited, whereas in the pendulum electro- 
scopes gavitation acts very differentiy upon 
them at difftrsnt degrees of divergence of the 
leaves, so that a repulsion of the leaves of 




15 



gold leaf, of the pith balls, feathers, &c., as 
the case may be, of 40°, does not necessarily 
imply a double impulse to that action which 
shows 20° ; on the contrary, it will be much 
more than this. The balance electroscope, 
(page 5,) is not so unequally influenced by 
gravitation, but is too rude an instrument for 
some of the very minute experiments which 
the student would sometimes find it requisite 
to perform. 

The manner in which the state of the elec- 
tricity, whether positive or negative, is dis- 
covered by the tortion electrometer, is by 
exciting it by a known body, as glass, and 
then observing if the ball be attracted or re- 
pelled by the approach or contact of the 
substance to be tried. 

Other instruments of extreme delicacy, and 
which we shall find it for the future sometimes 
convenient to use, are Volta's condenser and 
BennetVs electrical doubler. We will pre- 
viously to describing them show the principle 
upon which they depend. When an insulated 
conductor is opposed to one which is not in- 
sulated, it has its capacity of electrical change 
increased by that proximity, and is more sus- 
ceptible of an increased or diminislied. quan- 
tity of electric fluid than when freely insulated, 
because in the state of approximation a much 
more considerable charge will be required to 
produce the same intensity, or tendency to 
equilibrium. Now, were the contiguity of 
the opposed plates permanent, no advantage 
would be obtained ; for the principle which 
renders the insulated plate susceptible of more 
extensive electrical change, also prevents it 
from rendering that change evident ; it is 
therefore essential, that the plates should be 
80 arranged as to admit of alternate proximity 
and separation ; for example — 




Suppose the metal plate B be suspended 
by a wire A, and A itself suspended by two 
silk threads. Also, suppose that C is a second 
metallic plate phcrd u little below B, and that 
B is connected with the ground. Touch A 
with the excited glass rod, it will of course 
communicate a charge to B. If now the plate 
C be made to approach B gradually, yet not 
so close as to take a spark, it will influence 
the fluid in B to such an extent as to enable | 
B to take a greater charge than before ; and 1 



the nearer C is brought to B, provided no 
spark pass between them, the greater will be 
the effect of C approach. Now touch A a 
second time ; this new fluid will act still more 
upon that in C, and as action and reaction are 
equal, B will be acted upon a second time, 
and so on for several times. By this means 
B will be soon charged to a very much greater 
extent than it would have been if C had not 
been present, and an impulse, not sufficient 
to affect the gold leaf electroscope singly, 
may thus be made perceptible. The following 
instrument, 

volta's condenser, 
Shows a pair of these condensing plates 
attached to a gold leaf electroscope. The 
plate A is connected with the cap, and is of 
course insulated. The plate B is supported 
upon glass, but is connected with the ground 
by the chain ; it turns upon a joint at C. It 
is sometimes connected with another con- 
denser, when the plate B becomes insulated 
by taking off the chain. The two plates have 
a thin coat of gum lac varnish on their inner 
sides, to prevent contact, and in consequence 
entire dispersion. To use the instrument, 
touch the cap or plate A with the excited body, 
B being withdrawn, then approach B to A, 
and touch A again ; it may afterwards be made 
to touch a third or fourth time, or more, until 
the gold leaves show signs of divergence. 



B 


m 






f 


\lm 


m 


i 


1 








j 




i 




CI 


^ ^ 


{ 


. 



BENNETT S ELECTRICAL DOUBLER. 

This instrument is an improvement upon 
Volta'sj it being mare susceptible. It con- 
sists, as the cut represents, 
of a simple gold leaf elec- 
trometer, the top of which 
is a flat metallic plate, 
marked A, of a simi'ar 
plate B, which has a glass 
handle, and of a third plate 
C, also with a glass handle. 
The plates C and B are 
covered on their under-side 
with sealing wax varnish. 
To use the instrument, first 
put the plate B upon A, 
touch the plate B with the 
finger, and then before the 




lb- 



finger is removed, touch the plate A with the 
object to be tested. Take away the object, 
and also the finger ; take up B by its handle. 
Place C on B, and touch C with the finger. 
By this a portion of the electric fluid is dis- 
turbed in C, so that C becomes electrified 
plus, or minus, in the same manner as A. 
Place B upon A, and touch B with the 
finger, and apply the edge of C to A ; the 
electricity of C will then flow to A. Remove 
C, take the finger from B, and raise B from 
A. Proceed in the same manner for three 
or four times more, until so much electricity 
is accumulated in A, as to occasion the di- 
vergence of the gold leaves. We will now 
show the use of these instruments by ex- 
periments. 

The mode chosen by M. Becquerel to show 
most of the following experiments was to 
form the substances to be tried into small 
discs, about one-tenth of an inch thick ; to 
fix each to a varnished glass rod by way of 
handle ; to take one of these handles in 
each hand, and squeeze the two discs together. 
After separating them, each disc has to be 
presented to a delicate electrometer ; a single 
pressure is often sufficient to repel the small 
disc of Coulomb's tortion electrometer, but 
by repeating the contacts Dr. Thompson 
gays any electrometer may be aflfected. 

ELECTRICITY BY PRESSURE. 

Ex. 76. Pressure of Iceland spar. — Hauy 
directs us to press in the hand a piece of 
Iceland spar ; then by holding it to the 
electrometer we shall find it electrical even 
by this very minute amount of friction. 

77. Pressure of other stones. — The same 
may be done with the topaz, cnclase, arrago- 
nite, fluor spar, carbonate of lead, and rock 
crystal. 

78. Pressure of glass. — Press two plates 
of glass together, and examine them ; one 
will be found positively, the other negatively 
electrified. 

79. Pressure of metal. M. Libes fixed 

an insulating handle to a metal disc, and 
pressed it, holding it by the handle against a 
pitce of gummed taffeta ; the taffeta acquired 
positive electricity, and the metal disc nega- 
tive. The effect increases with the pressure, 
but it ceases altogether as soon as the tatleta 
loses its glutinosity, which renders it easily 
compressible. 

80. Pressure of cork. — Take two discs ; 
one of cork, the other of caoutchouc. After 
pressing them together the cork will be posi- 
tive, the caoutchouc negative. 

81. When cork is pressed against the skin 
of an orange it becomes positive, and the 
orange skin negative. 



82. Cork pressed against Iceland spar, 
sulphate of lime, sulphate of barytes, or 
fluor spar, becomes negative, while with 
cyanite, pit coal, amber, copper, zinc, and 
silver, it becomes positive, and the substance 
pressed against it of the contrary character. 

83. Insulated cork pressed against any 
part of the animal body, provided it be not 
moist, receives an access of negative elec- 
tricity. 

Note. — It is not necessary that the bodies 
pressed against each other should be of con- 
trary natures. When two discs composed of 
the same materials, as skin, amadou, &c. are 
pressed against each other, they upon sepa- 
ration exhibit diflerent states, as indeed might 
be expected from the analogous experiments 
of the ribbons, Ex. 52. It is often however 
necessary to heat one of the two similar 
bodies to render the effect more apparent. 
The greatest effect is seen when one of the 
substances is of an elastic nature. The better 
conductors they are, the more rapidly the 
bodies pressed together should be separated. 

84. Electricity affected by heat. — 
Take a piece of well dried cork, and cut it 
in two, by means of a very sharp knife, and 
then press the two cut surfaces against each 
other ; it frequently happens, that however 
hard the pressure may be, and however rapidly 
we separate the two surfaces, neither exhibits 
any signs of electricity after the parting. But 
if we slightly heat one of the pieces of cork, 
by holding it near the flame of a candle, and 
renew the pressure, we shall find each surface 
possessed of a different kind of electricity. 

85. Heat and contact. — Take two pieces 
of Iceland spar, press them against each 
other ; no effect will be apparent, but if you 
then warm one of the pieces, and renew the 
pressure, a very evident excitation will be 
apparent. 

86. Contact of metals. — When zinc is 
brought into contact with copper or silver, 
and again separated by means of an insulating 
handle, the zinc is found positive, and the 
copper or silver negative. The experiment 
is to be done thus : — Procure two circular 
plates, about 4 inches diameter, the one of 
copper, and the other of zinc, perfectly clean 
and bright. Let an insulating handle be 
screwed into the centre of each plate ; hold 
the plates by their insulating handles, and 
apply their flat surfaces together, suffering 
them to remain in contact about a second ; 
then separate them, and touch the insulated 
plate of the condenser with the copper. 
Bring the zinc and copper in contact with 
each other again ; then touch the condenser 
as before with the copper — repeat the opera- 
tion till signs of electricity are apparent by 
the divergence of the gold leaves. This ex- 



17 



periment requires very great care, and even 
with that will sometimes scarcely be satis- 
factory m tha result. If iron or manganese, 
or even plumbago, be substituted for the zinc 
plate, the result is the same ; but if gold or 
platinum are employed no electrical action 
takes place, from which IM. de Rive inferred 
that these and similar effects resulted from 
chemical action, and not pressure or contact ; 
in this case the experiment, and others which 
follow, belong to galvanism, and not free 
electricity. It is still a disputed point with 
philosophers. We shall presently show that 
they really belong to the part of the science 
we are now considering. 

87. Contact of powders. — Have a tin, 
zinc, or copper disc, 3 inches over, with an 
insulating handle. Spread out upon a smooth 
sheet of white paper any of the following 
substances, quite dry ; succinic, citric, oxalic, 
benzoic or boracic acid^ sulphur, silex, alu- 
mine, carbonate of ammonia or resin. Touch 
the powder with the plate of metal, and apply 
the latter to the electrometer, v/hen after 
several contacts electrical signs will be ap- 
parent ; the copper being in every instance 
positive. With the following powders it is 
negative, the alkalies and their carbonates, 
the earths, except silex and alumine. 

This and similar experiments show the near 
approach of those two divisions of science, 
di>tinguished as electrical and galvanic ; the 
latter being always attended, if not caused, by 
some chemical change, the former being as 
fur as we have hitherto been able to detect in 
cases of a similar character to this ; namely, 
when two dissimilar metals being operated 
upon at the same time are accompanied by 
any such alteration of properties. Yet we 
find in other cases that electrical and chemical 
effects are concomitant, but these are in cir- 
cumstances totally different from that of the 
mere contact of the bodies which we are now 
considering. In a galvanic circuit of metals 
moisture is necessary for full effect ; in an 
electrical circuit they, and every other part of 
the apparatus, should be perfectly dry ; we may 
also observe the following essential differences. 

In electrical experiments we see atti-action 
and repulsion take place between the bodies 
excited ; in galvanism there is nothing of the 
kind a})parent. Electricity has very little 
effect in causing chemical decomposition — 
galvanism does this by the simplest combi- 
nations. The strongest power of electricity 
has little effect upon a magnet, or to form 
one, whereas galvanism is immediately shown 
in its extraordinary connexion with mag- 
netism. Thus clear distinctions between the 
two sciences, or two divisions of the science, 
are at once apparent, and serve as criteria to 
arrange doubtful experiments, such as those 
which follow. 



' This tTeing premised, the explanation '>f the 
following very curious instruments will be 
easily understood, from what has been said 
of the condenser and doubler. Suppose two 
dissimilar metals, as copper and zinc, are 
placed in contact with each otner, electricity 
is excited ; one metal becomes positive, the 
other negative — the copper will be negative, 
the zinc positive. Suppose we place three 
pairs of such metals, the three pairs having 
their copper sides in the same direction ; each 
copper in connexion with its zinc, but the re- 
spective pairs varnished on the outside. Each 
pair becomes excited by the mere contact, 
and when they approach each other induction 
takes place, as we explained in describing the 
condenser, and the pairs act upon each other 
by mutual approach. The varnish prevents 
their coming into actual contact, and there- 
fore the effect is not dissipated, from the vai- 
nish being a non-conductor. The effect of 
each pair is very minute, but when the pairs 
of plates are multiplied to 1000 or more, 
the result becomes powerful and decided. 
These views induced De Luc to contrive an 
apparatus, which he called his dry pile, the 
effects of which are to a very great extent 
proportionate to the number of plates, or 
rather pairs of plates. The best account of 
this, and two or three similar instruments, 
is given by Mr. Singer, who himself made 
many experiments with dry piles of different 
extent and materials. These we will describe 
in Mr. Singer's own words. 

DRY PILE OR ELECTRIC COLUMN. 

Mr. Singer says, " The materials I prefer 
for these piles are thin plates of flatted zinc, 
alternating with writing or smooth cartridge 
paper, and silver leaf. The silver leaf is first 
laid on paper, so as to form silvered paper, 
which is afterwards cut into small round 
plates by means of a hollow punch. In the 
same way an equal number of plates are cut 
from thin flatted zinc, and from common 
writing or cartridge paper. These plates are 
then arranged in the order of zinc, paper, 
silvered paper with the silver side upwards ; 
zinc upon this silver, then paper, and again 
silvered paper with the silvered side up- 
wards ; and so on — the silver being in con- 
tact with zinc throughout, and each pair of 
zinc and silvered plates separated from the 
next pair by two discs of paper. An ex- 
tensive arrangement of this kind may be 
placed between three thin glass rods, covered 
with sealing wax, and secured in a triangle, 
by being cemented at each end into three 
equidistant holes in a round piece of wood, 
or the plates may be introduced into a glass 
tube, previously well dried, and having its 
end covered with sealing wax, and capped 
with brass ; one of the brass caps may be 



18 



cemented on before the plates are Introduced 
into the tube, and the other afterwards ; 
eaoh cap should have a screw pass through 
its centre, which terminates in a hook out- 
side." This screw serves to press the plutefi 
closer together, and to secure a perfect me- 
tallic contact with the extremities of the co- 
lumn. The instrument constructed in this 
way is shown beneath : — 



Ex. 88. If a column of about 1000 series 
is placed horizontally, with each of its ex- 
tremities resting on a gold leaf electroscope, 
AS shown in the cut, the electroscopes will 
each diverge ; that connected with the zinc 
extremity of the column will be positive, that 
connected with the upper or silver extremity 
will be negative. If the column be very 
powerful, the gold leaves of the electroscopes 
will alternately strike the sides of the glass, 
bat this motion is soon stopped by their 
sticking to it. 




THE PERPETUAL CHIME. 

Soon after the invention of the column, 
Mr. B. M. Foster discovered that when a 
sufficiently -extensive series was put together, 
its electric power was sufficient to produce a 
sort of chime, by the motion of a small brass 
ball between two balls, insulated and con- 
nected with the opposite extremities of the 
column. He constructed a series of 1500 
pairs, and by its agency kept a little bell- 
ringing apparatus in constant activity for a 
considerable length of time. Mr. Singer 
continues : *' I formed a series of from 12 to 
1600 groups, which are arranged in two co- 
lumns of equal length, which are separately 
insulated in a vertical position ; the positive 
end of one column is placed lowest, and the 
negative end of the other — their upper ex- 
tremities being connected by a wire they may 
be considered as one continuous column. A 
small bell is situated between each extremity 
of the column and its insulating support ; a 
brass ball is suspended by a thin thread of 
raw silk, so as to hang midway between the 
bells, and at a very small distance from each 
of them. For this purpose the b 



I connected, during the adjustment of the pen- 
dulum, by a wire, that their attraction may 
not interfere with it ; and when this wire is 
removed, the motion of the pendulum com- 
mences. The whole apparatus is placed upon 
a circular mahogany base, in which a groove 
is turned to receive the lower edge of a glasg 
shade, with which the whole is covered." 
An instrument of this kind it is supposed will 
go for ever ; we have had one which has gone 
for many months, and a friend of ours had 
one of 1200 pairs of plates, which had been 
goin^ three years when we saw it. 




Mr. Singer directs, that in order to pre- 
serve the power of the column, the two ends 
should never be connected by a conducting 
substance for any length of time. It is there- 
fore necessary, when laid by, that it should be 
placed upon two sticks of sealing wax, and 
that the terminal balls be ^ an inch or so from 
the table. And if a column which appears to 
have lost its power be thus insulated for a 
few days it will recover. There is another 
cause of deterioration, which is more fatal ; 
this is too much moisture — the paper discs 
therefore should be made as hot as possible 
before they are put together, or even sub- 
jected to a continued but gentle heat for some 
time before they are inclosed in the glass 
tube, and that being heated also the plates 
may be inclosed without the presence of any 
appreciable quantity of moisture. The size 
of the plates may be f of an inch in diameter, 
or less. With a column of 20,000 plates, a 
Leyden jar may be slightly charged, and 
minute sparks seen between a wire brought 
from the upper end, when it is made to 
approach the lower end. 

DE lug's iERIAL ELECTROSCOPE. 

A name given to an instrument of the same 
description as Mr. Singer's, intended to mark 
the number of oscillations made in a given 
time. For this purpose a single column of from 
1 to 2000 series may be supported vertically 



19 




on an insulating pillar. A bent wire with a ball 
at its lower end, is to be connected with the 
upper extremity of the 
column, so as to hang 
parallel with, and be at 
some distance from it ; 
the ball at its lower 
extremity being diame- 
trically opposite to a 
similar ball that is 
screwed into the lower 
cap of the column. To 
the same cap is also 
screwed a brass fork, 
with a fine silver wire 
stretched between its 
extremities ; this is 
placed above the ball, ^^^r^rirzrrs 
and projects beyond the ^^'^H'T "^ 
brass ball of the column, so that when the 
pendulum moves towards the ball it strikes 
this wire first, and receives a kind of jerk 
whi^h prevents it from sticking. The pen- 
dulum consists of a gilt pith ball, suspended 
by a very fine silver wire, which hangs pa- 
rallel to the bent brass wire, to which it is 
fastened at top. The arrangement is such, 
that the gilt pith ball would be always in 
contact with the brass ball that proceeds 
from the upper extremity of the column, if 
the apparatus had no electrical power, it 
therefore always returns to this situation ; 
when, after being attracted to the lower ex- 
tremity of the column, it discharges its elec- 
tricity by striking against the cross silver 
wire. 

sturgeon's perpetual motion. 
We believe this has never been described, 
but we remember that some years ago, Mr. 
Sturgeon showed us an instrument similar in 
its nature to the above of Mr. Singer's, but 
of one metal only. He procured a common 
box, about 6 inches square, and an inch deep ; 
this was to hold the pile or collection of 
metals. He used two kinds of zinc, one made 
rough by dipping it into very dilute sulphu- 
ric or nitric acid, or scouring it with sand 
and water ; the other made as smooth as pos- 
sible. These metals were very thin, and being 
dried, were cut into pieces with scissars 
roughly into squares about f of an inch 
on the side ; they were then arranged in 
rows in the box thus : — First, a piece of 
smooth zinc, then one of rough zinc, then 
three pieces of writing paper made hot in 
the fire ; again smooth zinc, rough zinc, 
and three pieces of paper, keeping the same 
order till the pile was completed. There 
were several rows which were laid backwards 
and forwards along the box, the sides of the 
rows not being allowed to touch each other, 
but their ends being rightly united with a 
piece of £inc reaching from one row to ano- 



ther. Tlie two extreme ends had connected 
with them an upright piece of brass, and a 
pendulum so supported on a wooden or metal 
stem, that it played from one to the other. 
We write from recollection, when we give 
1600 as the number of the pairs of plates. 
The following shows an instrument of this 
kind. We have made the poles to end in 
bells, and covered the whole with a glass 
shade, which appendage is necessary for all 
these instruments, the currents of air having 
a great effect in disturbing or even stopping 
their motion. 







ZAMBONl's PERPETUAL MOTION. 

This is an instrument of the same kind as 
the last, or as that of Singer. The only dif- 
ference consisting in the form of the instru- 
ment, and the material of the small plates. It 
is represented thus : — D is a box, containing 
a drawer ; on the centre of the top of the box 
is a glass pillar, with a steel point at top, C. 
Upon this rests a very light frame-work of 
wire or wood, with six arms at the lower 
part, upon each of which is suspended a 
small strip of thin sheet brass or gold. The 
drawer is filled with several raws of pieces 
of paper, about an inch square each, altoge- 
ther about 20,000 in number ; one side of 
the paper is covered with silver leaf, the 
other painted over with black oxyde of man-, 
ganese, honey, and water. The papers ara 
arranged so that they should form one con- 
tinued series throughout. Pieces of tin-foil 
unite the rows together. One end of this 
pile is connected with the pole or brass stud, 
A ; the other with the contrary pole, A. 
The strips of metal hanging from the cross 
arms, B B, strike one pole, and then proceed 
to the other to deposit the electric fluid they 
acquired by the first impulse. So in the ro- 
tation the several strips are in like manner 
affected, and the frame with its various arms 
is in continued motion, which it will main- 
tain for years. It is necessary that it should 
be covered with a glass shade, to prevent tlie. 
disturbance of wind, &c. These machines 



20 



often require to be set going with the finger 
in the first instance, or by turning the glass 
shade round to produce a slight current. 




EXCITAT^JN BY CHEMICAL ACTION. 

Ex. 89. Excitation of burning charr,{yal. — 
Charcoal, when burnt, sometimes gives out 
electricity ; at other times none at aU. It may 
be tried as follows : — Support a brass plate 
upon the top of a delicate e;':)ld leaf electro- 
scope ; then take a cylirutrical piece of char- 
coal, with flat ends, 2 inches high and 1 inch 
in diameter. Place this piece of charcoal 
vertically, 2 inches and 5, or 3 inches 
below the brass plate. The charcoal com- 
municates with the ground, and is to be 
lighted at the centre of the upper end, taking 
care that the fire does not reach the sides. 
A current of carbonic acid rises, and strikes 
against the plate, and in a few minutes the 
electroscope will show signs of disturbance. 
If the piece- of charcoal be so inclined that 
the carbonic acid is obliged to slide up the 
sides of the charcoal no effect is produced ; 
this is a very delicate experiment, and may 
require the aid of the condenser. The fol- 
lowing shows the arrangement of the appa- 
ratus : — 




90. Electricity of burning hydrogen. — 
The flame of hydrogen gives, at different 



times, very different indications of electric 
properties, but it may be made pretty steady 
in its effects upon the electrometer by the 
following method of Pouillet : — The hydro- 
gen gas is made to flow out of a vertical ghiss 
tube, the flame itself having a breadth of 4 
or 5 lines, and a height of about 3 inches. 
A coil of platinum wire is employed to con- 
duct the electricity from the flame to the 
condenser. When this coil is so much 
larger than the flame, as to inclose it, and to 
be distant from its external surface about 
4 inches, signs of positive electricity make 
their appearance. These signs become more 
and more intense as the distance diminishes, 
but when the coil becomes so small as to 
touch the flame, the electrical signs become 
weak and unceitain. Thus it appears that 
round the flame of hydrogen there is a sort 
of atmosphere, at least 4 inches in thickness, 
which is always charged with positive elec- 
tricity. 

91. If a very small coil of platinum 
wire b6 placed in the centre of the flame, ia 
such a manner that it is enveloped on all 
sides, and made to communicate with the con- 
denser, that instrument becomes immediately 
charged with negative electricity. Thus it 
appears that the outside of the flame of hy- 
drogen is always charged with positive elec- 
tricity, and the inside with negative electricity. 
It follows from this that there is a layer of 
the flame where the electricity is insensible, 
accordingly if we regulate the coil in such a 
manner that it penetrates nearly one-half into 
the brighter part of the flame all electrical 
indications disappear. — Tliompson. Similar 
experiments may be tried witii the flame of 
alcohol, ether, wax, oils, fat and vegetable 
bodies. 

92. In a strong phial put a niixture of 
oxygen and hydrogen gases, in the proportion 
of 1 volume of the former to 2 of the latter ; 
immerse in this quickly a slip of platinum, 
fastened to the inside of a good cork which 
fits the phial, holding the neck of the phial 
downwards, while inserting the platinum, 
and which should be made very oright pre- 
viously by immersion in sulphuric acid, the 
action of the platinum will be such, that the 
gases will combine and form water, sometimes 
with so much force, that their union will be 
attended with an explosion, the }ilatinum 
becoming red hot. This is an experiment of 
Dr. Faraday. The same had been observed 
before by Dobereiner, as to spongy or black 
platinum, and is the only way in which to 
account for the action of his lamp, in which 
a stream of hydrogen thrown upon spongy 
platinum heats this latter sufliciently to inflame 
the gas. The platinum acts as a medium 
to combine the hydrogen with the oxygen of 
the air. 



21 



EXCITATION BY CHANGE OF TEMPERATURE. 

This division of the subject forms what is 
commonly called thermo-electricity, which 
involves so many considerations distinct from 
free electricity, that we cannot extend the 
subject beyond the mere circumstances at- 
tendant upon the electricity of the tourmalin, 
and one or two other bodies. The tourmalin 
was early known to exhibit attraction to light 
bodies when warmed, and the early electri- 
cians have recorded numerous appearances, 
which this mineral exhibited when heated. 
The most interesting of these are as follows, 
previously observing that those tourmalins 
only, whose ends are dissimilar to each other, 
can be excited so as to show in a plain manner 
the contrary effects of the two ends. Black 
tourmalins seldom have electric properties. 
There are two modes of exciting this stone, 
namely slow and rapid heating and cooling, 
and exceeding small alteration of temperature 
is sufficient to render it electric. 

Ex. 93. Let a tourmalin be equally heated 
over all the surface, as for example, by dipping 
it into boiling water; then hold it to an elec- 
troscope, when the gold leaves will immedi- 
ately diverge, one end exhibiting negative, 
the other positive electricity, and will so 
continue all the time of cooling. 

94. Heat only one end of the tourmalin, 
while the other is not altered in temperature, 
one end will then exhibit electricity, while 
the other will show no effect. To try this, 
it may be previously fi^stened to a small stick 
of sealing wax. This is a very singular ex- 
periment, because it is an instance of one kind 
of electricity being apparent without the 
other. 

95. Suspend a long crystal of tourmalin 
upon a stick of wax. Heat one end and cool 
the other at the same time, by touching one 
ei:d with a piece of hot metal, and the other 
with a piece of ice ; removing these heating 
and cooling objects both ends of the tour- 
malin will be found electrical. 

96. To show these effects, M. Becquerel 
employed the following apparatus, which 
however is by no means necessary. The 
tourmalin is placed in a slip of paper, sus- 
pended horizontally within a glass cylinder, 
by means of a single thread of raw silk ; this 
cylinder reposes upon a metal plate, which 
is heated by means of a spirit lamp beneath 
it. In proportion as the inside of the cy- 
linder becomes heated, the tourmalin becomes 
electric, in consequence ot the elevation of its 
temperature. If it now be drawn up, as shown 
in the figure, until it is of the height of two 
minute balls and wires connected with two 
gold leaf electroscopes, upon applying the 
ends of the heated tourmalin to each of these 



alternately, both will be charged, one with 
negative, and the other with positive elec- 
tricity. 




Ex. 97. Put a heated tourmalin on the cap 
of an electroscope, and then let it cool. The 
gold leaves will diverge, and if the upper 
surface be connected by a bit of tin foil, or 
a wire, with the cap of a second electroscope, 
that also will diverge, with electricity of a 
contrary character, as may be proved by 
bringing them together, when the electricity 
of the one %Yill destroy that of the other. 

98. The electricity of each side, or of 
both, may be reversed by heating or cooling 
in contact with various substances, so if it is 
cooled or heated in contact with the palm of 
the hand, that side of it, which v.rould have 
been positive if cooled in the open air is 
now negative, and that which is now positive 
would have been negative. 

Most of the above properties have been 
also observed of other stones, particularly of 
boracite, axinite, mesotype, the silicate of 
zinc, tapaz, sphene, calcareous spar, ame- 
thyst, diamond, red and blue fluor spar, 
garnet, and many other bodies, though it 
appears probable that it is only in those 
crystals which are irregular that such ap- 
pearances can be noticed. In the melting 
and cooling of sulphur there are several 
analogous phenomena ; the nature of elec- 
tricity depending upon the nature of the 
vessel in which the experiments are con- 
ducted. 

99. The following experiment on the 
electricity of heat is one of Mr. Canton. He 
procured some thin glass balls, of about an 
inch, and an inch and'^ in diameter, with 
stems or tubes about 8 or 9 inches in 
length, and electrified them, some positively 
on the outside, others negatively, and then 
sealed them hermetically ; soon after he ap- 
plied the naked balls to his electrometer, and 
could not observe the least sign of their being 
electrical ; but holding them at the fire, at 
the distance of 5 or 6 inches, they became 
strongly electrical in a short time, and more 
so when they were cooling. These balls would 
every time they were heated give the electric 
power to, or take it from other bodies, ac- 



22 




cording to the plus or -minus state of it within 
them. Heating them frequently, diminished 
their power, but keeping one of them under 
water for a week, did not in the least impair 
it. The balls retained their virtues above six 
years. We have not tried this experiment. 

THE SULPHUR CONE. 

The apparatus by which this experiment is 
done is made as follows : — Take a large ta- 
pering wine glass, cover 
a portion of the outside 
tapering part with tin 
foil ; twist a wire, as re- 
presented, and upon the 
end of it suspend two fine 
pith balls by linen threads. 
Having ready some melted 
sulphur, and a thin glass 
rod, pour the suphur into 
the glass, and immerse 
the glass rod into the 
upper part as a handle ; 
hold it there till con- 
, then suffer i' *« ^^^^^^^ °^ itself — 
when quite cold the apparatus is complete. 
You must, however, be very particular that 
a chain, wire, or som^ other conducting sub- 
stance, connects the wire with the ground 
during the cooling o^ ^^^ sulphur, or no 
effect will be produced— that is if it has been 
melted in a pipkin. 

E,r. 100. Lift up by the glass handle, the 
sulphur within the conical glass, and at the 
the moment of separation, the pith balls will 
diverge, or separate from each other. Let 
the sulphur drop down again into the glass, 
and this action of the balls will cease. Again 
produce separation of contact, and they will 
again diverge ; and thus, for a considerable 
time, the alternate action will be kept up, 
even indeed for days and weeks. 

101. Melt some sulphur in an earthen ves- 
sel, put it in a melted state to cool upon a 
piece of metal ; it will upon separation be 
found highly electrical, as may be proved by 
holding it to an electroscope. 

102. Pour some melted sulphur, which 
has been heated in an earthen vessel, upon a 
piece of smooth glass. Upon separation of 
the sulphur, when cold, no electric ap- 
pearances are perceptible. 

103. Let sulphur be melted in a glass ves- 
sel, and afterwards left to cool, they will both 
acquire a strong electricity. The sulphur 
negative, and the glass positive, whether 
they be left to cool upon conductors or not. 

104. Let melted sulphur be poured into a 
cup of baked wood, it acquires a negative, 
and the wood a positive electricity ; but if it 
be poured into sulphur, or rough glass, it 
acquires no sensible electricity. 



EXCITATION BV CLEAVAGE 

Ex; 105. Take a piece of dry talc, warm it, 
then spht it rapidly ; hold one of the pieces to 
the electroscope, the effect is herevery strong { 
if the talc be split rapidly in the dark, a faint 
phosphorescent light will appear between the 
sides of it. , 

106. If we fix with mastic or shell lac an 
insulating handle upon each of the faces of a 
plate of mica, we may ascertain that each of 
the slices separated is in a contrary state of 
electricity ; the intensity of which increases 
with the rapidity of the separation. Before 
making these experiments we must well dry 
the talc, and observe that it is not already 
split. 

107. Make a large card warm at the fire, 
double it across, and tear it in half ; at the 
part doubled each fragment will become 
electrical, and the one in a contrary state to 
the other. 

EXCITATION BY EVAPORATION. 

Ex. 108. Place upon the cap of a gold leaf 
electroscope, a small tin dish or patty pan, 
having in it a red hot coal just taken out of 
the fire. Sprinkle upon the coal a few drops 
of water — the evaporation of this will set the 
gold leaves into considerable action. This 
will not succeed with either charcoal or coke. 
It does best with a hot iron put into the 
water. 




Volta, Lavoisier, La Place, and others, 
state that water never changes its condition, 
without electric effects being produced. 
Others contend that this is not the case, 
unless chemical change also accompanies the 
action. The electricity of steam, a recent 
discovery, and which we must defer the con- 
sideration of for .some chapters, will throw 
much light upon this subject. 



23 



CHAP. III. 

ELECTRICS AND CONDUCTORS. ELECTROPHORUS. CAUSE OP 
ELECTRICAL APPEARANCE. 

The only experiments on electricity known to the ancients, were, as before observed, the 
attractive powers of amber when rubbed ; and the very first set of electrical experiments 
tried by the moderns was to discover if any, and what substances possessed the same 
extraordinary properties. These experiments, and which were made by Dr. Gilbert early 
in the seventeenth century, were the foundation of the science of eleetricity, as they 
directed the attention of philosophers to the subject. Considering how universal a fluid 
it is, and how easily excited, it must be a matter of surprise, that the discoveries of 
Dr. Gilbert had not been some of them made long previously. In trying to elicit electric 
properties from various bodies, this physician was successful only in certain cases, parti- 
cularly in electrizing some stony materials ; and nearly a century passed before Dr. Grey, 
Desaguliers, and others, renewed the subject with that energy which might have been 
expected. The former of these gentlemen discovered that electricity might be communi- 
cated to, and would pass along certain bodies, as for example, that it would pass along 
hemp, but not along silk. Thus, that bodies were not possessed of the same characters 
was evident. It was afterwards found that those bodies which could be excited by the 
ordinary means then employed would not convey or conduct the fluid readily along them, 
and, on the contrary, those which conducted the fluid, could not be excited. Hence arose 
the two terms electrics and conductors. Both these terms are still retained in their 
original sense, but the former of them is to be understood to include only those bodies 
which show electric properties in ordinary circumstances when held in the hand, and which 
do not require to be insulated previous to excitation ; for it will have been observed in 
many of the preceding experiments, that conductors, as for example the metals, may, by 
taking proper means, be no less excited than other bodies, as was shown in JBa?. 86, 79, 
and 32, and which the next experiments will exhibit still more plainly. So that the term 
electric is not quite accurate, although retained for the sake of convenience. These 
electrical bodies are often called non-conductors, a term better in some respects than 
electrics, though not in others, as we shall see that a body may be a conductor in one 
condition, and a non-conductor in another. 

It will be seen from the above, that a particular substance may be an electric in one 
state, and a conductor in another ; thus glass and sulphur are both excellent electrics when 
in masses, but when pulverized become imperfect conductors. So green wood is a con- 
ductor ; baked wood a non-conductor ; baked still more into charcoal a conductor again ; 
and when in the state of wood ashes a non-conductor once more. Many bodies also are 
conductors merely because they contain water ; thus almost all highly-dried animal and 
vegetable matters are non-conducting. Dried glue, parchment, bone, ivory, hair, feathers, 
horn, tortoise-shell, wool, silk, gums, resins, wax, cotton, sugar, &c., &c., are electrios, 
yet as soon as either of them becomes damp, a conducting property is communicated ; 
hence the necessity of well drying electrical apparatus when in use ; and also the same 
fact shows the reason that machines of this kind act so imperfectly in damp weather, or 
in a room before a crowded audience, whose breath quickly settles in moisture upon the 



24 

various electrics around. Too great heat also impairs the insulating effect of glass, Sia 
for although it will not in ordinary temperatures suffer the fluid to pass along its surface, 
yet when heated to redness it becomes a good conductor; and so also is baked wood made 
very hot, melted resin, hot air, &c. 

Notwithstanding this, we for convenience sake divide all bodies into the two classes 
of conductors and non-conductors, or electrics and non - electrics . the former parting 
immediately with any fluid given to them, and the latter retaining it so as to be apparent 
to the senses. Thus air is an electric or non-conductor — were it not so, electrical experi- 
ments would be unknown, the fluid being dissipated as fast as it is accumulated ; water, 
on the contrary, is a good conductor, hence the necessity of keeping the apparatus dry, 
that the disturbed fluid may be retained. Metals are the best conductors, therefore we 
use them for such parts of our electrical machines as are intended for the transit of the 
accumulated fluid. Glass and silk are electrics, or non-conductors, consequently are 
available as bodies to be excited, and as capable of preventing its escape and dispersion. 
Thus of an electrical machine the connexion between the cushion and the earth is a 
metallic chain or wire, to allow of the passage upwards of electricity, the glass cylinder 
being rubbed sets it free, the brass or tin conductor collects it, and its glass support 
insulates it, and thus prevents its escape to the earth again. 



The following experiments show that metals 
may be excited equally with those bodies or- 
dinarily called electrics. 

Ex. 109. Electrncity of quicksilver. — In- 
close some quicksilver in a thin glass tube a 
foot long, and of an inch in diameter. Make 
the tube dry, cork it up, and shake the quick- 
silver briskly from end to end. If now the 
tube be held towards any electrometer or 
electroscope, it will show itself powerfully 
excited. 

110. Put a small cup upon tne gold leaf 
electroscope, and pour the quicksilver from 
the tube into the cup, when the divergence of 
the leaves will show the metal to be excited. 
It may be considered doubtful if the metal be 
here excited at all, or whether it be not the 
glass alone excited, and have communicated 
its electricity to the metal, but let it be re- 
membered, that when two bodies are rubbed 
together, they are both excited at the same 
time, but in a contrary degree. 

111. Let the two electroscopes, which were 
used in the last experiment, one of which 
was charged by the metal, the other by the 
glass, be touched together ; the electricity 
of them will not be destroyed, because we 
have applied to one of them the outside of 
the glass tube, whereas it was the inside that 
was subjected to friction. The inside there 
fore is in a contrary state to that of the 
metal, and the outside in the same state as 
the metal. The metal is negative — the inner 
side of the glass positive, the outer side 
iKgative, as may be tested in the usual way. 



112. Luminous barometer. — Let the tube 
which holds the mercury be exhausted of air, 
and then shaken briskly up and down the 
tube ; flashes of light will dart across the 
tube. This, which is an experiment of 
Mr. Hawksbee, may be done in a flask or 
large phial, and without any great degree of 
exhaustion ; even heating the vessel well, 
and thereby rarifying the air, will often be 
sufficient. 

113. Put a gold leaf electroscope under a 
tall open-topped receiver of an air pump. 
Place a small wooden mercury cup to close 
the top ot the receiver, pour a little mercury 
in it, an.'l exhaust the air beneath ; as the 
mercury filters through the cup it will become 
excited, as will be seen when the drops fall 
upon the electroscope. 

114. Place a smooth round plate of metal 
on a cake of rosin or shell lac, rub the metal 
with a cat skin ; draw it up by a silk threid 
previously attached to it, and it will be found 
excited. 

It will be evident that a knowledge of the 
individual conducting powers of all sou- 
stances is requisite to a rigiit understanding 
of the first principles of the science, and 
that even the simplest experiments may be 
conducted wiih success. The following table 
presents a series of conductors and electrics, 
beginning with those which have the greatest 
conducting power, and terminating with those 
that have the least. The order in which 
they possess tlie power of insulating is of 
course the reverse of this ; that is to say, 
the best or most perfect electrics are at ti o 



25 



bottom of the tabic. It may also be ob- 
served, that the middle of the table exhibits 
bodies almost neutral in their properties, 
being but very imperfect conductors, or very 
slight electrics : — 

The most perfect or least oxidable metals. 

The most oxidable metals. 

Charcoal ; especially from hard wood. 

Plumbago, or black lead. 

The mineral acids. 

Metallic salts and ores. 

Water and other liquids ; and snow. 

Living vegetables and animals. 

Smoke, soot, and steam. 

Rarified air and flame. 

Dry earths and stones. 

Pulverized glass. 

Flowers of sulphur. 

Dry metallic oxydes. 
Oils. 

Vegetable and animal ashes. 

Ice; when cooled down to 13° Fah. 

Phosphorus. 

Lime, dry chalk, and mnrble. 

Caoutchouc, camphor, and bitumen. 

Silicious and argillaceous stones. 

Porcelain. 

Baked wood. 

Dry atmospheric air and other gases. 

White sugar and sugar candy. 

Dry parchment and paper. 

Cotton. 

Feathers, hair, and silk. 

Transparent gems. 

Glass. 

Fat. 

Wax. 

Sulphur. 

Resins. 

Amber and gum lac. 

To discover if a body be an electric or not, 
hold it against the conductor of a machine 
when charged ; if a spark can now be taken 
by the knuckle from another part of the 
conductor, the substance under examination 
is an electric ; if not it is a conductor. If 
a liquid, a gas, or a powder is to be tried, 
inclose it in a glass tube ; should the spark 
not now pass it will be known to have been 
conveyed away by the liquid, &c. under 
trial. 

The following experiments will illustrate 
the foregoing remarks, and show the methods 
of distinguishing the bodies which belong to 
these two classes. 

Ex. 115. Let a metallic cylinder be placed 
upon silk lines, or upon dry glass ; bring an 
excited glass tube so as to touch it, and every 
part of the cylinder will attract and repel 
light bodies as forcibly as the exciteil electric 
itself, showing that metal is a conductor. 



116. Sujiport a dry glass rod on silken 
lines, bring an excited glass rod near it, and 
no attraction or repulsion will take place, 
showing that the glass rod is not a conductor. 

117. If the glass rod of the last experiment 
be wetted with water, it will show electric signs 
in the same manner as the metal of Ex. 115, 
but if with oil, very slight effects will be 
communicated, showing water to be a good 
conductor, but oil a very bad one. 

118. While you try the Ex. 115, place a 
lighted candle near to the metallic rod, and 
the fluid which would otherwise be discover- 
able in the metal will have been dissipated by 
the flame and rarified air ; they are therefore 
conductors ; yet it is evident, that air at its 
usual temperature and pressure is a non-con- 
ductor, otherwise few electrical appearances 
of any kind could be observed, as the air 
would dissipate or convey away the fluid 
accumulated. 

It will have been observed, that wherever 
we have shown friction, there has also been 
separation of contact ; and upon a strict ex- 
amination it will be found, that although the 
rubbing of two dissimilar bodies together 
may, and does occasion the electric fluid to 
be disturbed, yet it is only when these bodies 
are held apart, that each is found to put on 
electrical appearances. Thus in Ex. 4, the 
brown paper is the one body, and the coat 
the other. In Ex. 7, the coffee is the one 
body, and the mill in which it is ground the 
other ; so also in Ex. 15. The comb passing 
over the hair must certainly be separated in 
turn from those particular parts it touches in 
its course along, and not till then is it seen 
that those parts are electrical ; and thus in 
every experiment there is not merely friction, 
but separation of the parts rubbed together, 
where it is not so, no electrical appearance 
would be perceived, as is clearly proved by 
Ex. 100, where electric effects were percep- 
tible only when the sulphur was separated 
from the glass. An experiment similar to 
this is as follows : — 

Ex. 119. Pour some melted sulphur into 
a metal cap which is supported upon the 
top of a gold leaf electroscope ; dip a glass 
rod in it as a handle, and let it get cold ; 
when quite cold, lift up the sulphur by the 
handle, and the gold leaves will immediately 
diverge, the cup itself being electrified, and 
if the sulphur beheld to another electroscope, 
that will be shown also to be excited. As 
often as it is raised from the cup, the effects 
become manifest, and when put down again 
they cease. 

120. Take a piece of glass, about 5 inches 
long by 3 inches broad — warm it, wrap tin 
foil all over it, and rub the outside of the 
tin foil smartly with the hand. The glass 



36 



2G 



thus excited, held to the cap of Bennett's 
gold leaf electroscope, will not show any 
electrical effect while it remains wrapped in 
the tin foil, but if this be removed, and the 
glass alone be presented, the gold leaves will 
instantly diverge. 

The same is exemplified in the electro- 
phorus, an instrument which is described, 
and may be made as follows :— Procure a 
round piece of tin, about 10 inches over, and 
have the edge of it turned up about i of an 
inch, so as to be capable of holding some of 
the following mixture ; (melted over a fire,) 
1 pound of yellow rosin, and 2 ounces of 
wax. This being poured into it, and suffered 
to cool, one part of the electrophorus will be 
complete. Next provide a round plate of 
wood, about ^ an inch thick, and 6 or 7 
inches over, which must have a smooth edge, 
and without any sharp points or angles; 
cover this with tin foil, and fix a glass rod 
to the middle of it as a handle. This may, 
altogether, cost 2s, and is a really useful 
electrical machine, capable of showing all the 
fundamental facts of the science. The fol- 
lowing cut will render the description more 
evident : — 



placed upon a glass stand, and two pith balls 
be suspended from the rim of it ; whenever 
the upper plate is lifted up these balls also 
will diverge, showing that the lower plate 
also appears excited when separation of con- 
tact ensues. Many other experiments with 
this instrument will afterwards be shown 




121. To excite it, warm and wipe the 
glass handle, and also the resinous plate. 
Rub this plate briskly with a warm flannel, 
and put the wooden plate upon it, holding it 
by the glass handle — touch the wooden plate 
for a moment with the finger, and it will be 
full of the fluid in a disturbed state, not, 
however, apparent until the wooden plate is 
lifted up, when a spark may be taken from 
it ; put it down again, touch it with the finger, 
and lift the plate up again, (first removing 
the finger,) and a second spark may be 
taken, and so on for a considerable length of 
time. 

122. Fasten near to the edge of the upper 
plate of the electrophorus a bent wire, 
bearing on the end of it two suspended pith 
balls — whenever the upper plate is removed 
from the lower, both being excited and 
touched with the finger, as above directed, 
the pith balls will be violently repelled from 
each other. 

123. If the resinous plate be excited, and 




Numerous experiments of the last chapter 
evidence the same fact, which is rendered still 
more conclusive by the following machine, 
called 

THE CIRCULAR RUBBING MACHINE. 

This consists of a square frameof wood BB, 
supported by a square footA, having a circular 
rubber or cushion D, stuffed with flannel and 
covered with leather, which is turned by a 
handle at top E. This rubber rests upon a 
plate of glass C, about 8 inches in diameter. 
The under surface of the glass has pasted 
upon it a round piece of tin foil. 3 oi 4 inches 
over, with two pith balls hanging by fine 
wires, or a thread, from the centre of it. 




Ex. 124. Prepare the apparatus by 
warming the glass, and spreading a little 
amalgam on the cushion — turn round the 
handle, which will produce a friction, and 
excite the glass. In this state there will be 
no appearance of the fluid being disturbed, 
until the cushion be lifted up, when ths balls 



27 



will diverge — placing it down again their 
motion will cease, and thus they may be al- 
ternately moved by producing and separating 
contact. 

Electrical amalgam. — Melt in a ladle \ an 
ounce of zinc. When melted, add and stir 
up with it 2 ounces of quicksilver. When 
I old pound it with a little wax or grease, 



when it will be fit for use. This substance is 
of value to the electrician, as being the best 
of all matters to excite glass with, so that in 
the electrical machine such is indispensable, 
and if we had used it, spread upon a piece of 
leather, in Ejc. 6, 9, and others, instead of 
the old black silk handkerchief, the effect 
would have been much greater. 



CHAP. lY. 

OF THE ELECTRICAL MACHINE AND MANNER OF USING IT. 

In our future experimental researches on electricity it will be necessary to use a machine, 
for the purpose of accumulating the fluid in greater quantity than the glass tube or such 
simple means allows, and also of retaining it in such a condensed state as to afford the 
powerful effects of which it is capable. From the last chapter it became evident that to 
excite, accumulate, retain, and transfer the electric fluid, a due knowledge of electrics and 
conductors was necessary; — that the capability of excitation and retention depended upon the 
quality of the electric, and the power of a rapid transmission of the fluid ; upon the perfect 
conducting power of the material through or over which it was to pass. Electricians employ 
for the one purpose chiefly the metals, they being the best conductors ; and sulphur, glass, 
resin, and silk as electrics, or as bodies to be excited. The proper union of these forms 
an electrical machine. 



In the early history of the science, when 
attraction and repulsion only were to be ob- 
served, all that the electricians aimed at was 
to give the requisite friction to the electric in 
a more convenient manner than by the simple 
experiments of rubbing upon the sleeve, or 
with other light material. With this in lention 
Otto Guericke fitted a globe of glass; upon 




an axis. Upon giving it a whirling motion, 
and holding his hand against it at the same 
time, he was enabled to excite it with great 
convenience. Mr. Hawkesbee's machine, and 
which was so similar to this, that one illus- 
tration will serve for both, was the next con- 
trivance. It is shown in the cut. 

It will be seen that here is no cushion, no 
conductor, no means of collecting the fluid 
from the earth, and none to draw or collect 
it from the cylindtr, as we shall presently 
show are all necessary. Therefore, although 
answering the purposes then required, it is 
very inefficient compared to our more modem 
inventions. Otto Guericke had no means of 
forming a globe of sulphur but casting it in a 
glass globe, and then breaking the glass from 
off it. Mr. Hawkesbee used the glass globe 
itself rather than that of sulphur, and in that 
was the great difftrence between his machine 
and that of Otto Guericke. 

The next machine was invented by the Abbe 
Nollet. Of this description was the greater 
part of the machinps which were used about 
one hundred years since. It is represented 
annexed : — 



28 



(^* 




These were the machines, heavy aid ;Tn- 
wieldy as they seem, which were carried about 
from place to place for exhibition. The ad- 
vantage of this machine over the last was its 
different and more convenient form, and the 
appendage of a conductor, which was hung by 
silk lines from the ceiling. The globe was 
still rubbed by the hand. The conductor was 
a bar of iron, or generally a gun barrel, con- 
nected to the electric by a chain hanging noin 
it, and touching the revolving globe. 

In the next machine constructed, four 
globes were whirled at once ; it was a con- 
trivance of Dr. Watson, and is represented 
beneath : — 




The conductor was, as before, suspended 
from the ceiling, and connected by the various 
globes by unravelled gold lace hanging down 
from them. As it was evident that the hand 
could not be held against four globes at once, 
a cushion was appended to each globe, and 
hence arose another great improvement — in- 
deed the machine was now furnished with all 
its most valuable parts; a globe to be excited. 



a cushion to supply the fluid, and a prime 
conductor to collect it. Still, as will be evi- 
dent, it was very large and unwieldy, and 
the necessity of suspending the conductor 
from the ceiling a great inconvenience. The 
improvement therefore of Mr. Wilson was 
particularly acceptable to the electrician. 
This gentleman's machine is as follows : — 




A cylinder is substituted instead of a globe ; 
the cushion is placed beneath. This was a 
great improvement. The conductor was 
suspended on silk lines fastened to upright 
pillars of glass. Instead also of the uncertain 
method of a chain or fine wire hanging down 
from the conductor to the cylinder, Mr. 
Wilson substituted a second rod, which was 
terminated at the end by a row of points ; 
another great improvement. The greatest 
inconvenience of this machine was the great 
strength required to be given to all its parts 
to prevent the conductor from vibrating to 
and fro, when the cylinder was put in motion 
by turning the handle. 

The next machine was much more portable; 
it was invented by Mr. Nairne. The differ- 
ences between this and the former were that 
the globe was turned by means of some brass 
wheel-work contained in a box beneath the 
globe, and which for the first time was made 
to work by a vertical motion ; — the cushion 
was made with a spring, to produce equality 
of pressure, and the conductor was in a 
greater degree unconnected with the globe 
than before. It is represented beneath : — 




29 



A second machine, also we believe by Mr. 
Nairne, has a cylinder, working vertically, 
with a multiplying wheel beneath, and another 
on the table. The conductor is made of tin, 
and instead of a series of points attached to 
it, it has the edges of the end of the prime 
conductor cut like teeth. This was invented 
about 1760, and consequently after the dis- 
covery of the Leyden jar. It was used also 
entirely for medical electricity, which ac- 
counts for the Leyden jar B, and also for the 
electrometer at the side being attached to it. 
These, however, are in reality no parts of 
the machine itself. Mr. Nairne first used 
amalgam to the electrical machine. This 
machine is represented in the following 
tut : — 




Thus in the hands of Mr. Nairne, who was 
a celebrated optician in Cornhill, that which 
was before cumbrous and comparatively in- 
eifective, became a useful, portable, and 
easily- constructed instrument, rendered how- 
ever yet more convenient and powerful by the 
horizontal position of the cylinder, and the 
silk flap introduced by Dr. Priestley. This 
was the history of what is now called the 
cylinder machine, which is shown in its 
modern and most approved form, as follows. 
Be it observed, that the cylinder machine 
varies in having sometimes two conductors ; 
one attached to the cushion for negative 
electricity, and the other for positive elec- 
tricity ; this last is always present, and is 
called the pi'ime conductor. It may also be 
turned by a common handle, or by a multi- 
plying wheel, as found most convenient ; 
we decidedly prefer the former, particularly 
for a large machine. 

THE CYLINDER MACHINE. 




' A is a g.lass cylinder, having upon each 
end of it a cap of wood or brass, and sup- 
ported by a stand with two uprights. The 
end of one cap is turned with a pivot, which 
fits into a hole near the top of one of the 
uprights. The other cap is turned with a 
similar pivot, and has beyond this a flanch 
and a square gudgeon, upon which a handle 
D fits. This end of the cylinder is supported 
in a similar manner to the other end, but 
instead of a hole merely being bored in the 
upright leg, a portion is cut away, that the 
cylinder may be the more easily taken out 
and put up again in its place ; it may be se- 
cured when there by a pin run through the 
upright, just above the axis of the cap. 
Before the cylinder is a cushion, which ex- 
tends in length to within an inch of either 
end of the cylinder ; it is from 1 to 2 inches 
in width, according to the size of the cylin- 
der, and made by laying five or six folds of 
flannel over the wooden back of the cushion, 
and neatly covering these with leather. 
The cushion when finished should be soft, 
and yielding about as much as a wool mat- 
tress, and scarcely so hard as the bottom of 
a hair-covered chair. 

On the lower part of the cushion is glued 
a flap of leather (the rough side outwards), 
and on the edge of the leather the silk flap 
which passes over the cylinder when in action. 
B, the cushion, is supported sometimes by a 
thick rod of glass with a wooden spring at 
the top of it, as in the figure ; at other times 
a springy piece of wood alone is used. It is 
fastened at the top to the cushion by a hand- 
screw, which passes through the support, and 
is fixed by a thread in the back of the cushion 
itself. The lower end of the support for the 
cushion is made so as to slide backwards and 
forwards, either on the top, or still better 
underneath the stand, and is held in its 
position by a thumb-screw. The object of 
this sliding is to regulate the pressure of the 
cushion against the cylinder, as shown in the 
cut, or the cushion may be made a fix- 




30 



ture, and its pressure regulated by a screw 
behind it, as at the letter E, in the cut of 
the whole machine above given. When the 
cushion slides backwards and forwards, a slot 
or long hole is made in the foot board, and 
the small piece of wood which forms the foot 
of the cushion slides in a groove beneath the 
foot board. In the cut A shows the back 
of the cushion. B the leather flap. C the 
silk. D the wooden spring. E the glass 
support. F the cap, which unites the glass 
and spring. G the foot. H the holding screw. 
The part D is united to A by a round wooden 
screw on which a chain is hung when the 
machine is in use ; this chain ought to touch 
the ground. 

C represents the prime conductor, formed 
either of wood covered neatly with tin foil, 
or of metal. It has round and smooth ends, 
at one of them a ball and wire for the sus- 
pending of various apparatus, at the other a 
projecting wire furnished with a row of points 
to collect the fluid when, disturbed by the 
cylinder. It is necessarily supported upon a 
glass pillar, sometimes attached at the lower 
end to the same stand as the rest of the 
machine, in which case the conductor runs 
parallel to the cylinder, and has the points 
driven into the side instead of the end. At 
other times it is fixed to a separate foot as is 
to be seen in the figure beneath. At the top 
of the conductor are two or three holes to 
aflpDrd greater facility in performing experi- 
ments. 




To make a machine. — In makin;; a cylin- 
der machine observe carefully the following 
directions : — The centre of the cylinder, of 
the cushion, and of the conductor should be 
of the same height. The lower part of the 
cylinder, unless in a very small machine, 
should be at least 10 inches above the foot 
of the stand beneath. The glass pillar of the 
prime conductor not less than 14 inches long, 
the conductor itself about as long as the cy- 
linder, and from 2 to 3 inches diameter ; the 
points projecting nearly an inch. The silk 
flap should be thin, and extend to within an 
inch of the points. Fix the caps upon the 
cylinder thus : — Make some cement, (ac- 
cording to the receipt in p. 8,) which have 
melted ready for use ; roughen with a file 
the glass on each end of the cylinder, and 



bore a small hole through the axis of that 
cap which does not bear the handle ; this 
done, stop up the inner end of the hole again 
; with a small piece of dough, putty, or clay. 
-Now grease the outside of this cap well, put 
[it in an upright position, half fill it with the 
1 melted cement, warm well the end of the 
'cylinder, put it upright into the prepared 
cap, let it remain till the cement is hard, and 
then clear out the hole through the centre 
by a hot wire ; being very careful that it is 
at all times afterwards left open. This is 
necessary as a vent for the heated air, which 
of course will be liable otherwise to burst 
the cylinder, not merely when the other cap 
is fixed to it, but ever afterwards when the 
machine is in action. The hole being thus 
opened, the other cap may be fixed on in 
the same manner ; a second hole however is 
not necessary. The cause of greasing the 
outside of the cap is that any cement which 
flows over may not stick to it. 

By attending to the above description and 
observations, an electrical machine may be 
made out of a common sample phial, capa- 
ble of giving sparks, charging a Leyden jar, 
and performing most of the simple electrical 
experiments. 

To work the machine. — Warm the whole 
well before the fire, and cleanse it from all 
damp and dust. Take off the cushion, scrape 
away all dirt, spread evenly upon it some 
freslx amalgam, (a receipt for which see page 
27 ;) put it back in its proper place, and 
fasten to the screw which connects it with its 
upright a brass chain, the other end of which 
reaches to the table or floor, or the walls of 
the apartment. Upon now turning the han- 
dle, streams of fluid will be seen to issue 
from the cushion, and passing under the silk 
to fly off at its edges. To collect the fluid, 
place the conductor with its points about a 
quarter of an inch from the edge of the silk, 
which will so readily attract the fluid from 
the cylinder that sparks proportionate to the 
extent of the glass surface rubbed may be 
taken from it, being very careful however 
that the glass stand of the conductor be per- 
fectly dry. The pressure of the cushion 
against the cylinder is to be regulated by the 
screw on the stand at bottom. 

Note. — If the machine be small it will re- 
quire frequent warming ; the power of a 
machine is generally increased by rubbing 
the cylinder for a minute or two with a 
slightly.greasod rag, or by putting one hand 
upon the cushion. 

The rationale of the action going on is 
this : — The fluid passes from the earth through 
means of the floor, walls, &c., to the chain 
suspended from the cushion ; here friction, 
which is the cause of the disturbance, takes 
place. The disturbed fluid passes to the 



31 



glass cylinder, and is confined from escape 
by the silk flap ; that ceasing, the fluid 
would fly to anything around, particularly to 
a pointed body, or a lighted candle ; but this 
is prevented by the superior attraction for it 
from the nearer end of the prime conductor 
put to receive it. Thus it will be at once 
seen that an electrical machine resembles a 
pump ; the earth may be likened to a well 
of water ; the chain to the lower pipe of a 
p'ump ; the cushion is the sucker ; the silk 
the nozzle ; and the prime conductor is like 
a pail to hold the fluid. 

palmer's cylinder machine. 
Mr. Palmer, an optician of Newgate 
Street, has so far modified the cylinder ma- 
chine as to adapt two cushions and two 
prime conductors to it, as will be readily 
understood by the following figure and short 
description : — A is a thick glass tube, having 
a ball at the top, and two arms, projecting 
sideways, furnished with points as C C. The 
tube A. supports one end of the cylinder, 
and is itself supported upon a solid glass 
pillar D. B B are glass pillars, which sup- 
port the cushions and flaps. 




CUTHBERTSON S PLATE MACHINE. 

This machine is undoubtedly superior to 
the cylinder machine, both in power and de- 
gree of portability ; but it cannot be so 
readily made by an amateur, and it is attended 
by a great defect, namely, that the plate of 
glass which forms the electric to be rubbed 
is very apt to become starred or cracked 
from the centre outwards. This takes place 
from two causes ; one, unequal pressure of 
the cushion, and still more frequently from 
the following want of care. Previous to an 
electrical machine being worked it is usual to 
place it near the fire to become dry, and in 
a slight degree warm. Now it is evident 
from the shape of the plate machine, that the 
side of the plate would be placed, nine times 
out of ten, towards the fire, and of course 



the opposite side exposed towards the door 
of the room or window. The side nearest 
the fire becoming warm is expanded, while 
the other side, glass (being a bad conductor of 
heat,) will remain as at first ; the glass plate 
is therefore distorted, and if the door be 
opened by a person entering, a sudden con- 
traction takes place in the nearer side, which, 
added to the expansion of the other, cracks 
the glass at its point of support, or fulcrum, 
which is the centre. Again, if when the glass 
plate is unequally heated, the cushions be put 
on tightly, and the handle be then turned, 
fracture is almost certain. With these draw- 
backs upon its utility the plate machine is 
still better than the cylinder, especially for 
lecturing before a large audience, as it is less 
liable to be aff'ected by the moisture of the 
apartment, arising from breath and other 
causes. It is figured and described as 
follows : — 




A is the plate of glass, which is made cir- 
cular, and has a hole drilled through the 
centre for the admission of a spindle, so that 
it may be turned by the handle B. C C C C 
are four cushions, fixed tv,o and two together 
to rub against the glass. D D are two double 
flaps of black silk. E is the prime conductor, 
which is of metal, terminated by a ball H at 
one end, and after branching into two arms 
F F, which are bent at the part next the plate, 
terminating with points as at G G. I and J 
are glass rods to support the prime conductor. 
These are not both necessary if the machine 
be small ; the rod marked I will then be 
sufficient. The structure of the cushions 
and the prime conductor is seen in the an- 
nexed cuts. 

A represents two cushions, or rather two 
vertical pieces of wood, on the inner side of 
which two cushions are to be placed. The 
cushions merely fitting in a groove or hole, 
or else attached on a projecting pin or two, 
that they may be taken off and put on again 
readily on putting the machine in order. 
The cushion and also these pieces may be 



32 



•bout an inch wide, and of such a length as 
to leave 4 or 5 inches between their inner 
extremities and the brass flanch of the cen- 
tral axis of the plate. The pieces A, or 
cushions, may also take oft" by unscrewing 
the hand screw at the top, marked C, which 
passes through the top frame of the machine 
D. E is a screw to regulate the pressure of 
the cushion upon the plate. B represents 
the silk flaps ; thc-e being one to each side 
of A. These are sewed together around the 
outer edge, so that the plate revolves between 
them. Any common silk of a black color 
will answer for tViis purpose, and it is quite 
immaterial if it be previously oiled or not. 




The annexed figure shows the prime con- 
iductor, as separated from the machine, or 



rather a vertical representation of the whole 
machine, except the stand and cushions. 
A A is the plate of glass. B the handle. 
C C the supports. D D D the prime con- 
ductor, all of brass. E its horizontal glass 
support. F F bent metallic arms, with 
points to collect the fluid from the glass. 




Other machines have been invented, o 
more or less utility, but all these merge intc 
the foregoing, and are therefore easily 
understood. 



CHAP. y. 



ELECTRICAL ATTRACTION, REPULSION, INDUCTION, AND 
DISTRIBUTION. 

We have already said so mv-ch about electrical attraction and repulsion, that we have no^ 
but little to add, m.ore than to illustrate the subject by those more showy experiments whicl 
the greater power we have obtained by means of the electrical machine enable us to exhibit 
and to explain the laws which seem to regulate the degree and continuance of those efTectt 
Bearing then in mind the theory of Franklin, that a body may be charged positively o 
negatively, and that the electric fluid is repellant of itself, but attractive of all othe 
matter, we shall be able to establish these laws. 

1. Bodies that are electrified positively repel each other. 

2. Bodies that are electrified negatively repel each other. 

3. Bodies electrified by contrary powers attract each other. 

4. Those substances that are brought within the influence of electrified bodies become 
possessed of a contrary electricity, or electrified substances, without parting with their owi 
electricity act upon other bodies in their own neighbourhood ; producing in them at 
electricity which is contrary to their own, or bodies which are immerged in an electric 
atmosphere, always become possessed of an electricity contrary to that of the body in 
whose atmosphere they are imrnerged. 



33 

5. That the degree of attraction or repulsion is inversely proportionate to the square 
of the distance of the electric body and that it acts upon ; that is, if an uaelectrified body 
be offered to another which is electrified, consecutively at the three several distances of 
1 inch, 2 inches, and 4 inches, as the squares of these numbers are 1, 4, and 16, we have 
only to invert these, and we shall find that if at 1 inch distance, the attractive force be 16, 
at 2 inches it would be as 4, and at 4 inches as 1 only ; or, in other words, if the attractive 
force at 1 inch be as 1, at 2 inches it would be as ^, at 3 inches ^, and at 4 inches as ^, 
and so on for higher numbers. 

This fifth law, although important in proving the niceties of the science, and in showing 
that the laws of other sciences or powers of nature are accordant to those of electricity, yet 
as its full exposition will yield no experiments of a popular character, we will pass it over 
with the mere description of the method by which it is proved. It was ascertained by 
Mr. Canton, that an electrified body communicates its own electricity to all the particles 
of air which come in contact with it. These particles are immediately repelled, and their 
place supplied by a new set of aerial particles. The consequence of this must be, that 
the air immediately surrounding an electrified body must be also electrified, and must 
possess the same kind of electricity with it. It is obvious that the electrical density 
of this air must diminish according to its distance from the surface of the excited body ; 
hence, according to Lord Stanhope, the reason why bodies charged with the same kind of 
electricity repel each other is, that they may move to those parts of their atmosphere where 
the electricity is least. Bodies excited with different kinds of electricity, on the contrary, 
approach each other, because each moves towards the extremity of its electrical atmosphere. 
Without introducing the mathematical formulse of his lordship, as published by him in 
1779, we shall introduce the more easily-understood remarks of Coulomb, published seven 
years later. For the purpose of these experiments, Coulomb used his electrical balance, 
already described. Having electrified the two balls of the balance by means of the head 
of a large pin, the index of the micrometer standing at 0, the ball of the needle 
separated 36°. Secondly, having twisted the suspending wire 126°, the balls approached 
each other, and remained at 18° distance. The suspending wire being twisted 567°, the 
two balls approached within 8^° of each other. In the first case, the index of the 
micrometer being at 0, the balls separated 36°. In the second case, the distance of the 
balls was 18°, but as the micrometer was turned 126°, it follows that at the distance of 18° 
the repulsive force was 144°. Thus, when the distance is reduced to one-half the repulsive 
force is quadrupled. In the third case, the suspending wire was twisted 567°, and the 
two balls were reduced to the distance of 8^° from each other. Here the actual tortion 
was 576 or four times as much as in the second case, and there is only half a degree wanting 
to render the distance of the balls, in the third case, one half of what it was in the second. 
The distance being 8|° in the third case, 18° in the second, and 36° in the first. The half 
degree lost in the third experiment is to be accounted for by the loss or dispersion of the 
fluid during the experiments, which lasted four minutes. Thus it follows, that the repulsive 
forces exercised upon each other, by two balls charged with the same kind of electricity, 
are inversely as the square of the distances at which they are from each other. 

We will illustrate the other laws by more popular experiments, some of which may 
performed by the excited glass tube, and the rest by holding towards or annexing to the 
prime conductor of the electrical machine the apparatus described. 



34 



Ex. 125. Suspend from the ceiling a string, 
and from this a feather, attached to a thread 
of silk, or the ball of the pendulum electro- 
scope will do as well. Hold towards it an 
excited glass tube, the feather will first adhere 
to it, then be repelled, and if a finger be held 
near it, be attracted towards the finger. The 
attraction of the feather and tube is accounted 
for — they are differently electrified. The 
receding of the feather is also accounted for, 
for after touching each other they are simi- 
larly electrified ; but why the feather should 
seek the finger is not so apparent. It arises 
from a cause, which, instead of militating 
against the truth of Franklin's laws, does but 
prove the general applicability of the above. 
It was stated that when a body of any kind 
is electrified, it affects and repels the electric 
fluid contained in all the bodies near it, and 
thus the overcharged feather drives away 
some portion of the fluid in the finger, in 
consequence of which the part of the finger 
nearest to it becomes negative, or in a dif- 
ferent state from itself — therefore they are 
mutually attracted. 

126. Diverging threads. — Tie twenty fine 
linen threads together at each end, so that 
there may be about 8 inches distance from 
knot to knot ; hang this by a wire loop, fas- 
tened to one of the knots, to the conductor 
of the machine. Upon charging the con- 
ductor, the threads will recede from each 
other, forming a curious balloon-shaped 
body. 



^^=iO 




127. Expanding threads. — Instead of 
tying the threads at both ends, let the lower 
end be loose, and upon turning the machine 
they will form a brush. 

128. The glass feather. — Procure a glass 
feather, as made at the fancy glass shops, 
and stick it into one of the holes on the up- 
per side of the conductor ; when the machine 
is put in motion the radiation of all the fila- 
ments of glass will offer a most elegant 
object. 

129. The frightened head of hair.— As a 
variation of the last experiment, the head of 
a doll is furnished with a wig of hair, which 



is 2 or 3 inches long ; upon electrifying this, 
" each particular hair will stand on end" in 
the most grotesque manner, and thus it is 
with every person who is electrified, when 
on a glass-legged stool. This experiment 
becomes most effective, because seen more 
conspicuously, when the hair is of a grey 
color. 




130. Radiating feathers. — Let a metal 
ring be supported upon a glass pillar, and at 
six or eight equally-distant points around 
this ring tie a thread (not silk) a (ew inches 
long, the other end of which bears a feather. 
Connect the metal ring with the conductor 
of the machine by a wire or chain, and the 
feathers being electrified will repel each other 
until they will stand at equal distances like 
the spokes of a wheel. 




131. The electrified cloud.— Take a hand- 
ful of wadding or raw cotton, squeeze it to- 
gether tight, yet so that the threads shall not 
be entangled. Place it upon a flat, smooth 
board, connected with the prime conductor 
of a machine. Upon electrifying the board, 
the cotton will separate itself, and expand 
until it becomes a large fleecy mass, and if 
the machine be in good action, the whole 
mass of cotton will fly away. Indeed it may 



33 



always be made to fly off, if the quantity be 
proportioned to the strength of the machine. 
Let it be remarked, however, that it will soon 
fall to the ground, not only because of the 
attraction it has for other bodies, but because 
of the gravitation it naturally has, and which 
is not altered in any degree by the electriza- 
tion, unless an excited tube be constantly 
held towards it, when one power will, if 
strong enough, counteract the other. 

132. Electric fish. — Cut a piece of very 
thin leaf brass (such as is called tinsel will 
do) with an obtuse angle at one end, and an 
acute one at the other ; present the large end 
towards an electrified conductor, and, when 
the brass is within its atmosphere, let it go ; 
it will then fix itself to the conductor by the 
apex of its obtuse angle, and, from its con- 
tinual wavering motion, will appear to be 
animated. 




133. Suspended leaf. — Hold towards the 
ball at the end of the conductor a square 
thin leaf of brass or paper ; upon turning the 
machine, it will leave the hand and be sus- 
pended with one of its points upwards be- 
tween the hand and the conductor. 

134. The moving leaf.-~Mo\e the hand 
round, and at a uniform distance from the 
ball of the conductor, when the leaf of brass 
is suspended near it, and it will be seen to 
move with the hand in any direction which 
the latter may take. 

135. Animated thread. — Present a fine 
thread to an electrified conductor ; when it is 
at a proper distance it will fly towards, and 
stick to the conductor, and convey the elec- 
tric fluid from it to the hand ; remove the 
thread to a small distance from the con- 
ductor, and it will fly backwards and for- 
wards with great velocity, and in a very 
pleasing manner. Present the same thread 
towards one that hangs from the conductor, 
they will attract and join each other. Bring 
the finger, or a brass ball, near these threads, 
the ball will repel that held by the hand, 
and attract that which is affixed to the 
conductor. 

136. Dancing images. — To the end of the 
conductor, suspend a plate, made either of 
metal or wood, covered with tin foil, and at 
a distance of 3 or 4 inches under this a 
similar plate, but one that is rather larger. 



Place on the lower plate any little figures 
cut out of paper or pith. Take care that the 
lower plate is supported upon some con- 
ducting substance ; turn the machine, and 
the figures will raise themselves, and fly up 
and down between the two plates, formir\g a 
most ludicrous dance. 




137. Support the lower plate upon a glass 
bottle, or other insulator, and although all 
the rest of the apparatus remain as before, 
yet the figures will not dance. The reason is 
this, the upper plate being charged by its 
connexion with the machine, the figures are 
attracted by it, they becoming charged are 
repelled by the upper, and attracted by the 
lower plate. When they touch this their 
charge is removed by that contact, and con- 
veyed to the earth, while the figures jump 
up again for a fresh supply, and thus they 
move alternately from the one to the other 
plate. When the lower plate, however, is 
insulated, the extra portion brought to it 
cannot escape, and it becomes charged in the 
same manner as the upper one, therefore 
the figures have no tendency te move between 
them. 

Note. — If in cutting out the figure the head 
is heavier than the feet, it will dance head 
downwards ; damping the feet in the mouth 
will usually remedy the defect, but this, at 
the same time, gives them a tendency to ad- 
here to the upper plate, while wetting the 
head makes them dance on the lower plate. 
Female figures usually dance more regularly 
because of the weight of the lower part of the 
dress. In all the figures the head should be 
somewhat pointed, either by the adjunct of 
a steeple-crowned hat, or something similar 
put upon it. 

138. Dancing pith balls. — Place upon the 
lower stand, (mentioned in Ex. 136,) six or 
eight balls of the pith of elder, and cover 



36 



them over with a dry tumhler, Hang to the 
conductor a chaiw, which touches this tum- 
bler; upon turning the machine, although 
glass intervenes between the exciting power 
and the balls acted upon, yet the balls will 
fly rapidly up and down within the glass 
tumbler. In this instance, the outer part of 
the glass is by contact electrified positively ; 
the inner part, therefore, will be by induction, 
(afterwards to be explained,) electrified ne- 
gatively ; and the balls are flying up and 
down to supply the deficiency of the glass — 
each ball coming to deposit its load, and flying 
down again for another. 




139. The dancing pith ball experiment 
may be reversed thus : — Fasten to the con- 
ductor a pointed wire as before. Hold a dry 
and warm tumbler over the point, and turn 
the machine. After a few turns the tumbler 
will be charged withinside with positive elec- 
tricity. Place upon a table, or a metal plate, 
a few pith balls, and cover them over with 
the charged tumbler. They will now jump 
up and down, each one conveying some of 
the fluid away from the glass, and not towards 
it, as in the latter instance. They continue 
to dance long after the machine ceases to act, 
and when their motion has ceased altogether, 
it may be renewed by merely putting the 
hand upon the outside of the glass. 




140. To make pith and cork halls. — Pro- 
cure some of the thick young shoots of the 
common elder-tree, cut them into lengths 
between the joints, and push out the pith of 
each length by a smooth stick, as near as 
possible the size of the hole where the pith 
is, and dry it for use. When wanted for balls, 
cut out each ball moderately true with a pen- 
knife, and to round them more perfectly, 
and take off the rough edges, roll them very 
gently, with a circular motion, on a smooth 
tabic, and they will be fit for use Cork balls 



may be cut in the same manner, but to make 
them smooth each one must be placed upon 
the point of a needle, and turned round two 
or three times in the flame of a candle, or 
should the blackness thereby occasioned be 
an objection they may be rubbed with sand 
paper. 

141. Electric hells. — The apparatus thus 
called is of various forms, that put into action 
by attraction is represented beneath : — It 
consists of a rod or wire, having a hook to 
hang it up by, and a small chain at each end, 
terminated by a bell. There are, also, at 
three other parts depending from it three 
silk threads, one terminated by a third bell, 
the other two by metal clappers. The third 
bell, it win be observed, has a chain appended 
to it which reaches the ground. When this 
apparatus is suspended from the conductor, 
the wire at top, and the bells at the sides, 
become electrified — these latter, therefore, 
attract the clappers. They thus becoming 
charged, recede till they touch the centre bell, 
and thus the motion of the clappers, from 
one to the other, produces the sound of 
ringing. 




142, Electric swing. — Balance a small 
figure upon two fine silk strings, and place 
it within 3 or 4 inches of a ball which forms 
part of a conductor, while on the other side 
of the figure is a second ball connected with 
the ground. Upon putting the machine in 




37 



action, the figure will vibrate from one to the 
other. 

The above figure represents such an in- 
strument. A is a ball attached to the prime 
conductor of a machine. C is a ball con- 
nected with the ground. B is a stand above 
which is a figure suspended by silk, and sup- 
ported by two glass pillars ; though these last 
are not absolutely necessary, because the silk 
will be sufficient to prevent any charge the 
figure may receive from being dissipated 
before it arrives at C, the proper place to 
deposit it. The ball A may be dispensed 
with, if the pillars be glass, and the figure 
suspended on linen, the top of one of the 
pillars bemg connected with the conductor. 

143. The electric seesaw. — Suspend a strip, 
or fine rod of glass upon a centre, and upon 
each end of it support a light figure of pith. 
Let ovie of the figures have no conducting 
substance under it, nor yet touch the con- 
ductor when swinging upwards ; but let the 
other figure come against the ball of the 
conductor when it rises highest, and touch 
another ball connected with the ground when 
descending lowest ; if put properly under the 
conductor of a machine it will vibratp up and 
down — the opposite figure only acting as a 
counterpoise to it. 




This apparatus is annexed : A is the con- 
ductor. B the conducting figure. C the 
counterpoise ; and D the part connected with 
the ground, to carry away the fluid brought 
down by B. 

144. Electrical spider. — Cut out of a bit 
of cork the body of a spider ; furnish it with 
eight white thread legs, and run through the 
body a long black silk thread. Hold this up 
in one hand, so that it shall hang 2 or 3 
inches from the side of the conductor, and 
hold the finger about the same distance be- 
yond it — when the assistant turns the machine 
the spider will fly backwards and forwards 
between the conductor and the finger. 

145, The electrical rope dancer. — Sus- 
pend from the ball of the conductor two thick 
wires, about a foot long. The upper wire is 



connected with the conductor by a small chain 
or hook ; the lower one is hung to this, at 
the distance of 2 or 3 mches, by a silk thread 
at each end ; the lower wire is also connected 
with the ground by a chain. Place on the 
lower wire a paper or pith figure, and upon 
putting the machine in action, it will move 
alternately and briskly between them, x 




This experiment is but a modification of 
the dancing figures, described xnEx. 136. In 
the cut above given, the two wires appear 
unconnected with each other, the lower one 
having a stand of its own. This is a better 
form of the apparatus, because when con- 
nected together by silk, the figure put to dance 
is apt to cling to the silk, which destroys the 
eff'ect intended to be produced. 

146. Spinning sealing wax. — Fasten on 
to a thick wire a piece of sealing wax, about 
one inch long, by heating it, and thrusting 
the wire into it. Put the other end of the 
wire into a hole, either at the end or side of 
the conductor, so that the wax shall be at 
some distance off. Underneath where the 
wax is, either on the table or the floor, place 
a sheet of brown paper, merely to catch any 
drops which may fall when the wax is in- 
flamed. Provide yourself also with a lighted 
candle, and a sheet of white paper, Direct 
your assistant, (for in this experiment you 
must have one,) to turn the machine, and 
stop it exactly at the time you may desire. 
Then standing near the wax, hold the white 
paper 4 or 5 inches from it, and light the 
sealing wax. When well lighted, blow it out, 
and at the same instant let the machine be 
turned, and exceedingly fine threads of wax 
will be thrown ofi", and collected on the white 
paper, as long as the wax remains melted. 
Stop the machine, light, blow out the wax, 
and turn the machine as before — more of 
the filaments will be thrown off, and thus 
any quantity may be collected, and if scraped 
together by the point of a pin, it will re- 
semble the finest wool, such as cannot be 
procured by any other means. 

147. Electrified camphor. — Connect a 
spoou or small metal cup, with the conductor 



SB 



of a machine, light the camphor, and then elec- 
trify the conductor ; the melted camphor will 
throw out the most beautiful ramiiications as 
long as the machine is turned. This experi- 
ment is even more beautiful than that with 
sealing wax. 

148. The electrical pail. — Suspend to the 
ball, which projects from the prime conduc- 
tor, a small metal or wooden pail, having at 
the bottom of it a hole, so fine that water 
will pass only by drops. Pour a little water 
into it, and when electrified, the water instead 
of dropping only will pass out in a stream, 
and this will divide itself into several streams, 
each of which in the dark will be beautifully 
luminous. 




149. Insulate a small condensed air foun- 
tain and electrify it ; the jet will be minutely 
subdivided and expanded over a considerable 
space, but will return to its original limit 
when the electrization is discontinued. 

150. Suspend one pail from a positive 
conductor, and another from a negative con- 
ductor, so that the ends of the jets may be 
about 3 or 4 inches from each other. The 
stream proceeding from one will be attracted 
by that which issues from the other, and 
form one stream which will be luminous in 
the dark. 

151. Hang two pails about 4 inches apart 
on the same conductor, and the streams 
which issue from them will recede from each 
other. 

152. Place a metal basin on an insulating 
stand, and connect it with the prime con- 
ductor ; then pour a small stream of water 
into the basin, which in the dark will have a 
beautiful appearance, as the stream will be 
divided into a great number of lucid drops. 

153. Hold a pail which is furnished with 
several capillary tubes, placed in various 
directions, near an electrified conductor, and 
the water will stream out of those jets near 
the conductor, while it will only drop at in- 
tervals from those which are opposite to it. 
A most remarkable exemplification of the 
laws of induction is seen when the vessel con- 
taining the water is made of a long form, 



and placed at right angles to the prime con- 
ductor of a machine, minute holes being 
pierced on the underside of the tube at 3 or 
4 inches distant from each other. The tube 
should be suspended by silk. Upon turning 
the machine, the water from the ends will 
fall in streams attractive of each other, while 
from the middle hole it only drops. In the 
dark with a powerful machine, and 4 or 5 feet 
distance for the water to drop, this is a most 
splendid experiment. 

154. Conical drop. — Place a large drop of 
water upon the end of a smooth metal rod ; 
hold it to the prime conductor when excited, 
and the water will first assume a conical 
form, and then fly to the conductor. 

155. Let a drop of water hang from the 
ball at the end of the prime conductor, and 
hold towards it a wine glass or spoonful of 
water. The one will attract the other, so 
that the drop will lengthen itself according 
to the force of the electricity. 

156. Fiery sponge. — Suspend in like man- 
ner to the bucket a sponge dipped in water, 
and the luminous streams which issue from 
it will be more numerous and beautiful than 
even in the last example. 

157. Electric planet. — Suspend from the 
conductor of a machine a brass ring, about a 
foot in diameter, and underneath it, at about 
i an inch distance, a metallic plate connected 
with the ground. Place upon this plate, and 
within the ring, a very light hollow glass ball 
— turn the machine, and the little ball will 
describe an orbit around the ring, and turn 
at the same time about its own axis. 'The 
poles of it? rotation are nearly at right angles 
to the plane of its orbit. We have not tried 
this experiment. Mr. Adams says, " that 
it requires considerable attention to make it 
succeed, as a small difference in the apparatus, 
or in the force of the machine, &c., will 
occasion a failure." 

158. Electric swan. — Procure a waxen 
swan, and which may be bought for a few 
pence at the pastry-cook's, who use them to 
decorate twelfth-cakes ; cover the throat and 
breast very neatly with tin foil, which may 
be painted over afterwards to prevent its 
being seen ; or the whole may be covered 
with gold leaf. Let the swan float in a 
basin of water, which is supported upon a 
glass stand, suffer a chain to fall from the 
prime conductor to dip into the water ; turn 
the machine and hold a piece of bread to the 
swan, it will immediately turn to it, and 
approach as if to eat the bread. The swan 
may be made of cork, and if an electrical 
stand is not at hand, a very excellent one 
may be made with a wine bottle, a flat and 
smooth piece of wood being nailed to a peg 
which fits into the top of the bottle. A sheet 



39 



of paste-board or a cover of a large book 
made warm answers the same purpose. 



^^ 




159. Electric boat. — Make a small boat 
ot wood, with a cork figure apparently row- 
ing it ; upon presenting a finger, the boat 
will approach, and may thus be carried round 
the basin in which it is floating. 

HENLEY S aUADRANT ELECTROMETER. 

The repulsion which takes ])lace between 
bodies which are elec- 
trified, suggested this 
valuable instrument, the 
object of which is to 
ascertain the degree of in- 
tensity to which any elec- 
trified body is charged, 
particularly the Leyden 
jar. It consists of a 
shank of wood, with a 
brass ferule and point 
at the foot, which latter 
fits into one of the holes 
of the prime conductor, 
Bnd is terminated above 
by a wooden ball turned 
out of the same piece of wood, mostly ma- 
hogany. To the side of the shank and near 
the top, is glued or otherwise fastened a 
semicircle of ivory, graduated on the edge 
to angular measurement, so that the whole 
semicircle is divided into 180°, and of course 
the point of it most distant, or at right an- 
gles to the stem, is 90°. In the centre of the 
circle, of which the semicircle is the half, is 
supported on a pivot a very thin wooden 
pointer, so that it may move up and down in 
a vertical line. A pith ball is placed at the 
outer end. If this apparatus be inserted in a 
hole of the prime conductor, or any other ob- 
ject strongly electrified, the pith ball and its 
stem will rise by electrical repulsion, and 
indicate by the degree they cut, the strength 
of the electrization. The greatest energy or 
abundance of fluid will make it subtend the 




angle of 90°, a less degree of force GO, 50, 
40, &c. degrees. This, although a useful 
instrument, is by no means an accurate in- 
dicator of intensity, because of the effect 
which gravitation has upon it. All the elec- 
trometers and electroscopes, previously de- 
scribed, act by the same principle. 



INDUCTION. 

The circumstances of electrical repulsion 
taking place between bodies similarly electri- 
fied is a natural consequence of the fact that 
the electric fluid repels itself, and attracts all 
other matter. Suppose there are two con- 
ductors placed as in the following cut ; one 




of them being a small conductor furnished 
with three pairs of pith balls, placed near to 
the prime conductor of a machine. Let that 
prime conductor be charged by turning the 
machine, and although the small conductor 
does not touch it, it is evident from numerous 
of the former experiments that it will be- 
come electrical, in the same manner as the 
feather did when the excited tube was held 
towards it {Ex. 9). The fluid being re- 
pellent of itself, and the end A of the prime 
conductor being electrified plus, there will be 
a superabundant quantity of the fluid at the 
end A ; it will therefore repel the fluid of 
B C from the end B. If B C be insulated, 
this repulsion will drive the fluid from the 
end B to the end C. As A does not touch 
or give a spark or any appreciable quantity 
of its extra fluid to B C it follows, what 
indeed can be satisfactorily proved by other 
methods, that it merely disturbs the fluid of 
B C, driving it from the end B to that of 
C. B therefore will be electrified minus, and 
as the fluid driven from B is accumulated in 
C, it must be evident that C would be elec- 
trified plus, while the central point between 
them would be neutral. This may be proved 
by the following experiments : — 

Ex. 160. Suspend from the small conductor 
B C three pairs of pith balls, on fine linen 
threads. Turn the machine very gently, so 
as to cause the pith balls to diverge ; they 
will hang as in the figure, showing a neutral 
point where the balls are unaffected, and two 
other points where the fluid is disturbed, and 
which are therefore charged. 



40 



IGl. Hold an excited glass tube to the 
pair suspended from B, they will be attracted 
to the glass, showing themselves in a con- 
trary state to the glass ; they are thereby 
proved to be negative. Then hold the excited 
tube to the pair at C, and they will be re- 
pelled, showing that the excited glass and 
themselves are both electrified alike, which 
we know is positively. 

162. Try this experiment with three con- 
ductors, as in the annexed cut. When excited 
as before, either by the proximity of a 
charged conductor, or by an excited glass 
rod held towards them, beyond the con- 
ductor N, draw away the central conductor, 
and also the excited rod, the central con- 
ductor O will not be charged at all, that 
marked P will be positive, and that at N 
negative. 






e^ 



c^^^^^^idbi. 



163. When charged as before, as soon as 
O is removed, place the conductor N, so as 
to touch P. The disturbance of both will be 
neutralized by each other, showing that the 
quantity which is plus in one, exactly coun- 
terbalances that which is deficient in the otlier. 

164. While the last experiments are pro- 
gressing, and before the conductors are taken 
out of contact with each other, suddenly stop 
the machine, or remove the excited tube, ac- 
cording to that with which you are operating, 
and the fluid will arrange itself as at first ; it 
has become in a quiescent state, and conse- 
quently no divergence of any of the balls will 
take place. If there should be, it shows that 
the conductor has become charged with ac- 
cumulated, and not induced electricity, and 
therefore all the pith balls will diverge with 
the same electricity. It has in fact positively 
received fluid, and not merely had that in- 
herent in it disturbed. 

165. If these three conductors instead of 
touching each other, had been placed a little 
apart, they would each have given the same 
results as they now do together, as it must 
be evident that they now act as a single body. 
The same would be the case had the con- 
ductors been ever so numerous, for according 
to the laws of electrical induction, there can- 
not be a body electrified positively without 
the nearest body to it being electrified nega- 
tively, this next body will in like manner act 
upon a third, the third upon a fourth, and so 
on. Negative and positive being always op- 



posed to each other. Take the following 
illustration of a number of spots of tin foil 
pasted upon glass. Suppose them held near 
to an excited electric, all the spots would be 
endowed with positive and negative proper- 
ties, according to the letters annexed to them. 




In all cases of this kind, it must be evident 
that an electric must interpose between the 
two conductors, or they would act as one, so 
in the experiment of the three conductors, 
air which is an electric is between one and 
another. In the condenser described in p. 15, 
there is a layer of varnish between the plates, 
so also in the electrophorus, the resinous 
matter or cake interposes between the upper 
plate and the under plate. In the circular 
rubbing machine, and in the sulphur cone, 
although excitation is carried on, on the one 
side of a piece of glass, yet the effects become 
apparent on the other side. In truth in- 
duction takes place only because of the in- 
terposing electric. In the air we have proved 
that this effect diminishes according to the 
square of the distance. In glass the exact 
ratio is not stated, but in all probability it 
follows the same law, making due allowance 
for the solidity of gLss as a resisting medium, 
and for its power of electric conductibility 
compared to air. It is certain that the thinner 
the glass is of all electrical apparatus, the 
more powerfully it may be charged, and the 
more easily excited. 

The induction which so readily shows 
itself on sliort conductors, is still more con- 
spicuously exhibited in those of a considerable 
length. For example, let us take the three 
conductors of Ex. 163, and while acting, let 
us add two more to them, the whole being 
joined together. The last conductor when 
there were three, became positive as we saw. 
But the fifth is now positive, and tlie neutral 
one is the third. The fluid when there were 
three was only driven a short distance forward, 
and its presence there prevented any further 
action, but now with five conductors it is 
driven twice as far as before, and therefore 
offers less impediment to a greater effect. 
It follows then that the longer the conductor, 
the greater is the power or effect produced. 
This being tried, will become evident, for 
when there are five united conductors, or else 
a conductor as long as the five, the pith balls 
at the ends will diverge much more, by the 
application of a certain quantity of elec- 
tricity then when there are three conductors, 
or one proportionably shorter. From this it 
follows : — that the electric effect will be ex- 



41 



hibited much more strongly by long con- 
ductors than by short ones. If the greater 
electric effects are produced by very long 
conductors, a question relative to their greater 
or less diameter, or their greater or less so- 
lidity, would naturally suggest itself. Some 
experiments upon this subject will show us 
that it is not those conductors that have the 
greatest quantity of matter in their bulk, that 
conduct electricity the best, but those which 
have the greatest surface ; hence it appears 
that electricity passes over the surface, and 
accumulates there only. Yet in violent 
transmissions of the fluid it appears certain 
that the fluid passes through the whole sub- 
stance ; when treating of the mechanical effects 
of electricity, we shall see this abundantly 
exemplified. At present we have only to 
adduce an illustration or two of the ordinary 
accumulation of the fluid upon the surface 
of bodies, rather than of its passage violently 
through them, and for this we have the law 
of Coulomb — that the quantity of fluid ca- 
pable of being made apparent by excitation 
or transference is in proportion to the surface 
of a body along which it passes, or upon 
which it is accumulated. Thus a hollow 
cylinder is always as efficacious as one which 
is solid, and a large thin conductor will accu- 
mulate more fluid than a small one of more 
solid material. The power of a Leyden jar is 
always in proportion to its extent of surface, 
and not according to the thickness of the 
coating, and so on in numberless other simi- 
lar instances. The following experiments 
have been adduced to show that in excited 
bodies, or those which are charged with fluid, 
the fluid is only to be found disturbed at 
the surface. 

166. Support upon a glass rod a wooden 
ball, and bore various holes to different depths 
upon its surface, as represented in section 
below ; then support a wafer covered with 
gold-leaf upon a very fine and dry rod of shell 
lac. Charge the wooden ball by holding near 
it an excited glass tube. "While it remains 
charged, touch its surface with the supported 
gilt wafer, which immediately hold to a very 
delicate electrometer ; this will show that the 
wafer has imbibed some of the electricity 
from the surface of the ball. Again, pass 
the gilt wafer quickly and neatly to the bot- 
tom of one of the holes, withdraw it, and 
upon holding it to the electroscope, no effect 
w 11 be produced. 




167. The electric ivell. — Place upon an 
electric stool, a metal quart pot, mug, or 
some other conducting body, nearly of the 
same form and dimension, then tie a short 
cork ball electroscope, that is two cork balls 
suspended on a linen thread, to a silken cord. 
Electrify the mug, and hold the electroscope 
within it, when it will not be at all affected. 

168. Instead of the electroscope in the 
last experiment use a metallic ball, suspended 
by silk ; electrify the mug and withdraw the 
ball, it will be found not charged by its con- 
tact with the inner surface of the mug, though 
it may have been struck against its sides 
many times. 

Biot, the celebrated French electrician, 
constructed the apparatus shown beneath. 
It consists of a round metal ball, suspended by 
silk and covered with two caps, each furnished 
with a glass handle as represented, made of 
paper and covered with tin-foil, and such that 
when united, they accurately fit the surface 
of the inner ball. Let there be communi- 
cated to the ball any degree of electricity, 
then let the two caps, held by their insulating 
handles, be carefully applied to its surface. 
Upon the removal of these caps, it will be 
found that the whole of the electricity has 
been abstracted from the sphere, so that it 
will no longer affect the most delicate elec- 
trometer, while the two caps will be found to 
have acquired precisely the same quantity of 
electricity which had at first resided in the 
ball. 




The next circumstance to be observed is 
the effect of an extended or contracted sur- 
face in rendering apparent a minute quantity 
of electricity. It is not to be supposed that 
the communication of a trifling amount of 
force will affect a large body — or, that a 
little fluid spread over an extended space 
will be so apparent as if more concentrated. 
In electricity, as in mechanics, the means 
must be proportionate to the end to be 
effected, and that which will influence sen- 
sibly a small conductor will be unappreciable 
on one which is larger. Thus electrical 
intensity may be less, though the quantity is 
the same. This is illustrated by the following 
experiments of Biot, Coulomb, and Cavallo. 

G 



42 



The figure beneath represents the ap- 
paratus required. A is a roller of baked 
wood, wax or glass, supported upon two rods 
also of glass ; a strip of tin -foil reaches to 
the central axis at the end farthest from the 
handle, or else there is a fine wire which 
reaches from the metallic ribbon or long slip 
of tin-foil C, to the insulated electrometer 
E F. G is a silk string attached to F. On 
electrifying the cylinder, or rather the metal 
coil E, the balls of the electroscope diverge ; 
upon taking hold of the silk thread, and un- 
rolling the metallic lamina from the cylinder, 
the balls gradually collapse, thus indicating 
a diminution of electrical intensity. Again, 
winding up the lamina, the balls will diverge 
as at first, making an allowance for a trifling 
dispersion of the fluid during the experiment. 




169. Make a number of pasteboard plates, 
cover them with tin-foil, and suspend them 
from each other by a metallic thread, a handle 
of glass or a silk cord being attached to the 
upper plate. Let the plates rest on each other, 
and place the whole together upon the top of 
a gold leaf electroscope, electrify them so 



that the gold leaves diverge ; then gradually 
draw them up by the silk thread at the top, 
when the diverging will diminish in proportion, 
and again increase when let down as at first. 




170. Insulate a metallic cup, or any other 
concave piece of metal, and place within it a 
pretty long metallic chain, having a silk 
thread tied to one of its ends. To a wire 
proceeding from the cup suspend a pith ball 
electroscope. Then electrify the cup by 
giving it a spark with a knob of a charged 
bottle, and the balls of the electroscope will 
diverge. Lift up one end of the chain, when 
the balls will collapse, let it down again and 
they recede as at first. 

171. Excite a long strip of flannel, or a 
silk riband, by rubbing it with the fingers, 
then holding the knuckle to it, take as many 
sparks as the riband will give, but when the 
riband or flannel has lost the power of giving 
any more sparks in this manner, double or 
roll it up. By this operation the flannel 
appears to be so strongly electrical, that it 
not only gives sparks to the hand brought 
near, but throws out spontaneous brushes oi 

I light, which appear very beautiful in the dark. 



CHAP. VL 



INFLUENCE AND DIFFERENT EFFECT OF BALLS AND POINTS. 
ELECTRICAL AURA. 

The preceding chapter, treating of the diff'usion of the electric fluid over the surface of 
bodies electrified, took no account of the particular character of their terminations ; it was 
supposed that they were all rounded off by balls, or globular terminations to the conductors. 
Let any of the experiments of attraction and repulsion be tried at the same time that a 
sharp-pointed needle is suffered to project from the conductor, or the end or side removed 
from the cylinder of the machine, and it will be apparent that the fluid is thereby dissi- 



43 



pated, so great is the power possessed by points in dispersing the fluid, that a single needle 
or pointed wire suffices to dissipate the whole fluid collected by a large machine. Hence 
the reason why all parts of the electrical apparatus, which is to hold accumulated electri- 
city, must be made round and smooth. As points have, in the cases mentioned above, the 
power to dissipate the fluid, so if they are attached to any surrounding object within the 
influence of the machine, they will draw it thence. It is for this reason that a row of points 
is placed on the side or end of the conductor nearest to the cylinder, the fluid being thereby 
attracted from the glass, to which it adheres rather strongly, to the prime conductor. We 
learn also the necessity of removing from the machine all pointed articles, of whatever nature 
they may be ; likewise persons who wear head-dresses, and other garments with sharp 
points and edges. In electrifying a gentleman, and afterwards a lady, on a glass legged 
stool, a very great difference is often perceptible in the strength of the spark which may 
be taken from each, entirely owing to the difference of their dress. We have in electrifying 
a lady frequently seen in the dark that the whole of the lace border of a head-dress has 
been perfectly luminous from the dispersion of the fluid, when of course but very small 
sparks could be obtained. A sharp pointed shoe is very apt to throw off the fluid, so is 
also a cravat pin, a metallic chain, and the point of a watch key. No dispersive effects 
however take place when the points of any of these articles are covered ; for it is not 
merely sufficient that a point should be present, but that it should at all times project 
beyond the general surface, or no effect is produced. The influence of points is easily 
seen in the dark, and the very different appearances then put on by the electric light 
proves the law of induction before explained, in a very perceptible manner, for even the 
very appearance of the light at the point will immediately inform us of the nature and 
state of the electricity of the body to which it is appended. 



E.V. 172. Escape of the fluid to a hall— 
Hold a ball towards the prime conductor of 
a machine, when at a certain distance, 
according to the strength of the machine, a 
spark will pass between the conductor and 
the ball. 

173. Escape of the fluid to a point. — 
Hold a pointed wire towards the prime con- 
ductor, and the fluid will be drawn off; but 
silently, and without a spark. 

174. Hold a sharp needle at a few inches 
distance from a charged conductor, and try 
with the other hand to take a spark ; it will 
be found that a spark will not pass to the 
hand until the needle is withdrawn, although 
the needle may have been held at double the 
distance at which the spark would otherwise 
have flown across. 

175. Brush of electric light. — Present a 
pointed wire to a conductor, which is electrified 
negatively, a lucid cone or brush will be seen 
diverging from the point, and the quantity 
of fluid will be increased. This is best done 
with a machine which has an insulated 
cushion. In directions to work a machine 
in page 30, it was recommended to hang a 
chain from the cushion to the ground. To 
try the above experiment, take away the chain 
from the cushion and hang it to the prime 



conductor — then hold the point towards the 
cushion. 

176. Star of electric light. — Hold a 
pointed wire towards the prime conductor, 
when in action, a star will be perceptible on 
the point, and not a brush as before. 

177. Attach a point to the outer side or 
end of the prime conductor, and a brush of 

I light will issue from it, while a star is seen 
] upon all of the points which are towards the 
i cylinder. 

j 178. Remove the conductor for some con- 

j siderable distance from the cylinder, brushes 

I of fluid will start from the cylinder, and stars 

I seen upon the points of the conductor. Place 

I a pointed wire on both prime conductor and 

cushion, and make the points approach each 

other ; a star will appear on one and a brush 

on the other, the conductor parting with its 

fluid, and the cushion receiving it. The pre- 




44 



ceding will be the appearance in the dark 
from the two points. 

179. Place a row of conductors, as in Ex. 
162, and let each be furnished with a point at 
each end, all the points farthest from the 
prime conductor will show brushes of light, 
and all the others stars. The stars indicating, 
as will be evident, the negative state, and 
the brushes of light the positive condition. 
The reason of these appearances is thus ex- 
plained by Dr. Roget. " The diverging lines 
on the one side, and their inflections on the 
other, represent exactly the paths of particles 
flowing out as from a pipe, and urged for- 
wards as by a force which gives them such a 
projectile velocity, as to prevent their spread- 
ing out beyond a certain distance from the 
direct line of projection. But this very ve- 
locity will carry the particles, that happen to 
have deviated most, somewhat beyond the 
point to which they are attracted ; whilst the 
attraction to this latter point will tend to 
deflect them from the line of their path, and 
gradually turn them back, so that they will 
arrive at the point of attraction by very dif- 
ferent paths, and even some by a retrograde 
motion. Hence while, in the first case, they 
form a diverging cone of rays, in the latter 
they must be distributed on all sides of the 
j)oint, like the rays of a star. The annexed 
diagram will sufficiently illustrate this ex- 
planation by representing the supposed course 
of the particles of electric fluid, passing 
through the air from the positive to the ne- 
gative point." 



The above reason is plausible, but scarcely 
satisfactory, because it takes no account of 
the quantity of fluids emitted or absorbed, 
nor yet for the distance of the points from 
each other, or the impulse with which the 
fluid escapes. It also supposes two points 
opposed to each other, without this there is 
a difficulty in conceiving that the star should 
be equally perfect in a variety of circum- 
stances. The following explanation appears 
more satisfactory. The electric fluid, by its 
momentum, flies off from a positive or sur- 
charged point in a brush, like fire from a sky 
rocket. The negative point being a mere 
receiver, collects the fluid from every thing 
around, equally on all sides ; hence it exhi- 
bits not a cone but a star of light. 

180. Electric flyer. — Place upon the con- 
ductor a pointed wire, and balance upon this 
a cross or star of wires, every ray of which 



is bent towards the end in the same direction, 
as represented beneath. The fluid issuing 
from these various points will turn the star 
of wires round in the opposite direction. 




A'o/e. — In the dark, the fluid from the 
various points will resemble a circle of fire, 
and this is rendered more brilliant if the ends 
of the wires are tipped with tallow or sealing 
wax. 

181. Compound flyer, round- abbut, 8fc. — 
A number of flyers may be made to revolve 
at the same time, if made very light, and 
delicately supported. A number of similar 




contrivances may be made as a round-about, 
such as is seen at fairs, provided the points 
which are to give it motion are properly 
placed — one among these is 

182. The electrical inclined plane. — In 
which a flyer is furnished with a small grooved 
pulley at each end of an axis tluit bears it, it 
is placed on two wires which are supported 
by glass. W hen this is connected with a 
moderately powerful machine, the flyer im- 
mediately begins to turn round, and traverses 
up the wires. 




183. Electric flyer with bells.— This ap- 
paratus is represented annexed. It consists ot 
a stand with differently-toned bells arranged 
upon it ; in the centre is a glass rod, and this 
supports a flyer, which flyer has depending 
from one of its arms a wire and a silk string 
bearing a brass ball, (the only use of the wire 



45 



is to keep the string somewhat steaay, also 
the opposite arm of the flyer should bear a 
ball as a counterpoise for the weight of the 
wire and string.) To use it, take away the 
conductor of the machine, and put the flyer 
in the same place as the points of the con- 
ductor usually are, when it will turn round, 
and the ball striking against them of course 
rings the bells. 




j\^7y/e._All these varieties of apparatus 
turn roun.d the same way, whether electrified 
positively or negatively. 

184. Electric orrery. — This apparatus is 
/seen beneath. It represents the sun, earth 
/ and moon.. The earth and moon are balanced 
exactly as in the last experiment ; they are 
at their centre of gravity, upon a pointed 
wire, bearing at its other end the sun; 
this wire has a point projecting sideways near 
its farthest extremity. The moon also bears 
a side point, thus (every part being nicely 
balanced,) the earth and moon revolve round 
each other, and both together round the sun 
— making one of the best possible illustra- 
tions of the real motions of these heavenly 
bodies. The whole apparatus may be 6 inches 
long — the sun, &c., may be of wood. 




jects through the head of the mill, ready to 
bear the sails. Make the sails of paper with 
a fine wire running along the back and end 
of each, a point of it projecting beyond the 
other edge. Let the centre of these sails be 
a small ball of metal, or else wood or pith 
gilt — fix the sails in this ball, and place the 
whole upon the point of the needle. Upon 
turning the machine the mill will revolve 
rapidly. This apparatus may be across the 
sails from one extremity to the other 4 or 5 
inches — the other parts in proportion. 




18G. Electric breeze or aura. — Bring an 
excited glass tube near a point that is fixed 
to the end of a positively electrified con- 
ductor, and the luminous brush will be turned 
out of its direction by the action of the ex- 
cited tube ; if the tube be held directly op- 
posite to the point, the brush will vanish. 

187. Fix the point to the end of the ne- 
gative conductor, the lucid star will turn 
towards the excited tube. 



185. Electrical windmill. — Make a wind- 
mill of card or baked wood ; up its centre put 
a wire, the lower end of which may fit a hole 
in the conductor, the upper end must support 
a needle put crosi^'ays, so that its point pro- 



188. Efect of a point to the glass feather. 
—Try tht Ex. 128 with the glass feather, and 
while the filaments of glass are extending in 
all directions by electrical repulsion, hold 
towards them a needle; they will be repelled 
from the needle, because the needle point 
draws away their accumulated fluid, the fila- 
ments thus restored to a natural condition 
adhere to the neighbouring filaments until 
they obtain a fresh supply. 

189. Instead of a point in the last experi- 
ment, hold a metallic ball towards the excited 
glass feather, and instead of receding from 

I the ball, the filaments of the feather will cling 
I to it, because its fluid not being drawn off 
I is attracted by the opposite state of the ball. 
I The head of hair or divergent threads may be 
I used instead of the glass feather. 

' 190. Hold a point towards the electric 
swan, and it will recede from the hand; hold 
a ball and it will approach. 

191. The diving ball. — Place a small pith 
or cork ball upon a tin saucer full of oil, 



46 



electrify the saucer, and hold a needle towards 
the ball ; the ball will plunge beneath the 
surface immediately. To explain this, it is 
to be remembered that oil is an electric. As 
soon then as the needle is presented to the 
ball, it draws away its electricity, which oc- 
casions the ball either to go to the side of the 
vessel or to the bottom of it for a fresh supply. 

192. The travelling ball.— Excite the 
brown paper of Ex. 4, lay it on a table and 
place a pith ball upon it, a quarter of an inch 
in diameter. The ball will run about until 
it becomes charged by the electricity of the 
paper. It will then stop, and if a needle be 
now presented to it, the little ball will roll 
away to another part of the paper. In this 
manner the ball may be made to roll back- 
wards and forwards for some minutes, or 
until it has completely dispersed all the dis- 
turbed fluid of the paper. 

193. T/ie pointed canoe. — Make a boat or 
canoe of cork or wood, and place a figure in 
it, poising a large needle in the manner of a 
spear, let this float in water, connected with 
the prime conductor, and hold the hand 
towards it ; instead of approaching the hand, 
the boat will recede from it. 




194. Fasten a blunt pointed wire, or still 
better a point of wood to the prime conductor. 
Turn the machine, and hold your face or the 
back of your hand against the point, when a 
breeze from the point will be very sensibly 
felt. Do the same with a point placed on the 
cushion, and a breeze will also be felt from 
the point. 

195. Instead of the face or hand, if you 
place a lighted candle near either of these 
points, the flame will be blown aside, by the 
breeze issuing from the point. 

196. Let a feather be driven about the 
room by an excited glass tube, as explained 
in Ex. 14. While so driving hold to the 
feather a pointed wire, the feather will be 
repelled, although there are here two bodies 
near to each other, which by the law of in- 
duction we know must be electrified difl'e- 
rently, and therefore should be attracted. 

To explain this, let it be remarked that air 
is always blown from an electrified point, 
whether that point be positive or negative — 
a fact often brought forward as an argument 
in favor of there being two electrical fluids, 
though it seems very easy to explain the 



curious phenomenon by other and more 
simple means. 

It is evident that the air in the neighbour- 
hood of an electrified point must itself be- 
come charged with electricity, no matter 
whether positively or negatively. The fluid 
is repellent of itself, the particles of air then 
to which it is communicated become neces- 
sarily repellent of each other, in the same 
manner as the particles of sealing wax of 
Ex. 146, or those of water in the Ex. 148, 
149, &c. Being repellent these particles 
escape, and the air rushing in to fill what would 
otherwise be a vacuity, produces a re-action 
suflicient to occasion the motion of the flyers 
and other apparatus. The reason why the fluid 
proceeds from the points in the form of a brush 
is easily accounted for — the wire of which 
the point is the termination is itself electri- 
fied, and therefore repellent of any particles 
similarly charged. The fluid in its escape 
must naturally then choose such a path as is 
the most open or free from repulsion, which 
will naturally be that in front of the point, 
and farthest away from the machine. In the 
case of a negative wire it is somewhat diffe- 
rent. The negative point, as before ob- 
served, seeks the fluid from all quarters, and 
in drawing the fluid, as in the former case, 
it draws the particles of air, in which the 
fluid is contained, from all directions. As 
action and re-action are equal, it follows that 
as many particles as are attracted must be 
either absorbed or repelled — electricity is 
absorbed by the negative point, but not air. 
The particles of air then must be again thrown 
off", and these, which before attraction were 
in a natural electrical condition, have now, 
owing to having had their fluid abstracted, 
become negative. The wire and point being 
negative also, the particles are thrown off" ia 
a brush in the same manner as the positiv* 
particles were from the positive wire. 

In all the above experiments the point has 
been free, and projecting from or towards 
the electrified body, and also has had an un- 
interrupted communication with the ground, 
or with the body electrified. Were either of 
these circumstances altered, the point would 
not act as we have seen it, but rather in the 
same manner as a ball would ; that is, the 
fluid would either not be drawn off at all, or 
it would pass away with sparks, or sudden 
interrupted flashes. 

197. Stick several needles into a piece of 

cork or other matter, so that their points may 

not be covered, place this mass of points .at 

j the bottom of a tin mug, with smooth edges, 

' electrify it well, and if the needle points are 

i below the edge of the mug, none of them 

will be luminous, showing that none are 

giving off" the fluid. 



45 



198. Thrust a sharp pointed wire through 
the centre of the rind of half an orange, so 
that the rind forms a cup around it. Let not 
the point project beyond the edge of the rind, 
and holding it towards a charged conductor, 
no effect will take place, except the general 
attraction of the fluid for the whole of the 
apparatus. Now project the point forwards 
by little and little, then as soon as it emerges 
from the rind, the peculiar silent action of 
drawing off the fluid commences, and a star 
of light becomes visible. 

199. Drill in a brass ball, which is 3 inches 
in diameter, a conical hole, which is about as 
large as a farthing on the outside, and tapering 
towards the centre ; drill a small hole through 
the opposite radius of the ball to admit a 
pointed wire. Let the wire project 2 inches 
beyond the ball on the side of the wide opening 
of the hole, and hold it to the prime conductor 
when charged. Taking the ball which ought 
to be of metal, or wood covered with tin-foil, 
in one hand, and the blunt end of the pointed 
wire in the other ; the projecting point will 
draw away the fluid silently. Still holding the 
ball steady, gradually withdraw the wire, 
when it gets near to the surface of the ball, it 
will take a small spark, and when drawn fur- 
ther in as strong a spark as if the ball alone 
were there. 

200. Electrical cross. — Form a cross of two 
thin leaves of talc, and paste upon them spots 
of tin-foil, just or nearly touching each other, 
and with a wire point at each end support 
this very nicely, as represented, on two 
wires. Place it near the prime conductor, 
and turn the machine, when the fluid passing 
from the centre to each of the points will 
produce beautiful streams of light, constantly 
in motion in consequence of the rotation of 
the cross. 




Note. — This cross may be made horizontal 
instead of vertical. This experiment is given 
in the Annals of Electricity, but we doubt its 
success, as the points take sparks, and do not 
throw off or attract the fluid in brushes. 

201. Hold towards the ball of a charged 
conductor a spiral tube, furnished with a ball 
at the end, and contrary to the usual character 
of a point it will take a spark. This is owing 
to the interrupted nature of the conductor 
which connects the point with the hand or 
with the ground. 

202. Support a pointed spiral tabe, as 
represented beneath, and have a flyer affixed 
to the upper end ; place it near to a charged 
prime conductor, when the fluid passing into 
the points turns the flyer on its axis. — Ann. 
Elec. 




203. To pierce a vessel of oil.— Partly fill 
a thin phial with oil, cork it, and thrust a bent 
wire through the cork, so that the lower end 
of the wire shall be about ^ an inch below 
the surface of the oil. Let there be a ball at 
the upper end of the wire. Take a spark 
from the prime conductor by the ball, holding 
the phial so that the thumb rests on the out- 
side of the phial opposite to the point. Al- 
though the wire is pointed at the lower end, 
yet the spark will be so strong as to perforate 
the glass. The oil will be curiously agitated. 
This expei'iment appears most beautiful when 
made in the dark. After the first hole is made, 
turn the end of the wire round towards ano- 
ther portion of the glass tube, and a second 
hole may be made in the same manner. The 
spark appears larger when passing through 
oil than when passing through the air. 

Other effects of points will manifest them- 
selves through every part of the subject. 



48 



CHAP. VIL 

ELECTRIC LIGHT AND SPARK. LUMINOUS TRANSFERENCE. 

The electric fluid shows itself in the several forms of a diffused light, of a brush, a star, 
and a spark, which spark varies in intensity, so as to be at some times scarcely perceptible, 
and at others, (when occasioned by the rapid progress of an immense quantity of the fluid;) 
like a flash of intense brilliancy ; sometimes straight and undivided, at others long and 
zigzag ; also of various colors and degrees of vividness, according to the nature of the 
conductor whence it is taken, or the density and character of the air, or other electric 
through which it passes. In the more gradual dispersion and weaker manifestations of the 
fluid, no noise is perceptible, a mere phosphoric appearance presenting itself as in Ex. 1 7 
and 20 ; and as may be tried also by any of the experiments of the last chapter ; for 
example, if the flyer, Ex. 180, be made to revolve in the dark a circle of brilliancy will be 
perceptible. Another effect is perceptible in Ex. 202. If a large quantity of fluid be 
escaping from a point, a whizzing noise becomes apparent. With a little more forcible 
emission of the fluid the whizzing becomes changed to a crackling, and the phosphoric 
light to a series of minute sparks. The noise and brilliancy increases in proportion to the 
impulse and quantity of the fluid, until a flash of lightning and a clap of thunder exhibits 
the most violent effects of its sudden passage from one overcharged body to another in 
its neighbourhood which by induction is dissimilarly electrified. These effects however 
are only the same in the same circumstances. Thus a negative spark is usually red, short, 
and straight. A positive spark is of a bluish white, long and zigzag. This only supposes 
that it is taken in the usual condition of the air, and from one metallic ball to another ; for 
in rarefied air the noise ceases, and that which would in the atmosphere have been a con- 
centrated and rapid spark, becomes a series of large, long brushes of diffused fluid. The 
same taken from different woods or other matters, or through various gases, becomes 
changed in color, no less than brilliancy. The brilliancy is also very greatly influenced by 
the distance at which the spark is taken. If the machine be put into action, and nothing 
be presented towards the terminal ball of the prime conductor, the fluid will escape in 
fitful flashes into the atmosphere around. If any round conductor be held in the hand, or 
if the closed hand itself be held at some distance from where these flashes issue, they will 
be seen to have a tendency towards it, and as the hand is made to approach to the prime 
conductor, so they will take a determinate form, color, and noise ; first, when at the 
greatest striking distance, they will appear as faint, blue, and very zigzag sparks, like 
distant weak lightning ; bringing the hand a little nearer, the sparks are more vivid, and 
consequently, whiter — they are thicker, well defined throughout their whole length, zigzag 
as before, and attended with a louder and quicker snap. At a less distance still, the 
brilliancy and snap is further increased ; while the zigzag character is by degrees lost, unti 
at length the spark is so rapid as to be almost continuous, short, thick, and straight, as 
we see in that dangerous, though rarely witnessed kind of lightning, in which the heavens 
seem to burst, and pour down a short perpendicular stream of intense volume to the earth, 
killing and destroying every thing within many yards of its passage. 

Such is the electric spark, and it may be advisable to remark, before proceeding 
further, how it is that the power of an electrical machine should be estimated. It is 



49 

common to hear a person observe, relative to some machine, that it will give a spark so 
many inches long, without stating how such a spark is to be measured. If he take all the 
forks of the zigzag into account, undoubtedly it will much increase the measured distance ; 
but this is not fair — still less is it to measure the spark upon the excited cylinder, for here 
the repulsion of the fluid from the overcharged conductor is assisted by the charged surface 
of the glass itself, and the attraction of the negatively -charged cushion. The true length 
of spark which a machine will give is to be measured by the distance between the termi- 
nating ball of the prime conductor, and a metallic ball held in the hand, when approaching 
them gradually to each other, and (the machine being in good action) a spark will pass 
between them. By this means of measurement, the real power of a machine may be 
known. The explanation of induction will have shown that the longest spark is always to 
be obtained from the end of the conductor, and also that the conductor should be of a 
considerable size. The sound is occasioned by the momentary agitation into which the air 
is chrown by the passage of the fluid. Also the object which takes the spark should be 
round, and presented quickly towards the conductor. 



Ex. 204. To obtain a crir2.wn spark. — 
Take a spark through a bpjl of box-wood, 
and it will appear of a beautiful crimson. 
This is better done with a sh'-n-k from a Leyden 
jar, as it is only a very strong spark taken 
exactly through the centre of the ball which 
will succeed, and even then it is very apt to 
pass over the surface. 

205. A red spark. — ^xa.^ a piece of gilt 
leather over a metal ball, and take a spark 
with the surface of the leather, and the spark 
will be red. 

206. Green spark. — Use a piece of silver 
leather instead of gold, and the sp:uk will 
appear of a green color. 

207. Red spark. —Take a spark from the 
conductor with a wet cabbage or other large 
leaf covering over the hand, and it will be of 
a red color. 

208. Place upon the conductor of a ma- 
chine a little cup full of water, or else place 
upon the table a tumbler full of water, with 
a chain which reaches from the conductor so 
as to electrify the water. If now a spark be 
taken from the surface of the water by a 
metallic ball, or still better by the finger, the 
spark will be red. 

209. Place a piece of ice on the conductor, 
and take a spark with another piece of ice, 
and the spark will be very red. Ice is, 
when below 13° of temperature Fahr., an 
electric, and therefore will not take a spark, 
but in a room it would necessarily be covered 
with a film of water. This would act suffi- 
ciently as a conductor, so that a small spark 
may be taken readily by this substance. 

210. Yellow spark. — Lay upon a dry sheet 
of white paper, a train of powdered charcoal, 
and take as long a spark from it as it will 
give, one end of the train being connected by 



a chain or wire to the prime conductor, and 
the other end having the knuckle or ball held 
in the hand presented to it ; gradually approach 
the ball to the charcoal, so that the fluid 
may run along it, and the spark will be of a 
yellow color. 

211. Prismatic colors in electric light. — 
Take a triangular glass prism, and hold it near 
the eye, while any luminous experiment is 
being performed, and the seven prismatic 
colors, or colors of the rainbow, will become 
evident, showing that the electric light is of 
the same nature as that of the sun. 

212. Brilliant blue spark through nitrogen. 
— Pass a spark through a vessel filled with 
nitrogen, and it becomes intensely brilliant, 
and of a splendid blue color, equal to that of 
burning brimstone. The apparatus, which is 
convenient for trying experiments of this 
kind, is as follows : — A is a glass receiver, 
holding about a pint, it has a wire and ball 
inserted in two opposite sides B and C. B is 
capable of sliding backwards or forwards, so 
that it may be made to approach or recede 
from the other. The receiver is placed in the 
pneumatic ti-ough, and is filled with the re- 
quired gas, in the ordinary way practised by 
chemists. For some gases a mercury or oil 
trough must be employed. During the ex- 
periment one of the balls must be connected 
by a wire with the prime conductor as at D, 
and the wire of the other held in tlv Land. 




39 



50 



213. Spark through oxygen, whitish. — 
Pass a spark through oxygen gas, and it will 
be whiter than in the air, and also less bril- 
liant. The effect in these two gases is singular, 
the brilliancy of the spark being increased in 
the nitrogen, which is not a supporter of 
combustion, and decreased in oxygen, the best 
supporter. 

214. Spark through hydrogen, reddish. — 
Pass a spark through a very strong small tube, 
filled with pure hydrogen, and it will be of a 
red color. In this experiment you must be 
very careful that the vessel be entirely filled 
with hydrogen, for if a small quantity of 
atmospheric air or oxygen be present, ex- 
plosion will ensue. 

215. Spark through carbonic acid gas, 
greenish. — Pass a spark through carbonic 
acid gas. The spark will be very similar to 
that in air, except that it will have a little 
green in it. It is more irregular than in air. 

\ 216. Spark through chlorine, whitish. — 

Pass a spark through chlorine, and the sparks 
are very white, and bright throughout, never 
presenting those dark intervals that appear 
in sparks drawn through air, azote, or other 



217. Variously colored through coal gas. 
— Use coal gas instead of the above ; with this 
gas the spark is sometimes red, at others 
green, and both colors often appear in the 
same spark. The result is here worthy of 
observation. Coal gas being a composition 
of carbon and hydrogen, and the spark being 
red with hydrogen only, and greenish with 
carbonic acid gas, the nearest approach we 
have to pure carbon in a gaseous state. Yet 
not merely in the chemically united coal gas, 
but also in the mechanical mixture of car- 
bonic acid and hydrogen, both colors are 
perceptible. It is to be supposed that the 
gases become polarized and disunited by the 
passage of the fluid through them. 

• 218. No spark through acid vapors. — Use 
a volatile acid, such as fluoric acid, nitric acid, 
hydrochloric acid, or sulphurous acid. Pass 
it up to the top of the mercury, and very 
little light, if any, will be apparent, acids 
being so good conductors, that the fluid passes 
readily and invisibly though them and their 
vapors. A mercurial trough, instead of the 
usual pneumatic trough must be used in the 
experiment, and in others where a gas or 
vapor condensible in water is necessarily 
present. 

In proportion ns the rarity of any medium 
is increased, w less intensity of electricity is 
required to render it luminous, and a spark 
becomes extended in proportion to (he rare- 
faction of the air through which it is made 
to pass. Thus if the fluid be only sufficiently 



strong to cross an inch space in a vessel filled 
with air, it will pass through 2 inches if the 
air be exhausted one-half ; and 4 inches if 
the rarefaction be continued to one-fourth 
the original quantity, and so on to greater 
amounts. It assumes a more diffuse arid 
brush-like form, and a different and fainter 
color ; passing through vapors, more or 
less rarefied, will also produce other effects. 

219. Indigo light through the Torricellian 
vacuum. — Seal a short wire within one ex- 
tremity of a glass tube of 30 inches long, so 
that the wire may project a little within its 
cavity, and screw a ball on the external end 
of the wire ; fill the tube with quicksilver, 
and invert it in a basin of the same ; a va- 
cuum will be formed in the upper part of the 
tube, which will occupy most space when the 
tube is vertical, and gradually diminish as 
it is inclined. A spark which in the open air 
would pass through only ^ of an inch, will 
pervade 6 inches of this vacuum with facility ; 
and if the quicksilver be connected with the 
ground, a current of faint indigo-colored light 
will pass through the upper part of the tube, 
whenever its ball is brought near an electrified 
conductor. 

220. Blue and purple light in vmtery 
vapor. — Previous to the inversion of the tube, 
let a drop of water be placed on the mercury 
at the open end, and secured by the finger ; 
whilst the tube is inverted, it will rise to the 
top, and when the finger is removed, and the 
quicksilver descends, the water will expand 
and extend the vacuum, and through this 
expanded vapor a current of electricity will 
become luminous, and of various blue and 
purple colors, accomjing to its intensity. 

221. Beautiful green light in etherial 
vapor. — Instead of water, use a itfi drops of 
ether, invert the tube, and pass a stream down 
it. If the Sf)ark be strong, the flashes will 
appear of a beautiful green color. 

222. Green color in hot mercurial vapor. 
— Fill the glass with very hot mercury, or, 
still better, suffer it to boil in the tube itself, 
and then invert it. The color of the light 
within, and which passes through the vapor 
of mercury, will, if the tube be very hot, be of 
a bright green color, and very brilliant. As 
the temperature diminishes, it loses its vivid- 
ness, and when cooled to 20° below zero Fahr. 
it is invisible. It is then in fact a perfect 
vacuum, as there is no air present, and the 
vapor of the mercury which first filled the 
tube is condensed. 

223. Color altered by degree of ex- 
haustion. — Admitting to the above a very 
small quantity of air, and gradually and 
slowly increasing it, the flashes are at fir.-t 
green, then sea green, then blue, and then 
purple. 



51 



224. Faint yellow in the vapor of tin. — 
Make a vacuum by means of fused tin } the 
electric light at temperatures below zero will 
be yellow, and very faint indeed, requiring 
almost absolute darkness to be perceived. 

225. Reddish purple in vapor of oil. — 
Make a vacuum in a similar tube with boiling 
oil, the light will be of a reddish purple, and 
much more brilliant than that through the 
vapor of mercury. 

226. Pure white light. — Make a vacuum 
above chloride of antimony, by boiling it in 
the tube. This salt boils at 388°. The light 
is of a pure white and very brilliant. 

227. Take an air pump receiver of 12 or 
14 inches high, adapt a wire, pointed at its 
lower extremity, to the top of the receiver, 
letting the point project an inch or two in 
the inside. Place the receiver on the plate 
of the air pump, and electrify the wire at its 
top positively. Whilst the air remains in the 
receiver, a brush of light of very limited size 
only will be seen, but in proportion as the 
air is withdrawn by the action of the pump, 
this brush will enlarge, varying its appearance, 
and becoming more diffused as the air becomes 
more rarefted, until at length the whole of 
the receiver is pervaded by a beautiful blush 
of light, varying its color with the intensity 
of the transmitted electricity, and producing 
an effect which is in the highest degree 
pleasing. 

AURORA FLASK AND TUBE. 




An instrument is sold by the philosophical 
instrument makers to show the passage of 
the fluid through rarefied air, without the 
employment of an air pump. It is repre- 
sented at A beneath. Fig. B is also a similar 
instrument varied only in form ; the descrip- 
tion of the one will therefore serve for the 
other. A, which is called the exhausted flask 
or aurora flask, may be made of a common 
oil flask, though sold usually of three or four 



times the size. A portion of the thicker end 
is covered with tin foil on the outside suffi- 
cient in quantity, that when held by the hand, 
the glass itself may not be touched. The 
neck is fitted with a brass cap and ball, with 
a pointed wire projecting inside. This ball 
should take off and show underneath it a 
screw, with a valve opening outwards, that 
the flask may be partly exhausted of air. No 
tin foil is necessary inside. B is a long wide 
tube of glass, fixed to a foot, and furnished 
with a cap and ball, and pointed wire at top, 
with the valve at the foot. By means of the 
valve in either of these instruments it is ex- 
hausted partly of air, by means of the air 
pump, then the ball being screwed on A and 
the foot on B, both will be fit for use. B is 
usually called the aurora tube, the appear- 
ance presented when electrified being exactly 
that ofiered by the aurora borealis in high 
latitudes. 

Ex. 228. To imitate the aurora borealis. 
— Make the flask very hot before the fire, 
hold it by the tin foil, and hold its ball to a 
charged prime conductor. Very long and 
brilliant flashes will pass along the partly- 
exhausted flask. The same thing occurs when 
the long tube is held to the conductor, or 
placed on the table near the conductor. The 
flashes will continue long after the removal 
of the tube from the machine. 

229. A result of the same nature, but far 
more beautiful, is seen when the aurora tube 
is 3 feet long and 4 inches wide, and which 
has a wire through the upper part of it, that 
may be pushed up and down ; two plates are 
placed inside, one a fixture near the bottom, 
the other moveable up and down by the wire, 
so that the plates may be made to approach 
and recede from each other. The fluid will 
in this apparatus pass in a continued and 
beautiful stream. 

230. While you are trying either of these 
latter experiments, place a hand against the 
side of the receiver or tube, as the case may 
be, and the fluid will be attracted by the hand 
towards the side of the vessel. 

231. Take the aurora tube B, warm it» 
thoroughly exhaust it of air, and while at- 
tached to the air pump, hold one hand at the 
top, while with the other hand holding an 
amalgamated leather, excite the outside of the 
tube, faint flashes of light will appear in the 
inside of the tube, showing that one side of 
the glass is excited when the friction is ap- 
plied to the other. The success of this ex- 
periment depends entirely upon the degree 
of exhaustion. 

232. Exhaust the aurora tube B of air, 
and fill it with nitrogen, the flashes of light 
now seen will be of great beauty. Draw 
away by a condensing syringe half the con- 



52 



tents of nitrogen, and the flashes will be of 
a line white color, and present one of the 
most brilliant appearances that the whole 
science presents. 

233. Light in rarefied gases. — Exhaust 
the tube, and introduce oxygen, the flashes 
will be now very close and compressed, and 
of a whitish color, but not brilliant. When a 
small quantity only is introduced, the form 
and appearance are better, but still the ap- 
pearance is not so good as with common air. 

234. Invert the tube and introduce a very 
small quantity of hydrogen ; the brushes are 
very fine in form and distinctness, but of a 
palish red color, and with a soft velvety ap- 
pearance. When the gas is very much rarefied, 
the flashes are of a pale green. 

235. Instead of the above, use the coal 
gas, and the brushes are short, strong, of a 
greenish color, and difficult to produce, 
unless very much rarefied. 

236. Use now carbonic acid gas. This 
produces a very poor brush, of a reddish 
purple color. 

The transference of the electric fluid in 
the state of spark presents to us numerous 
experiments equally beautiful, though very 
difterent in character from those which we 
have shown when the light passes through 
different media. The length and brilliancy 
of the spark being accordant with the strength 
of the machine, or the degree of intensity 
with which the conductor is charged, it fol- 
lows, that the rapidity with which sparks 
would be given off is also dependent upon 
the same cause ; thus by the aid of a power- 
ful machine we may produce so rapid a 
succession as to illuminate a whole apart- 
ment, and if we diminish their size we may 
in the same proportion increase the number 
of sparks in a given time ; hence the origin 
of what are called luminous devices, luminous 
tvords, &.C., and which are among the most 
beautiful of electrical experiments. They all 
are contrived upon the fact, that if you in- 
terpose an insulated conductor between a 
charged body and another, which is receiving 
a spark from it, you change that spark into 
two sparks; if you interpose two such objects, 
you occasion three sparks, and so on ; that 
is, the fluid having a tendency to fly off from 
a charged conductor to the ground, or to a 
negative bodynear it, takes always the nearest 
course, and is not diverted from its path by 
intervening conductors provided they are 
insulated ; if they are not insulated, of course 
they form the nearest passage for the fluid, 
and it will go no farther than to the nearest 
of them, when it will at once pass away. 
The explanation of this effect will at once be 
attributed to induction, especially as adverted 
to under E^. 165. In making electrical 



1 devices, the following rules are always to be 
i borne in mind. 1st : That the sum of all the 
! spaces on the glass, between one piece of tin- 
i foil and another, must be much less than the 
. length of the spark which the machine will 
' give ; in fact, altogether this aggregate space 
1 should be less than an inch. 2nd. The fluid 
I always traverses from the prime conductor 
■ to the earth, and will, other circumstances 

• being equal, always take the shortest course. 
j 3rd. If the spaces in any two lines of dots 
' be greater than the distance between that 
. line and the next, the spark will fly across the 
1 lines, instead of going along both of them. 
'■ 4th. The least possible space between one 
I dot and another is sufficient, even if it be as 
I fine as a hair. 5th, The lines must never 
' cross each other, unless on different sides of 

• the glass. 6th. When used they must be 
I quite dry and warm. 

I 237. Shot chain. — Cut a number of shots 

I half in two, and string them on a thread of 

! black silk, at the distance from each other 

i and of the size shown beneath. Take 1, 2 or 

: 3 inches in length of this chain, according to 

the strength of the machine, and holding one 

end of this in the hand, take a spark with 

the other end. The spark instead of being 

single will appear distinct at each interstice 

between the shots, so that the whole has a 

most beautiful and interrupted luminous 

appearance. 

238. Luminous spangles. — Sew amunber 
of metallic spangles upon a black silk ribbon 
very nearly to touch each other. Suffer a 
spark to run along the spangles, and a beau- 
tiful line of light will be visible. The ribbon 
may be a foot or more in length. 

239. Spiral tube. — This consists of two 
glass tubes, placed one within the other. On 
the outside of the inner tube are fastened, 
with common paste, spangles of tin-foil, 
(punched out of the sheet of tin-foil with a 
small hollow punch ;) the two ends of the 
tubes are wrapped round with tin-foil, and 
cemented each into a brass cap, taking care 
that the tin-foil at the ends, and the spangles 
and the brass caps are all in contact with 
each other. To use the spiral tube, hold one 
end in the hand and the other apply to the 
conductor, when a spark will pass along the 
whole length. 



V,..-" 



240. 5"^^ of spirals. — This is an experi- 
ment of extreme beauty. There are six spiral 



53 



tnbes set round a stand in a circle, the under [ 
part is covered with tin-foil, connecied with 
each spiral, and with the lower stand, to 
convey away readily the fluid. B shows a 
glass pillar in the centre, and A a brass wire 
terminated by balls, which turns freely upon 
the top of B, so that as it revolves, it shall 
come very near to each of the spiral tubes in 
succession ; the top of A is placed so near to 
a ball which hangs from the prime conductor 
of a machine, that sparks may pass in rapid 
succession to the centre of A. If while the 
apparatus is thus placed, A be turned round 
by the hand, it will communicate a spark to 
each of the spirals in its rotation, and they 
will rapidly be illuminated. 




are better made without any frame ; if they 
have a frame, it must be of baked wood. 

242. Luminous crescent. — This is best 
made by straight strips of tin-foil pasted on, 
and connected at the edges as shown be- 
neath, and then the places for the sparks 
cut with a knife. 



241. Devices on glass. — Procure a piece 
of common window glass, 3 inches wide, and 
12 or more long. Make a design on paper 
of the device you desire to have ; lay this 
beneath the glass ; then cover the upper 
surface with common paste, and with the 
point of a knife, or top of a pencil, place a 
series of tin-foil spangles, according to the 
figure you have drawn. Press the pieces 
down so as to lie flat, then let it dry. When 
dry, wash off the superfluous paste, and put 
a brass ball or bullet at one end, when the 
device will be fit for use ; the bullet or ball 
may be prepared by holding it in a vice, and 
cutting it about half through so as to admit 
the edge of the glass. Upon holding this at 
one end, and taking a spark by the other, 
the device will be illuminated. These devices 

, •'«•• ;~i« ,..« •<•• ««•• •«§• aKa aios { 

,.: S § : : I s I 3 I f : I : I ; L 

»««■ «««» ;.«a £».S 5..S %t,l Uiil r 




Note. — It is usually supposed to oe ne- 
cessary to make a cross cut at the luminous 
places, and to peck out the two small corners 
thus liberated. This, however, is quite un- 
necessary, merely drawing the knife across is 
quite sufficient. It may be advisable to state, 
that after the strips are pasted on, they should 
be suffered to dry, and the general surface 
carefully washed with warm water before 
cutting them across. 

243. The following device is made on both 
sides the glass ; the spangles being on owe 
side, the straight lines on the other. 



!V\ /\ /\ /\ /\ /\T 



244. It is sometimes extremely difficult 
to arrange the strips when both sides of the 
glass are to have a certain portion, as in the 
following star, where it is evident that the 
fluid would not run round if the spangles 
were placed all on one side, as it would at 
once pass away to its destination, the hand. 
It must however be made to travel over the 




54 



whole distance. By the different shading of 
the cut, it will be seen what must be pasted 
on the one side and what on the other. 

245. Luminous word. — In the same man- 
ner a word, such as electric fire, light, &fc., 
may easily be made. It is best dorte by 
pasting the tin-foil in a whole piece over the 
glass, and laying a flat ruler upon it, cutting 
the various lines, and then tearing off the 
tin-foil which covers the intervening places. 
By this means the lines may be preserved 
straighter than by the other method. 



Devices of this kind may be further orna- 
mented by colored varnishes spread over 
them, which will cause the spark to be varied 
in color, when seen on that side upon which 
the varnish was placed. 

246. Revolving spiral. — The following ap- 
paratus is the contrivance of Mr. Sturgeon. 
The figures beneath show the front and side 
appearance of the apparatus, the same letters 
applying to each. A A is the foot board. 
B B an upright wooden support. C a staple 
which forms with the top of B a support for 



the axle and small pulley P. A cord passes 
from this to the multiplying wheel W. S is a 
glass stem upon the top of which is the wire 
ring O O. The axis is terminated in form 
by a brass ball, on the two opposite sides of 
which are two short spiral tubes ; these are 
put in motion by the wheel, cord and pulley. 
If while the spiral is made to revolve, sparks 
be taken from the machine by the ball shown 
on one side of the ring O, they will pass down 
the spiral tubes, and produce a most beautiful 
effect. *• 




CHAP. YIIL 



THE LEYDEN JAR AND ELECTRIC SHOCK. 

The year 1745 was famous for the most surprising discovery that had yet taken place in 
the science of electricity. This was the wonderful accumulation of its power by glass, or 
the means of concentrating its effects by the Leyden jar, as it is called, and which took its 
name from Mr. Cuneus, a native of Leyden, who was led to its discovery as follows : — 
Observing that electrified bodies, exposed to the common atmosphere, which is always 
replete with conducting particles of various kinds, soon lost their electricity, and were 
capable of retaining but a small quantity of it, he imagined that were the electrified bodies 
terminated on all sides by perfectly dry electrics, and removed from the conducting influence 
of the surrounding air, that they would be capable of attaining a stronger power, and of 
retaining it a longer period. The easiest method that suggested itself was to inclose a 
conducting body in a warm glass phial. He tried with common water in a phial, corking 
the phial, and thrusting a wire through the cork, which touched the water. After taking 
a few sparks from the machine to the wire, and holding the phial by the outside, he 
removed it from the machine, and endeavouring afterwards to take out the wire with the 
other hand he felt a shock immediately in his arms and breast ; this being quite unexpected 
was a matter of great astonishment, and it may be added, terror also. 



65 

It was this astonishing experiment that gave eclat to electricity. From this time ;t 
became the subject of general conversation, every body was eager to see, and notwith- 
standing the terrible account that was reported of it, to feel the shock, and in the same 
year in which it was discovered, numbers of persons in almost every country in Europe, 
got a livelihood by going about and showing it. The'Leyden jar is nearly as simple now 
as it was then, and easy as electrical instruments are to make and manage generally, this 
is one of the most so. It has just been stated, that water was placed within the phial, 
and the hand on the outside. These acted not from any peculiar virtue in the hand and 
in the water, but merely because they were both conductors, and of course any other con- 
ductors, if equally good, would be equally efficacious. We have shown that metals are the 
best conductors of all ; it follows then that partly lining and covering the phial with a 
metallic substance, as brass dust or tin-foil, will be still more efficacious, as well as more 
convenient, as it leaves the hands at liberty and prevents the annoyance and dampness of 
water. A Leyden jar then described as lined and covered with tin-foil, differs in principle 
in no degree from Mr. Cuneus's bottle of water, and the explanation of the one therefore 
becomes that of the other. 



THE LEYDEN JAR 

Consists of a glass phial or jar of any size, 
it is usually made with a large mouth, for the 
sake of convenience. The 
lower part is lined with tin- 
foil, to about 2 inches from 
the top ; the outside is also 
covered with tin-foil up to 
£he same line, as is seen in 
the cut. There is a wire, 
with a ball at top, connected 
with the inner coating. The 
jar is now complete, and 
being dried and slightly 
wrarmed, is fit for use ; for 
the greater convenience of 
holding the ball and wire 
tightly, the jar is usually 
made with a wooden lid at 
top, and a chain reaching 
from the wire, which is fastened to the lid, 
down to the bottom of the phial, where it 
rests upon the inner coating. When there 
is a lid, it should be made of baked wood, 
and turned with smooth edges. 

Ex. 247. To charge and discharge ajar. 
• — Place the brass ball of a coated jar in 
contact with the prime conductor, while the 
outside communicates with the table, turn 
the cylinder, and the bottle will in a little 
time be charged. To discharge the jar, or 
restore it to its natural state, bring one end 
of a conducting substance in contact with the 
outside coating, and let the other be brought 
near the knob of the jar which communicates 
with the inside coating ; a strong explosion 
will take place, the electric light will be visi- 
ble, and the report very loud. If it is coated 
very low this part of the surface may be 




charged very high, but a considerable part 
of the glass is not charged at all. When a 
jar is charged very high, it will often explode 
or discharge itself over the glass from one 
coated surface to the other ; or, if the glass 
is thin, it will make a hole through it, and 
swell the coating on both sides, the glass in 
the hole will be pulverized, and very often a 
variety of fissures will proceed from it in 
various directions. 

248. To receive the shock. — Charge the 
Leyden jar ; then touch the outside coating 
with one hand, and the knob with the other 
The jar will be discharged, and a sudden pe- 
culiar sensation will be perceived in the 
wrists, arms, or chest, according to the size 
of the phial. This is called the electric 
shock. 

249. To communicate the shock. — Let the 
several persons who are to receive the shock 
arrange themselves in a line or circle as most 
convenient. Let them carefully join each 
other's hands without gloves, let tne person 
at one end of the line take hold of a chain 
which is connected with the outside of the 
bottle, and let the person at the other end of 
the line touch the knob of the bottle when 
charged. The shock will pass along the 
whole line of persons. In receiving a shock 
in this manner persons are generally unwil- 
ling to be at the either end of the line, thinking 
that it is stronger there than in the middle of 
the line, but this is a great error, as they all 
receive it equally, and would do so if there 
were a regiment of soldiers receiving a shock 
at the same time. 

250. To pass the shock without feeling 
it. — As shocks are not agreeable, the elec- 
trician generally discharges the phial by means 



ot what is called a discharging rod. This is 
either a semicircular piece of wire with a ball 
at each end, or else two wires with balls at 
the outer ends, and jointed at the lower ends 
where they are received into a socket, into 
which a glass handle is fastened. Hold the 
common discharging rod firmly, and dis- 
charge a phial by it, he will not receive a 
shock. If the phial be a very large one, or 
if he hold it lightly, he will feel perhaps a 
slight tingling of the fingers, when the shock 
passes, but this is all. If he be furnished 
with the glass handled discharging rod, or 
jointed discharging rod, as it is called, he 
may by setting its knobs at a proper distance, 
discharge even the largest battery without 
danger. It is usual for the sake of conveni- 
ence to fasten a chain to one of the arms oi 
the discharging rod, which communicates 
with the outside of the phial. 




251. To ascertain the intensity of a 
charge. — Fasten the quadrant electroscope, 
(described in page 39) to the conductor, or if 
more convenient to the knob connected with 
the inside of the phial. As this lattt-r becomes 
charged, the stem and ball of the electroscope 
will rise up until it attains 85 or 90°, when 
the bottle will be fully charged, consequently 
no greater effect will ensue ujion turning the 
machine longer. 

DISCHARGING OR MEDICAL ELECTRO- 
METER. 

A, bottle will endeavour to throw off its 
electricity from the inside to the outside, the 
more as it becomes charged with greater in- 
tensity, as observed in Ex. 244, and if the 
two coatings be placed so close to each other, 
that the attraction between the two coatings 
overcome the resistance of the glass, a dis- 
charge necessarily takes place. On this fact 
the discharging electrometer is constructed. 
A is supposed to be a cross section of the 
prime conductor of an electrical machine. 
B is a brass cap, forming the end of the elec- 
trometer. It is made with awire beneath to fit 
the hole of the conductor. C is a bent glass 
tube. Da brass ball at the end of it. E is awire 
with a brcss ball at each end, which wire is 
moveable backwards and forwards. When a 
shock is to be taken, the ball E is placed at 
a certain distance from the surface of A. A 
is connected with the inside of the Leyden 
jar, which communicates the shock, and the 
chain is connected with the outside of the 
jar. When the jar is charged to such a degree 
of intensity, as to acquire force enough to 



strike across from A to E, the discharge will 
spontaneously take place. The ball at E 
must be set at a greater or less distance from 
A, according to the strength of shock re- 
quired. If a shock is to be given to a com- 
pany, when this electrometer is to be used, 
tliey must form part of the circuit between the 
outside of the bottle and the electrometer. 




ELECTRICAL BATTERY. 

A series of jars is called an electrical bat- 
tery. This powerful instrument is so arranged 
that all the outside coatings are connected 
together by standing in a box lined with tin- 
foil ; and all the inside coatings are also 
connected by their wires meeting in a ball at 
the top. It is charged and discharged in 
the same way as a single jar, and has of 
course precisely the same effect, but propor- 
tionably more powerful. 




BALANCE DISCHARGER. 

For discharging a battery at a certain de- 
gree of intensity an instrument is sometimes 
used, in which electric repulsion is the acting 
principle. This is represented beneath : — 

A is a foot-board, supporting two glass 
pillars B and G. C is a brass ball and 
socket, fitting upon B, and by a hook at- 
tached to it holding the chain H. The ball 
C bears at top a brass arm and ball F, which 
are fixed immoveably to it. Upon an axis 
running throut^h C is supported the balance 
D E also of metal. In order that this ba- 
lance may play up and down so that E shall 
be able to reach and fall upon G, a slot or 
long aperture is made on two opposite sides 
of C, wide enough for the wire to pass 
readily. There is also a chain attached to 



5/ 



the socket of G, marked I ; and a small 
moving weight between C and E to be slipped 
backwards and forward, as required. To 
understand the mode of action of tliis valuable 
discharger, it is to be remembered that bo- 
dies when electrified similarly repel each 
other in proportion to the degree of their 
electrization. Now connect H with the 
inner part of the battery, and I with the 
outer, and see that the balance is loaded a 
little, by moving the small sliding weight 
between C and E. The brass part of the 
balance connected with H will become 
charged, and when sufficiently charged to 
overcome the balance weight, the ball E will 
be repelled downwards, and fall to G ; as 
this is connected with tlie outside of the 
battery it will be discharged by the contact 
of G and E. It is to be remarked that 
while repulsion will go on between F and E 
attraction will arise between E andG, there- 
fore there is a double force to drive down E. 




Explanation of the shock. — The expla- 
nation given of the phenomena of the Ley- 
den jar is that of induction. Glass is sup- 
posed to contain, at all times, on its two 
surfaces, a large quantity of the electric 
fluid, which is so disposed that if you increase 
the quantity on one side the other must throw 
off an equal proportion ; or, when one side 
is positive, the other must be negative. Now, 
as no more of the electric fluid can be forced 
on one side than can go off on the other, 
there is no more in the bottle after it is 
charged than there was before ; the quantity 
is neither increased or lessened on the whole, 
though a change may be made in its place 
and situation ; i. e. we may throw an addi- 
tional quantity on one of its sides, if, at the 
same time, an equal quantity can escape 
from the other, and not otherwise. This 
change is effected by lining parts of its two 
surfaces with a non-electric, through the 
mediation of which we are enabled to convey 
the electric fire to every physical point of the 
surface we propose to charge, where it exerts 
its activity in repelling the electric particles 
naturally belonging to the other side ; all oi 
which have an opportunity of escaping by the 
lining in contact with this surface, which, for j 



that purpose, must communicate with the 
earth. When the whole quantity belonging 
to this surface has been discharged, in conse- 
quence of an equal quantity thrown upon the 
other surface, the bottle is charged as much 
as it can possibly be. The two surfaces are 
at this time in a state of violence ; the inner, 
or positive side, strongly disposed to part 
with its additional fire, and the outer or 
negative side, equally desirous to attract what 
it has lost ; but neither of them capable of 
having a change in its state eflected, without 
the equal and contemporary participation of 
the other. That notwithstanding the vicinity 
of these two surfaces, and the strong dis- 
position of the electric fluid contained in one 
of them, to communicate its super-abundance 
to the other, and of that to receive it, yei. 
there is an impenetrable barrier between 
them ; for, so impermeable is glass to the 
electric fluid, (though it permits one side of 
it to act on the other,) that its two surfaces 
remain in this state of contrariety till a com- 
munication is formed between them, by a 
proper, conductor, when the equilibrium is 
suddenly and violently restored, and the 
electric fluid recovers its original state of 
equality on the two sides of the glass. 

We shall be able to prove the truth or 
error of this reasoning by the following 
experiments. 

252. To charge a sheet of glass. — The 
principle of the Leyden phial is seen very 

perfectly in a sheet of 
glass, such as is repre- 
sented. Tin-foil is to be 
pasted on each side, to 
/ ii \ within an inch or more 
• I jii V of the edge ; fasten a 
thread, holding a pith 
ball, to the tin-foil on 
each side with a piece of 
wax ; connect one coat- 
ing with the ground, and 
louch the prime con- 
ductor with the other, 
the plate of glass will be 
charged, and the pith balls fly out to some 
distance ; connect the two sides together with 
a wire, the shock will pass, and the pith balls 
will become at rest. 

253. Magic picture. — Procure a frame of 
dry wood, and furnish it with a glass, as a 
picture-frame usually is, cover this with tin- 
foil, as inEx. 252 ; cover the back with a loose 
piece of dark paper, or a thick dry paste- 
board, cutting a small hole in the middle, in 
order to bring through it a strap of tin-foil, 
which is pasted upon the coating of the 
under side of the glass, and reaches to the 
frame ; now cover the tin -foil on the f;ice of 
the glass with a picture of any kind, and the 
instrument is complete. To use it, put a 

8 




piece of money on the picture, and holding 
it by the frame where the tin-foil is, charge 
the picture by presenting a ball from the 
conductor to the money. When charged, 
take hold of the frame by the other hand, at 
some other part of the frame, and direct 
another person to hold that part which you 
have just quitted with one hand, and to take 
off the money with the other. His attempt to 
do so will discharge the sheet of glass, and he 
will receive a shock in the fingers, while he 
will be quite unable to take off the money. 
This amusing apparatus is represented in the 
following cut : — 




2i>4. Electric pendulum. — Construct an 
instrument of wire, with pith balls at the end 
of it, as represented. Hang this on the 
charged plate of glass, when it will vibrate, 
so that its balls touch each side alternately, 
and finally discharge the jar. 




A charged jar may be handled with im- 
punity, provided we are careful never to 
touch the outside'and inside of it at the same 
time, as may be easily proved. 

255. To discharge a iar gradually with 
the finger. — First, put the jar on an in- 



sulating stand, then touch the outer and 
inner coating alternately with the finger, and 
a small spark will pass each time, and finally 
discharge the jar. 

256. To wipe out a jar when charged. — 
Insulate the jar on a glass legged stool, being 
careful not to touch the stool or outside 
coating, either with your hand or clothing. 
Take off the cover by the ball, only a small 
spark will pass to the finger ; holding a hand- 
kerchief in your hand, dip your hand care- 
fully into the jar, wipe it out with the hand- 
kerchief, and draw it carefully out again, 
then put on the cover as at first. Now dis- 
charge the jar in the usual way with the 
discharger, and you will find that although 
it has been thus handled, yet you neither re- 
ceived any shock in wiping it out, nor was 
the fluid silently dissipated. 

257. To show that an insulated jar cannot 
be charged. — Screw a Leyden phial, whose 
coating is free from points, upon an insu- 
lated stand, and place it so that its knob may 
be in contact with the conductor, (taking 
care that no conducting substance is near 
the coating of the jar,) turn the cylinder 
round a sufficient number of times to charge 
the phial, then examine it with a discharging 
rod, and you will find it had received no 
charge ; which shows clearly, that except the 
electric fluid can escape from one side of the 
jar, it can receive none on the other. 

258. To charge a jar negatively. — Insu- 
late two Leyden bottles ; let their coatings 
be in contact, and while you charge the in- 
side of one positively, let a person, standing 
on the floor, touch the top of the other with 
his finger, and it will be charged negatively. 

259. To discharge a jar silently. — Pro- 
cure a Leyden jar, which has a hole in the 
top of the ball, charge it, insulate it, then 
screw a pointed wire on to the ball. This 
will soon discharge the jar silently ; or the 
orrery or flyer formerly described may be 
substituted for it. 

260. Electrical spider. — Make an object 
in the shape of a spider — its body of cork, 
with eight legs of white thread, about an inch 




59 



long, and suspend it by a thick black silk 
thread. This will play between the knobs of 
two phials, if one be electrified positively, 
and the other negatively ; or will discharge 
a phial, if suspended at a equal distance from 
the knob at the top, and a knobbed wire 
proceeding from the bottom of it. 

261. Let a coated jar be set on an insu- 
lating stand, and let its knob be touched by 
the knob of another jar negatively electrified ; 
a small spark will be seen between them, and 
both sides of the insulated jar will be instanly 
negatively electrified. 

262. Fasten a pith ball electrometer by a 
little wax to the outside coating of a jar, 
slightly charge it with positive electricity, and 
set it on an insulated stand, the ball will either 
not diverge, or only a very little ; bring the 
knob of a jar which is strongly charged with 
positive electricity, near the knob of the 
former, and the balls will diverge with posi- 
tive electricity. 

263. Let the same jar, with the pith balls 
affixed to its outer coating, be slightly charged 
negatively and then insulated ; bring the 
knob of a jar, which is strongly electrified 
negatively, to that of the insulated one, and 
the pith balls will diverge with negative 
electricity. 

264. Charge a jar positively, and then in- 
sulate it ; charge another strongly with ne- 
gative electricity, bring the knob of the 
negative jar near that of the positive one, 
and a thread will pass between them ; but 
when the knobs touch each other, the threads 
after being attracted will be repelled by both. 

These experiments seem to show that the 
negative electricity is sometimes superinduced 
on the positive, and for a few minutes after 
theyare separated both will appear negatively 
electrified, but if the finger is brought near 
the knob of that jar on which the negative 
electricity was superinduced, it will instantly 
be dissipated ; a small spark will strike the 
finger, and the jar will be charged positively 
as at first. 

265. To charge a jar by its own fluid. — 
Let the rubber, and also the prime conductor 
of an electrical machine, be both insulated. 
Connect the inside of a Leyden jar which is 
also insulated with the prime conductor, and 
the outside of the same wire with the cushion. 
Upon turning the handle, the phial will be- 
come charged on the inside by the same fluid 
which is taken from the outside. 

266. Take two equal jars, with a quadrant 
electrometer attached to the knob of each. 
Place one of them in contact with the posi- 
tive conductor of the machine, and the other 
with the negative conductor. When the 
machine is turned both jars will charge, and 



to the same height, as may be seen by the 
receding index of each electrometer. Re- 
move the jars from the machine, and place 
them on two separate insulating stands ; 
connect their knobs by an insulating or 
glass-handled discharging rod. No explosion 
will ensue, although they are oppositely 
electrified ; for their electricities depend on 
the attraction of their outer surfaces, which 
in this insulated state have no means of 
communication. Connect the outer surfaces 
by a wire or other conductor, and repeat 
the experiment — an explosion will take place, 
and both jars will be discharged 

267. Hold a clean and dry pane of glass 
by one corner, and pass it before a bail con- 
nected with the prime conductor of the 
machine, so that the ball may successively 
come in contact with eveiy part of the mid- 
dle of the pane of glass, whilst the finger or 
any uninsulated substance is opposed to it 
on the opposite surface ; by this process the 
glass will be charged. Apply the discharging 
rod to the opposite surfaces ; an explosion 
will ensue. Make the contact with the dis- 
charging rod again in another part of the 
surface — another explosion will be procured ; 
and in this way many are sometimes obtained 
in succession. 

268. Repeat the experiment of charging 
the pane, and then place it between two 
plates of metal of about half its size. On 
the application of the discharging rod, but 
one explosion will be procured, but it will 
be louder and more brilliant than those pro- 
cured from the uncoated pane. Hence it is 
seen that the use of the metallic coating is 
to connect the effects of every portion of 
the surface of the jar, so that it may be 
charged or discharged by the simple appli- 
tion of the machine or discharging rod to 
one portion of its surface 

269. Place an uncoated jar beneath the 
conductor of the machine, and suspend a 
chain from the conductor so as to hang in 
the centre of the jar ; on turning the ma- 
chine the chain will move round, and apply 
itself in succession to every part of the in- 
ternal surface of the jar, which by that 
means receives a charge. Apply the dis- 
charging rod, and the chain will return over 
the parts with which it has been in contact, 
and thus by a few of its revolutions the jar 
will be discharged. 

270. Take a Leyden jar, coated on the 
mside as usual, but with a coating of only 
1 inch high on the outside ; during the 
charge and discharge of this jar ramifications 
of electrical light will be seen on the outside. 

271. Jars with moveable coatings. — Pro- 
cure a jar, with a double set of moveable tin 
coatings, either of which may be adapted to 



60 



it at pleasure, the outer coating being a tin 
case large enough to admit the jar easily 
within it, and the inner coating a similar 
case sufficiently small to pass readily in the 
inside of the jar. The charging wire of the 
inner coating should be surrounded by a 
glass tube covered with sealing wax, to serve 
as an insulating handle, by which the inner 
coating may be lifted from the jar when that 
is charged without communicating a shock 
to the operator. Arrange the jar with its 
coatings, and charge it, it will act in every 
respect as an ordinary coated jar ; charge 
the jar, and without discharging it, remove 
the inner coating by its insulating handle. 
If this coating, when removed, be examined, 
it will be found not at all, or but slightly 
electrified ; lift the jar carefully from within 
its outer coating, and examine that — it also 
will evince no sign of electricity. Fit the 
jar up with the other pair of moveable 
coatings, that have not been electrified, and 
apply the discharging rod ; an explosion and 
spark will ensue, proving that the coatings 
are only the conducting materials from one 
side of the glass to the other, and that it is 
the glass itself on which the fluid is accu- 
mulated. The following cut shows the usual 
form of these jars : — 




272. Diamond jar. — Take a bottle, whose 
exterior coating is formed of small pieces of 
tin-foil, placed at a little 
distance from each other. 
Charge this bottle in the 
usual manner, and strong 
sparks of electricity will pass 
from one spot of tin -foil to 
the other, in a variety of 
dire(-tions ; the separation 
of the tin-foil making the 
passage of the fluid from 
the outside to the table 
visihle. Discharge this bot- 
tle by bringing a pointed 
wire gradually near the 
knob, and theuncoated part 
of the glass between the spots will be plea- 
singly illuminated, and the noise will resem- 
ble that of small fired crackers. If the jar 
is discharged suddenly, the whole outside 
isiiiface appears illuminated. To produce 
».litse appearances the glass must be verv dry. 





273. The double jar. — This instrument is 
seen in the margin. It is used for various 
experiments, and shows how 
necessary it is to connect 
the outside and inside of the 
same jar together, before it 
will be discharged. Place 
the double bottle on a table 
not insulated, and charge the 
upper bottle A positively by 
coimecting its ball with the 
conductor. Tlie outside of 
A therefore, and also the in- 
side of B will be negative, 
and the outside of B positive. 
Now connect by the dis- 
charging rod the outer coating 
of B with the inner coating of A, and no 
shock will pass between them. Again, con- 
nect the outside of B with the inside of B, 
and a shock will pass. Now connect the 
inside of A with the inside of B, and a second 
shock will be obtained. A series of bottles 
may thus be arranged, and a series of shocks 
obtained by one charge only. 

274. To convey a shock to a distance. — 
Amusement is often excited by giving a person 
a small shock unexpectedly. This may be 
done easily by a small Ley den jar holding 
about halt a pint. It may be held in the 
hand of the operator, without danger, by 
its outer coating, he holding at the same time 
a chain connected with the coating. The 
other hand should hold a glass handled dis- 
charging rod, connected with the other end 
of the chain. If he touches a person with 
the ball of the discharging rod, and also with 
the knob of the small charged phial, a shock 
will pass along the chain, and through the 
person, without affecting the operator. It 
is usual to employ for the above purpose a 
coated director, which is a Leyden jar, made 
of the following form, and coated in the 
ordinary manner. 



275. The electrical sportsman. — This ex- 
periment is to illustrate the fact that a jar 
will be liable to discharge itself when the 
two coatings are too close to each other. 
The inner coating of the Leyden jar is con- 
nected with two wires ; one of which pro- 
ceeds to the birds — the other proceeds to 
within a short distance of the muzzle of the 
gun. The birds are made of small bits of 
pith, with a portion of feathers to each to 
represent wings. They ai'e attached to 
pieces of linen thread, 4 or 5 inches long. 
The gun is connected with the outer coating 
of the wire proceeding from it to the figure. 



61 



and a slip of tin-foil which is pasted alongj 
the figure to the muzzle. Connecting the! 
wire with the electrical machine in action f 
it will of course become charged, during ( 
which time the birds will elevate themselves | 
by electrical repulsion ; when the bottle is| 
charged to a certain extent, the distancei 
between the muzzle of the gun and ball near, 
it will not be sufficient to restrain the pas-[ 
sage of the fluid, which will therefore pass 
between them, occasioning at the same time 
a flash of light, a loud report, and the 
falling of the birds. 




276. Cavallo's self- charging Ley den jar. 
— Take a glass tube of about 18 inches in 
length, and an inch or an inch and half dia- 
meter. It is immaterial whether one of its 
ends be closed or not. Coat the inside of it 
with tin- foil, but only from one open ex- 
tremity of it to about the middle ; the other 
part remaining uncoated. Put a cork in at 
the coated end, and let a knobbed wire pass 
through the cork, and come in contact with 
the coating. The instrument being thus pre- 
pared, hold it in one hand by the naked 
part, and with the other hand dry rub the 
outside of the coated part of the tube, but 
after every three or four strokes you must 
remove the rubbing hand, and touch the 
knob of the wire, and in so doing a little 
spark will be drawn from it. By this means 
the coated end of the tube will gradually 
acquire a charge, which may be increased to 
a considerable degree. If then you grasp 
the outside of the coated end of the tube 
with one hand, and touch the knob of the 
wire with the other, you will obtain a shock, 
&c. In this experiment the coated part of 
the tube answers the double offiee of elec- 
trical machine, and of Leyden phial. 

277. Instead of a tube this instrumei.t 
may be constructed with a pane of glass, in 
which case it will be rather simpler, but it 
cannot be managed so easily, nor yet charg( d 
so high as the tube. A piece of tin-f( il 
must be pasted only on one surface of the 
pane, leaving about 2^ inches or 3 inches of 
uncoated glass all round. .This done, hold 
the glass by a corner, with the coated side 
from you, and with the other hand rub its 



uncoated side, and take the spark from the 
tin-foil alternately, until you think that the 
glass may be sufficiently charged ; then lay 
the glass with its uncoated side flat upon one 
open hand, and on touching the tin-foil with 
the other hand you will receive the shock. 

Adamses portable jar. — Mr. Adams, an 
optician of the last century, invented the 
following simple apparatus, whereby a shock 
may be procured without t\id aid of an 
electrical machine. A is the small Leyden 
phial or jar that holds a charge. B is a bent 
wire to discharge the jar. C is a varnished 
ribbon to be excited, and comaiunicate its 
electricity to the j ir. D are two hare or 
other skin rubbers, which are to be placed 
on the first and middle fingers of the left 
hand. 




278. To charge the jar. — Place the two 
finger caps D on the proper fingers ; hold 
the jar A at the same time at the edge of the 
coating on the outside, between the thumb 
and first finger of the hand ; then take the 
ribbon in your right hand, and steadily and 
gently draw it between the two ribbons D on 
the two fingers, taking care at the same time 
that the brass ball of the jar is kept nearly 
close to the ribbon, while it is passing 
through the fingers. By repeating this 
operation thirteen or fourteen times the 
electrical fire will pass into the jar, which 
will become charged, and by placing the 
discharger C against it, as shown in the 
figure, you will see a sensible spark pass 
from the ball of the jar to that of the dis- 
charger. If the apparatus is dry, and in 
good order, you will hear the crackling of 
the sparks when the ribbon is passing 
through the fingers, and the jar will discharge 
at about the distance of ^ an inch from the 
balls. 

279. To electrify a door knob, ^c. — We 
often hear of persons electrifying the handles 
of doors, the pulls of bells, &c., yet this is 
a very difficult experiment to manage. First 
there must be a Leyden jar in readiness, and 
this must be kept charged, which of itself is 
difficult, then the outside of the jar must 
have a wire connected with it, which reaches 
under the carpet or otherwise, so as to be 
concealed beneath a person's feet, when 



6-2 



standing at the electrified door, a circum- 
stance almost impossible if in the street, and 
not always easy of accomplishment in a room. 
It is absolutely necessary that this wire should 
be trodden upon by the person to be shocked. 
The knob, knocker, or bell pull of the door 
should be furnished with a second wire, 
coming near to the ball of the inside of the 
charged bottle, but not so near as to draw off 



the fluid. It must be placed so that when 
the knob is turned, the knocker lifted or the 
bell pulled, this wire may come within strik- 
ing distance of the bottle, which will conse- 
quently be discharged. The fluid passing 
along the wire, the knob to his hand, his 
body, and finally the wire beneath his feet to 
the outside of the bottle, when the circuit 
will be of course complete. 



CHAP. IX. 

MECHANICAL, CHEMICAL, AND MAGNETIC EFFECTS. 

The following experiments show the effects of the electric fluid when thrown against, or 
passing through various substances, some of which it displaces, others illuminates, others 
inflames, and a fourth kind of objects it rends to atoms in its passage. Many of these 
effects induce us to attribute a material character to the electric fluid, and to believe that 
it is a substance, imponderable as far as we know, as are light and heat, yet nevertheless a 
matter rather than a power ; not like gravitation, and the centrifugal force, powers of nature, 
but, like air, one of its solid but subtle elements, the occasion of numerous luminous 
phenomena of common occurrence, and therefore considered by the ancients as elemental 
fire : — whether it be so, present knowledge seems to confirm rather than to deny. Pro- 
fessor Faraday, and other philosophers of equal learning, hold this opinion, and believe that 
heat and electricity are but modifications of each other. In some respects their efTects 
are identical, as many of the experiments of the present chapter will show ; in other respects 
they appear perfectly distinct. 

1. Fire will inflame combustible substances, so will electricity. 

2. Heat is produced by friction, so is electricity. 

3. The best conductors of heat are mostly also the best conductors of electricity. 

4. Metals are melted by heat and also by electricity. On the contrary, it is alleged. 
Firstly, that the electric fluid has a strong scent which simple heat has not. Secondly, 
an increase of heat produces an increase of fluidity ; but bodies charged positively are not 
thereby rendered fluid. So also, thirdly, a deprivation of the electric matter which a sub- 
stance may contain does not cause the same congelation as that occasioned by abstracting 
caloric from it. Fourthly, caloric not only heats but expands bodies, the electric fluid 
does not produce this effect ; however long a body may be electrified, it neither becomes 
hotter to the touch, nor more extended in dimensions. Fifthly, nothing analogous to the 
nature of electrical attraction or repulsion can be discovered in heat. 

It is said by those who deny the materiality of the electric fluid that it is only the 
agitation of the air which produces its various effects, and that the compression of the air 
causes those ignitions by the fluid, which we shall presently allude to. To confute this 
opinion by positive experiment may be difficult, yet an appeal to the reason will soon show 
the incorrectness of the opinion ; look at the lightning, and then say can this mighty phe- 



63 

nomenon be occasioned by any compression of the air which the mind can conceive. 
Even supposing that the air would be thus compressed, how immense must be the power 
which could thus compress it, and what is this power but the electric fluid. Besides this, 
electrical appearances can be produced in a vacuum ; the motion of the fluid, also, is 
inconceivably more rapid than the quickest motion of the air that we are acquainted with. 

We shall endeavour to show that in some of the experiments the air is scarcely con- 
densed at all, and would not produce the effect if it were. If the air were condensed, as 
the fluid passes from the positive to the negative side of the apparatus, it would be con- 
densed at that point only ; or if we suppose two electric fluids, rushing towards and 
meeting each other, the concussion, and consequently the condensation, could only take 
place at some point near to the extreme end, neither of which appear to be the case, as in 
whatever manner the experiments may be varied, there does not appear to be any reason to 
think that the inflammation takes place at any one point of the inteijjupted circuit rather 
than at any other point. Besides which, when the inflammation of air and hydrogen gas 
take place, the interruption of the circuit is extremely minute, and the air in a much 
less quantity, so as to diminish very much the probability of this assumption. 

These remarks and the experiments which illustrate them, clearly show that the 
electrical fluid is different in its nature from those elements with which it alone can be 
compared ; we are therefore bound until knowledge shall so progress as to explain more 
fully the kingdom of nature to consider the electric fluid as a material body, imponderable, 
and with properties peculiarly its own. The following experiments will afford much 
amusement and instruction. 



E.r. 280. Stand a card upright upon a 
table, by a little narrow foot made of cork so 
that but a slight force is necessary to overturn 
it. Hold towards one side of this a point 
connected with the prime conductor of a 
machine. The breeze passing from the point 
will blow down the card. 

For experiments of this kind it is most 
convenient to use a flexible tube, this is a tin 
or brass tube, furnished at one end with a 
joint and socket to fit into one of the holes 
of the prime conductor, and at the other 
with a screw, upon which may be fastened 
either a ball or a point as different experi- 
ments require. It is made usually of three 
joints connected together by a piece of chain 
covered with silk. The joint which bears the 
ball or point, bears a glass handle ; so that 
a person taking hold of this may move the 
point about as he pleases, without destroying 
its insulation. The following shows this con- 




venient instrument, which is used for many 
other purposes in electricity. The joints 
may be 15 inches long each. 

281. The card instead of being supported 
upon a stand, may be suspended by a fine 
wire, or a linen thread from the ceiling, when 
according to the strength of the fluid the 
card will be repelled. 

282. Electrical ioa^.— Hold the charged 
point towards the sails of a small vessel 
floating in a basin of water. The impact of 
the fluid against the sail, occasions the vessel 
to float away from it. The sail should be of 
white paper. 




283. Electrical vane. — Make a vane or 
wheel of paper, or thin pasteboard, (such as 
is represented annexed) and suspend it by a 
pin upon a piece of brass at the centre. Hold 
the positive charged point towards one side 



64 



of it, and opposite the floats, when the wheel 
will be put into rapid rotatory motion. 




The wheel may Be suspended vertically, 
instead of horizontally, and a system of 
wheel-work put in motion by the same means. 
Several of these contrivances were invented 
by Mr. Ferguson, one of which is represented 
beneath : — 




TTW!lTiiwi!iiiii:iililiiiiil;iiiilliiilliiliiiiiiii:rai!:iii iiiiii^ 



284. Fill a very small, thin glass tube with 
water, pass a strong shock through it, the 
expansion of the water, occasioned by the 
passage of the fluid, will burst the tube and 
scatter the water. This is a pretty experi- 
ment if the tube is fitted up to a hulk, as a 
mast. The shock would then represent a 
flash of lightning, the mast would be struck, 
and the rigging fall overboard, while by adding 
one of the other experiments afterwards de- 
scribed, the hulk may be made to take fire. 

285. Water expanded. — Discharge a bat- 
tery through a drop of water, previously 
placed on the knob of one of its bottles ; the 
whole will be instantly exploded into vapor. 
The sparks will be much longer than com- 
mon, and more compact. 



28G. Quicksilver dissipated. — bend a 
discharge to a greater or less distance through 
one or more drops of quicksilver, the dis- 
charge diff"uses itself into a fine spray, and 
drives the drops into vapor ; part of it rising 
into the air as smoke, the other part remaining 
on the glass. 

^287. Kinnersley^s air t?iermometer. — This 
js an instrument tor showing the expansion 
of air when an electrical 
shock is passed through 
the instrument. A is a 
glass tube, upon both ends 
of which a brass cap is 
cemented. B a thermo- 
meter open at both ends, 
and with a scale attached 
to the back. This tube 
passes through the upper 
brass cap, and nearly 
reaches the bottom of the 
under cap. F is a brass 
ball and wire cemented to 
the under cap, a simihu- 
sliding ball and wire C 
passes air tight through a 
collar of leather on the 
upper cap, so that its batt 
may be placed at difterent 
distances from the ball ot 
the fixed wire F. The plate of the upper 
cap is made to unscrew, so that colored water 
may be j)ut in previous to the performance 
of the experiment. By the rising of the 
water in the thermometer tube over the scale 
above the result of the experiment is seen. 





288. Coward's electrical air thermometer. 
— This instrument, a cut of which is seen 
above, diflers but little from Kinnersley's 
It is however more convenient in use. A is 
the glass tube. C and D the balls for the 
shock to pass, and B the thcrmomtter tube, 



65 



and which is bent upwards at the lower part. 
Previous to using the instrument, fill the 
tube B to the height of about 2 inches with 
a colored fluid ; on the surface of which in 
the long arm is to rest a light guage made 
of quill, part being cut so as to act as a 
spring, which will hold it at any part of the 
tube. 

289. To show the expansion of the air by 
either of these instruments, pass a shock 
from one ball to the other ; in consequence 
of this the fluid will be driven up the tube. 
To see to what extent, Mr. Kinnersley's elec- 
trometer must be viewed at the time, but as 
in Mr. Coward's the spring quill guage will 
retain the position to which it has been 
driven, this instrument may be inspected 
whenever convenient. 

290. Henlet/^s universal discharger, for 
performing numerous electrical experiments, 
it is necessary to use an instrument like the 
following, which consists of a rectangular 
wooden foot, upon the middle of which rises 
a short wooden pillar, with a screw on the 
side of it. Into this fits a shank, bearing a 
small table 4 or 5 incnes in diameter, upon 
the top of the table is let in a piece of ivory, 
which it will be observed is a non-conductor. 
The side pillars shown are of glass, except at 
the top, where is fastened a metallic cap, 
with a universal or ball and socket joint, or 
some other joint which allows an equable 
motion in every direction, to a short hori- 
zontal socket above. Wires 6 or 8 inches 
long pass through these sockets. Their outer 
ends are terminated by rings, their inner 
ends are blunt points, but covered with balls 
which slip off and on. Thus by the con- 
struction of the instrument, the balls may 
be supplanted by points, and both one and 
the other placed at any distance from each 
other that may be desired. If one of the 
rings or wires be connected with the outside 
of a Leyden jar or battery, and the other 
wire attached to one end of a discharging 
rod, when the discharge of the jar or bat- 
tery is made, the shock will pass through 
whatever substance is placed between or upon 
the balls o*f t*he universal discharger. 




The table is in some experiments taken 
away, and a small press put in its place. 
This press is formed of two pieces of baked 
wood, about 4 inches long and 2 wide ; 




the lower one fixed on a 
shank that fits the centre 
socket of the discharger, 
and the upper one con- 
nected to the lower by two 
thumb screws, as shown 
in the cut, so that any 
thing placed between the 
boards of the press may be held there se- 
curely while a shock is sent through it. 

291. Electrical bomb. — The next figure 
represents the electrical bomb, the firing of 
which, if firing it can be called, where no fire 
is, is accomplished by a strong shock of a large 
Leyden phial or battery sent through it. 
The bomb is made of ivory, with a small 
short bore in it, so formed that the ball, 
which may be of ivory or cork, can be im- 
bedded a trifle more than one half in the 
bomb, and a cavity of a smaller size be be- 
hind it, with two wires entering this small 
cavity. When a strong shock is passed 
through these wires, the air withinside will 
be agitated, and throw out the ball. 




292, Fill the cavity or chamber behind the 
ball with two or three drops of water, pass 
the shock through, and the expansion of the 
water will be so great as to throw out the 
ball with greater force than before. 

293, Paper rent. — Rest upon the table of 
the discharger a piece of white paper, 4 or 
5 inches square, and placing the balls about 
2 inches from each other, send a shock along 
the surface of the paper, when it will be 
rent in pieces along the line which the fluid 
travels. 

294. To fracture sugar. — Place between 
the two balls of the discharger a small lump 
of sugar, and send a shock through it ; the 
sugar will most likely be broken ; if not, 
send a second and a third shock through it, 
when, unless the shocks have been very small, 
or the lump very large, it will be broken into 
many pieces. If this experiment be performed 
in the dark, the sugar will give out at the 
time of the shock, and for half a minute 
afterwards, a strong phosphoric light. 

295. To pierce a card. — Pass a shock 
through a card, by placing the balls of the 
discharger on each side of and close to the 
card, a minute hole will be pierced throtigh 



66 



the card, and what is very singular a burr or 
projecting edge will be formed on each side of 
the card. A shock may be passed through 
three or four cards at once, and each have 
its double burr. 

296. Hang to the ceiling four or five sheets 
of brown paper, and pass a shock through 
them, the whole of the paper will be pierced 
without being in the slightest degree moved. 
Upon smelling the part of the paper which 
has been pierced, it will be found to have 
imbibed a strong odour analogous to that of 
phosphorus. 

297. Either of the above experiments, and 
indeed most others may be performed without 
the aid of the universal discharger ; for ex- 
ample, if a few cards or sheets of paper be 
held against the outside of a Leyden jar, and 
one of the knobs placed close to the paper, 
while the other knob approaches the inside 
of the jar, the charge will pass and pierce 
the cards. 

298. Introduce two wires into a piece of 
soft pipe clay, and pass a strong shock through 
them ; the clay will be curiously expanded 
in the interval between the wires. The ex- 
periment will not be successful if the clay 
be too moist or too dry. 

299. Splintering wood. — Drill two holes 
in the opposite ends of a piece of wood, which 
is \ an inch long, and \ of an inch thick ; 
insert two wires in the holes, so that their 
ends within the wood may be rather less than 
\ of ail inch distant from each other. Pass 
a strong charge through the wires, and the 
wood will be split with violence. 

300. Coin stuck to ajar. — Charge a large 
jar, and place a shilling or other piece of coin 
between the knob of the discharger and the 
coating of the jar. 

301. Charge a very large jar, connect its 
outside with one that is ten or twelve times 
smaller, make a communication between their 
inner coatings with the discharging rod, and 
the small jar will be broken, the quantity o. 
electricity transferred to it being beyond the 
proportion of its size. 

DIRECTION OF THE FLUID. 

The mechanical effects of electricity have 
been employed to indicate the course of the 
electric fluid in the discharge, and thus to 
confirm the proposition that assumes positive 
electricity to be an accumulation of electric 
fluid, and negative electricity to be a defi- 
ciency, in opposition to the hypothesis first 
proposed by Du Faye, that positive and ne- 
gative are two distinct electric powers. 

302. The direction of the electric fluid is 
rendered visible when a Leyden jar, which 



I has been rendered slightly damp by breathing 
on it, is placed with its knob in contact with 
the positive conductor of the machine in a 
darkened room. When the jar is fully charged, 
if the turning of the machine be continued, 
the electric fluid will be seen to pass from 
the inner to the outer coating over the un- 
coated interval in luminous streams, pro- 
ducing an effect similar to that of water 
overflowing from the top of a vessel that is 
kept constantly supplied. If the jar be re- 
moved, and its knob placed against the ne- 
gative conductor, the stream, when the jar 
is overcharged, will evidently pass in a con- 
trary direction, that is from the outer to the 
inner coating. A certain degree of damp- 
ness is necessary in this experiment, to pre- 
vent the discharge of the jar by spontaneous 
explosion, in which case the fluid passes too 
rapidly from one surface to the other to ad- 
mit the ascertainment of its direction. If 
the moisture be not sufficient, divergent 
brushes of light pass from the positive to the 
negative surface at intervals, instead of the 
continuous streams before described. 

303. Discharge by withdrawing atmos- 
vheric pressure. — Place a charged jar on a 
small glass stand under the receiver of an 
air pump. As the receiver is exhausting, the 
electric fire will issue from the wire of the 
jar in a very luminous pencil of rays, and 
continue flashing to the coating till the air is 
exhausted, when the jar will be found to be 
discharged. The direction of the rays of 
light will have the appearance of tending to 
or verging from the jar, according as it is 
charged positively or negatively. 

304. The belted bottle.— Thh instrument 
shows the passage of the fluid during the 
charging of the bottle, and is but a modifi- 
cation of the last experiment. Tlie coating 
both inside and outside is put ou as repre- 
sented. The belt on the outside is only put 
in contact with the lower part of the coating 
by means of the sliding piece on the outside. 
The wire within is attached to the inside of 
the bottom. In charging, the lower part be- 
comes charged first, and the fluid will be 
seen to pass upwards inside in flashes, while 




67 



if the connecting piece be withdrawn, the 
fluid will be seen to pass downwards on the 
outside from the belt to the lower part. 

305. Place a lighted taper between the 
wires of the universal discharger, they being 
4 inches apart, and the flame midway between 
them. Connect the coating of a small charged 
jar with one wire, and bring its knob in con- 
tact with the other ; if the charge be just 
sufficient to pass the interval without ex- 
plosion, the flame of the taper will be con- 
stantly blown from the positive wire to that 
which is negative. 




306. Construct an apparatus, such as is 
represented beneath. There being a small 
metal cup at each side, supported by a glass 
rod, and a lighted candle in the middle be- 
tween them. Into each cup put a small piece 
of phosphorus — connect one chain with the 
prime conductor, and the other with the 
cushion. Turn the machine, and the fluid 
will pass from the positive cup to the lighted 
wick, and driving this forwards against the 
opposite cup will soon heat it so as to fire 
the phosphorus, while there will appear no 
emanation of the fluid from the negative cup. 




307. The next figure represents an appa- 
ratus similar to the last, except that it has 
wires instead of cups, and a light vertical 
wheel in the centre. Upon connecting the 
wires with the diff'erent parts of the machine, 
and putting it in motion, the wheel will turn 
from the positive to the negative side. 




308. Lay two straight sticks of sealing 
wax on the table of the discharger parallel to 
each other, so that the juncture of tlreir 
rounded edges may form a groove ; on this a 
large pith ball is to be placed, and the wires 
of the discharger are to be arranged with 
their points in the direction of the groove, 
and at 4 inches from each other, the ball 
being equally distant from both. On passing 
a small charge from one wire to the other, 
the ball will be driven from the positive to 
the negative ; and this effect will be constant 
if the terminations of the wires are pointed, 
which they should be for these experiments 
of transmission. If blunted wires be em- 
ployed, the ball will frequently vibrate be- 
tween them, and apparently render the 
result equivocal. 

309. Lateral discharge. — The following 
cut represents a small conductor insulated, 
and nearly touching a charged jar. There is 
a second conductor, also insulated and nearly 
touching the former, and in a straight line 
with it. Make the discharge by a discharging 
rod, from which a chain hangs that does not 
touch the bottom of the jar, and the farther 
conductor will receive an electric spark, which 
quits it again almost at the same instant. 
This electrical appearance without the circuit 
of an electrical jar is called the lateral ex- 
plosion. This may be tried in other ways. 




310. Place on a dry board a little bran or 
other light matter, and lay along it a wire 
which forms part of a discharging circuit for 
a large jar or battery. Upon making the 
discharge, the bran will be scattered from its 
place by the lateral explosion, and the greater 
the force of the explosion, so much the 
greater of course will be the scattering. It 
is not surprising therefore, that heavy bodies 
should be removed to considerable distances 
by a strong flash of lightning. Dr. Priestly 
imagined that this lateral explosion was pro- 
duced by the explosion of the air from the 
place through which the electrify discharge 
passes. This lateral force is not only exerted 
in the neighbourhood of an explosion, when 
it is made between pieces of metal in the 
open air, but also when it is transmitted 
through pieces of wire that are not thick 
enough to conduct it properly. The smaller 
the wire is and the stronger the charge, the 



68 



greater is the dispersion of light bodies near 
it. The following are examples of lateral 
explosion. 

311. Discharge a Leyden jar by means of 
a common wire discharging rod, or one which 
has no glass handle to it. Holding the wire 
firmly, no sensation, or very little will be 
felt in the hand, but hold it very lightly and 
discharge the jar a second time, and a very 
disagreeable trembling of the fingers will be 
felt, owing to the action of the fluid laterally. 
The same is the case when a spark is taken 
from the prime conductor by a ball and wire 
held loosely in the hand, though no sensation 
is felt when the wire of the ball is grasped 
firmly. 

312. Let two wires be fitted into a groove 
on the surface of a piece of smooth maho- 
gany, ivory or sealing wax, in such a manner 
that by sliding the wires backwards or for- 
wards, their ends may be placed at any re- 
quired distance from each other. When they 
are about ^ an inch apart, place a thumb or 
finger over the interval, and pass a charge 
from wire to wire ; the thumb will appear 
perfectly trawsparenc during the passage of 
the spark beneath it, but no unpleasant 
sensation will be felt. 

313. Substitute a jar of water or any 
colored fluid, in the place of the thumb ; 
when the discharge is made, the fluid will be 
distinctly and curiously illuminated. 

314. Place the ends of the wires at the 
distance of f of an inch, and over the in- 
terval lay a thick piece of pipe-clay or of 
pumice stone ; when the charge passes, these 
opaque substances will appear perfectly 
transparent. 

The light of the electric fluid in passing 
through an interval of air near to or in the 
middle of a semi-transparent body, or one 
which becomes luminous by the influence o» 
an intense degree of ordinary light, com- 
municates to it a luminous appearance some 
times of some lengthened duration. 

315. PhospJioric vapors. — Put a piece of 
common phosphorus on the point of a wire 
which hangs from the prime conductor of a 
macliine. Until the machine is turned, the 
vapors will ascend, but when the conductor 
and wire are electrified, supposing the wire 
hanging in the same position, the vapors are 
carried downwards, and form a very long 
cone of electric light, which is seen perfectly 
distinct from it. When the electrization is 
discontinued, the vapors ascend as at first. 

31G. Phosphorus inflamed. — Place a piece 
of phosphorus, as in the last experiment, or 
in any other way projecting from the prime 
conductor, and by means of a metallic ball 
held in the hand take a spark from it. This 



will inflame the phosphorus. A ball for all 
such purposes as this should have a wire 
handle to it, the wire being grasped, and the 
ball held beyond the hand. 

317. Candle re- lighted. — Instead of the 
phosphorus, in the last experiment, substitute 
a candle, the flame of which has just been 
blown out, and which has a long snufF; upon 
passing a shock or spark through the incan- 
descent part of the wick, the candle will be 
re-lighted. 

318. Canton's phosphorus illuminated. — 
Take some of the powder of Canton's phos- 
phorus, and by means of a little spirits of 
wine stick it all over the inside of a clean 
glass phial, then stop the phial, and keep it 
from the light. To illuminate this phos- 
phorus, draw several strong sparks from the 
conductor, keeping the phial about 2 or 3 
inches from the sparks, so that it niay be 
exposed to their light ; the phial will after- 
wards appear luminous, and remain so. for a 
considerable time. 

319. Cut out in pasteboard, or so^t wood, 
the figure of a cresce:^ or any of the planets ; 
cover this equally witii the white of an egg, 
beat up till it is (^^ite smooth, over which sift 
the phosphorus through a fine lawn sieve, 
then let it dry, and blow off all that is not 
fixed by the egg. To make the experiment, 
place the object in the communication be- 
tween two directors, and discharge the jar, 
when the whole will become beautifully lu- 
minous ; care must, however, be taken to 
hold the directors at a little distance above 
the phosphorus, for if it passes through it, 
the whole of the powder in the track of the 
fluid will be torn off. 

320. Place a small key on the phosphorus, 
and discharge a Leyden phial over the phos- 
phorus, and then throw the key off" from it, 
and when it is exhibited in the dark the form 
of the key and all its wards will be perfectly 
seen. 

321. Place a piece of dry chalk on the 
table of the universal discharger, and adjust 
the wires on its surface, with their ends at 
1 inch distance from each other. Pass a 
strong charge from wire to wire, and after 
the explosion a streak of light will be evident 
in the track of the discharge. It will con- 
tinue luminous for several seconds. 

322. Place upon or within a brisk fire, a 
few oyster shells, and calcine them until they 
cease to emit smoke, and appear burnt 
through ; this may be from a quarter of an 
hour to two hours, according to the strength 
of the fire and compactness of the shells. 
Many of them will exhibit the prismatic 
colors when exposed to the lig4it of the sun. 
Mr. Wilson excited some of these shells by 
electricity as follows : — 



69 



323. Prismatic illumination. — Mr. Wilson 
placed upon a metal stand, which was rounded 
at top, and about ^ an inch in diameter, a 
prepared shell, and near the middle, where 
the color-making parts predominated, he 
brought the ends of a metal rod, and then 
connected the two metals properly with the 
coatings of a charged phial, in order to dis- 
charge the fluid. In this circuit there was 
left, designedly, an interval of about 3 inches, 
unoccupied by metal, and next one side ot 
the glass. The discharge was made by com- 
pleting the circuit with metal where the in- 
terval was left. The shell at that instant was 
lighted up to great advantage, so that all the 
colors appeared perfectly distinct, and in 
their respective places. These colors con- 
tinued visible for several minutes, and when 
they ceased to appear, a white purplish light 
occupied their places, which lasted for a con- 
siderable time. And notwithstanding this 
experiment was repeated with the same and 
other shells, the colors continued in their 
respective relative situation, and nearly o( 
the same degree of brilliancy. — Adams. 

324. Pass a shock over the surface ot 
native sulphate of barytes, this mineral will 
appear luminous with a fine green light ; the 
same is the case with the native carbonate 
of barytes, but less brilliant. — Sinyer. 

325. Pass the shock over or through dry 
acetate of potass or succinic acid, or boracic 
acid, it will appear green and very brilliant ; 
with borax more faint. — Singer. 

326. If the shock be taken over rock 
crystal, it will be first red aud then white ; 
if over quartz, it will be of a dull white. — 
Singer. 

327. To fire ether or spirits of wine. — 
Procure a small metallic cup similar to that 
presented in tJie following cut : — Fix it by its 
stem to the prime conductor. Pour a small 
quantity of spirits of wine into the cup or 
still better of ether, take a spark through 
the middle of the spirits, and they will be- 
come inflamed. To insure perfect success at 
all times, a thing absolutely necessary in a 
lecture, let the cup be heated slightly before 
being attached to the conductor. This will 
occasion an evaporation from the spirit, and 




the spark the more readilv inflame the 
spirituous vapor. 

If you have not a cup similar to the above, 
a common table spoon, warmed and held in 
the hand, will completely answer the pur- 
pose. While so held full of spirit, the spirit 
is to be held towards the ball at the end of 
the prime conductor, so that a spark may 
pass through the liquid. 

328. Or, let a person standing on an in- 
sulated stool and connected with the prime 
conductor hold the cup with spirits in his 
hand, and let a person on the floor take a 
spark through them, and they will be fired. 
The experiment answers equally well, if the 
person on the floor holds the cup or spoon, 
and the insulated person takes the spark. 

329. The foregoing experiment may be 
agreeably diversified in the following manner. 
Let one electrified person, standing on an 
insulated stool, hold the spirits ; let another 
person, standing also on an insulated stool, 
hold in his hand an iron poker, one end of 
which is made red hot ; he may then apply 
the hot end to the spirits, and even immerge 
it in them, without firing them ; but, if he 
put one foot on the floor, he may set the 
spirits on fire with either end. The spirits 
cannot be kindled by an insulated person ; 
because, as the electric fluid cannot escape 
through him to the earth, he is incapable of 
drawing a spark sufficiently strong to inflame 
them. 

330. Hydrogen inflamed. — Make some 
hydrogen gas, by putting a handful of iron 
nails, or the same quantity of pieces of zinc 
into a wine bottle ; to these add half a pint 
of water and a wine glassful of sulphuric 
acid. Have ready prepared for the bottle 
a cork which fits it, and through which the 
stem of a tobacco-pipe passes. The mixture 
will soon throw up bubbles of gas; when it is 
supposed that these have displaced the air of 
the phial, cork it up, so as to suffer the gas 
to pass out only through the stem of the 
pipe. Here it maybe collected in a collapsed 
bladder fastened to the other end of the stem, 
or, if preferred, the bladder may be tied to 
the top of the cork itself. The gas will soon 
fill the bladder. When enough for use has 
been collected, the stem may be broken, so 
as to separate the bladder and the bottle, 
and the part still attached to the bladder is 
to have a small plug inserted in it, lest the 
gas should escape. Procure some strong soap 
suds and blow some bubbles by means of the 
gas collected. Take care to touch these when 
ascending with a ball fastened to the end of 
the flexible tube described in page 63, the 
tube being connected with the prime con- 
ductor when the machine is in action, and 
held by its glass handle, A spark witl thus 



70 



be given to the soap bubble, and the gas 
inflamed. It will give a loud report at the 
moment of inflammation. 

331. Lighting a stream of hydrogen. — 
While hydrogen gas is passing out of the 
bottle in which it is generated take a spark 
through the stream of the gas, by holding 
the bottle in one hand, so that the top of the 
pipe is near to the conductor, and taking a 
spark from it, with a metal ball held in the 
other, the gas will be inflamed. 

332. Lighting the candles of a theatre, 
8fc. — The carburetted hydrogen or coal gas 
of the shops will answer the same purpose. 
Let an apparatus be constructed similar 
to the following, which represents two chains 
A and B, attached to two balls projecting 
from a wall by means of two glass rods. 
The apparent candle is a tube, through the 
top of which gas is issuing in a small stream. 
If a shock from a Leyden jar be sent along 
the wires or chains, however long those wires 
may be, the gas will be inflamed, and the 
apparent candle lighted. Several contrivances 
of the same kind may be placed in diff"erent 
parts of a theatre, when, if the chain passes 
from one to the other, all the candles will 
be lighted at the same moment. Be it ob- 
served, that the interval between the balls 
A and B should be very small, much less 
than represented in the cut. Even i of 
an inch is quite sufficient, and the whole 
apparatus may be entirely concealed, if wires 
are used instead of chains ; and supposing the 
candle-shaped case be made of baked wood 
or ivory, the wires may traverse up one side 
and down the other, branching off" from the 
lower part, where being in the shade thej 
would not be observed. 




333. Volta's hydrogen lamp. — Volta con- 
trived a lamp upon the principle of the elec- 
trophorus, which lighted hydrogen by a very 
small spark. His lamp is shown in the fol- 
lowing cut, where the instrument is seen in 
perspective and in section. A is a leaden 
bottle, which has a pipe from the top of it, 
through the bottom, and extending some 
distance below, as shown at B. The case is 
divided into two compartments, the lower 
one into which B dips is filled with water. 



The bottle A is for the generation of hydro- 
gen gas. The gas passes down the tube B 
through the water, and occupies the tube and 
cock E. Whatever surplus gas there is, 
presses upon the surface of the water, and 
drives that water up the tube C into the upper 
vessel. The tube C ought to reach near the 
bottom of the reservoir O. Whenever the 
cock E is turned, the gas rushes out of a 
small orifice H, where there are two wires 
separated from each other by a small interval. 
One of these wires is connected to the lower 
plate of the electrophorus seen at F, and is 
a fixture. The other wire G is connected 
with the cock E, and meets the former wire 
near enough to give a spark, whenever the 
cock E is turned ; and as this also lets on the 
gas, this is inflamed by the spark, and in its 
turn lights the candle in the front of the in- 
strument. The only trouble required to put 
this ingenious machine in action is to rub the 
lower plate of the electrophorus with a warm 
flannel occasionally to excite it. 





It is evident that by means of a small jet 
of gas issuing from a minute orifice, as in 
the above instrument, and a shock or spark 
passing in like manner over a minute inter- 
val in the jet, candles properly placed may 
be ignited, and in any number, provided the 
aggregate of all the spaces over which the 
electric fluid has to skip be not greater than 
the striking distance of the jar. Also it will 
be remarked that a shock from a jar is better 
than a spark for most experiments in which 
apparatus are attached to walls, &c., as the 
wires, &c. need not then be insulated, although 
they necessarily must be so if a spark only 
is employed. 

334. Hydrogen pistol. — The simplest 
form of the hydrogen pistol is seen beneath. 
It consists merely of a tube of brass, about 
\ an inch in diameter, and 5 inches long, 
fastened on to a baked wooden handle, shaped 
like that of a common pistol. Where the 
trigger is ordinarily placed, is a short ivory 
tube, which fastens into the brass tube, so 
as to reach about half way across it. This 
piece of ivory is pierced so that a wire may 
pass through it. The inner part of the wir.i 
is at a small distance from the ii.ner part of 



71 



the top of the tube, and the outer end of it 
is terminated by a small ball. If then a 
spark be taken by the barrel, and at the same 
time that the finger touches the ball of the 
trigger, a spark will pass from the tube to 
the point of the wire inside, and thence to 
the trigger to the hand. 




A better kind of electrical pistol is seen be- 
neath. A is a chamber, which with its tube is of 
metal. A cap covers the end B. Upon taking 
this cap off, and unscrewing the instrument 
at C, the structure will be seen, as shown 
below the cut of the perfect instrument. C 
is the screw, one end of which fits upon A, 
the other end is for the cap. In the middle 
of C is a short glass tube D, through which 
runs a wire E F, terminated by a small ball 
at F, and bent upon itself at E, in such a 
manner that the end of it very nearly touches 
the screw of C, as shown at the point G. 
The spark being received at F, runs along 
the wire, leaps the interval G, where it fires 
the gas, and finally passes to the outer tube 
which is held in the liand. 




335. To Jill the pistol.— Apytly the mouth 
of the pistol to the opening of the bottle, 
and the common and inflammable air will 
mix together, because the former being 
heavier than the latter will naturally descend ; 
keep the pistol in this situation about fifteen 
seconds, then remove it, and cork the pistol. 
If the pistol is held too long over the bottle, 
and is entirely filled with inflammable air, it 
will not explode ; to remedy this, blow strongly 
into the muzzle of the pistol ; this will force 
out a quantity of the inflammable air, and 
occasion a quantity of common air to enter 
the pistol, which will then readily explode. 

336. To fire inflammable air. — Bring the 
ball of the pistol which is charged with in- 
flammable air near the prime conductor, or 
the knob of a charged jar ; the spark which 
passes will fire the inflammable air, and 
drive the cork to a considerable distance. 
This air, like all others, requires the presence 
either of common air, or else of vital air, to 
enable it to burn ; but. if it is mixed with a 
certain quantity of common air, an explosion 
will take place in passing the electric spark 
through it. 



337. Mr. Cavallo's pistol. — Mr. Cavallo 
recommends a pistol made in the following 
manner, to those who wish to make experi- 
ments on the explosion of hydrogen and 
oxygen, or with known quantities of common 
air and hydrogen. It consists of a brass 
tube, about 1 inch in diameter and 6 inches 
long, to one extremity of which a perforated 
piece of wood is securely fitted ; a brass wire, 
about 4 inches long, is covered, except its 
ends, first with sealing wax, then with silk, 
and afterwards with sealing wax again. This 
wire is to be cemented in the perforation of 
the wooden piece, so as to project about 2 
inches within the tube, the rest is on the 
outside ; that part of the wire which is within 
is bent, so as to be only about the tenth of 
an inch from the inside of the brass tube. 
An instrument such as this forms part of the 
apparatus to the next experiment,and a shock 
passing from C to D inflames the gas within. 

338. To inflame a bladder of gas. — Pro- 
cure a plug of baked wood or ivory, about 
the size of a large cork, and insert in it two 
wires, at about ^ an inch distance from each 
other, as is shown at A and B. At the lower 
end the wires are to approach to within ^ of 
an inch of each other, at the upper end they 
may be turned into loops or rings, that the 
whole may be hung up to a ceiling or wall, 
Dy a silk cord, and the loftier the ceiling, or 
more distant the wall, the better. In the 
middle of the ivory let there be a third hole, 
not stopped by a wire, in order that a bladder 
may be filled with hydrogen gas by means 
of it. A plug must be ready to fit it. Tie 
a bladder tightly to the ivory tube, fill it with 
hydrogen gas, mixed with common air, plug 
up the hole where the gas entered, hang up 
the bladder, connect two chains to it, one to 
each of the wires, send a shock through the 
whole, and the gas will be inflamed, making 
a terrific explosion. 



.-^'^ 




339. The magic vases. — This amusing 
piece of apparatus is seen annexed. The 
structure is evidently upon the principle of 
the electrical pistol. The two vases A and B 
have each a hollow brass chamber at top, 
part of the side of which is cut away in one 
of the figures to show the wire withinside. 
The wire is continued downwards through 
the entire stem, and connected with the chain 
at the bottom. To use the vases, load them 



72 



in the same way as the pistol was loaded 
with hydrogen gas, and cork thetn up ; after 
which, connect the tops Fand G together by 
a chain, as represented ; also let the chain E 
be attached to the discharging rod, and the 
chain D to the outside of a charged jar. 
Upon making the discharge, the fluid will 
pass up the stem of the vase connected with 
E, pass out at the end of the wire, across to 
the side of the chamber, setting fire to the 
gas within and throwing out the cork. It 
thence proceeds by the chain to the outer 
case of the other chamber to the point of its 
wire, inflaming the gas in the other vase, and 
downwards out at the foot along the chain D. 




If the chain at top be changed to a wire 
a mile in length, so that the fluid may pass 
the whole of that distance, yet the rapidity 
of its motion is such, that the two chambers 
of gas will explode so simultaneously as to 
be heard but as one report. A variety of this 
experiment, and which occasions considerable 
amusement, is made by asking a person to 
hold the vases one in each hand ; when the 
shock is passed he will of course feel it, as it 
will pass through his arms, and being accom- 
panied with a loud report, it will, though 
trifling in itself, mostly occasio!i coiisiderable 
alarm to the person receiving the shock, and 
equal amusement to the bye-staViders who 
know that his alarm is groundless. 

340. Rosin inflamed. — Wrap round one of 
the balls of a discharging rod sotne tow, let 
it lie loosely, and when tied on dip and roll 
it in powdered rosin, discharge a Leyden jar 
with this discharger quickly, when the rosin 
will be inflamed. 

341. Fill a flat porcelain dish with water, 
and on the surface of the water strew a quan- 
tity of powdered rosin ; place two wires on 
the opposite sides of the dish, with their 
ends near the surface of the water, and at 4 
or 5 inches distance from each other ; pass 
the charge of a jar from one wire to the 



other, and the resin in the track of the ex- 
plosion will be inflamed. 

342. Rosin house or fire house. — The fol- 
lowing cut shows what is commonly called 
the rosin house, but it is not so likely to 
succeed as the simple means of firing rosin 
first given (in Eoe. 340.) The whole external 
case is of tin, painted in the front according 
to the fancy of the maker. Attached to the 
chimney and side of the house is a glass tube, 
terminated by the brass ball A, with which 
is a wire proceeding down the tube into the 
house, where it is terminated by a second ball 
B. Through the opposite side of the house 
is a second glass tube, wire and two balls, 
marked at C and D. The wire of this part 
is capable of sliding backwards and forwards, 
that the balls wilhinside may be made to 
approach each other more or less according 
to the strength of shock to be passed through 
them. The balls C and D are loosely covered 
with tow, and dipped in or sprinkled with 
powdered yellow rosin. When the shock is 
passed from A to D, the rosin will most 
probably be inflamed. 




343. Gunpowder fired or scattered. — 
There are several ways of firing gunpowder 
by means of electricity, but it is only to be 
done with absolute certainty when the fluid 
is made to pass through a portion of water, 
or other conductor which is sufficiently im- 
perfect to allow the fluid to pass slowly along 
its course, as it appears than when the fluid 
passes with its accustomed rapidity through 
metallic conductors, with but a small space 
of air intervening, it has not time to ignite 
the powder. The latter is therefore scattered 
but not inflamed, and even when the powder 
is tightly compressed into a cartridge or 
rammed in a cannon, the firing of it is by no 
means certain even by a very powerful bat- 
tery, whereas by making a minute quantity 
of water a means of communication l)etween 
the diff'erent sides of the jar or battery em- 
ployed, a very small charge, and indeed a 
very small jar will be sufficient We have 
often failed in firing gunpowder by a large 
battery according to the old method, and 
always succeeded by the method recommended 



73 



by Mr. Sturgeon about to be described, even 
with a Leyden jar holding no more than a 
pint. It may be important to consider these 
various methods, as the right understanding 
of them may assist in maturing an applica- 
tion of this science lately introduced, namely, 
the inflammation of charges of gunpowder, 
intended for the blasting of rocks. 

344. Fix a small cartridge on a metallic 
point, which is fitted to a wooden or glass 
handle ; make a communication from the 
wire to the ground, then present the cartridge 
to the knob of the phial, and the gunpowder 
will be fired by the passage of the electric 
stream through the cartridge. — Adams. 

345. Electrical cannon. — The following 
cut shows the electrical cannon. The ball at 
the top has a wire attached to it which passes 
down a short tube of ivory into the chamber 
of the cannon, in the same manner as in the 
hydrogen pistol. The cannon which has a 
small bore is charged in the usual maimer with 
gunpowder. The wire of the ball is pushed 
down to its place, and when the point of the 
wire is within a short distance of the lower part 
of the bore it is properly prepared. The 
outer part of the pistol is connected with the 
outside of the charged phial, and by making 
a connexion by means of the discharging rod 
with the inside or knob of the bottle, the 
charge will pass, and sometimes intiame the 
gunpowder. 




ball at one end, and screwed into a brass cap 
at the other. B is a glass pillar. C a chain. 
D a metal stand. E a piece of linen thread 
dipped in water, connected with D, and with 
the chain F. To use the instrument, place 
a little gunpowder upon the top of D. Wet 
the thread E. Connect C with the outside 
of a Leyden jar, and F with the inside of 
the same by the discharging rod. When the 
shock passes, the gunpowder will bo inflamed. 

347. Electrical powder-house. — The fol- 
lowing cut shows the apparatus so called ; 
one side is removed to show its interior. 




34G. Sturgeon's firing of gunpowaer. — 
Construct an apparatus as shown in the fol- 
lowing cut, where A is a wire with a very small 




It is made of seven pieces of wood, sn 
united together by hinges, that when the 
powder withinside is inflamed the whole of 
the sides will fall down flat with the table. 
A represents an ivory cup filled with very 
dry gunpowder, having a wire through each 
side, and nearly meeting in the middle ; a 
shock is passed from P through a piece of 
wetted thread B, then through the powder, 
and out again to the chain N. 

348. Electrical fort. — The next cut re- 
presents a fort of baked wood with three 
cannons. They are so connected, that if a 
shock be passed from G to Y, it shall pass 
through all the cannons, at the same time 
there shall be such a disruption of contiguity 
j as that the gunpow^der with which the can- 
j nous are fired shall receive the shock ; and 
I if, as we have before observed, a string dipped 
j in water, or a plate of water be made a part 
I of the circuit, it will at the same time be 
j inflamed, and in each case so instantaneously, 
! that the various cannons, however many of 
Ihem there may be, will go off, with but a 
single report. The chain G proceeds to C. 




10 



74 



where it enters the cannon by a wire passing 
through a small piece of ivory. The outside 
of this cannon is connected with the wire E. 
This passes to the outside of the next cannon 
B. A nozzle of ivory in the touch-hole of B 
conveys the circuit to the touch-hole of the 
cannon A, the outside of which leads to the 
chain F. The wire between A and B is sup- 
posed in the cut to be supported by a short 
glass rod, or a stick of sealing wax, between 
the two cannons. The wetted string may 
be attached to either end as may be most 
convenient. 

349. Gunpowder scattered. — Use the 
same apparatus, and pass the shock through 
it in the same ma;;ner as in the last experi- 
ment, but take the thread away and substi- 
tute a wire or cliain in lieu of it. Upon the 
shock passing, the gunpowder will be scat- 
tered, but not inflamed. 

350. Gun2)owder inflamed by a shock 
thronyh water. — TheEjr.34G may be varied 
by adopting the following apparatus, and 
which is so plain as scarcely to need an ex- 
planation. The gunpowder is placed in an i 
ivory cup, with two wires at a short distance 
from each other in the centre chamber, one 
chain leads to a director or discharging rod 
ready to discharge the bottle, the other dips 
into an earthenware dinner plate, full of 
water. The gunpowder will be fired when 
the shock passes. 



nected by an iron chain which passes through 
the tube. Furnish it with a wooden handle. 
Discharge any Leyden jar with this dis- 
charging rod, and the chain will be beauti- 
fully luminous. 





The following experiments are notinstances 
of combustion, but are so closely connected 
with the part of the subject we are now con- 
sidering, that they may be introduced, if not 
with propriety, at least with convenience. 

351. The chain illuminated. — Form an 
iron chain by cutting wire into lengths about 
2 inches each, and turning up the ends, link 
one piece to another ; hang this around a 
room by silk strings, and pass a shock along 
it, when it will appear beautifully luminous 
at every link of the chain ; ap])earing like a 
continued line of the most brilliant star-like 
sparks. 

352, The luminous discharger. — Bend a 
tuhe of glass into a semicircle, put a brass 
cap on each end, and let the caps be con- 



353. Spiral illuminated. — Take a round 
board well varnished, and lay on it a chain 
in a spiral form, let the interior end of the 
chain pass through the board, and connect it 
with the coating of a large jar ; fix the ex- 
terior end to a discharging rod, and then 
discharge the jar ; a beautiful spark will be 
seen at every link of the chain. The chain 
may be sewed on in order to retain it in its 
position. 

354. Marks impressed on paper. — If in- 
stead of using a board for the nbove experi- 
ment, we lay the chain either in a spiral, or 
any other manner on a sheet of dry white 
paper, supported by a book, when the shock 
is j)assed, the chain will he illuminated as 
before, and will leave a black burnt mark 
upon the paper at every link of the 
chain. 

355. Luminous board. — Procure a board 
of any length, and send it to a baker's, to be 
baked for two hours ; afterwards jilnne it, 
and lay along it, seven, nine, eleven, or thir- 
teen strips of tin-foil, an eighth of an inch 
wide. These slips are to be put on and con- 
nected together at the ends, exactly in the 
same way as the strips upon the glass in Ex. 
245, except that they are to be put on with 
glue. The spaces between the slips being care- 
fully cleaned off immediately with warm water 
and afterwards wiped dry. Draw with chalk 
any desired word or sentence upon the slips, 
and with a penknife cut through the tin-foil 
slips wherever a spark is desired to be. Be 
the cut ever so minute, provided it pass quits 
through the slip, it will suffice. Before use, 
let the board at all times be well dried by 
standing at the fire for some hours, as the 
glue will be very apt to attract moisture from 
the air. Pass a shock from one end of the 
board to the other, and the whole will become 
luminous from end to end. We have by this 
means sent the shock of a gallon Leyden jar 
through an extent of 180 feet, illuminating 
four boards, with the words " Good night, 
all's well," in well proportioned letters, 13 
inches high, and by the same shock also 



75- 




rendered luminous 300 feet of iron chain, 
and fired a bladder of gas in the distance. 

356. Eggs illuminated. — This is usually 
done by means of a little apparatus called 

the egg stand, and which 
is represented in the mar- 
gin. This consists of a 
wooden frame, with a piece 
of metal let into the bot- 
tom ; a chain attached to 
this is connected with the 
outside of a Leyden jar. 
There are three wooden 
slides to hold as many 
eggs. A wire and ball 
passes through the upper 
part of the frame, so as 
to touch the top egg, and 
the eggs are lo touch each 
other, A shock is passed 
through the eggs by touching the upper 
ball with a discharging rod, which reaches to 
the inside of the charged jar, whose outside 
is united to the chain at bottom. The eggs 
will become beautifully luminous, and the 
shock in passing will make a sound as if the 
egg shells were broken, as indeed they will 
be if the shock be large. A quart jar is 
quite sufficient for this experiment. The 
eggs, if eaten immediately, will have a 
strong taste of phosphorus ; and will very 
soon afterwards become putrid, that is to 
say, in two or three days. When broken, 
the white and yolk will be found completely 
interna ingled with each other, if several 
shocks have been passed through the eggs. 

357. Illumination of oranges. — Substitute 
three oranges for the eggs of the last experi- 
ment, and send the shock through them ; they 
will appear luminous. As oranges are not 
good conductors, the experiment succeeds 
best when the upper wire is made to pene- 
trate the topmost orange, and when there is 
a short piece of wire between every two, it 
being thrust about half an inch through the 
rind of each. A single orange may very 
conveniently be illuminated by thrusting 
through its sides the points of the wires of the 
uni?ersal discharger. 

The most remarkable effects of combustion 
that are produced by electricity result from 
its action on metals and their oxydes. 

358. Gold leaf melted. — Place a strip oi 
silver or gold leaf about h an inch wide on 
white paper, pass a strong shock through it, 
the metal will disappear with a bright flash, 
and the paper will be stained with a purple 
or grey color. 

359. Take three pieces of window glass, 
each an inch wide, and 3 inches long, place 
them together with two narrow slips of gold 
leaf between them, so that the middle piece 



of glass has a strip of gold on each of its 
sides ; the extremities of the gold slips should 
project a little beyond the ends of the glass ; 
pass the charge of a large jar through the 
gold strips, they will be melted and driven 
into the surface of the glass. The outer strips 
of glass are usually broken, but that in the 
middle frequently remains entire, and is 
marked with an indelible metallic stain on 
each of its sides where the gold leaf rested. 
The prt>s of the universal discharger, de- 
scribed in page 65, is very convenient for 
holding the slips when performing this ex- 
periment. 

The colors produced by the explosion of 
metals have been applied to impress letters 
or ornaments on silk and paper. The outline 
of the required figure is first traced on thick 
drawing paper, and afterwards cut out in the 
manner of stencil plates. The drawing paper 
is then heated and placed on the silk or paper 
intended to be marked ; n leaf of gold is 
then laid upon it, and a card over that ; the 
whole is then placed in a press or under a 
weight, and a charge from a battery sent 
through the gold leaf. The stain is confined 
by the interposition of the drawing paper to 
the limit of the design, and in this way a 
profile, a flower, or any other outline figure 
may be very neatly impressed. 

360. Wire melted. — Pass a strong shock 
through an inch or two of fine watch pen- 
dulum wire, and it will be melted. Try this 
experiment until you have found the greatest 
length of ware that can be melted by a certain 
jar, charged to a certain height by the 
quadrant electrometer. Then join a second 
jar to the first, charge them to the same 
height as before, and increase the length of 
wire to four times that which was melted 
by the single jar, and the whole of this will 
in like manner run into drops. If there are 
three jars, it will melt 9 inches of wire, and 
so on for other numbers. 

361. Instead of charging the single jar to 
the same intensity as before, use two jirs, 
connect them together, and charge them to 
half the intensity ; there will be melted the 
same length of wire as by the single jar 
which was charged to double the height. 

The fusion of wire may therefore be em- 
ployed as a measure of the quantity of elec- 
tricity accumulated on any charged surface ; 
for the preceding experiments show that any 
given quantity of electricity will fuse the 
same length of wire, whether it be disposed 
in two jars or one ; and hence it may be 
concluded, that the greater or less intensity 
of a charge does not materially affect its 
wire-melting power. This test is therefore 
practically useful, for the various electro- 
meters measure only the intensity, and are 



76 



equally affected by one jar as by a battery 
of one hundred. When the fusion of wire 
is taken as a test of electrical power, care 
should be taken that the length of the circuit 
is always the same, and that the degrees of 
ignition are uniform ; for a wire maybe melted 
with but slight variations of appearance, 
when very different quantities of electricity 
have been transmitted through it. The lowest j 
degree of perfect ignition ought therefore to ! 
be obtained in all comparative experiments, 
and its phenomena should be uniform, that j 
is, as soon as the discharge is made, the 
wire should become red hot in its whole 
length, and then fall into drops. In order 
to ensure a perfect uniformity in this respect 
throughout a series of experiments, Pro- 
fessor Hare has invented the apparatus 
shown benealh : — This consists of two bent 
arms, which diverge from a centre, as a pair 
of compasses, and when adjusted are held 
tight by a screw at the centre. A reel of 
fine pendulum wire is fixed at one end by a 
screw, and at the other by a small pair of 
nippers. The whole is of baked wood, with 
glass supports. 




The melting of metals by electricity may 
be considered as a chemical rather than a 
mechanical effect, particularly as upon ex- 
amination the melted metals are found after- 
wards not in a metallic state, so much as in 
that of an oxyde. It is not supposed in these 
cases that the electric fluid acts otherwise 
than by raising the temperature of the metal, 
so as to enable it to combine with the oxygen 
of the surrounding air ; the same cause will 
often reduce an oxyde to a metallic state, 
particularly of such metals as are thus re- 
duced by heat. Mr. Cuthbertson made many 
experiments upon this subject, using for the 
performance of them a somewhat extensive 
battery, though such is not by any means 
necessary for the majority of cases. Besides 
the reduction of metallic oxydes, electricity 
often occasions still more evident chemical 
changes, and although its power in this re- 
spect does by no means equal that of gal- 
vanism, yet when we are enabled to procure 



a powerful stream of the fluid, as in the elec- 
tricity of steam afterwards discussed, the 
effect of free electricity in producing chemical 
and magnetic changes is by no means incon- 
siderable. The following experiments will 
illustrate a few facts relative to this subject. 

362. Prismatic colors produced. — Place 
a smooth and flat piece of metal between 
the points of the universal discharger, pass 
several explosions of a battery through the 
wires, and the discharger will gradually form 
on the metal different circles, beautifully 
tinged with the prismatic colors. The circles 
appear rooner, and are closer to each other, 
the nearer the point is to the surface of the 
metal. The number of rings or circles de- 
pend on the sharpness of the points, the 
experiment therefore succeeds better if a 
sharp needle is fastened to one of the points 
of the discharger. This experiment has been 
thought to account for the fairy rings, dis- 
coverable on downs and meadows, but this 
appearance is now thought to be derived 
from the growth of a certain species of fun- 
gus, whirl) has the peculiar property of v.ot 
growing on any spot where it has grown 
before ; a single plant then first arises, the 
second season others spring up around its 
site, the third year still further off, and so 
on for a length of time. We do not give the 
above as our own opinion, but as one pretty 
general among naturalists. These prismatic 
electrical cireles are marked most distinctly 
upon such metals as melt with the least heat. 

363. E^dnciion of vermiUior). — Color a 
card wit^h vermillion, mixing it up with water 
and a little gum, such as that already pre- 
pared in the boxes of water colors, place it 
when dry upon the table of the universal 
discharger ; the wires being one on each sid t 
of the card, at about the distance of 1 inch 
from each other. If the charge be now 
passed through the wires, the fluid will pass 
across the surface of the card to the part over 
the negative wire, and it will there perforate 
the card in its passage to the negative wire. 
The course of the fluid is permanently in- 
dicated by a neat black line on the card, 
reaching from the point of the positive wire 
to the hole, and by a diffused black mark 
on the opposite side of the card around the 
perforation, and next the negative wire. 
These effects are very constant, the black 
line always appearing on the side of the card 
which is in contact with the positive wire, 
and the perforation being near the negative 
wire. 

364. Draw a line \ an inch broad on a 
card with tincture of litmus, take a number 
of sparks from a machine along tlie wetted 
line, and the litmus will be changed to a red 
color ; this arises from the action of the elec- 
tric fluid occasioning the formation of nitric 



77 



?.cid by a chemical union of the nitrogen and 
oxygen of the air through which the fluid 
passes. 

365. Decomposition of iodide of potassium. 
— Damp a piece of white paper with the 
iodide of potassium ; upon taking a series of 
sparks along the card the compound is decom- 
posed, the oxygen of the air combines with 
the potassium, and suffers the iodine to 
escape, as may be known by the peculiar 
odour of that substance, and by holding over 
the card any article which has just been 
starched, and which by the action of the 
iodine will become of a bright blue color. 

3G6. Reduction of tin. — Introduce some 
oxyde of tin into a glass tube, so that when 
the tube is laid horizontally, the oxyde may 
cover about ^ an inch of its lower internal 
surface. Place the tube on the table of the 
universal discharger, and introduce the 
pointed wires into its opposite ends, that the 
portion of oxyde may lay between them. 
Pass several strontj shocks in succession 
through the tube, replacing the oxyde in its 
situation, should it be dispersed. If the 
charges are sufficiently powerful, a part or 
the tube will soon be stained with metallic 
tin, which his been revived by the action or 
the transmitted electricity. 

367. Reduction of mercury . — Perform the 
same experiment with Vermillion in a tube, 
the mercury will be separated, and that with 
such facility that the charge of a very mo- 
derately-sized jar will be fully sufficient. 

368. Acid and alkaline effects. — Take a 
small glass tube of the shape of the letter V, 
each arm of it being about 4 inches. Fill it 
to 2 inches in depth with water slightly co- 
lored with litmus. Put a cork in each end, 
with a very fine pointed wire projecting in- 
side the corks, so as just to touch the liquid ; 
connect the outer end of one wire with the 
prime conductor, and the end of the other 
wire with the cushion ; the chain from the 
latter, and which usually connects it with the 
ground being removed. Upon passing a 
stream of electricity through the tinged 
water, the positive end will soon appear red, 
owing to the formation of nitric acid. If, 
when this is the case, the apparatus is re- 
versed so that the positive side becomes the 
negative, the blue color will be restored, 
showing that in free electricity, as well as in 
galvanism, the two poles produce acid and 
alkaline properties. In this experiment it is 
best to have the wires covered with sealing 
wax, except at their points. 

369. Oil of tartar crystallized. — Take a 
glass tube about 4 inches long, a quarter of an 
inch in diameter, and open at the both ends; 
moisten the inside of the tube with oil ot 
tartar per dciiquiem, that is, pearlash which 



has liquified by contact with the air. Tlieu 
fix two pieces of cork into the ends of the 
tube, and pass a wire through each cork, so 
that the ends of the wires which are within 
the tube may be about three quarters of an 
inch asunder. Connect one wire with the 
outside coating of a large jar, and form a 
a communication from the other to the ball 
of the jar, so as to pass the discharge through 
the tube ; repeat this several times, and the 
oil of tartar will very often give manifest 
signs of crystallization. This is supposed to 
arise from the formation of nitric acid by 
the electrical action upon the air, and this 
uniting with the oil of tartar forms nitrate 
of potass or saltpetre, the same as in Ex. 
364. 

370. Decomposition of water. — The power 
of electricity in decomposing water was first 
discovered in 1 789 by M r, Cuthbertson. The 
manner of performing the experiment was 
by using a glass tube, a foot long, and -i- of 
an inch in diameter, through one end of 
which was inserted a gold wire, which pro- 
jected an inch and \ into the tube, which, 
after its insertion, was hermetically sealed. 
The other end of the tube was left open, ex, 
cept that a cork loosely covered it; a wire of 
the same description passed through this 
cork, so that its extremity came to a distance 
of about ^5 an inch from the first wire. The 
tube was then filled with distilled water, 
from which the air had been extracted by 
the air pump, and inverted in a vessel con- 
taining mercury. A little common air was 
let into the top of the tube, in order to pre- 
vent its being broken by the discharge. 
Electrical shocks were then passed between 
the two ends of the wires through the water 
in the tube, by means of a Leyden jar which 
had a square foot of coated surface. At each 
explosion, bubbles of gas rose to the top of 
the tube, and when sufficient water had been 
displaced to lay bare the wires, the next 
shock kindled the gases, and caused their 
reunion ; thus decomposition and recomposi- 
tion were eflFected by the same agent. 

Dr. Wollaston published in the Philoso- 
vhical Transactions a description of analysing 
water by the transmission of sparks, instead 
of shocks. Tiie following is from his paper 
on the subject : — " Having procured a small 
wire of fine gold, and given to it as fine a 
point as I could, I inserted it into a capillary 
glass tube, and after heating the tube so as 
to make it adhere to the point, and cover it 
at every part, I gradually ground it down, 
till with a pocket lens 1 could discern that 
the point of gold was exposed. The success 
of this method exceeded my expectations ; I 
coated several wires in the same mannery 
and found that when sparks from the con- 
ductors before mentioned were made to pass 



78 



through water, by means of a point so 
guarded, a spark passing to the distance of 
^ of an inch would decompose water, when 
the point exposed did not exceed one seven- 
hun<h-edth of an inch in diameter. With 
another point which I estimated at one fifteen 
thousandths, a succession of sparks one- 
twentieth of an inch in length aftbided a 
current of small bubbles of air." In these 
experiments the gases were liberated at both 
poles. Dr. Faraday however has devised a 
simple plan for evolving the gases, so that 
oxygen shall make its appearance at the one 
pole and hydrogen at the other, and also for 
other electro -chemical decomposition. The 
following is Mr. Faraday's description of his 
apparatus. " Upon a glass plate, placed 
over, but raised above a piece of white paper, 
80 that shadows may not interfere, put two 
small slips of tin- foil ; connect one of these 
by an insulated wire with a machine, and the 
other with the discharging train or negative 
conductor. Provide two pieces of fine 
platinum wire , bent as in the figure an- 
nexed, so that the part D F shall be nearly 



Pz/- 



upright, while the whole is resting on the j 
three bearing points P E F, place them as i 
«hown beneath, the points P N become then | 
the decomposing poles.'' 





371. Place a large drop of muriatic acid, 
rendered blue by sulphate of indigo, so that 
P and N may be immersed in it at opposite 
sides ; then send a current of electricity 
through it from a good machine, and chlorine 
(shown by its bleaching effects) will be 
evolved at P. 

372. Place a drop of solution of the iodide 
of potassium, mixed with starch, between the 
poles, and the current will evolve iodine at P. 

373. Put a drop of solution of copper 
between the poles, and the current will then 
cause the precipitation of metallic copper 

at N. 



374. Moisten a very small slip of litmus 
paper in a solution of caustic potash, and 
then pass a succession of sparks over its 
length in the air, the electricity will by de- 
grees neutralize the acid, and consequently 
form with it the nitrate of potass or saltpetre, 
so that the paper becomes touch paper. 

375. The composition of water. — In the 
experiments on the electric pistol the noise 
and flash of light were occasioned by the 
chemical union of the hydrogen, or gas in- 
jected into it with the oxygen of the air. Now 
chemists are aware that this union produces 
water, this is evident, by inspecting the 
pistol after it has been several times fired, 
when it will be found quite damp with the 
moisture so formed. 

376. Eudiometers. — The fact of certain 
gases being iufiamed by the electric spark 

has given rise to various instru- 
ments called eudiometers, one 
of the most simple of which is 
shown in the margin. It con- 
sists of a thick glass tube closed 
at the upper end, and open 
below, where it dips into a cup 
or basin of mercury. It is 
graduated along the side, and 
has two wires through the 
upper part which approach 
each other. The tube may be 
supported in any convenient manner. The 
tube is filled with mercury or water, (according 
to the kind of gas to be operated upon) ; it 
is then reversed, and the gas to be operated 
upon suffered to ascend the tube, until a 
certain quantity has been introduced. The 
electric spark or shock is then j)assed from 
the one wire to the other, when the gas is 
inflamed. The result is seen by the product 
left. In some cases the maximum effect takes 
place with the first shock ; with others not 
until after some hours' electrization. The 
following table shows the result of all these 
actions : — 

Opera-led upon. Result. 

Cwriitiion air and hydrogen. . . . Water and nitrogen. 

Oxygen and hydrogen Water. 

Chlorine and hydrogen Hydrochloric acid. 

Hydrochloric acid and oxygen Chlorine. 

Carbonic oxide and oxygen Carbonic acid. 

Nitrogen and oxygen Nitric acid. 

Sulphurous aciri and oxygen . . Sulphuric acid. 

Oxygen and ammonia Water and nitrogen. 

Hydrochloric acid Hydrogen. 

Fluoric acid Hydrogen, 

^,., J Nitric acid and 

Nitrous gas j nitrogen. 

Sulphuretted hydrogen Sulphur & hydrogen. 

Ammonia Hydrogen & nitrogen 

Olefiant gas Charcoal fiihydrogen 

The communication of magnetism to 
needles depends upon a fact which was 




79 



unknown wlien experiments with that object 
were first made ; that is, that the electrical 
fluid and fhe magnetic fluid act in directions 
opposite to each other. Thus magnetism 
induces a magnetized needle to turn north 
and south, or in other words, the magnetic 
fluids of the earth have a tendency or di- 
rection to those points, while the electrical 
currents of the earth have a direction east 
and west, or round the equator, correspondent 
to the apparent motion of the sun in its 
course. It is more than probable that the 
magnetic currents of the earth are derived 
from, or occasioned by the electrical ; at any 
rate the science of electro- magnetism shows 
us that whenever an electrical current sets in 
one direction, any matter which has a ten- 
dency to become magnetic will arrange itself 
at right angles to the electrical course. In 
magnetizing a steel needle by electricity, 
therefore to produce a constant effect, it is 
necessary to lay the wire which conveys the 
fluid across the needle to be magnetized. If 
the electrical current crossing it once only 
produces a certain effect, crossing it twice 
will produce one that is double ; a third 
course will be still stronger, always allowing 




the fluid to run in the same direction. Now 
the only way to make an electric shock pass 
several times across a needle without passing 
through it, is to twist the wire which conveys 
the current into a helix around the needle, 
the latter being for the time wrapped in 
paper, and the various coils of the helix 
being drawn out, so that they shall not touch 
each other, as represented in the preceding 
cut. That end of the needle nearest to the 
inner coating, or that end which is shown in 
the cut to be connected with the discharging 
rod, will be a north pole. 

This method of making a magnet by elec- 
tricity is certain, even with a Leyden jar of 
a pint size ; whereas, by the old methods 
described beneath, the success is at all times 
very uncertain, even with a strong battery. 
The following are the experiments alluded to. 

377. Place a steel wire in the direction 
from north to south, and pass a moderately 
strong charge of a battery through it ; it will 
become magnetic, the end that lies southward 
being the south pole. 

378. Render a steel wire slightly magnetic, 
and place it in the magnetic meridian, with 
its south pole towards the north. A strong 
charge of a battery will either destroy its 
magnetism, or reverse its magnetic poles ; if 
its magnetism is merely destroyed, a second 
charge will magnetize it anew, but with 
reversed poles. 

379. Place a steel wire in a perpendicular 
position, and pass a strong charge through 
it ; it will become magnetic, the upper end 
being the south pole. If this end be now 
placed downwards, the transmission of ano- 
ther charge will destroy its magnetism, or 
reverse the poles. 



CHAP. X. 



THE ELECTROPHORUS AND ELECTRICAL CONFIGURATIONS. 



The electrophorus is fully described in page 26. It was once called the perpetual elec- 
trical machine, in Consequence of its power of giving off electrical appearances for a long 
time after having bt^en once excited, as already explained. In working this simple and 
useful instrument, there is a little inconvenience arising from the necessity of touching 
the upper plate whenever it is placed upon the lower one ; this may be obviated by pasting 
a very narrow slip of tin-foil across the lower resinous plate. As the only object of 
touching it is to supply it with fluid from the bottom of the lower plate, it is evident that 
a slip of tin foil immediately connected with the lower side will still better answer the 



80 

purpose than the finger of the operator, which is only connected with the lower aide 
by means of his body, the ground, and the table. Why the electric virtue remains in 
the electrophorus is easily explained. We will suppose the lower cake to be of resinous 
substances. When rubbed then with flannel, it becomes negatively electrified ; when the 
upper plate is placed upon it, it will of course by the law of induction induce a contrary 
state in the upper plate, and the upper plate will necessarily be electrified plus ; when a 
finger touches it, or when it becomes by any other means uninsulated, it will consequently 
take a spark from the finger or other connecting body. The finger being removed, and 
the plate lifted up, it will remain electrified plus, and consequently be ready to give up 
the spark which it had just before taken. Placing it down on the resinous electric a 
second time, induction is again occasioned, it will again take a spark, which it will in like 
manner give up. Thus the action is continued for a great length of time, the electricity 
of the resinous plate being all the time undisturbed, and consequently not diss'pated. 
The following experiments are interesting, and differ from all previously recorded. 



380. To recover the force of an electro- 
l horus. — Place the metallic plate on the 
resinous plate, touch it as usual ; then take 
it up, and discharge it on the knob of a 
Leyden jar ; repeat this operation several 
times, this will charge the jar. Now place 
the jar on the cake, and move it over its 
surface, holding the jar by the knob ; this 
will augment the force of the electrophorus, 
and by reiterating the operation it will be- 
come very powerful. 

381. Place a piece of metal on an excited 
electrophorus, it may be of any shape ; a pair 
of triangular compasses are very convenient 
for this purpose. Electrify the piece of metal 
with the power which is contrary to that of 
the electrophorus, and then remove it by 
means of some electric, and afterwards sift 
upon the electrophorus some finely powdered 
rosin, which will form on its surface curious 
radiated figures. When the plate is negative, 
and the piece of metal positive, the powder 
forms itself principally about those parts 
where the metal was placed ; but it the plate 
be positive, and the spark negative, the 
part where the metal touched will be free 
from powder, and the other parts more 
covered. 

382. Electrical configurations. — Draw 
over the surface of a piece of warm glass, or 
of a resinous electrophorus, the knob of a 
charged Leyden jar. This will of course 
charge or electrify it in those places touched 
by the knob. Wrap up some powdered rosin 
in a piece of muslin, and sift it on the excited 
plate. The rosin will cling in a most beau- 
tiful radiated manner to those parts which 
have been touched by the knob ; a small 
distance beyond this will be a mark quite free 
from the powder, while over the rest of the 
plate, and where no excitation has taken 
place, it will merely cover the surface, as it 



would any other body not excited. The 
reason of this action is as follows : — The 
Leyden jar being charged positively, the 
streak which it makes upon the plate is ot 
course positive also. Rosin, when let fall 
from the muslin, is negatively electrified, it 
therefore clings to the parts charged posi- 
tively. Then again, we have shown that any 
body being electrified is surrounded by an 
electrical atmosphere, and beyond this it 
produces a contrary state of electricity in 
any thing adjacent ; thus the rosiu adheres 
to the line made by the charged jar, in a 
dense mass, beyond this it adheres in streams 
or ramifications, because of the positive 
electric atmosphere on the two sides. A 
little beyond this is a negative atmosphere 
arising from induction, here no powder ad- 
heres, but rather is driven away, the particles 
being negative and repelling each other. Out 
of the limit of this clear space no action is 
perceptible, and all appearances purely elec- 
trical cease. The next experiment shows 
this in a still stronger light, 

383. Configuration by red lead and sul- 
vhur. — Mix together equal parts of powdered 
red lead and sulphur, put them in a small 
sieve or a piece of muslin. Sift these pow- 
ders on a piece of warm glass which has 
been drawn over or touched with the knob 
of a charged Leyden jar. The powders how- 
ever intimately mixed will separate from 
each other, because by the sifting one of 
them becomes negatively electrified, the other 
positively. In falling, therefore, each will 
be attracted by such part of the glass as is 
in a contrary state to itself, and form distinct 
lines and marks on the glass of the most ex- 
traordinary and beautiful appearance. The 
red lead being electrified positively by- the 
sifting, adheres to the outsirie lines in little 
stars or dots, which as the electricity of tho 



81 



sulphur is strongly negative, it adheres to the 
central space, where it appears as a line of 
small specks or stars, the property of a ne- 
gative action ; while the red lead is in brushes 
or ramifications, showing its positive condi- 
tion. These beautiful figures may be pre- 
served for years if made on a sheet of glass 
which has a frame to it like a picture, the 
glass being after the experiment reversed 
towards the back, so that it may not be rubbed 
off by accident. A piece of black paper behind 
it heightens the effect greatly when to be 
preserved. If too much powder be sifted on 
it, the surplus may be blown off without 
injury. The next cut will give some idea, 
although a very inadequate one, of this 
beautiful and curious experiment. 




384. Projection of chalk. — Suspend the 
lower plate of the electrophorus against the 
wall, that in this and the following experi- 
ments the grosser part of the powder may 
fall to the ground, and no more adhere to 
the plate than is attracted there by the elec- 
tricity diffused thereon. Let a small jar be 
charged very weakly, draw its knob over the 
resinous plate, and then taking a clothes 
brush in one hand, and a piece of chalk in 
the other, rub the chalk upon the brush near 
to the surface of the plate ; this produces a 
plain white line without any ramifications. 
When the charge is stronger, the ramifica- 
tions are proportionably extended, resem- 
bling so many beautiful white feathers. 

385. Place a circular brass plate with an 
insulating handle upon the resinous plate, 
and communicate a spark from the charged 
jar to the brass plate. Take this off by its 
insulating handle, and project chalk upon the 
lower plate. This produces a very regular 
circle of ramifications about 4 inches long, 
proceeding from the circumference of the 
space covered by the brass plate, and within 
the circle are a number of irregular figures 
somewhat like stars. A shock made to pass 
through the same plate generally produces 
more distinct ramifications, and sometimes 



without any stars within the circle ; at other 
times with a quantity of minute specks. 




S86. In performing an experiment similar 
to the last, let the brass plate be drawn along 
towards the edge of the electrophorus whilst 
touched with the knob of a jar ; a very beau- 
tiful figure will be produced at the projection 
of the powder. 

387. Draw over the plate a jar strongly 
and negatively charged, and afterwards a 
pointed wire, held in the hand only, is to be 
drawn over the same figure. When chalk is 
projected, a beautiful ramified figure is pro- 
duced in the middle of the negative one. 

388. A conical tin funnel is to be placed 
with its base on the middle of the resinous 
plate, and a negative strong charge given by 
connecting the discharging rod with the 
under side of the plate ; then a positive 
charge is to be given in the same manner. 
Let the funnel be thrown off, and the chalk 
projected. Beautiful ramifications are now 
produced both within and without the circle. 

389. A knob of wood, about an inch in 
diameter, is to be placed upon the wire of a 
jar which is charged highly positive, and the 
knob drawn over the plate so as to touch the 
surface. This produces a beautiful figure, 
the middle of which is smoothly covt red with 
chalk, and the sides finely ramified with 
shades. 

390. Let the flame of a small wax taper 
be at about an inch distance from the middle 
of the resinous plate ; then let the knob of a 
positively-charged jar be suddenly brought to 
the flame, and both the jar and flame be in- 
stantly taken away again. In this experi- 
ment when the chalk is projected, a circular 
space, about 4 inches in diameter, will be clean 
and free from powder ; the rest of the plate 
uncovered, except by a great number of small 
circular or elliptical spots, which shows that 
the electrical fluid passed to the plate in de- 
tached balls, like some atmospheric meteors. 



82 



CHAP. XL 

ATMOSPHERIC ELECTRICITY, &c. 

Many atmospheric phenomena have a resemblance to what we may suppose to be 
occasioned by a great accumulation of the electric fluid. It is therefore not surprising 
that the earlier electricians acknowledged the similarity of many of those natural pheno- 
mena with the experiments which their comparatively small machines enabled them to 
perform. The very appearance of lightning induced philosophers long to believe that it 
was only a grander species of electricity, excited without the intervention of human art ; 
but the proof that they should be actually the same fluid, and should arise from the same 
cause, and be subject to the same laws, was reserved for the comprehensive and active 
mind of Dr. Franklin. He made the bold assertion, and with a kite made of a silk hand- 
kerchief, brought lightning from the clouds, and proved his assertion by performing with 
it all the experiments then known. 



Ex. 391. Electric kite. — A kite properly 
adapted for the purpose of atmospheric 
electricity may be made and managed as 
follows : — Tie together in the form of a cross 
two canes, or still better two thin rods of 
deal, about 3 feet long each. To the four 
corners of the cross-sticks fasten the corners 
of a large silk handkerchief ; a loop must be 
made by piercing a hole in two parts of the 
handkerchief, and a string fastened to one of 
the sticks, in the manner of the loop of a 
boy's kite ; indeed a common kite will an- 
swer the purpose quite as well as one of silk, 
except that if it is to be used in stormy 
weather, the latter will by wet soon become 
spoiled. The size also is of very little con- 
sequence, except that the larger the kite the 
higher it will usually ascend, and therefore 
for this cause, and this alone, a large kite is 
most effective. The kite itself being formed, 
and having a common kite tail attached to 
it, or else long strips of calico sewed toge- 
ther, which will be found more convenient ; 
it must be furnished with two or three pointed 
thin copper wires fastened to the loop, ex- 
tending upwards a few inches above that part 
of the kite which flies highest, and projecting 
from each other as seen in the figure. 




The string is the next object of importance, 
that evidently is the best which has a fine 
wire or two passing down it. Most persons 
desiring this string have taken the trouble to 
wind the wire around the whole length of 
string previously bought, not knowing that 
were they to take the fine wire to any string 
spinner, he would weave it up along with the 
hemp at once, putting a wire into each strand, 
if required, and at the expense of a mere trifle 
additional. Supposing a person should be in 
such circumstances or situation that this 
string cannot very easily be procured, the 
best substitute for the wire will be found in 
soaking a common string in salt and water 
for an hour or two previously to using it. It 
will thus imbibe sufficient moisture to render 
it a good conductor, even in a very dry at- 
mosphere, where string wetted with water 
only would become useless. The upper part 
of the string must be carefully connected 
with the pointed wire carried above the loop. 

The lightning, or electric fluid, being thus 
attracted at the kite, and led downwards by 
the string, it must be retained from passing 
silently to the earth beneath. For this pur- 
pose it will be necessary that the lower end 
of the string be attached to a cord of silk, 
about 3 feet long, to be kept quite dry, and 
for convenience of operating, a large key is 
usually tied at that part where the string and 
silk are united. The kite being raised, the 
electric fluid will pass down to the key, here 
being stopped by the silk cord, it will be 
given off* in sparks or flashes, more or less 
powerful, in accordance with the quantity of 
lightning which may be in the air. The 
operator may easily conduct it elsewhere, or 



83 



charge his conductors or batteries without 
difficulty. 

No philosophical instrument is more sim- 
ple in form and easy to construct than the 
electric kite, yet no one needs more care in 
its management. To fly it when a thunder 
storm is approaching would be attended with 
the greatest danger, unless every precaution 
be taken. In this state of the atmosphere 
the raising and lowering of the kite requires 
the utmost circumspection ; to let the string 
wind out immediately from a ball in the hand, 
making thereby the body a part of the con- 
ductor is too venturesome ; the string should 
pass over and touch an iron railing, or 
through a ring fastened to a metal rod driven 
deeply into the ground, whilst the person 
who holds it is placed upon a dry glass-legged 
stool, or otherwise insulated ; as for example, 
upon a pile of books, or paper. When up a 
sufficient height, the remainder of the string 
may be fastened to the key, and the operator 
is then able to remove himself to a safe dis- 
tance. It is advisable also that the electric 
fluid should never be introduced into a dwel- 
ling house, for a thunder storm is a terrific 
agent to tamper with, and once invited into i 
our houses, may occasion dreadful damage, 
ere it be allayed. We have seen flashes o. 
4 or 5 feet in length, and once when we left 
our kite up during a stormy night, the key 
appended to it seemed as it were a ball o» 
fire, illuminating all around, and the very 
kite and string appeared as if enveloped in 
lambent flames. Fortunately, to operate in 
weather like this is not necessary. The 
calmest and brightest evenings of summer ; 
the densest fogs of autumn ; and the clearest 
frosts of winter, yield mostly as much fluid 
as is convenient to use ; in either time small 
sparks will be visible, and may be felt by a 
knuckle presented to them, when they will 
be found very different from those usually 
afforded by the electrical machine. The air 
will be found positively electrified ninety- 
nine times out of each hundred, yet the 
sparks as given by the kite string will be 
red, comparatively short, make but little 
noise, and be felt so much more pungent 
when passing to the hand, that they rather 
resemble the vibration, or small shock, than 
that known as the electric spark. 

392, The proof afl'orded by numerous expe- 
riments with the electric kite, that the air was 
at all times charged with electricity, and also 
that the degree of disturbance and character 
of the fluid varied at different times, rendered 
philosophers anxious to construct some sim- 
ple apparatus which should enable them to 
do this without the trouble, delay and danger 
of the kite. They therefore turned their 
attention to construct more simple instru- 
ments, some of which were to be used as a 
permanent apparatus, others for temporary 



purposes only. As these instruments varied 
from each other only in a small degree, and 
were all dependant upon the same principle, 
we shall describe but two of them. The'first 
is called from its inventor and use, Cavallo's 
atmospheric electrometer. It is represented 
beneath, and consists merely of a common 
jointed fishing rod, without the last or smallest 
joint. From the extremity of this rod pro- 
jects a slender glass tube covered with sealing 
wax, and having a cork at its end, from 
which a pith ball electrometer is suspended. 
There is a small string also which runs the 
whole length of the apparatus, to render the 
electrometer insulated when required to be 
so. It is fastened by a pin to the cork ball 
at the top, so that by pulling the string, it is 
separated from the cork, and leaves the pith 
balls suspended from the waxed glass rod ; 
when used, the rod is thrust out of a window, 
the string is then pulled ; when the pith balls 
diverge, they are then pulled in and examined. 




393. Cavallo's rain electrometer.— This 
nistrument differs from the former in many 
respects ; it is represented beneath. A is a 
strong glass tube, about 2 feet and a -^ long, 
having a tin fanncl cementod to its extremity, 
which funnel defends part of the tube from 
the rain. The outside surface of the tube is 
wholly covered with sealing wax. C is a 
piece of cane, round which brass wires are 
twisted in different directions, so as to catch 
the rain easily, and at the same time to make 
no resistance to the wind. The cane is fixed 
into tho tube, and a piece of wire proceedinf 




84 



from it goes through the tube, and is ter- 
minated by a ring, upon which a pair of pith 
balls are suspended. This instrument is at- 
tached to the side of a window frame, with 
the funnel projecting outwards, while the 
pith balls are preserved dry within. 

Franklin also contrived one or two electric 
instruments of the like nature to Cavallo's at- 
mospheric electrometer, the object of which 
was principally to indicate to him when a 
thunder storm was approaching. The whole 
of this apparatus is very simple, consisting 
merely of a long pointed rod, which proceeded 
through a glass tube, that was let into the 
roof of the house. The rod bore at the lower 
end a clapper, suspended on silk, while there 
was a lateral communication by means of a 
wire with an insulated bell. When therefore 
the fluid was in any considerable abundance, 
the bell became charged, it therefore attracted 
the clapper, which being then repelled, dis- 
charged itself by striking against the other 
bell. Thus ringing was kept up. 




M. Bichman examining an apparatus of 
this kind too nearly, was struck by the light- 
ning which descended, and fell a sacrifice to 
his too ardent and incautious love of science. 

This last apparatus it is evident will only 
act when the fluid is in some abundance, 
and is not adapted to measure or indicate 
those minor indications which belong to calm 
weather, while Mr.Cavallo's instruments were 
more troublesome than they need have been. 
To obviate these inconveniences, M. Saus- 
Bure contrived the following more simple and 
effective instrument : — 

Saussure's atmospheric electrometer con- 
sists of a glass case or bottle, with a metal 
foot, and four pieces of tin-foil up the sides 
in connexion with the bottom. Withinside 
the glass are two very fine silver wires, 
swinging freely in a loop above, and ending 
below in two small pith balls. The upper 
part of the instrument, is a brass cap, to 
defend the bottle from the wet, terminated 
by a ball and a rod of 3 or 4 feet in length, 
made in joints, and pointed. (The uj)per 



wire is left out in the cut) In fine weather 
the hood or cover is taken off. When stand- 
ing out of doors, the pith balls diverge, as 
soon as fluid is attracted by the point of the 
rod 




The above remarks and experiments show 
not merely that electricity exists in the at- 
mosphere, but that it is sometimes at least 
in an accumulated form, or similar to that in 
which we witness it in the charged Leyden 
jar. Thoughts then will arise as to how it 
gets into the atmosphere, and this being 
accounted for we may be at a loss to find any 
analogy between the atmosphere, and a Ley- 
den jar, and therefore we may not see clearly 
how the air can become charged so as to 
receive and deliver up a charge of fluid in so 
distinct a manner as in » flash of lightning. 
These doubts we will endeavour to remove. 
First. Its presence in the atmosphere may 
easily be imagined from the experiments 
with the gold leaf electrometer in page 9, 
and still more so from the electricity of eva- 
poration in page 22 ; indeed, evaporation 
alone is amply sufficient to account for all 
the effects which take place. Although the 
evaporation of a few drops of water manifest 
but a small effect, yet the whole amount of 
the fluid thus disturbed may be imagined, by 
stating that 5280 millions of tuns of water, 
are, as is imagined, evaporated from the 
Mediterranean Sea alone in one summer's 
day. It must be observed also that other 
causes are always in action, as currents 
of wind impinging upon the earth's surface, 
the motions of all bodies, chemical change, 
&c., sometimes adding to this accumulation, 
sometimes decreasing it ; and thus it is that 
different parts of the air are differently elec- 
trified at the same time. 

The next question to clear up is the man- 
ner in which the atmosphere becomes charged 
to the degree, and in the manner of a Leyden 
jar. This also may be illustrated by direct 
experiments, which will not merely show the 
fact that it does become so charged, but also 



85 



how other electric atmospheric phenomena 
take place, and to what cause may be ascribed 
man]/ of the phenomena which are observed 
in the course of common electrical experi- 
ments. It may be more fully proved as 
follows : — 

394. Cover two large boards with tin-foil, 
suspend one by silken strings from the ceil- 
ing, and then connect it with the conductor. 
Place the other board parallel to the former, on 
an insulating stand that may be easily raised 
or lowered to regulate the distance of the plates 
from each other. Or place the boards in a 
vertical situation parallel to each other, on 
insulating stands of the same height. In 
most cases this form will be found more con- 
venient. These boards may be considered 
as the coating to the plate of air which is be- 
tween them. Connect one of the boards with 
the prime conductor, and the other with the 
ground ; turn the cylinder, and that one which 
has been united to the prime conductor will 
be electrified positively, while the other will 
be negative. The space of air between the 
two plates acts as a plate of glass, it separates 
and keeps asunder the two electric powers. 
Touch the negative plate with one hand, and the 
positive plate with the other, and a shock will 
be received similar to that from a Leyden jar. 

395. Place half a ball or any other emi- 
nence on the lower plate, supposing them to 
be horizontal. The spark in this case will 
strike the eminence, and the plate of air be 
discharged. The experiments with these 
boards will be more pleasing if one surface 
of the upper board is covered with gilt lea- 
ther. The two plates when charged are 
supposed to represent the state of the earth 
and clouds during a thunder storm ; the 
clouds being in one state, and the earth in 
another. — Adams. 

396. Pillars of sand and whirlwind imi- 
tated. — Place bran or small pieces of paper 
in the middle of the lower board. When the 
machine is put in action, these will be alter- 
nately attracted and repelled with great ra- 
pidity, and agitated in an amazing manner. 
This experiment is very similar to that of the 
dancing figures, Ea\ 136, but owing to the 
very much greater size of the boards, and 
the lightness of the objects, a very curious 
phenomenon is generally observed, namely, 
that each particle of bran turns on its axis 
at the time it is moving up and down ; and 
if the electricity be strong, the whole unite 
into a column which turns on its axis, and 
often rolls along until it arrives at the edge 
of the board, where it flies off. This ex- 
periment is an exact imitation of a whirlwind, 
and also of the rolling pillars of sand -which 
are so much a terror to the African traveller. 

397. Imitative earthquake. — Place a build- 



ing, which is formed of several loose pieces 
of wood, on a wet board in the middle of a 
large basin of water ; let the electric flash from 
a battery be made to pass over the board, or 
over the water, or over both, the water Mill 
be strongly agitated, and the building thrown 
down. 

398. If a long narrow trough of water be 
made part of the circuit in the discharge of 
a battery, and a person's hands be immersed 
in the water at the time of the explosion, he 
will feel an odd vibration in the water, very 
different from an electrical shock. The quick* 
stroke from the repercussion of the air and 
the vapor is communicated to the hand by 
the water, and the hand receives a shock 
similar to that received by a ship at sea 
during an earthquake. 

399. Glaciers imitated. — The cause of the 
irregularity on the surface of glaciers has been 
much discussed of late years, and among 
other theories it has been supposed to have 
arisen from the passage of strong currents 
of electricity over them. This theory is 
somewhat supported by passing a strong 
shock over the surface of a sheet of ice, 
which becomes impitted with numerous ca- 
vities and irregularities, similar to, but of 
course on a much smaller scale than in 
nature. 

400. Aurora Borealis. — This is ad- 
mittedly electrical, and is so easily and 
exactly imitated as to leave no doubt of the 
fact. We will refer to the experiments in 
Vacuo, described in page 51, where this 
phenomenon is explained : and the identity 
becomes the more evident from the circum- 
stances that whenever it appears, the atmo- 
sphere is found replete with the electric 
fluid ; and, secondly, because it equally with 
electricity affects the magnetic needle. It 
puts on appearances different from lightning 
because it occurs at a considerable elevation 
above the earth, where, as before explained, 
the air is much rarefied. 

401. Falling stars. — Whenever the electric 
fluid is at a more moderate height, and in a 
more concentrated form, it occasions those 
electrical appearances, known to us as falling- 
stars or n-.eteors ; these are generally consi- 
dered indicative of rain, and not without 
some cause, inasmuch as rain, hail, snow, 
&c. are always produced by any sudden 
electrical change that takes place. 

They may be imitated by passing a shock 
through a long exhausted tube, similarly 
constructed to that described and figured as 
the Aurora flash, page 51, but not exceeding 
^ an inch in diameter. 

402. Rain, sAow, $fc. — It has been said 
by some that the reason rain, &c. falls in 



86 



drops, and still more so, why snow appears 
in light fleecy flakes is owing to electrical 
repulsion, as is somewhat proved by the ex- 
periment of the expansion of a fleecy feather 
when driven off by an excited tube, and also 
by the spun sealing-wax. 

403. Fiery rain. — Thus also can we in 
some degree explain the fiery rain mentioned 
in the Scriptures, and by various ancient 
writers, certain it is that every drop of rain 
which falls during a thunder-storm is charged 
with the fluid, and therefore contributes to 
divest the storm of its fury. 

404. Waterspout. — The waterspout, that 
wonderful and terrific object, is too easily 
explained by electric attraction to leave any 
doubt that its cause is a highly -charged state 
of the air, and we are confirmed in this con- 
clusion by the means taken to disperse it, 
namely, by firing cannon and pointing sharp 
weapons at it. Ex. 154 and 155, showeff"ects 
very analogous to the waterspout. The fol- 
lowing cut gives the usual appearance of this 




terrific phenomenon ; the sea beneath it is 
agitated, and rises up in a short column ; 
the cloud above stretches downwards in the 
formof a funnel, sometimes remaining steady, 
but more frequently moving forwards, and 
involving in destructive torrents of water 
every thing it touches ; and so great is often 
its power, as to draw up fish and other ob- 
-jects : hence the frequent accounts we read 
of showers of frogs ^ fish, S(c. 

IDENTITY WITH LIGHTNING. 

The identity of the electric fluid with light- 
ningwasone of the first-established facts rela- 
tive to atmospheric electricity, and as it was 
the first in time, so it is also in importance to 
us, teaching not merely the origin and proper- 
ties of that mighty power of nature, but also 
how to escape from its direful effects. The very 
appearance of lightning would induce us to at- 
tribute it to electricity, nor is this supposi- 
tion in any way weakened by our experimental 
researches. If we compare the properties of 
electricity with those ot lightning, we shall 
find them closely analogous, or rather 
identical. 



405. Lightning destroys animal and ve<, e- 
table life, so does electricity. — Procure a 
mouse, and send a strong shock through his 
body from head to tail, and the poor animal 
will instantly fall dead. To pass the shock 
through the head or chest seldom kills, but 
if it pass along the spinal marrow it always 
does, the tail should therefore always form 
part of the circuit. 

406. When the animal is dead, pass a 
second shock in the same manner as that 
which killed it, and the fluid instead of pass- 
ing through the animal will pass over it, and 
consequently be luminous. This is a curious 
experiment, as it shows that the substance of 
the animal ceases to be a good conductor 
with its life. It is a well-known physiological 
fact, that in the bodies of persons killed by 
lightning, as well as of animals killed by an 
electrical shock, the blood does not coagu- 
late, but very soon becomes putrid, and the 
flesh black. Lightning passing over the skin 
of a person scorches it in the same manner 
as an ordinary flame would do, and the after 
sensation is very similar. 

407. Pass a very small shock through a 
flounder, or other fish, and it will be deprived 
cf life instantly. 

408. Put several fish into a basin of water, 
and send a shock through the water, the fish 
will be killed in a moment. 

409. Pass a strong shock from the top to 
the root of a balsam or geranium plant, and 
although no immediate eff'ect will be apparent, 
yet the plant will be eff"ectuaUy killed, as 
will be evident after a few days. 

The efi'ect of lightning in destroying va- 
rious things opposed to its passage, in setting 
fire to combustible substances, rending trees 
and disturbing the magnet, we have shown 
in the chapter on the mechanical and other 
effects of electricity to be easily occasioned 
by the rapid progress of the fluid through 
them. Their identity therefore is clearly 
established, and the importance of electricity 
as well as its universal agency, becomes more 
conspicuous as we advance. Our preservation 
from lightning is evidently of the first im- 
portance, and the manner best to accomplish 
this was first suggested by Dr. Franklin. 
Soon after his important discovery of the 
true nature of the electric fluid, he pointed 
out the utility of conductors to buildings. 
The necessity of these was admitted by all, 
but philosophers could not agree among 
themselves as to these conductors, whether 
they should be terminated by a point or a 
ball. Those who contended for the superior 
efficacy of a ball, maintained that a point 
drew the fluid from a greater distance than 
a ball, and therefore the cloud was as it were 
invited towards the building. As many 



87 



experiments were brought forward in fur- 
therance of these arguments, it had many 
supporters, till Franklin, by his ingenious 
explanation of their experiments, and one of 
his own, set the matter for ever at rest. The 
following experiments are those now alluded 
to:— 

410. Fasten the head of hair of Ea;. 129, 
or the glass feather of Ex. 128, to the prime 
conductor, and turn the machine, while the 
hair or the filaments of the feather are di- 
vergent, hold towards them a ball; the fila- 
ments will immediately be attracted, and will 
cling round the ball ; but hold a point instead 
of the ball, and they will be repelled. 

411. Franklin's cloud. — Fasten three loose 
pieces of cotton wool upon a linen thread, 
so that they shall hang at about 2 inches dis- 
tance from each other, or else fasten three 
fleecy feathers in the same way. Adjust this 
apparatus to the prime conductor, turn the 
machine, and hold a ball and point alter- 
nately to the outermost feather. When the 
ball is held, the feathers will clasp the ball, 
but when the point approaches, the first 
feather recedes to the second, the second to 
the third, and the third to the conductor. 

These experiments apparently prove that 
the fluid is more attracted by the ball than 
the point, but this conclusion is erroneous ; 
the reason of the recession of the feathers in 
the last experiment is not because they are 
repelled by the point, but because the point 
rapidly deprives the outermost feather of its 
fluid, and then that feather being in a neutral 
state retires, or is attracted to the next. 
The point acts in like manner upon this, 
which occasions them both to retire and so 
on. Thus it is with a pointed lightning con- 
ductor, it draws off the fluid from a thunder 
cloud so rapidly as to take away the cause of 
danger. It is however to be tested, whether 
in neutralizing the cloud it does not endanger 
the building ; this is not so, provided the 
conductor is perfect, and offers a continuous 
metallic course from the fluid to the ground, 
its ultimate destination. If the conductor be 
inadequate, it will be melted, if it be inter- 
rupted, although it be pointed, yet a shock 
will as readily pass along it as if it were 
terminated by a ball, and as we have seen 
from experiments in a former chapter a 
concussion and consequent injury must al- 
ways take place when this is the case. The 
following apparatus are peculiarly adapted 
to show the truth of this position : — 

412. Thunder house. — This ingenious ar- 
ticle is made of an upright piece of baked 
mahogany, formed like the gable of a house, 
as B B, and placed upon a wooden stand. A 
wire marked C runs downwards throughout 
its whole length. It is terminated above by 
a ball A, which being unscrewed shows a 




point beneath it. In one or two parts of the 

gable are square pieces of wood cut out. 
A These are ^ of an inch 
thick, and 1 inch square 
on the side. They are 
shown at D and F ; are 
made so as to fit loosely 
into a hole cut partly 
into the gable to receive 
them, and have a wire 
running across each, so 
placed, that putting in 
the pieces in one way, 
the wires shall with C E 
_ form a continuous and 
^uninterrupted line, and 
when put crosswise, 

there shall be a want of contiguity at that 

place, as shown at D. 

413. Pass a shock from A to E, while the 
ball remains on and the wire is continuous, 
and it will make a loud report, without dis- 
turbing either piece of wood. 

414. Pass a shock, or rather endeavour to 
do so, with the upper ball taken off", so that 
the point is displayed. The fluid will pass 
and discharge the jar, but not in the manner 
of the shock, and no report will be heard. 

415. Now place either of the pieces of 
wood crosswise, and restore the ball to the 
top. The shock will pass and throw out tae 
piece of wood that was placed crosswise, 
but not disturb the other piece. 

416. Let the piece of wood be placed 
crosswise, as in the last experiment, but re- 
move the ball. Upon discharging the Ley den 
^"ar, a real shock will pass, and the wood will 
be displaced, although a point terminates 
the apparatus. 

417. Electrical pyramid. — This is an 
apparatus of the same nature as the last, 

and is to be used in the 
same manner. A is a four- 
sided pyramidal piece of 
wood, or more usually con- 
sists of four pieces fitting 
on to each other. A line 
runs down the whole in 
front, and is moreover con- 
tinued down the base B ; 
continuity being occasioned 
by a small square, as in 
the thunder house. This 
is marked D in the cut, 
and is seen with its wire 
placed sideways. Upon 
this moveable square, and 
upon the back of the base, 
the upper portion is supported by three 
balls. When a shock is sent from E to F, 
the square D is thrown out, and the upper 
part of the pyramid falls. 




88 



Tlius it is proved, that lightning conductors 
should be sufficiently large, lest they should 
be melted, and continuous lest they should 
give a shock rather than draw off the fluid 
silently and harmlessly. Also we learn from 
JBx. 197, and following, that the point with 
which they are terminated above should pro- 
ject for some height above the highest parts ot 
the building. Thus it is that chimnies are so 
often injured, but not from this cause alone ; 
they being lined with soot, which is a good 
conductor, induces the flash to take that 
course. Therefore during a thunder storm 
it is dangerous to get near a lofty tree or a 
prominent chimney, so on a plain ; even a 
sheaf of corn is sufficient to direct the course 
of the lightning, inasmuch as straw is a good 
conductor, though not so good as the human 
body ; thus life would be endangered, for the 
fluid always takes the best conductor. 

Strange as it may appear, yet it is a fact, that 



many persons are killed without any electric 
matter passiug through them at all, and thus 
we are not wholly safe even when the storm is 
wasting its fury upon other objects. This is 
easily accounted for by electrical induction, 
as follows : — When a charged cloud passes 
over a man, it affects all the fluid in his body, 
for as the fluid repels itself, the natural 
quantity he possesses is driven to his feet, 
which therefore become electrified positively, 
or have more than their natural share, while 
his head becomes negative. As soon as the 
overhanging cloud is discharged by striking 
a tree, rock or other object, the equihbrium 
of his body is immediately restored, and that 
with such impetuosity that convulsion or 
death is the consequence. Birds roosting in 
trees are thus often killed, or in cases where 
death does not ensue, blindness is the fre- 
quent result. 



CHAP. XII. 



MEDICAL AND ANIMAL ELECTRICITY. 



This part of the subject, although of importance in a physiological point of view, yet 
scarcely is entitled to a place here, because of its yielding few or no experiments ; a short 
account however of administering electricity medically may be advantageously admitted ; 
and we would premise the account by stating, that electricity should always be ad- 
ministered gently at first, and its power only increased when the gentle application is 
found ineff'ectual, except in cases of paralysis, or when used to remove obstructions ; 
its full power may be at once administered ; but even here the shock of a quart Leyden jar 
should never be exceeded ; the frequency of the shocks, and not the strength of them being 
most to be relied upon. Also we would remark that no danger to life can arise from the 
administration of electricity in any way, unless, as before observed, it be sent along the 
spine, or perhaps through the brain. We have been more than once thrown down by the 
power of the shock, but even by the passage of a large battery through the arms have felt 
no ill effects, unless perhaps a slight head-ache. Strong shocks are however extremely 
unpleasant, and we trust that our experimental friends will not operate with any but a 
small jar, at all times, unless a large number of persons are to receive the charge, and 
even then to be very careful to exclude young children and delicate persons, as the fear 
alone may occasion distressing effects. 

Electricity, according to the mode of its administration. Is either sedative, stimulant, 
or deobstruent ; hence the propriety of its application to diseases of quite contrary cha- 
racter. We have applied it to palsies, rheumatisms, inflammations, contractions of the 
muscles, amaurosis, chilblains, tumours, sprains, and other diseases and accidents. The 
methods of electrifying are five ; first, simple electrization, or merely subjecting the person 
to the action of electricity, by placing him on a glass-legged stool, and connecting him with 
the electrical machine when in use. Second, drawing the fluid from the particular part of 
his body which may be aftected ; this is either done holding towards h«m a wooden point. 



89 




when a cooling and refreshing breeze is perceptible, or by placing your hand upon his 
clothing, when if any woollen or silk interpose between your hand and his body he will feel 
a peculiar pricking sensation, occasioned by innumerable sparks issuing from the part 
beneath the hand, and which will soon occasion a great degree of warmth in that part. Or 
a third method is to draw the fluid from him by means of sparks, taken by the knuckle, or 
else by a wire with a metallic ball at the end of it. If the operator hold this tight he 
will not feel the sparks himself. A stronger way of drawing off electricity is by means 
of what are called vibrations, and a still stronger, sparks. For these two last the patient 
either stands, or sits on an ordinary chair, and not on the glass stool before mentioned. 

The following apparatus is all that is essentially necessary, though many other articles 
have been described and recommended. The first essential is a glass-legged stool; if 

required for cheapness it may be a piece of 
board, made smooth, and with round edges, 
supported upon four wine bottles, pegs being 
driven into the under-side of the board to fit 
the necks of the bottles ; solid glass legs are, 
however, infinitely better. In using the stool, 
a large sheet of brown paper or pasteboard ; 
or, still better, a piece of oil-cloth, larger 
than the stool itself, is to be placed beneath it on the floor, to prevent the filaments of the 
carpet, or the dust of the floor, from drawing away any of the fluid accumulated. 

The next requisite is a flexible tube or connector ; as a chain must necessarily have 
n any edges or points, the stool should be connected to the machine by a chain which 
is sewed up in silk, and afterwards varnished or covered with India rubber; thus there 
vill be no loss of fluid. But for numerous purposes the instrument called a flexible tube 
is much better. This is explained in page 63. 

A wooden or metal point is sometimes used ; by this a gentle stream of electricity, is 
given to or taken from a patient, according as the point is held in the hand of the operator, 
(ihe patient being on the electrical stool,) or attached to the glass-handled flexible tube, 
tie patient being on the ground, or rather not insulated. These simple instruments^ 
with the exception of a wire with a brass ball at the end of it, are all that are necessary 
fcr the administration of the electric fluid, except when shocks are to be given. In 
tlis case a Leyden jar is indispensable. Any Leyden jar may be used, but the one 
shown, and described beneath, is most convenient for medical purposes. 

Medical Jar. — This is like an ordinary Leyden jar, covered and lined to a certain height 
with tin-foil, as at B. A wooden cap is then prepared for it, and a hole just admitting a glass 
tube A, is bored in the middle of the cap. The tube reaches below to within 2 inches of the 
bottom, and projects upwards above the cap, about 3 inches. 
This tube is also partly lined and covered with tin-foil, so 
placed that rather more than an inch of the glass is left 
uncovered at the lower end, and about 2 inches at the upper 
end. The tube is cemented to the top of the bottle, and a 
smaller cap cemented on the top of the glass tube ; but 
before this last is cemented on, three hooks are drilled in 
it ; one for a hook wherewith to suspend the phial from the 
conductor, the two others are to be left open ; one of them 
to admit a wire to touch the inner coating of the tube, the 
other a second wire, sufficienl«ly long to reach to the coating 
of the phial — these are shown in the cut at C and D. A 
wire is also tv\isted round the outer coating of the inner 
tube, which projects outwards sufficiently to touch the inner 
coating of the phial. On the outer coating of the phial is 
fastened a hook, marked F, for the convenience of attaching 
a chain. This bottle is always used in connexion with' the 
medical electrometer, described in page 56 ; and also with a pair of directors, glass- 
handled instruments, shown in the margin. 

These directors are for two purposes, first, that by means of their balls they shall be 
able to direct the fluid or shock to any particular part only, and confine it thereto ; and 
secondly, that the operator, holding the glass handles, may not participate in the shock, 
which passes in a straight line from the ball of the one director to the ball of the other, when 
they are respectively connected by chains, the one to the outside of the medical bottle, 
the other to the sliding piece of the electrometer. When both wires are in the bottle, the 




44 



90 

the whole bottle is chargea, and the strength of the shock is considerable; but when the 
longer wire is drawn out, the only one left will be that which tuuches the inner coating of 
the tube, and this tube being so small, the shocks which will pass will be less energetic than 
those given by the larger bottle, and will altogether have a different character. They are, 
indeed, intermediate in effect between sparks and shocks, and are called vibrations. 

Animal electricity partakes more of the nature of galvanism than that free state of 
frictional electricity, which is our present subject. The power of giving shocks appears 
wholly confined to fish ; no species of any other race of animals, havhig any power analogous 
to the complicated apparatus found for this purpose, applied to the electrical eel and the 
torpedo. Several of the former of these fishes have of late years been brought to this country, 
and experimented with. The shock is indeed sudden and momentary, like that from a 
Leyden battery, but the effects when a continual current is produced by connecting the 
head and tail of the animal in decomposing water, forming and disturbing a magnet, 
giving a faint spark only, even under the most favorable circumstances, and giving the 
shock only when the circuit is wholly formed of good conductors, (requiring even the 
hands to be wetted,) and the whole of its electrical power taking its origin among wet, 
fleshy, and dissimilar animal substances, show the propriety of excluding an account of the 
animals, interesting as is their nature and wonderful their powers. 



CHAP. XIII. 

HYDRO-ELECTRICITY, OR ELECTRICITY OF WATER. 

The fact that the issuing of steam through an orifice should give rise to electrical ap- 
pearances was not merely unknown, but not even suspected, until little more than three 
years since, when an account appeared in the Philosophical Magazine, that the boiler of a 
steam engine near Newcastle being defective, (the joint or fiaunch of the safety valve having 
given way, so that the steam, which was at a pressure of 35 lbs. per square inch, was issuing 
forcibly through the aperture,) a Mr. Patterson, who was standing near, upon touching 
the weiglit of tlie safety valve, felt a pricking sensation in the fingers. A few days after- 
wards the same being repeated, induced a greater attention to the subject, when a spark 
was elicited ; and proper apparatus being procured, a shock, and other electrical phenomena. 
Thus this wonderful discovery was made, and as it may well be imagined soon bruited 
abroad, drawing the attention of philosophers to the subject ; particularly the indefati- 
gable and erudite chemist and electrician. Professor Faraday, who has lately read a paper 
to the Royal Society, entitled, " On the Electricity evolved by the Friction of Water and 
Steam against other Bodies." The object of the experiments detailed in this paper is to 
trace the source of the electricity which accompanies the issue of the steam. Professoi 
Faraday relates that electricity is never excited by the passage of pure steam, but only 
v;hen water is also present ; hence he concludes that it is altogether the effect of the friction 
of globules of water against the sides of the opening, urged forward by the rapid passage 
of the steam. The effect of this is to render the steam or water positive, and the pipes 
from which it issues negative. Heat, by preventing the condensation of steam into water, 
likewise prevents the evolution of electricity, which again speedily appears by cooling the 
passages, so as to restore the water which is necessary for producing the efftct. Water 
will not excite electricity unless it be pure ; the addition to it of any soluble salt or acid, 
even in minute quantity, is sufficient to destroy this property. The addition of oil of 
turpentine, on the other hand, occasions the development of electricity of an opposite kind 
to that which is excited by water. A similar and more permanent eff"ect is produced by 
the introduction of olive oil along with the water. Similar results were obtained when n 
stream of compressed air was substituted by steam. 

These experiments and conclusions of Professor Faraday are interesting, and the more 
so, as by them we are able to show by fact what we could before these discoveries only 
infer, namely, the mighty power called into action by the currents of air, vapor and mois- 
ture of the atmosphere ; indeed, it is evident, that a gun cannot be discharged, not even 
an air gun, nor yet a comrnou tea kettle give suam irom its spout, without exciting the 
electric fluid, nor is it in small quantities either, as the following account of the largest and 
most powerful electrical machine ever constructed will show. It is that machine now in 



91 




use, and daily exhibited at the Polytechnic Institution, Regent Street, London, and known 
as Mr. Armstrong's hydro- electric machine, that gentleman having been the maker of it, 
and its power being derived from the friction of water as above described. 

A A A A A A are six green glass supports, 3 feet long. B is a cylindrical tubular 
boiler of rolled iron-plate | inch thick ; its extreme length is 7 feet 6 inches, 1 foot of 

which is occupied by the smoke chamber, making 
the actual length of the boiler 6| feet : its dia- 
meter is 3| feet. The furnace D, and ash-hole 
C, are contained within the boiler ; and are 
furnished with a metal screen to be applied for 
the purpose of excluding the light, during the 
progress of one class of experiments. F is the 
water guage ; E the feed-valve. J J, are two 
tubes leading from the valves K K to the two 
tubes H. A and I are forty-six bent iron tubes, 
terminating in jets ; either half or the whole of 
which may be opened by means of the levers 
G G. L is a valve for liberating steam during 
the existence of the maximum pressure. M is 
the safety valve ; N is a cap covering a jet, that 
is employed for illustrating a certain mechanical 
action of a jet of steam. O is the first portion 
of the funnel, P the second portion, which slides 
into itself by a telescope joint, so that the boiler 
may be insulateJ ..:_:. „Iie experiments commence. The boiler is cased in wood. 

The next figure, which may be called the prime conductor, but which is not used for 
that purpose, is a zinc case, furnished with four rows of points. It is placed in front of 

the jets, in order to collect the electricity from 
the ejected vapor ; and thus prevent its returning 
to restore the equilibrium of the boiler. The maxi- 
mum pressure at the commencement of the ex- 
periments is 80 lbs. ; which gradually gets reduced 
to 40 or lower. The portion of the apparatus, 
•^ which is peculiarly connected with the generation 
> of the electricity, is a series of bent tubes with their 
:' attached jets. Each jet consists of a brass socket, 
I containing a cylindrical piece of partridge wood, 
with a circular hole or passage through it, i of an 
inch in diameter, into which the steam is admitted through an aperture. The peculiar 
shape of this aperture appears to derive its efficacy from the tendency it gives the steam to 
spread out in the form of a cup, on entering the wooden pipe, and by that means to bring 
it and the particles of water, of which it is the carrier, into very forcible coUision with the 
rubbing surface of the wood. 

The electricity produced by this engine is not so remarkable for its high intensity, 
as for its enormous quantity. In no case, antecedent to this, has the electricity of tension 
taken so rapid a stride towards assimilating with galvanic electricity. Mr. Faraday's 
experiments on the identity of the electricities had shown how small was the quantity 
obtained from the best machines ; and had given good reason to expect that chemical effects 
would be exalted when the quantity could be increased. And such is the case here ; a very 
remarkable experiment in illustration of this is, that not only is gunpowder ignited by the 
passage of the spark, but even paper and wood shavings will be inflamed when placed in the 
course of the spark passing between two points — such an effect was never before produced 
with C( mmon electricity. In like manner, chemical decompositions are effected much more 
readily by means of the hydro- electric, than by that from the common machine. The 
current, when passed through a galvanometer, caused the astatic needle to oscillate between 
20^ and 30^ ; it also formed an electro-magnet, which deflected a needle. In these various 
experiments care is taken to place the conductor very near the jets when quantity is 
required, and to remove it beyond the striking distance for intensity. 




PAOE 

Abb6 Mollefs machine 27 

Acid and alkaline effects ... .77 

Action, electrical, what 3 

Adam"s portable jar 61 

vErial electroscope 18 

Air thermometer 64 

Amalgam, to make 26 

Amber, attraction of 4 

Animal electricity 88 

Atmospheric electricity 82 

Attraction, &c 4, 5, 32 

Aura, or breeze 45 

Aurora borealis 51 

Aurora flask, &c 51 

Balance discharger 56 

Ball, diving, &c 45, 46 

Balls and points. &c 42 

Barometer luminous 24 

Battery 56 

Bells ringing or chime 36 

Belted bottle 66 

Bennetfs doubler 15 

Bennett's electroscope 7 

Biot's apparatus 41 

Board, luminous 74 

Boat attracted 39,63 

Bomb 65 

Brush of light 43 

Camphor arborescent 37 

Cannon 73 

Canoe, repellent 46 

Card, pierced 65 

Cat, shock from 7 

Cavallo's electrometers 83 

Cavallo's pistol 71 

Chain illuminated 74 

Chemical action, excitation by 20 

Chime, perpetual 18 

Circular rubbing machine 26 

• Cleavage, excitation by , 22 

Cloud, electrified 34 

Cobwebs, sensation of 7 

Coin stuck to a jar 66 

Colored sparks 49 

Condenser 15 

Conductors, what, &c. . .4, 23, 25 

Configurations 80 

Coulomb's electrometer 14 

Coulomb's balance 14 

Coward's electrometer 64 

Crescent, luminous 53 

Cross, luminous 47 

Crystallization of oil of tartar 77 
Culhbertson's plate machine. .31 

Cylinder machine 29 

De Luc's dry pile 17 

De Luc's electroscope 18 

Devices on glass 53 

Directions of the fluid, &c 66 

Director, coated 60 

Directors 89 

Discharger, balance 56 

Discharger, luminous 74 

Discharger, universal 65 

Discharging electrometer ... .56 

Discharging rod 56 

Door knob, to electrify 61 

Doubler, Benneti's 15 

Dry pile 17 

Du Kay's system 10 

Earthquake, imitated 85 

Effects, mechanical, &c 62 

Eggs, illuminated 75 

Electrical machines 27 



INDEX. 

PAOE 

Electric column 17 

Electric fluid, states of 3 

Electric light from paper. &c. 7 

Paper, adhesion to a wall 5 

Paper rent by a shock 65 

Pendulum 58 

Electrics, whar, &c 4, 23, 25 

Electrometers . .13, 39, 56, 64, 83 
Electroscope, gold leaf 5, 6, 7, 8 

Electroscope balance, &c 5 

Electrophorus, &c 26, 79, 80 

Electroscope, pendulum 6 

Eudiometers 78 

Evaporation, excitation by . . . .22 

Excitation, modes of 3, 13 

Falling stars 85 

Feathers, adhesion of 5 

Feather driven about the room 6 

Feathers, radiating 34 

Fiery rain 86 

Fish and leaf 35 

Flexible tube 63 

Flyer with bells 44 

Flyers 44 

Fort and battery 73 

Franklin's system 10 

Franklin's <;lo d 87 

Franklin's bells 84 

Gases, experiments in 52 

Gas inflamed .69, 71 

Glaciers imitated .' 85 

Glass feather 34 

Glass plate, &c. excited ..5,6 

Gold leaf melted 75 

Gunpowder scattered, &c. 72, 74 

Hair electrified 6 

Hare's wire holder 76 

Hawkesbee's machine 27 

Head of hair, repellant ......34 

Heat, electricity by 21 

Henley's electrometer 39 

Henley's universal discharger 65 

Hydrogen lamp 70 

Hydrogen pistol 70 

Images, dancing 35 

Inclined i)lane 44 

Induction, &c 39 

Insulation 4 

Jar, Leyden 55, 56 

Kite 82 

Kinuerslcy's air thermometer.. 64 

Lateral discharger 67 

Leyden jar 54, 55, 61 

Light and spark, &c 48 

Lightning, cause of, &c 80 

Loaf sugar, luminous 7 

Machines 27 

Magic picture 57 

Magic vases 71 

Magnet, making of 79 

Marks impressed on paper 74 

Medical bottle 89 

Medical electrometer 56 

Medical electricity 88 

Metals, excitation of »..24 

Nairne's machine 28, 29 

Negative electricity, what. ... 10 

Non-conductors, what 23 

Oranges illuminated 75 

Orrery 45 

Otto Guericke's machine 27 

Pail of water 38 

Palmer's machines 31 

Perpetual chime 18 



pAok 

Perpetual motions 9 

Phosphorus intlamed P8 

Pillars of sand 85 

Pith balls moveable 35 

Pith balls, to make 36 

Planet, revolving 38 

Plate machine 31 

Plate of air charged 85 

Positive electricity, what 10 

Powder house 73 

Press 65 

Pressure, electricity of 16 

Prime conductor, what 30 

Prismatic colors produced ... .76 

Prismatic illumination 69 

Pyramid or obelisk 87 

Quadrant electrometer 39 

Quartz, light from 7 

Rain, snow, &c., cause of 85 

Reduction of oxydes 76 

Repulsion 6. 32 

Ribbons, experiments with ... 12 

Rope dancer 37 

Rosin, inflamed 7 

Rubbing machine 26 

Sealing wax, attraction of ... . 4 

Sealing wax, spun 37 

Seesaw 37 

Set of spirals 52 

Slicrt of glass to charge 57 

Shock, how communicated ..55 

Shock, explanation of 57 

Shot chain 52 

Singer's electric column i7 

Singer's electroscope, &c . . 8, 9 

Spangles, luminous 52 

Spider 37. 58 

Spiral tube, &c 52,54.74 

Spirits of wine, inflamed ....69 

Sponge and fountain 38 

Sportsman 60 

Star of light 43 

Steam, electricity of 91 

Stockings, experiments with ..12 

Stool 89 

Sturgeon's perpetual motion . .19 

Sugar fractured 65 

Sulphur cone 22 

Swan, attracted 38 

Swing, electrical 36 

Symmer's experiments 12 

Thunder house 87 

Thread.3, diverging, &c 34 

Tin, reduction of 77 

Tourmalin, experiments with 21 

Tube, flexible 63 

Universal discharger f>5 

Vane and mill work 64 

Vessel of oil, to pierce 47 

Vermillion, reduction of 76 

Vibrations, what 89 

Volta's condenser 15 

Volta's hydroL'cn lamp 70 

Water, composition of 78 

Water, decomposition of ....77 
* Faraday's apparatus lor 78 

Waterspout 86 

Watson's machine 28 

Whirlwind, imitated 85 

Wilson's machine 28 

Windmill 45 

Wire melted 75 

Word, luminous 54 

Zamboni's perpetual motion . . 19 



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AND SCIENTIFIC PEOCESSES ; THE AECANA OE TKADE AND MANUFACTUKE ; 

DOMESTIC ECONOMY, ETC. ETC. 

By C. W. FRANCIS, F.I..S. 



The title of this Work shows its nature and extent, as well as its utility and comprehensiveness ; 
indeed it contains all that is really useful upon an infinite variety of subjects ; and while it forms 
a valuable Book of Reference to the Druggist, Perfumer, Dyer, Bleacher, Operative Chemist, 
Confectioner, Potter, Pyrotechnist, Victualler, Distiller, Artist, Color Maker, Gilder, Grainer, 
and others, whose employments especially depend upon the accuracy of their Preparations ; it 
comprises those very numerous Receipts, Arts, and Processes, which, without forming the 
especial object of particular trades, are of general utitlity and iuterest, either as a source of 
domestic economy, scientific research, or artistical amusement. 

It is a standard and authentic Work of Reference, of Universal Information, useful to 
the Tradesman and the Artist, by informing them of the operations and processes of others : — to 
the Chemist and Druggist, as a vade rnecum of all his professional formulae ; — to the Amateur, 
as a record to assist his views upon all subjects ; — and to the Manager of a PamOy, as a faithful 
synopsis of numerous operations, and a register of authentic Receipts, valuable to him in saving 
expense, and procuring and using for some important purpose, a material or preparation which 
most frequently cannot be purchased without much trouble and expense. 

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THE 

COMPLETE GUIDE TO THE FINE ARTS. 

containing 

Instructions to enable those who have not the assistance of an Instructor, to become Masters 
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COOLING DRINKS. 

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THE ART OF 

MODELLING WAXEN FLOWERS, FRUIT, 

i'C. ^c. ^c. 

Illustrated with Numerous ^Vood Engravings of Moulds, Patterns, Parts of Flowers, Fruit, &c. 
By G. W. FRANCIS, P.L.S. 

AUTHOR OF THE LITTLE ENGLTSn FLOEA, GHAMMAE OF BOTANY, TAVOEITES OF THE 
FLO WEE GAKDEN, ETC. ETC. 

Knowing well how much the art of Making Waxen Flowers and Fruit is practised hy 
Ladies, and how much more it would be pursued, were there a plain and correct Guide to the 
operation, the Author has prepared the present little Work, hoping that, as the instructions are 
the result of experience, it will forward the views and remove the difficulties of the learner in 
the delightful occupation of imitating such beautiful objects. 

There are no illustrations of natural objects more exact and pleasing than those made 
of wax, more especially the representations of TVuit and Flowers. So exact indeed are they, if 
well made, that the most practised eye cannot some times detect the real from the artificial. 

In Fruit, the choicest specimens of every clime may be thus assembled in a single vase, 
in all their apparent lusciousness and perfection ; while in their waxen prototypes, lovely Flowers 
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drawing room, when grouped with taste and blended with harmonic contrast, these waxen 
objects are not to be surpassed, whether we look at them as records of foreign productions 
seldom seen — of extrr.crdinarily beautiful specimens of home growth — of favorites which it is 
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rest upon. Indeed all lovers of flowers (and -who are not ?) must admire these, their lovely 
images, transparent, vivid, and brilliant as they are. 

The very beauty of Waxen Fruit and Flowers induces the belief that to make them must 
be difficult. " I can never make any so beautiful as these," is a very oft repeated expression 
upon v\dtnessing even a single group. Yet, in truth, no art is of more easy attainment ; a little 
patience and a little taste are the whole mental requisites ; these superadded to ordinary care in 
the manipulation, cannot fail very shortly to render proficient the most inexperienced. The chief 
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manner ; and this and eveiy other information is fully treated of in the pages of this Work. 



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CHEMICAL EXPERIMENTS; 

By G. W. FRANCIS, F.L.S. 

Illustrating the Theory, Practice, and Application of the Science of Chemistry, and containing 
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WITH ENGRAVINGS OF APPARATUS, ETC. 
The Chemist and Druggist will find in this Work the best method of manufacturing every 
substance which he is likely to want. The Lecturer will recognize the most remarkable 
properties of them all clearly pointed out by such Experiments as are easy and striking. The 
Student will be able to refer to, and to repeat the Experiments of the Class-room with facility. 
The Manufacturer will find the economical principles of his Trade illustrated, and the best 
Receipts for his articles given ; while he who seeks amusement only will have a wide field before 
him, from which he may cull the choicest flowers. 

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ELECTRICAL EXPERIMENTS; 

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THE 
SELF INSTRUCTING LATIN CLASSIC, 

Whereby a perfect knowledge of the Latin Language may be readily acquired, without 
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A KEY TO THE PROPHECIES, 

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manu;al of practical levelling. 

Particularly as applicable to Railways and Canals ; 

WITH EXPLANATORY ENGRAVINGS. 

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AUTHOR OP THE DICTIONAKT OF ABT3 AND SCIENCES, CHEMICAL EXPEHIMENTS, ETC. ETC. 

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THE ARITHMETICIAN'S GUIDE, 

Being a system of Arithmetic Designed for the Use of Schools ; with an Appendix consisting 
of Bills of Parcels, Bills of Exchange, Receipts and Notes. This Work contains upwards of 
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By ROBERT WILLIAM WOODWARD. 

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. .■!»«. ■ .U ' . ^ti^T-:- 



THE 

DICTIONARY 



OF 



PRACTICAL RECEIPTS; 



CONTAINING 



MEDICINAL PREPARATIONS; CHEMICAL OPERATIONS; ARTISTICAL, ORNA- 

MENTAL, AND SCIENTIFIC PROCESSES; THE ARCANA OF TRADE 

AND MANUFACTURE; DOMESTIC ECONOMY, ETC. ETC. 



BY 

G. FRANCIS, F.L.S. 

AUTHOR OF THE DICTIONARY OF ARTS AND SCIENCES ; CHEMICAL EXPERIMENTS ; ELECTRICAL 

KXl'ERIMENTS; THE DICTIONARY OF TRADE, COMMERCE, AND NAVIGATION; 

MANUAL OF LEVELLING ; ANALYSIS OF BRITfSH FERNS ; LITTLE 

ENGLISH flora; FAVORITES OF THE FLOWER GARDEN; 

GRAMMAR OF BOTANY; ETC., ETC. 



The title of this Work shows its nature and extent, as well as its utility and com- 
prehensiveness ; indeed, it contains all that is really useful upon an infinite variety 
of subjects ; and while it forms a valuable Book of Reference to the Druggist, 
Perfumer, Dyer, Bleacher, Operative Chemist, Confectioner, Potter, Pyrotechnist, 
Victualler, Distiller, Artist, Color Maker, Gilder, Grainer, and others, whose em- 
ployments especially depend upon the accuracy of their Preparations *, it comprises 
those very numerous Receipts, Arts, and Processes, which, without forming the 
especial object of particular trades, are of general utility and interest, either as a 
source of domestic economy, scientific research, or artistical amusement. 

It is a standard and authentic Work of Reference, of Universal Information, 
useful to the Tradesman and the Artist, by informing them of the operations and 
processes of others : — to the Chemist and Druggist, as a vade mecmn of all profes- 
sional formula ; — to the Amateur, as a record to assist his views upon all subjects ; — 
and to the Manager of a Family, as a faithful synopsis of numerous operations, and 
a register of authentic Receipts, valuable to him in saving expense, and procuring 
and using for some important purpose, a material or preparation which most 
frequently cannot be purchased without much trouble and expense. 

In One Vol. Bound in Cloth, Is. M. 
Eleven Pauts at 7^/., or I^'outy^eour Nos. at \\d, each. 



This Useful Work contains npwards of Five Tho-usand Receipts, a 
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CONTENTS OF THE NUMBERS OF THE 

DICTIONARY OF PRACTICAL RECEIPTS. 



Contents of No. 1. Abemethy's Biscuits— Aber- 
nethy's Black Draught — Abemelhy's Medicines — Aber- 
nethy's Pills — Abscesses, Acute and Chronic, Treaimpnt 
of — Absorption of Moulds, &c. — Absorbent Powders lor 
Horses — Accarie's Purified Opium — AocidentH, assistance 
in cases of Fracture. Fire, P'rost, Fi's. Drowning or 
Hanging. Children in Convulsions, Poisons, Starvation — 
Acetic Acid, Glacial or Solid — Acetic Embrocation of 
Hartsliorn — Acetic Lotion for Ringworm — Acetate of Lead 
Pills — Acidity, to Correct- -Acid Medicines — Acid Soap 
—Acidulated Drops — Aconite, Extract of — Acorn Coffee 
— Acorus, or Sweet Flag, Oil of — Acoustic Balsam — 
Acoustic Oil; Huile Acoustic — Adhesive, or Strapping 
Plaister — iEgyptiacum — vEthiop's Mineral — Agrimony 
Tea — Ague — Ague Drop, Tasteless — Alabaster, to Work, 
to Etch, to Clean, to Join, Staining of. to Preserve Objects, 
to Polish — Albata, Aroentine, or German Silver — Albu- 
men — Albumen Powder, Flake Albumen, Soluble Solid 
Albumen — Albuminous Varnish — Alcohol, to Strengthen 
— Ale Brewing — Ale, Amber — Ale from Sugar. 

2. Ale from Vegetables — Ale Bitters — Alkaline Medi- 
cines — .\lkanet, Extract of — Alkermes Cordial — Alkermes, 
Confection and Syrup of — Allspice, Essence of — Alloy — 
Almonds, to Blanch — Almond Bloom— Almonds, Burnt — 
Almond Cakes — Almonds, Candied — Almonds, Confection 
of — Almond Cream — Almond Custard Ice— .Almond Emul- 
sion. Milk of Almonds — Alnionds Essence of Bitter — .Al- 
mond Flavor — Almond Hard Bake, to make — Almond 
Honey Paste — Almond Ice Cream — Almond Icing for 
Cakes — Almond Jeliy — Almond Linctus — Almond Mix 
ture — .\lmonds Oil of — Almond Oil Soap — Soap of Bitter 
Almonds — Almond Paste — Almond Powder — Almond 
Powder, French — Almond Rock Cakes — Almond Rout 
Cakes — Almond Savoy Cakes — Almonds, Syrup of, Sirop 
DOrgeat — Aloes Medicines, Compound Decoction. Ene- 
ma. Extractor, Tincture, Pills, Compound; Powder, Tinc- 
ture of. Wine — Alterative Medicines, Balls for Horses, 
Laxative, for Grease, for Strangles — Alum Baskets and 
Ornaments— Alum Baskets, to Color — Alum, Burnt — 
Alum, Cubic — .\lum Medicines, Eye Water, Ointment, 
Plaister, Poultice, Solution of. Sugared, Wash, Whey — 
Alum in Bread to Detect — Alum in Wine to Detect — 
Alum Mordant — Alum White — Alumina, or Alum Earth 

— Alumina, Acetate of — Amadou, or German Tinder — 
Amalgam for Injections — Amalgam Electrical — Amalgam 
for Water Gilders — Amalgam Varnish — Amber, to Work 

— Amber, to Join and Mend — .Amber, Balsam of — Amber 
Varnish, Black— Amber <iold Size — .Amber Varnish, Pale 
— Amber and Lac Varnish — Amber Liniment — Amber. Oil 
and Resin of — .\mber. Soluble — Ambergris, qualities of. 

3. Ambergris, Artificial — Ambergris, Essence of — 
Ambergris Hair Powder — Ambergris Perfume — Amber- 
gris So:tp — Ambergris, Spirit of — Ambergris Wash Balls 
— .\mi)oyna Wood, to Imitate by Painting — Ambretle 
Perfume — .\mbrette. Spirit of — American Biscuits — Ame- 
rican Blight, Cure for — American Mead — .Amethyst Paste 
— Ammoniacal Preparations, Acetate of. Embrocation, 
Liniment, Plaister, Spirit of. Aromatic Spirit of. Com- 
pound Spirit of. Foetid Spirit of, Succinated Spirit of. 
Lavender Water — Ammoniacum, Essence of — Ammoni- 
acum. Fomentation of — Ammoniacum, Mixture o' — Ana. 
tomical Preparations — Anatomical Injections — .Anchovies 
British — .^n<;hovy. Essence of — Anchovies, Transparent 
Essence of — Anchovy Powder— Anderson's Scotch Pills 
— Angelica Green, to <^.andy — Angelica. Spirit of — Ange- 
lica Cream — .Angel Water— Animal Charcoal — Anise — 
Anise Creme — .Anise Powder — Aniseed, Balsam of — Ani- 
seed Cordial — Anisette de Bordeaux — Annatto, English — 
Annatto Puritied — Annatto to Dye Wool with — Annatto 
to Dye SilK — Annatto to Dye Cotton — ."Vunatto to Color 
Cheese — Anodyne Medicines, Bolus, Drops, Enema, 
Essence, Fomentation, Julep, Mixture. Liniment, Poul- 
tice, Necklaces — Anodyne Ball for Horses — Anodyne 
Drench for Horses — Antacid Medicines, Draughts, Mix- 
lure. Powder — Anii- Asthmatic Powder — Anti-Attrition 
Paste — Anti-Bilious .Medicines — Anti-Emetic Medicines 
— Anticardium — Antimonial Powder — Antimony, Regulus 
of — Antimonial Wine — Anti-Scorbutic Medicines, Infu- 
sion, Mixture, Juices, Wine — Ami-Septic Medicines, 
Draught. Komentatron, Oargle, Mixture — Anti-Spasmodic 
Mediiines, Draught. Enema, Vlixture.s, Pills — Ants, to De- 
stroy — .\perienl Medicines, Draught. Powder, IMlls, He. — 
Apiary, to Establish — Apoplectic Balsam — Apoplexy. 



4. Apples, to Preserve — Apples, to Dry — Apple Bis- 
cuits — Apple Bread— Apple Cheese — Apple Jelly — .Apple 
Marmalade — Apple Paste — Apple Sugar — Apple-tree 
Canker, to Cure — Apple- water Ice, Apple Ice Cream— 
.Api>le Wine, White, Bed — Apricots, Green, to Preserve- 
Apricots, Ripe, to Preserve — Apricot Biscuit — Apricot Ice 
— Apricot Paste — Apricot Wine — Aquafortis, Single, 
Double, Strong, Spirit of Nitre, Dilute, Proof, Compound 
— .\qua Potens — .Aqua Kegia — Arabic Gum. to Clioose 
and Test — Archil or Orchil — Archil, to Dye Wool — Ar- 
chil, to Dye Silks — .^rgentum Musivum — Armenian Ce- 
ment, or Turkish Glue — Aromatic Medicines, Confection, 
Draught, Electuary, Fomentation, Mixture, Plaister, Pills, 
Powder, Tincture — Aromatic Spirit of Ether — .Aromatic 
Vinegar — Arquebusade Water — Arrack, .Mock, or Vaux- 
hall Nectar— Arrow Root, to Test — Arrow Root, British 
— .Arsenical Paste — Arsenical Soap — Asarabacca SnufT — 
Asiatic Dentifrice — .Asphaltic Mastic — Assafoeiida, Emul- 
sion of — .As3;>foetida .Mixture — Assafoetida Pills — \ssa- 
foBtida Plaister — Assafoeiida, Tincture of — Assayer's Acid 
— Assayer's Muriatic Acid — Assayer's Fluxes, Crude or 
White Flux, Black Flux. Cornish Reducing Flux. Cor- 
nish Kehning V\ux — .Asses' Milk, Artificial — Asthma — 
.Asthmatic Elixir — Astringent Medicines, Draught, Ene- 
ma, Fomentation. Gargle, Infusion, Lotion, Mixture, 
Ointment. Pills — .Astringent Cattle Medicines, BhIIs for 
Horses. Drench for Hor.ses, Enema or Clyster for Horses, 
Ointment for Horses. Powder for Horses — Ausburgh 
Beer — .Auld -Man's Milk — Aurum Musiyum — Auruin So- 
phisticum — .Austrian Wine — Azure Blue. 

5. Bacon, to Cure — Badigeon, to Make — Badolier's 
Vinegar — Bailey's Itch Ointment — Baldness, to Cure, 
Oil for. Pomatum for, Wash for — Baldwin's Phosphorus 
— Balloons from Tarkeys' Crop.s — Balloons, Varnishes 
for — Bailey's Digestive Draught — Balsamic Vinegar — 
Balm Water — Balm Wine — Balsamic Injection — Balsa- 
mic Powder — Banbury Cakes — Bandoline for the Hair — 
Barbadoes Cream— IJarbadoes Water— Barberry Cream 
— Barberries, to Preserve — Barberry Drojis — Jelly — Bar- 
clay's Antibilious Pills — Barege V\ ater — Bark Peruvian, 
Tm«ture of. Compound, Simple. Concentrated— Barker's 
Tooth Tincture — Barley Bannocks — Barley Sugar — 
Barley Su^ar Drops, or Kisses — Barley Water — Barn- 
stable .Ale, to Brew — Basil Wine and Vinegar — Basilicon 
Ointment — Basilicon Powder — Bass's Pale Ale, In<lia 
Ale. ice. — Bates's .Anodyne Balsam — Ba eman's Pectoral 
Drops— Uates'a Stiptic VVash— Bath Bricks— Bath Buns— 
Balh Cakes — Bath or Liquorice Pipe — Batteries. Solu- 
lulions for. Dmiell's Battery, Gro»'e's Battery, Leesons 
Battery, Smee's Battery, Sturgeon's Battery, Wheat- 
stones Battery — Battley's Green Senna Powder — Batt- 
ley's Liquor Opii Sedativus — Bavarian Ale — Baume's 
Spirit of Wine — Bays. Oil of — Bear's Grease — Beauty 
Water — Bedford Biscuits — Bee. Sting of, to Cure — Beech 
Black — Beer — Beer for the Table — Beer from Sugar or 
Treacle— Beer from Pea Shells — Beer, to Improve — 
Beer, to Prevent Acidity in — Beer, to render Intoxicating 
— Beer, when Foxed, lo Restore — Beer, when Frosted, 
to Restore— Beer to Restore when Sour, Flat, &c.— Beer 
Bottled to Ripen. 

6. Beer Poultice — Beet Root Sugar— BeJadonna, 
Tincture of— Bell .Metal— Belloste's Pills— Bell's Bougees 

— Bending Glass Tubes — Benjamin, Flowers of — Benzoin, 
Tincture of — Bergamot, Oil of — Bergamot Perfume — 
Bergamot Water — Berlin Green — Berlin Vinegar — Ber- 
ries, Wine from — Bestucheffs Nervous Tincture — Bice, 
Bidilery Ware — Bilberry Wine — Birch Oil — Birch Tree 
Sugar — Birch Wine — Bird Lime — Birds in Gardens, ic — 
Biscottes de Bruxelles — Biscuits, to make — Biscuit Drops 
— Biscuits of Fruit — Biscuits, Purgative — Bishop- Bistre 
Bitters, Medicinal — Bitters for Liqueurs, Ike. — Black-ash 
— Black Chalk — Black Composition — Black Drop — Black 
Dyes— Black Draught— Black Enamel— Black Flux- 
Blacking for Shoes, 6ic. — Blacking Cakes — Blacking Balls 
— Blacking the E.lges of Books and Paper — Black Japan 

— Black Lozenges — Black Reviver — Black Varnish for 
Metal— Blackberry Wine — Black Lead Pencils, artificial 
— Black LeadDr.^.wings, to Fix — Blad.lers, &c. to Prepare 
— Blaine's Powder — Blanched Copper — Blancmange — 
Bleaching Liquid — bleaching Liquid Extemporaneous — 
Bleeding; at the Nose— Blight on Rose Trees, to Destroy 
—Blistered Fuel. Cure for— Blister Liquid— Blister Plaster 
-^Blisters for Horses, 



CONTENTS OF THE NUMBERS OF THE 

DICTIONARY OF PRACTICAL RECEIPTS, 



Contents of No. 7. Blond Lace, to Blanch— Blood, 
Powdered — Biood Cement — Blood, Spitting of — lilue 
Ashes— Blue Black— Blue Dyes, for Cotton. Silk, Wood ; 
Hone, Ivory and Feathers — Blue Enamel — Blue Kve 
W.iter— Hlue Fire— Blue MottledWash Balls— Blue Oiiit- 
meni — Blue Paints, for House Paiming, Artists, Water 
Colors. Distemper — Blue, or Mercurial Pill — Blue Signal 
Lights, Bengal Lights — Blue Stone or Blue Vitriol —Pale 
Colored— Blue Verditer—BlueWriting Ink— Boerhaave's 
Astringent Powder — Boerhaave"s Red Pill — Bohemian 
Glass, Crown, Flint, Plate — Boiled and Baked Oil — Boils 
— Bologna 1 hosphorus — Bologna Sausages — Bologna 
Wash Balls — Bon Bons— Bone Black, Dye.s for Bed, 
Scarlet, Black, Purple. Yellow. Brown, Blue, Green — 
Bone Glue — Bone Grease — Books. Gilding the Edges — 
Books, Lettering the Backs — Books, to remove Stains 
from — Boot Powder — B^ot Varnish — Boots, Waterproof- 
ing — Boot Tops, to Clean — Borax, Gurgle — Borax, Glass 
of — Bordeaux, or Parisian Cakes — Bordeaux, Imitative — 
Bosse's Hard Varnish — Botany-bay Cement — BottleGlass 
— Bottling of Malt Liquors — Bolts in Horses — Bougie — 
Bougavil. White — Bouquet de laReire — Bouquet Water 
— Box-Wood for Engraving, to Choose, to Prepare, to 
Draw upon — Boyle's Depilatory — Boyle's Fuming Liquor 
— Bramble Biscuits — Bran Bread, to make — Brandy, 
British — Brandy from Beet Root, to make — Brandy from 
Potatoes, to make — Brandy, to give apparent Age to — 
Brandy, to give a Bead to — Brandy Balls — Brandy 
BUiers — Brandy Flavor — Brandy Shrub. 

No. 8. Brass — Brass Ornaments to Preserve — Brass 

"Work. Bronzing — Brass, Pa.stes for Cleaning — Brazil 
Snuff— Brazil Wood Lakes— Brazil Wood. Tincture of— 
Bread, to make, on Cobbett's Plan — Bread, to Prepare in 
the Method of the London Bakers — Bread Excllent. to 
make — Bread from American F'lour — Bread, to Detect 
Adulteration in — Bread without Yeast — Broad Seals — 
Breakfast Powder — Brea'li, to Sweeten — Bree's Anti- 
Asthmatic Plaister — Breeches Ball — Bremen Green — 
Brewing — Brewing t'tensils, to Preserve — Brick, Oil of 
^-Brick, Oil of. Fictitious — Brilliant Composition for 
Fire-Works— Britannia Metal, or Tutania— British Gum 
— British Oil — British Tooth Ponder — Broduin's Nervous 
Cordial — BrokenKnoes of Ilorse.s — Bronze, for Statuary, 
for Medals, for Cutting Instruments, for Mortars, foe 
Ornaments — Bronze of the Ancienis— Bronze Liquids — 
Bronze, to Darken — Bronze Powders — Bronze to, with 
Oil Color — Bronze, Printing in — Bronzing. Cleaning for — 
Brown Dyes, for Cotton, for Silk, for Wool, for Wood — 
Brown Enamel — Brown Paints, for House Painting. Ar- 
tist's Colors, Water Colors — Brown of Prussian Blue — 
Brown Pink— Brown Ointment — Browning for Cookery — 
Browning of Gun Barrels--Brucine Pills-- Bruises — Bruises 
of Horses — Brunswick Black Cheap — Brunswick Green 
— Buccaned Meat — Buckthorn, Syrup of — Bug Poisons — 
Bull's Eyes — Bunions. 

No. 9. Buns — Burgundy Pitch Plaister— Burns and 
Scalds — Burnt Sugar. Solution of — Burton Ale. to make 
a Hogshead of — Butter, to Clarify — Butter, to Improve — 
Butter, to Preserve — Bu ter preserved wiih Honey — 
Butler, to Pack — Butter Biscuits — Butterflies, to Take 
Impressions of — Buxton Water — Butter of Antimony — 
Cacao — Cajeput, Liniment of — Cajeput, Oil of— Cajeput. 
Opodeldoc — Cake — Calamine, Prepared — Calamine Ce- 
rate or Ointment, Simple, Compound — Callot's Soft 
Engraver's Varnish — Calomel, to Test if Pure— Calomel 
Pills — Calomel, Flowers of — Calomel Ointment — Calo- 
type Paper — Caluinbo Bitters— Calves to Bear, without 
the Cow — Camomile Drops — Camomile, Essence of — 
Campbell's Green Liniment — Cameos, &c. to Carve — 
Camphorated Chalk. Varnishes. Copal. Sandarac, Spirit, 
Vinegar, Wine, — Camphor Balls, Balls in Farriery, Cake, 
Liniments, Simple, Compound, Draught, Drink for Horses, 
Emulsion Ointment, Mixture — Camp Vinegar — Canals, 
Cement for — Candied Sugar — Candles, to Make — Can- 
tharides. Oil of. Tincture of— Canton's Phosphorus — Can- 
ker in Apple Trees, to Cure — Canvas Prepared fur Painters 
— Caouchoucine, how Prepared — Caouchoucine. to De- 
prive of Odour — Caoutchouc. Liquid — Caouichouc, sol- 
vents for — Caoutchouc, Varnish — Caoutchouc Balloons — 
Capeis, French, English — Capillaire — Capsicum Spirits 
of — Capsules for Medicine — Captain's Biscuits — ^aramel 
Sugar — Caratch Sauce — Carbonated Lime Water — Car- 
damon. Tincture of. Simple and Compound — Cardamon 
Water — Carmine, to Prepare, Adulteration in. Liquid, 
Blue, Purified, Lake from Madder. 



No. lO. Carminated Lake for Crayons— Carmina- 
tive Medicines Drinks for Cattle — Carraway Brandy, 
Cordial, Water, Comfits — Cascarilla, Tincture of. Water 
— Casks, Seasoning of when New, to Sweeten when 
Musty, Match for Sweetening — Cassel and Cologne Earths 
— Cassia. Electuary of. Conserve of— Cassis, Batifia de — 
Cassius, Purple Precipitate of- -Castile Soap, English 
Imitation of — Castor. Tinctures of, Oil Clyster, Oil 
Draught— Case Hardening— Catchup, Mushroom, for Sea 
Store — Caterpillars, to Prevent their Ravages— Calachu 
Ointment, Tincture of, Confecti<>n of. Lozenges, to Make 
—Cathartics. Pills— C:itheter — Catherine Wheels— Ca- 
tholicon Duplicatum Rheo. P.— Cauliflowers, to Pickle 
— Caustic Medicines, Common, Mild, Lunar, Liquid, 
Opiate ; for Canker in Horses — Cayenne Pepper, Reduced. 
Prepared, Essence of. Brandy, Wine, and Vinegar— Ce- 
drat Cordial, Essence of — Celery, Essence of — Cement — 
Cephalic Snuff, Plaister — Cerate, Simple — Ceru.^e Oint- 
ment — Chalk, Compound Powder of. Precipitated. Pre 
pared— Chalybeate Pills. Iron Powder. Water Artificial, 
Wine — Chamberlain's Restorative Pills — Chnmpagne, 
Imitation of — Charcoal, to Make. Crayons for Drawing, 
Poultice — Cheese Cakes. Cement— Chelsea Pensioner, 
Buns— Cheltenham Salts, Water. Imitative —Chemical 
Wash Balls — Cnemists' Bottles, Colors for. 

No. 11. Cherry Bounce or Brandy, English. Imita- 
tive, American, French, Water, Wine — Cheshire Cheese, 
to make: Salt, Basket, Common, Bay, Fishery — Chival- 
licr's Alcohol— Chevenix's Antimonial Powder— Chian 
Turpentine, Fictuiou.s — Chicken Pox — Chilblains. Lo- 
tions for. Ointments for — Chille Vinegar — China or Glass, 
Cement for — China Ink. Locksoy — Chinese Composition 
for Japan Work, Fires for Fireworks, Flyers, Paste, Pro- 
pagation of Fruit Trees, Sheet Lead, Yeilow, to make 

Chings Worm Lozenges— Chintz, to Wash— Chlorinated 
Soda — Chlorine Gas or Liquid — Chocolate — Chocolat a la 
Vanille — Chocolate Stomachic. Brandy, Drops, Cream, Ice 
— Chrome Red. Yellow — Cider, to make, from Raisins, to 
Improve, Champagne, Wine — Cinnamon Cakea, Comfits, 
Cordial, Lozenges, Soap. Syrup of. Water and Spirit — 
Circassian Cream, Citric Acid — Citron Cordial, Oil of. 
Peel, Candie«l — Citronella — Clairet, Rossalie de six 
Grains— Clarence B.scuits— Claret Rags, Imitative, to 
Darken, to Fine, to Manage, when Foul to Restore— 
Clarifying Powder. 

No. 12. Clary Wine — Clater's Drink for Sheep- 
Cleansing Poultice for Cattle— Cloth Clothes, to Scour 

Clothes, to Perfume, to Preserve, Ball, Powder— Clotted 
Cream — Clove Cordial, Pinks, Extract and Syrup of. 
Lozenges— Clover Sped, to Detect Doctored— Clutton's 
Febrifuge Spirit— Cluzell's Kerme.s— Coal Balls— Cobalt 
Blue — Cochineal, Syrup of. Wash Balls — Cochrane's 
Cough Medicine — Cockroaches, to Destroy— Coffee Bis- 
cuits. Milk. Ice, Ratafia, Substitutes for, Corsica, Cur- 
rant. Egyptian, American. Holly, Broom. Rice, German, 

French, Rosetta, Rye. Iris, Sassafra.s — Coindet's Pills 

Coins of Sulphur. Moulds for — to Make — Colchicum, 
Powder of. Tincture of. Vinegar — Cold or Catarrh — Cold 
Cement. Cream — Colepresse's Cider — Colic Ball for 
Horses — CoUett's Tooth Ache Drops — Colley's Depila- 
tory— Colocynth Clyster— Coloring for Liquors— Com- 
position Ornaments — Comfits — Concrete — Confectionary 
— Congreve Lucifers — Constant White — Contrayerva 
Pills. Powder— Copaiba Balsam, Mixture of. Salts of— 
Copal, Solvents for. Varnishes— Copper for Engraving, 
to Gild, to Tin, Medallions, Plates, Copper Plate Printing 
Inks— Copperas, Green, Green Vitriol Calcined, Water. 

No. 13. Copying Machine — Coral for Grottos, 
Powder, Syrup, Tooth Powder —Cordial Ma.ss Corian- 
der Cordial — Cornachin Pills — Corn to Preserve — Corne- 
lian — Cornish Fluxes, &c. — Corns — Corrosive Sublimate 
— Cosmetic— Costorphin Cream — Cotton Goods. Bleach- 
ing of— Cough, Medicine for. Lozenges,— Court Plaister 
— Cowslip Mead, Wine — Coventry Cakes — Crackers — 
Cracknels— Cramp in Bathing, in the Leg. in theS'omach 
—Cranberry Jelly— Crayons foi Drawing, Colors for. 
White, Carmine and Lake, Vermillion, Y'ellows, Blue, 
Browns, Greens, Black, I'aste for. Method of making, 
Marks, to Erase, Drawings, to Fix, for Drawing on Glass 
—Cream. Iced, of Tartar. Balls, of Roses. Substitute for 
— Crespit^ny's Pills— Crickets, to Poison— Crimson, to Dye 
Silk— Crocus, of Gold, of Iron, of Antimony— Cross Buns r.„t 

— Croton. Tincture of- Crows from a Field, to Ba.ii.sh ,„ 

—Crucibles, Composition of— Crumpets— Crystal Giass, 
Powder, of Tartar — Crystallized Microscopic Objects. 



CONTENTS OF THE NUMBERS OF THE 

DICTIONARY OF PRACTICAL RECEIPTS, 



Contents of No. 14-. Crystallized Windows — 
Crystals of Salts, Varnish — Cubebs. Tincture of — Cucum- 
bers, to Piokfe. Vinegar — Culley's Salve for Rot in Siieep 
— Cumin Plaister, Water — Cup Cakes — Curd for Cheese 
— Cheese Cakes, Soap — Curling Fluid — Cura9oa — Cui 
rant Clear Cakes, Jam, Jelly, Shrub, Wine — Curry 
Powder, Imitative, Wine, Lord Clive's Powder — Cutler's 
Cement — Custards — Cuts — Cypress Powder, Gross — 
Cyprus Wine, to Imitate — Cyrillo Pomatum — Daffy's 
Elixir — Daguerre's Photogenic Paper — Damask Powders 
— Dampness in Beds, to Detect — Damp Walls — Damsons 
to Bottle, Cheese, Wine — D'Arcey's Digestive Lozenges 
— Dead Fire for Fireworks — Deafness — De Brun's Eye- 
Water — Decanters, to Clean — De la Motfe's Golden 
Drops — Uelcroix's Povvdre Subtile — Delescotfs Myrtle 
Opiate — Demulcent Electuary — Dentifrice Electuary — 
Depilatories — Derbyshire Spar, Cement for — Detergent 
Medicines — Devil's Elixir — Devonshire Cider — Dextrine 

— Diachylon Plaister — Diagrydium — Diamonds, Paste 
for — Diaphoenix Electuary — Diaphoretic Antimony — 
Diarrhoea, to Check. 

No- 15. Diet Drinks — Digestive Lozenges, Medi- 
cines — Dinner Pills — Dippel's Oil of Hartshorn, Acid 
Elixir — Discharge, Colors to — Distemper in Dogs, among 
Cattle — Distillation of Simple Waters, to Preserve 
Flovvers, for— Diuretic Medicines, Balls for Horses, Salt 

— Dixon"s Antibilious Pills — Dolfuss' Acetous Acid — 
Dolichos, I^lectuary of — Donovan's Mercurial Ointment 

— Dorchester Ale — Doses, to Regulate — Dover's Powder 
— Dragon's Blood, Fictitious — Drowning Recovery from. 
Stripping, Removal of the Body, Warmth, Fresh Air, 
Inflation, Fomentations, Cordials, Bleedino — Drunken- 
ness, Recovery from — Drying Oils for the Painters — 
Du|)uytrens Eye Salve— Durietz's Anti-Hysteric Elixir 
— Dutch Cinnabar, Drops, Pinks, Terras — Dyer's Aqua 
fortis. Spirit — Dysentery — Ear- Ache — Earthenware, 
Enamel for — Ear- Wigs, Traps for — East India Pills, Tan- 
jore Pills — East India Pomatum — Eaton's Styptic Wash 
— Eau D'Arguebusade, de Bouquet, de Cologne, de Luce, 
d« Marechale, de JMelisse des Carmes, de Mille-Fieurs, 
Divine, Sanspareil — Eccles Cakes — Edinburgh Ale — 
Itch Ointment — Efl'ervescing Emulsion, Poultice — Eggs, 
Pickled, to Preserve, Flip — EgyiJtian Azure — Elder 
Brandy, Flower Wine, Ointment, Wine — Elecampagne. 
or Candy Cake. 

No. 16. Electrical Cement, Varnish — Elephant's 
Milk — Elixir of Vitriol — Embrocation, Common — Eme- 
ralds, Imitative — Emetics— Emollient Enema, Poultice 

— Enamel for Saucepans, &c. — Encaustic Painting, 
Medium for — Enema, Common — Engineer's Cement 

— English Verdigris — Enuraviugs, Cleaning of — En- 
graviuifs, to Transfer to Plaster — Epilepsy, Electuary 
tor — Ergot, Essential Solution of — Escharotics — Essen- 
tia Bina — Essex Ale to Brew — Etching Acids, for 
Biting in, for Copper, for Glass, for Marble and Stone — 
Etching Ground — Etching Ground, to Lay — Etching on 
Glass, a Varnish (or Covering preparatory to — Exihe- 
(piar Ink — Kxeter Oil— Extempore Smelling Salts — Eye 
Sah'c — Eye Snuff— Eye Waters — Face, to Take a Cast 
from — Fainting Fits, to Recover from— Fancy Biscuits, to 
make — Farcy Balls for Horses — Feathers for Bedding to 
Cleanse — Feathers for Ornamenis, to Prepare — Fenouil- 
lette— Fetid Pills for Hysterics— Fever Ball for Horses, 
Fever I'owder for Horses — Fermentaiiou, to Manage — 
Fermentation. Accelerators of^ — Fermentation, to Check 
or Stop — Fever— Field's Extract of Vermillion — Figures, 
of Varnishing — Filberts, to Preserve — Filters, to make. 

No. 17. Filtering Bag — Filtering Machine — Fin- 
cham's Purifying and Disinfecting Liquid — Finings, for 
Beer or Ale — Fire, to Escape from — Fire and Water- 
Proof Cement — Fue-Proof Paint — Fire Proof Stucco — 
Fish, to Preserve with Oil, Acid, Creosote, Sugar — Fish, 
to Preserve Alive — Fish Oil Paints — Fit Drups — Fixature 
for the Hair — Flake White — Flash — Flatulence, Remedy 
for — Flemish Glue — Flexible Paint — Flint Glass, Com- 
position of — Florentine Lake, to Prepare — Floors, Cement 
for — Florey B ack — Flour, to Dete<;t Adulterations in — 
Flour I'aste. to make — Flower of Ointments — Flowers, 
to Restore — Flowers, to Extract the Perfume of— Fluid 
Magnesia — Flute Key Valves — Fluxes — Flux, Remedy 
Jor— Fluxes for Enamels — Fly in Sheep — Fly on Turnips, 
}^o Destroy- Fly Water— Foils, to Make— Foils, to Silver 
f — Foils to Color — Foliage, Plaster Casts of — Fomentations 
— Ford's Laudanum — Foreign Wine- Fossil Woo>is for 
the Microscope — FothorgiU's Pills — Fox's Cream for the 
Hair— '.".-acturcd Limbs. 



NO- 18. Frankfort Black— Freckles and Sunburns 

-Freeman's Bathing Spirits — Freezing Mixtures for 
making Ice Artificially — French Cement — French Glue 
— French Oil for Furniture — French Polishing, &c. — 
French Pomaae — French Red, French Sealing Wax — 
Fresco, Colors for — Friar's Balsam, &c. — Frit — Fronti- 
niac. Imitative — Fruit Biscuits — Fruits, to Bottle — Fuel. 
Manufactured — Fuligokali — Fulminating Powder, to 
make — Fulton's Decorticated Pepper — Fumigating Pas- 
tiles — Foul Rooms to Fumigate — Furniture Polishes — 
Furs, to Preserve — Fuse for Military Shells — Fusees, to 
make — Fusible Alloys — Fusible Metal. Casts from — Gal- 

banum, Plaister of. kc. — Gall, to Purify for the Artist 

Gall Drops — Gall Opodeldoc — Gall Stone, an Artist's 
Color— Gall, Syrup of— Gallipot Varnish — Galls Oint- 
ment, &c. — Galvanized Iron — Gamboge Pills — Gargle, 
Commom — Garlic Balls for Horses — Garlic, Syrup of — 
Garlic Vinegar— Garnets, Artificial— Gascoigne's Powder 
— Gelatine — Gelatine from Bones — Gem Cutter's Paste — 
Gems, Red Sulphur — Gentian, Infusion of,iic. — German 
Blacking — German Paste — Gilder's Varnisu — Gilding. 

No. 19. Gilding Liquid or Pickle— Gilding Metal 
or Alloy— Gilding Wax — Gilead, Balm of. Factitious — 
Gin — Gin, Finings for — Ginger Beer in Bottles — Ginger- 
bread — Ginger Cakes — Ginger, Essence or Tincture of — 
i Ginger, to Candy — Ginger Candy — Ginger Lozenges — 
j Ginger Candy and Drops— Ginger to Preserve — Ginger 
, Powders — Ginger, Mock Preserved — Ginger Brandy or 
{ Cordial— Ginger, Syrup of — Giii;;er Wine — Glaire— 
Glass, Cutting and Breaking of — Glass, to Drill, for 
Thermometers — Glass and Porcelain, to Gild — Gla.ss, to 
Powder — Glass, to render Opaque — Glass Bottles to 
Clean — Glass, Staining of — Glass, Staiiiiiij^ Colors for, 
F^lesh, Black, Brown, Red, Rose Color, Bistre and Brown 
Red, Green, Yellow, Orange, Purple, Biue — Glass Cloth 
and Paper — Glass Grinder's Cement. 

No. 20. Glass Seals— Glauber's Tincture of Iron- 
Glaze for Pottery Ware ; for Porcelain, White Ware, 
Printed Ware, I'aintcd Ware, Raw Glazes, Ironstone 
Ware, Green Ware, Red Pottery Ware — Glaze for 
Cooking — Glazed Boards, to Clean — Glazier's Putty — 
Gloves, to Clean ; Kid Gloves, Doe or Buckskin Gloves 
— Gloves to Dye — Gloves, Perfumes for — Glues — Glue 
Cement — Glue Varnish — Godbold's Vegetable Balsam — 
Godfrey's Cordial — Godfrey's Smelling Salts — Gold 
Allocs — Gold Articles, to Cleanse — Gold, lo Color, Green, 
Red— Gold Cordial— Gold Beater's Skin— Gold Ink— 
Gold-colored Lacker — Gold Lace and Embroidery, to 
Clean — Gold, Liquid or Potable — (iold Powder — (iold 
Rain— Gold Sealing Wax — Gold Shells— Gold Size- 
Gold, Solder for — Gold Varnish for Leather — Goose- 
berries, lo Keep — Goosebirry Champagne — Gooseberry 
Cheese — Gooseberry Ice — (Jooseberry Jam — Gooseberry 
Jelly — Gooseberry Marasquin — Gooseberry Vinegar — 
Gooseberry Wine — Goulard's Extract of Lead— (iou- 
lard's Eye Water — Goulard's Liniment — Goulards Oint- 
ment — Goulard Poultice — Gouttems Aeres — Gout, Cor- 
dial, Lincius, Liniment — Grapes, to Preserve — Grape 
Wine — Gravel — Grease from Cloth, to Remove — Greaiie 
from Paper, to Remove. 

No. 21. Grease from Silks, to Extract — Grease of 
Horses Heels — Grecian Water — Green Balsam — Green 
Bice— Green Dyes — Green Dye for Black Cloth — Green 
Fly, lo Destroy — Green Ink — Green Oil — Green Oint- 
ment — Green Precipitate — Green Sealinij Wax — Green 
Tooth Powder — Green Liniment — Greenough's Tincture 
for the Teeth — Greeu Paints — Gregory's Powder — Gren s 
Benzoic Acid — Grenoble Ratafie — Grey Lotion — Grey 
Dyes — Grey Colored Fire — Grithn's Tinciure — Grind- 
stones, Artificial — (irindle's Cough Drops — Gripes in 
Horses, Remedies for — Grosvcnor's Tooth Powder — 
Guaiacum. Infusion of — Guaiacum Mixture — Guaiacum 
Tincture of — Guestonian Embrocation— Guido's Balsam 
Gum Anglicum — Gum Arabic, Mucilage of, Emulsion — 
Gum Julep, Lozenges and Pastiles, Paste for Comfits, 
Plaister, Seals — Gumption for Artists — Gun Powder, to 
make. Barrels, Browning of, Cotton, iletal — Gut, for 
Anglers— Guthrie's Black Ointment — Guthrie's Eye Oint- 
ment — Guy's Powder of Ethiopia — Guyot's Spirit — Hah- 
iieman's Wine Test — Halford's Sir H. Nervous Tincture 
Hair for Wigs, to Prepare— Hair. Superfluous, to Remove 
— Hair, to Sort and Clean.se — Hair to UleaL-h— Hair to Dye 
— ilair Powder, for Lime, Rice, Flour, &c. — Hair Powder 
Perfume — Ilamliurgh Pickle — Hams, to Cure — Ilame- 
lin's Cement, to Make— TIniid GrtMiado — ll.tnman's Hair 
Dye— Hard C ' . ;■ ' n> -•• \ V 



CONTENTS OF THE NUMBERS OF THE 

DICTIONARY OF PRACTICAL RECEIPTS, 



Contents of No. 22. Harness Maker's Jet an 1 
Paste — Hartshorn, Burnt, Drink, Shavings, Jelly, and 
Spirit (>f — Hatfield's Gout Tincture — Hats. Stiffening and 
D>e f(>r — Hay Stacks — Headache — Heading for Beer — 
Healing Poultice for Cattle — Heartburn Lozennes, &c — 
Hellebore, Extract, Infusion, Ointment, and Tincture of — 
Helmont's Elixir of Proiiriety — Heinet's Dcntrifice — 
Hemlock, Extract, Infusion, Ointment, Pills, and Tinc- 
ture of — Heni)ane, Extract, Ointment, and Tincture of — 
Henry's Ammonia Water, Aromatic Vinegar. INIajjuesia, 
Potass Water, and Soda Water — Herpes — Hiccough — 
Herrenschaund's AVorm Specific — Hides, to Tan — Hiera 
Picra — Higgins's Cement — HilTs Oil of Vitriol — Hippo- 
eras — Hoarseness — HolTman's Pills — Hollands Gin — 
Holy Thistle, Infusion of — Homberg's P^rophorus — 
Honey, to Choose, Clarify, Cerate, Water, and Balsam of 
— Hooper's Pills — Hooping Cough — Hops, Extract. Infu- 
sion, and Tincture of — Hfrehound, to Candy, Infusion, 
and SyruD^of — Horn, to Dye and Stain — Horse-hair, to 
Curl and Dye — Horse-radish, Gargle, Infusion, Powder, 
Vinegar, Spice, and Spirit of, &c. 

No. i23- Hot Cement — House Painting, Colors for — 
Hiiiles Antiques, L'Orange, L'llose La Tuberose, De 
Venus, and Liquereuses — Hungarian Liniment— Hungary 
Water — Huxharn's Bjrk Tincture — Hyposulpliue of S'>da 
— Hysterics — Ices, Ice Cream, and Iceing for Cakes — 
Iceland Moss Jelly — Illumination Fire — Impenetrable 
Mortar — Imperial Drinks and Liquids for the Hair — 
In.tantations, Theatrical — Indestiuctible Ink — Indian 
Cement and Corn Foods — Indian Hemp, Tincture and 
Extract of, and Lozenges — Indian Ink, to Choose and 
Imitate — Indian-rubber Blacking Tubes, Oil, &c. — 
Indigestion — Indigo, to Prepare and Obtain, Blue and 
Sulphate of— Infant's Preservative — Inflammation. 

No. 24. Influenza — Infusions — Injections, Metallic 
— Ink, Black — Intoxication, Insensibility and Apparent 
Death from — Insecls. Bites and Stings of — Iodine, Solu- 
tion of — Iodine and loduretted Medicines— Ipecacuanha 
Linctus. Lozenges, Pills, Powder, Tincture, and Extract 
of— Irisn Moss Jelly — Iron Cement, Gilding, Liquor, 
and Sand — Iron, Medicines of — Iron to Tin, and preserve 
from Rust — Iron-Work Blace — Iron Plates, Tinning of — 
Isinglass Cement, iic. &c. 

No. 25. Isinglass Glue, Jelly, and Mucilage — Issue 
Peas and l-'laisters — Italian Bre.id, Cream, and Varnish — 
Itch — Ivory Black, to make — Ivory, to Bleach. Dye, 
Etch, Smooth. &c.— Ivory Jelly— Jackson's Itch Oint- 
ment — Jalap, Draught, Elixir, and Powder of — Jamaica 
Pepper Water — James's Analeptic Pills and Powder — 
Jams of Fruit, to keep from Moucd — Janin's Eye Oint- 
ment — Japan for Leather and Tin-ware — Japan Gold 
Size and Ink — Japanese Cement — Japaniier's Copal Var- 
nish—Jasmine, Essence and Oil of. Hair Powder, Po- 
matum, and Water— Jaundice in Cattle and Horses — 
Jaunemange — Javelle, Eau de — Jellies— Jesuit's Drops — 
Jets of Fire — Jeweller's Rouge — Jordan's Balm of Ra- 
kasiri — Josse's Purified Opium — Julin's Aquafortis — 
Juniper Berries, Decoction, Infusion, Extract, Oil, and 
Spirit of — Jujube Paste — Kali Praeparatum — Keene's 
Marble Cemeni — Kemp's White. 

No. 26. Kennedy's Corn Plaister— Kennett Ale— 
Kermes Lozenges and Minerals — Kersey's Pills — Kid 
Glove Cleaner — Kidder's Sweet Sauce andSavoury Spice 
— King's Cordial and Yellow — Kino Imitative and Powder 
— Kirkland's Neutral Cerate — Kirschwas.ser — Kitchen 
Pepper— Kitchiner's Essence of Herbs, Pills, Eelish and 
Superlative Sauce — Knox's Disinlecting Powder — Kcech- 
lin's Liquid — Koumiss — Knuckel's Phosphorus — Kuseque 
Powder Kuslitien's Metal for Tinning — Labdanum Spu- 
rious — Labels of Botues, to preserve — Lac to Bleach, Lake, 
Spirit, and Tincture of — Lac-water Varnish — Lixquer 
for Brass, for Tin, and for Philosophical Instruments — 
Lacquering, to prepare Brass for, of Old Work, and Pro- 
cess of — Lactate of Iron Lozenges— Lactic xluid Lozenges 
— Lady Kent's Powder — Laenneo's Sedative Drauuht, 
and Remedy for Tooth-Ache— La Fayette's Cakes— Lake 
Colors — Lamp Black— Langelolte's Prepared Opium — 
Lapis Divinus, and Medicamentosus — Lard— Lurdner's 
Prepared Charcoal— Lasteyrie's Lithography Ink— Lau 
danum, and of Quinces — Laughing Nuts — Laurel Oint- 
ment — Lavender Drops, Vinegar, Oil of. Water, and 
Ammoniacal — Laxative Medicines, Balls for Cattle — 
Drenches for Cattle— Lead as a Poison, in Wines— Dust 
and Grains Lotion of, Plaister, and Lead Tree — Leake's 
Pills— Leather, Dyeing of. 



No, 27. Leather, to Clean, &c. — Leaves, Casting, &c. 
— Le Blonds Varnish for Prints — Le Bosse's Hard Var- 
nish— Le Dray's Marmorelum — Leeches, Application of 

— Lemeris Solvent for Antimony — Lemonade, &c. — 
Lemons to Preserve with Sugar, Biscuits, Brandy, 
Cakes. Cheese Curd, Concrete Oil of. Cream and Jelly, &c. 
Le Mori's Ointment — Lenitive Electuary — Lenses, Cement 
for — letters, to Disinfect — Lettuce, Extract of — Levure 

— Light Balls — Lightning, to Escape from — Lignum*« 
Antiscorbutic Drops — Lilac, to Dye Silk — Lime, Chlo- 
ride of — Lime Cylinders, for Oxy-llydrogen Microscopes 

— Lime Liniment — Lime Sulphurtt of — Lime Water 
— Linctus, or Lohoch — Linen, to Bleach — Liniment • 
Linseed Oil, Purifying of. Poultice, and Tea — 1 Jn 
Salve — Liqueur de Pressavin — Liquid I'oil for Glass 
Globes, Glue, Pounce, &c. &c. . 

No. 28. Liquid Soap, Eouge, and True Blue — 
Liquoililla — Liquor Ammoniaj, and Potassas- Liquorice 
I.,ozenges, Extract of. Juice, ani to llefine — Lisbon Diet 
Drink, and Wine — Litharge, and Plaister — Lithographic 
Chalk. Ink. Transfer Ink, Transfer Paper — Litmus, and 
Paper — Liver of Sulphur, and of .\ntimony — Locatelli's 
Balsam — Lockyer's Pills — Logwood, Kxtract of — Lohoch 

— London's Patent Solid Salt — London Ale — Lord Mayor's 
Cake — Lotion — Lovage Cordial — Lowitz's Acetic Acid — 
Lozenges — Lucifer Matches— Ludolph's IMagistery of 
Opium — Lugol's Solution of Iodine — Lumbago — Lunar 
Caustic — Lundy foot's Sniifl" — Luting for B..ltles— Lutes 
for joining Apparatus — Lymingion Salt — Lynch's Embro- 
cation — Macaroons — Macaron, Creme de — Macaroni — 
Mace Ointment — Macquer's Acid Soap, Arsenical Salt — 
Madden's Vegetable Essence — Madder Lake, and Red to 
Dye — Madeira, British — Madeira, to tine — Maggots in 
Sheep — Magnes Arsenicalis — Magnesian Drink — Mag- 
nesia Lozenges, Mixture of, Water — Magnets, Artificial. 

No. 29. Magnets, to preserve — Mahogany-colored 
Cement, Imitation of. Stains, Varnish — Mahomed's 
Electuary — .Mallan's Succedaneum— Malmsley, British — 
!Malt. Extract of. Patent, Poultice, to Make, Vinegar, 
to determine the Qualities of — Maltha, or Greek Mastich 
— Mange, Remedies for — Manheim Gold — Manna Linctus 
and Lozenges — Maple, to Imitate — Maraschino de Lara, 
French — Marble. Imitative, to Stain, to Clean — Marbled 
Soap Balls— Marbling the Edges of 13ooks, the Covers of 
Books — Marechaie,Eau de — Marechal Hair Powder, and 
Pomatum — Marine Glue and Soap — Marking Ink for 
Linen — Marking Linen, New mode of — Marlborough 
Cakes — Marmalade— Marriott's Dry Vomit — Marsden's 
Anti-Scorbutic Drops— Marseilles Vinegar — Marshall's 
Mixed Oils, and Cerate — Marsh- Mallows, Decoction of. 
Fomentation, Lozenges, Paste, and Syrup of — Martin's 
Varnish — Massicot — Mastic (iallipot Varnish, Mortar — 
Mastic Varnish Compound and Camphorated — Mastica- 
tories — Mathieu's Vermifuge — Matthews' Injection for 
Piles — Matthews' Pills — M auger s Varnish — Mead. 

No. 30. Mead Wine — Measles, &c. — Mecca, Balm 
of — Mechi's Razor Paste — Medallions, &€ — Megilph — 
Melons, to preserve — Mercurial Balls for Horses, &c. — 
Mercury, Honey of, to Purify — Merangues — Metallic 
Paper — Metals, Cement for — Meteoric Iron — Metheglin — 
Mezereon Ointment — Microscope — Microscopic Objects — 
Mildew in Wheat, &c. — Military Fever — Milk. &c — 
Mille Fleurs, Eau de. Ices — Mince Cake, &c. — Minde- 
rerus, Spirit of — Mineral Chameleon, Marmorelum, &c. 

No. 31. Minium and Mineral Orange — Mint, Infusion 
of. Mint Water— .Mixed Fruit Wine— Mixed Oils— Mock 
Gold — Modelling Wax— Moire Metallique — Mole, to Dis- 
perse — Monicon, or Damonicon — Montpellier Yellow — 
Mordants for Dyeing — Morella Cherry Syrup, and Wine 
— r>lorocco Leather — .Morphia, Syrup of — Morison's Pills 
— Mortar, to Make — Morveau's Preservative Phial, W.hile 
— Mosaic Gold — Mottes (de la) Golden Drops — Moulds. 
Elastic, &c. — Mountain Wine — Mouih or Indian Glue. 
Modelling Wax for — Muffins — Mulberry Syrup, and Wine 
— Multum — Mum— Mummy Brown — Mumps — Munro's 
Cough Medicine — Muriatic Acid Gargle — MuscadelWine 
— Mushroom Ketchup, &c. — Musk, Artificial, &.c. — Mus- 
tard Electuary of, &c. — Mynsicht's Elixir of Vitriol — 
Myrrh, Gargle of. &c. — Myrtle Water — Nankeen Dye — 
Naplie, Kau de — Naples Biscuit and Yellow — Najjoleon's 
Pills — To Preserve Objects of Natural History — Narcotics 
— Nectar — Neroli, Essence of. Wash Balls— Nervine Oint- 
ment—Nervous Cordial— Nettles, Sting of— Neutral Tint 
— Newman's Opium — Newmarket Oil — Night-Mare — 
Nine Oils — Nipples, Chapped, to Heal. 



CONTENTS OF THE NUMBERS OF THE 

DICTIONAIIY OF PRACTICAL RECEIPTS, 



Contents of No. 32. Nitre. Gargle of— Nitre 
Linclus of--Xitre LK>zenges— Nivernoise Sauce— Non- 
pareil Saiice->"Norfolk Leather Preserver — Norris's Drops 
—Norwich Biscuits— Nosegay. Essence of— Nottingham 
Ale— NoiitHeur's Cure for Wi.rms— Novargent— Noyeau 
— Noyeau Crenie de — >'uirs Sauce — Nutmeg Corili il — 
NutBieg. Kssence of— Nutmeg. Spirit of— Nutmeg, Syrup 
of- NuxVomica, Extract .if— Nux Vomica Liniment of— 
Nux Vomica. Tincture of— Oak Bark. Garble of— Oak. 
Graining of— Oak Varnish— Ochres— Odontalgic— Odon- 
talgic Drops— Odontalgic Tincture— Oil ColorCakes- Oil, 
t(. take from Boards— Oil Varnish— Olibanum. Compound 
.Mixture of— OiibaTiuin. Electuary of— Oliver Biscuits- 
Onion's Fusible Metal— Onions to Pickle— Ophthalmia 

— Ophthalmic Ointment — Opiate. .Anti-Tubercular — 
Opiate Confection- Opiate en Puudre— Opiate Mixture- 
Opiate, or Thebaic Pills- Opium Cerate— Opium Ex- 
tract of — Oj>ium LoAenges— Opium Ointment — Oi)ium 
Pills — Opium Plai^ter — Opium, Syrup of — Opium, Tinc- 
ture of— Opium, Vineuar of — Opodeldoc— Optician's 
Cement— Orangeade — Orant-e Brandy— Orange Cordial 
—Orange Cream— Orange Cr.-me d' — Orange Flower 
Powder -Orange Flower Kalafia— Orange Flower Soap — 
Orange Flower Water— Orange Juice. Syrup of— Orange 
Lake— Orange Marmalade— Orange Peel. Infusion of— 
Orange Peel Ratafia— Orange Peel. Syrup of— Orange 
Peel, to Candy— Orange Peel Water — Orange Pomatum 
—Orange PulTs— Orange Tarts— Orange Wine— Orfila"s 
Ilair Dye— Orgeat Paste— Orpiment—Ofria Loxenges— 
Orris Perfume— Ottar of Eoses— Oxalic Acid, to Detect 
— Oxycroceum, &c. &c. 

. No. 33. Oxley's Tincture for Tooth-ache— Oxyge- 
nized Lard— Oxymel— Oyster Ketchup — Oyster-Shell 
Powder — Paint. Flexible — I'aint. to Remove theSmell of 
— Painter's Cream — Panada — Paper Bleaching — Paper 
Glazing of— Paper Paste— Paper Powder, or Pollen 
Powder — Paper, Staining of. Yellow, Crimson, Green, 
Orange, Purple — Papier de Surete — Papier Mach»§e — 
Paracelsus's Plaister— Parchment— Parchment Glue— 
Paregoric Elixir — Pareira Infusion of— Parfait Amour— 
Paris's Test for Wine.&c— Parisian Dentrifice — Parisian 
Soft Varnish— Parkers Cement— Parliament Cakes— 
Parmentier's Salad Vinegar— Parmesan, to imitate — 
Parolic, or Universal Cement — Parsnip Wine — Passover 
Cakes — Paste for Book- Binders, 4ic.—Pastiles— Pat- 
chouli. Essence of— Patent Cement— Patent Ink— Patent 
Mustard — Patent Yellow — t'auline Confection — Pavilion 
Cakes — Payen's Alcohol — Peaih Blossoms. Syrup of— 
Pearl Powder— Pearl Soft So«»p— Pearl Water— Pearls, 
Discolored, to Whiten— Pears, to Dry— Pears to Pre- 
serve— Poclorals-Pencil Drawings, to Preserve— Penny- 
royal, Essenceof — Pennyroyal Water — Pepper. Electuary 
of — Pepper Salve — Pepper, Tincture of — Perpermint 
Cordial — Peppermint Drops — Peppermint. Essence of — 
Peppermint Lozenges — Peppermint, Oil of — Peppermint. 
Spirit of — Peppermint Water — Percussion Caps, Priming 
for — Perfume for Scent Boxes — Permanent White — Per- 
petual Ink — Perry — Persian Cream — Peruvian Balsam, 
Emulsion of — Peter's Pills— Pew's Cement — Pewter. 

No. 34.. Phial Glass— Phosphoric Alcohol— Phos- 
phoric Ether — Phosphoric Oil — Phosphoric Writing — 
Phosphorus Bottles — Phosphuret of Sulphur — Photogra- 
phic Paper — Daguerre's Ueceipt — Golding Bird's Receipt 
—Photogenic Drawings, to make — Photogenic. Drawings, 
to fix — Piccalilli, or Indian Pickle — Picromel — Picture 
Frames, Gilding of — Pictures, to Clean — Picture Varnish 

— Pierre Divine — Piles, or Hoemorroids, (Three Receipts) 
— Pimento, Spirit or 1 incture of — Pinchbeck — Pine- 
apple Ice, (Four Receipts) — Pink Saucers. Pink Dye — 
Pinks. Syrup of — Pin Wheels— Pistachio Cream — Pitch 
Ointment, (Two Receipts)— Pit Coal Black— Pith Balls, 
for Electrical Uses — Plague Water — Plaster of Paris, to 
Cast in. (Two Receipts)— Plaster Casts. Polishing of, 
(Three Receipts) — Plaster Figures, Bronzing of — Plate 
Glass, Composition of (Two Receipts)— Plate Powder, 
(Three Receipts) — Plated Articles, to Clean — Platinize, 
Metal Goods to — Platinum Moir. or Spongy Platinum — 
Platinum Ointment — Pliable Varnish for Umbrellas — 
Plombiere Ice, or Swiss Puddings — Plunket's Ointment 
for Cancer — I'lunkefs Ointment — Plums, to Preserve — 
Plummer's Cement — Plummer's Pills — Plummer's Pow- 
der — Pollard Oak — Polychrestum, Elixir of — Pomambra, 
or Sweet Balls, (Two Receipts) — Pomatum, (Four Re- 
ceipts) — Pomatum, Scents for. (Six Receipts) — Pongibou 
Snuff- Pontefract Lozenges — PontifTs Sauce— Poplar 
Buds Ointment— Poppy Lozenges— Poppy Oil, to Dry, 8tc. 



No. 35. Poppies. Syrup of — Poppies, Tincture of — 
Porcelain, or China — Porcelain. Enamels for — Porcelain, 
Colors for — Port Wine, Imitative — Port Wine, to Fine — 
Port Wine, to Improve — Portable Glue — Portable Soup 
— Porter, to Brew. (Three Receipts)— Port Fires — Port- 
land Powder, for Gout — Poriu»>al Water — Portugal Cake- 
Potatoes, to Preserve— Potatoes, I'rosted, to lise — Po- 
tatoe Bread — Potatoe Jelly — Potatoe Paste — Pot Pourri — 
Pots des Brins — Pounce, (Three H^-ceiptrt) — Pound Cake, 
(Four Receipts)— Powell sDinreiic Drops— Powell's Bal- 
sam— Pradier's Poultice f.ir ihe Gout — Precipitate Oint- 
ment, White Red. — Presburg Z veiback. or Biscuits — 
Pricked British Wine*, to Restore — Prince Rupert's 
Drop.s — Princes Cordial — Printers" Ink. (Fi ur ReceipU<) 
— Printing Inks, Colors for. Red, Blue. Green. Brown, 
Lilac. Lilac Pink. Oranije and Black — Printers" Rollers 
— Printers' Types— Prints, to Bleach — Prints, to Copy. 
(Five Receipts) — Prints, to Transfer to Wooil — Prints, 
to Size before coloring — Prints. Varnishes for Colored, 
(Three Receipts) — Primrose Vinegar — P^metheau 
Light Boxes. &c. &c. 

No. 36. Propiiety, Elixir of — Prunella. Salt of— 
Prussian Blue, (ThreeReceipts)— Prussian Cakes— Prus- 
sian Green, (Two Receipts) — Prussic .Acid Lotion, 
(Three Receipts) Prussic .\cid Mixture — Punch, (Four 
Receipts) — Punch a la Romaine — Pun<h-waler Ice — 
Purging Medicines, (Six Receipts) — Purging Mixture — 
Purging balls for Horses, (Two Receipts) — Purl, ('l'v\o 
Receipis) — Purple Knamel — Purple Fire, (Four Re. cipt-.) 
— Purple Precipitate of Cassius —Purple Tableltes — 
Putty for Glaziers, Flexible — Pirola, Infusion of— Pyro- 
ligneous Acid, or Wood Vinegar — Pyro|>hori, (Two Re- 
ceipts) — Quass — Quassia, Extract of— Quassia, Infusion 
of — Queen Cake — Queen's Cordial — Queen^ Metal — 
Queen's Y'ellow — Quick Match — Quicksilver Ointment. 
(Two Receipts) — Quills, Preparation of. (Four Receipts. 
Dutch Method, French Method. English Method. Aus- 
trian Method) — Qumce Marmalade — Qumce Wine — 
Quinine. Medicines, viz. Cerate, Essence, Lozenges. Oint- 
ment, Wine, and Syrup — Quin's Sauce, (Two Receipis) 
— Ragout Spice — Raisin Vinegar— Raisin Wine — Rasp- 
berries, to Preserve whole — Raspberry Cordial or Brandy 
— Raspberry Cream — Raspberry Drops — Raspl)erry lee 
— Raspberry Jam — Raspberry Jelly — Raspberry Paste 
— Raspberry Rock — Raspberry Syrui) — Raspberry Vine- 
gar Syrup- (Two Receipts) — Raspberry Wine. (Two 
Receipts; — Ratafia, Red. Dry Sharp, and Common — 
Ratafia Cakes — Ratafia, Essence of, Aic. &c. 

No. 37. Ratcliffe's Cough Mixture— Razor Paste 
— Red Chalk Crayons — Red Crockery, Glaze for, Dyei. 
Enamel, Red Ink, Lead, and Stains for Gla.ss— Reece s 
Remedy lor Flatulence — Refrigerant .Medicines — Regency 
Buns — Rembrant's Etching Varnish — Rennet Whey — 
Resin Cerate, (Yellow Basilicon) — Resin Buiibles, Rey- 
nolds's Specific for Gout. flic. — Rhatany, Extract of — 
Rhatany Root, Tincture of — Rheumatism — Rhodium, 
Oil of— Rhubarb, to distinguish good from bad — Rhubarb, 
Extract of — Rhubarb. Infusion of — Rhubarb. Mixture — 
Rhubarb Pills — Rhubarb Powder— Rhubarb, Tincture 
of, and Rhubarb Wine — Rice Biscuits — Rice Cakes — 
Rice Glue— Rich Plum Cake— Rich Seed Cake— Riga 
Balsam — Ring Gold — Ringwood Ale — Ringworm — Ro- 
chelle Salt — Roche's Embrocation for Hooping Cough — 
Rockets, Compositions for Filling, Rains for. Stars. Sticks, 
length of — Rock-work and Reservoirs, Cement for — 
Roman Candles, Roman Cement, &c. &c. 

No. 38. RoseatePowder— Rose Cerate-Lip Salve 
— Rose Hair Powder — Rose Lozenges — Rose Oil for the 
Hair — Rose Drops — Rose Pearls — Ro.se Pink — Rose Soap 
Rose Water, and Rose Wine — Rose's Glaze for Earthen- 
ware — Roses, Conserve of, Essence of. Honey of. Infusion 
of, 8c Linctus of — Rosemary. Oil of. Essence of. and Water 
— Rosewood, to Imitate— Rouge — Rout Cakes. Biscuits — 
Rousseau's Drops — Rowland's Kalydor. Macassar Oil — 
Royal Essence — Ruby, to Imitate — Rudius's Pills — Rue, 
Confection of. Ointment — Rufus's Pills— Rum Shrub — 
Rusks — Ruspini's Tooth-powder, Tincture for the I'eeth 
— Rymer's Cardiac Tincture — Sack Wine. Imitation of — 
Sitffron, Tincture of — Sage Wine — Sailor's Flip — Salberg 
Wash — Saline Draught — Saloop — Samphire to Pickle — 
Sandarac Varnish — Sap Green, Preparation of — Saraapa- 
rilla. Decoction of — Satins and Sarsenets, White, to Clean 
— Savoy Cake.s — Saxon Blue — Scald Head Ointment — 
Scarborough Water Cake.s — Scamniony, Electuary of — 
Scarlet to Dye Cloth — Scarlet Fever — Scent Powder — 
Scheele's Green — Scheele's Prussic .\cid — Scotch Ale. &c. 



CONTENTS OF THE NUMBERS OF THE 

DICTIONARY OF PRACTICAL RECEIPTS 



No. 39. Sootfh Buns, Cream, Marmalade, Salt, 
Seed Cakes, Short Bread — Scott's Pills — Scouring Drops 
— Scrofula — Scrophularia Ointment — Scudaniore's Gout 
Lotion — Sculptors" Vlodels. Composition foir — Scurvy- 
grass, Conserve of, Spirit of — Seal Engravers' Cement — 
Sealing Wax— Seals, to take Wax Impressions from — 
Sea Sickness — Sedatives — Sedative Mixture— Seed Bis- 
cuits — Seeds, Packing Garden — Seidlitz Powders, Water 
— Selt/.er Water — Selvvay's Essence of Senna — Semolina 
— Senega, Infusion of — Senna, Electuary of — Senna, Infu- 
sion of. Simple, Compound, and Tartarized — Senna Mix- 
ture, (Black Draught) — Senna Powder, (Batley's Green) 
— Senna, Tincture of, Compound — Sepia — Serpentary, 
Infusion of — Serpentary, Tincture of — Shaving Oil — 
Shaving Paste — Sheep-skin Rugs — Sheldrake's Oil — 
Shells, Mending and Cleaning of — Sherbet — Sherry to 
to Fine a Butt of— Sherry, to Improve — Ship Biscuits -- 
Shoemakers' Black— Short Bread — Shot Metal— Shrews- 
bury Cakes — Shrub — Silk. Bleaching of— Silk, to Clean 
—Silk, to take Stains from — Silkworm Gut— Sillabub — 
Silver Coin of Britain — Silver Frosted or Matt — Silver 
Tree, to prepare — Silvering Copper Ingots — Silvering 
Powder — Simple Cerate — Simple Ointment — Singleton's 
Golden Ointment— Size, (Soft Glue) — Size for Artists — 
Skeletons, preparation of — Sloes, Conserve of — Slov? 
Match — Small-pox, inc. &c. 

No. AO. Sniellnme's Eye Ointment — Smith's Solder 
for Tin — Smoke, Essence of— Smut in Wheat, to prevent 
— Soap Cerate, Enema or Injection. Essence of, Linctus. 
Liniment, Liquid — Soda Cakes, Lozenges, Powders, Water 
in Bottles — Soft Toilet Soaps — Solders, viz. Common or 
Tinman's. Soft, for Steel Joints, Silver for Jewellers, 
Silver for Plating, Gold. Plumber's, Glazier's, Pewterer's, 
Hard. Fine, Fusible — Brass Solder for Iron, Copper- 
smiths, &c. — Solomon's Balm of Gilead — Sore Throat 
(Sev«>n Keceipts, Common, Putrid. Inflammatory. Ulce- 
rated. Gargle, &c.) — Soy, English — Spearmint, Essence 
of — Specula Metal — Speediman's Pills — Spermaceti, to 
Refine— Spermaceti Cerate or Ointment, (Two Receipts) 
Spermaceti Linctus — Spielmann's Eye Ointment— Spike, 
Oil of. Imitative — Spilsbury's Anti-Scorbutic Drops — 
Spirit Varnish — Spirituous Lotion — Spitting of Blood, to 
Prevent — Sponge, Bleaching of — Sponge Biscuits — Sponge 
Cake — Sponge Lozenges — Sportsman's Cordial — Sprains 
— Sprats, Essence of — Spruce Beer — Spruce Beer 
Powders — Spruce, Essence of — Squibs or Serpents — 
Squill Mixture — Squill Pills — Squills, Conserve of - 
Squills. Honey of — Squills. Linctus of — Squills, Oxymel 
I of — Squills. Syrup of — Squills, Tincture of — Squills, 
I Vinegar of — Squires Elixir — Standard Measures. -Vlloy 
for — Starch, Sugar from — Starch Lozenges — Siarch 
Manufacture of — Starkey's Pills — Starkey's Soap — 
Stavesacre Oin'ment — Steel Lozenges — Steel and Plati- 
num, Alloy for — Steel to Color Blue— Steel, to distinguish 
from Iron— Steel, to Gild — Steel Goods, to preserve from 
Rusl, &c. &c. 

No. 4-1 . Steel Mixture, (Three Receipts)- Steeis's 
Opodeldoc — Steinacher's Nitric Acid — Stephens's 
Remedy for the Stone — Stereotype Plates. Alloy for — 
Sterrys Plaister — Stimulant Enema — Stimulant Lini- 
ment — Stimulant Mixture — Stimulant Pla'.ster — Stoerck's 
Pills — Stomachic Draught — S'oiiiacliic Electuary — Sto- 
machic Elixir — Stomachic Tincture — Stomachic Wine — 
Stopping-out Varnish — Storax Pills — Storey's Worm 
Cakes — Storm Glass for foretelling the Weather — 
Stoughton's Elixir — Strains, Embrocation for — Stramo- 
nium Lincture of — Stramonium Ointment — Stranguary. 
Treatment of — Strawberry Jam — Strawberry Wine — 
Straw Bleaching — Stiuve's Lotion for Hooping Cough — 
Strychnine Mixture — Strychnine Pills — Strychnine Spirit 
of — Styptics — Styes in the Eye-lids. Treatment of — St. 
Yve's Eye Ointment — Succedaneum. Mineral — Sugar 
to Boil and Clarify — Sugar Candy — Sugar Rock — Sugar 
Vinegar — Sulphate of Zinc Ointment — Sulphur, Balsam 
of— Sulphur Bleaching by — Sulphur Coins, to make — 
Sulphur, Electuary oi. Simple, and Compound — Sulphur 
Lozenges — Sulphur. Milk of — Sulphur Moulds for Medal- 
lions, &c. — Sulphur Ointment — Sulphur, Precipitated 
Milk of — Sulphur Seals. Medals, Coins, &c. — Snlphur, 
Tincture of — Sulphur, to obtain Pure — Sulphuret of 
Mercury Cerate — Sulphuric Acid Ointment — Suppository. 
Purgative, Sedative and for Worms — Swinton's Daffy's 
Elixir — Sydenham's Lenitive — Sympathetic Inks. viz. 
Black, (Two), Brown, Blue, Yellow, Red — Syrian (farnet. 
to Imitate — Syrup Cream, or Cream Syrup — Table Ale— 



, Table Beer— Tain, Eau de, (Thyme Water)— Talc Water 
I —Talc. Oil of —Tamarinds, Conserve of — Tamarinds 
and Senna — Tannin Ointment— Tar Ointment — Tar Var- 
nish—Tar Water— Tartar Emetic— Tartar Emetic Mix- 
ture—Tartar Soluble — Tartar, Soluble Cream of— 
Taylor's Defensor, &c. &c. 

No. 42. Taylor's Mixed Oils— Taylor's Red 
Bottle— Taylor's Remedy for Deafness— Tears of the 
Widow of Malabar— Terra Cotta— Terra Japonica. Tinc- 
ture of— Terra Sienna — Terro-Metallicum. for filling 
Decayed Teeth— Thibaut's Balsam, to Heal Cuts and 
Wounds, and stop Bleeding — Thieves' Vinegar— Tin. 
Crystalized— Tin, to Coat with Bismuth— Tin Mordants 
—Tin Powder— Tin Tree, to Prepare— Tinning Pins and 
Tacks — Tipsy Cakes — Tobacco, British Herb — Tobacco 
Ointment — Tobacco, Enema of— Tolu Loaenges — Tolu 
Tincture of— Tomato Sauce— Tombac, Red and White 
— Tonic Medicines, (Nine Receipts)— Toothache Drops 
(Eight Ditto)— Tooth Powder, (Eight Ditto)— Topaz, to 
Imitate the— Tortoise-shell. Joining of— Tortoise-Shell 
Boxes — Touch Paper— Tourney Cement — Tracing Papers 
(Nine Receipts) — Tragacanth, Compound Powder of — 
Transparent Soaps — Treacle Beer — TreacU, to make 
Brandy from — Tripharmlc Ointment— Trotter Oil, to 
Purify— Tunisian Cement —Turkish Bloom— Turkish 
Depilatory — Turlington's Balsam — Turners' Cerate for 
Chilblains- Turners Work, Polish for— Turpentine Bal- 
sam of — Turpentine, Enema of— Turpentine, Linctus of — 
Turpentine Liniments for Rhumalism, Lumbago, &c. — 
Turpentine Mixture— Turpentine Varnish— Tutania. or 
Britannia Metal. German, and Spanish- Type Metal. 
Small — Typhus Fever- Ultramarine— Ultramarine Arti- 
ficial—Usquebaugh—Valerian Mixture— Valerian. Tinc- 
ture of— Vancouver's Cement — Vandyke Brown — Vanilla 
Cream — Vanilla, Essence of — Vanilla Lozenges — Varnish 
—Varnish, to Polish— Varnishes, Colors for, viz. Black. 
Yellow. Blues. Greens. Reds, Purples, Brick Red. Buff. 
Violet, Pearl Grey, and Flaxen Grey — Vauquelin's 
Tincture 'of Spirit of Turpentine — Velno's Vegetable 
Syrup — Velvet. Satin, Silk, &c. Colors for Painfng on. 

No. 4.3. Velvet. &c.. Color* for Painting on— Venus, 
Huile de — Veratrine, Liniment— Veratrine Ointment — 
Verdigris— Verdigris. Liniment of. Ointment, Plaister— 
Verditer. Blue — Verjuice Water for Iceing — Vernii- 
celli— Vermifuge, or Worm Mixtures— Vermillion— Ver- 
vain's Balsam— Vidonia Wine, to Fine— Viganis' Elixir 
of Vitriol — Vinaigre Dentifrique, Cosmestiques — Vinegar, 
to make. Ointment— Violet Powder, Perfume, Syrup of 
— Vitriolic Elixir — Vitriol, Sweet Spirits of — Wafers, 
Manufacture of— Wafers, (in Cookery) VValker's Jesuit's 
Drops—Walls, to preserve from Dampness — Walnuts to 
Bleai-h. Extract of, to Pickle, Ketchup — Want's Powder 
— Ward's Antimonial Pills. Essence for Head-Ache, 
Paste for the Piles. Sweating Powders. White Drops — 
Ware's Golden Ointment — Warner's Cordial — Warming 
Plaister— Warts— Wash Balls— Wa.ip, on Swallowing a 
— Watchmakers'Oil — Water Cement — Water Color Cakes 
— Waterloo Crackers— Water-proof Boots, Cloth— Wax, 
Bleaching and Purifying of. Imitations of. Candles. Imi- 
tative Lute or Cement. Ointment — Webster's Antibilious 
Pills, Diet Drink— Wedel's Oil — Wedgewood Composition 
of Mortars— Weeds, Extirpating— Welsh Ale— Weld Yel- 
low — WestphalianEsseiice of Wood Smoke— Whipt Cream 
—White Briony, Extract of. Camphorated Ointment, 
Enamel, Hellebore, Extract of, Lotion or Wash, Metal, 
Precipitate, Precipitate Ointment— Whitlow — Whortle- 
berry Mixture — Whyte's Tincture of Bark — Wigg Cakes 
— William's Stucco — Wilson's Prepared Asphaltum — 
Windsor Ale, Soap — Wine Bitters — Wines, to Fine or 
Clarify, to Correct when Harsh, to Correct when Acid, 
to Clear Foul or Ropy — Wine Vinegar— Wood Staining. 

No. 44. Wool Bleaching — Worms — Wormwood, 
Conserve, Extract, and Essence of — Writing Fluids — 
Wych's Stucco — Yeast, to Preserve, Substitutes for, 
and Poultice — Yellow Dipping Metal. Dyes. Ink, Lotion 
or Wash, Resin Soap, and Stain for Glass— Yolk of Egg 
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Date Due 




rm 1 1 1B9S 














































































































































L.brary Bureau Cat. No 1137 






QC51].n 



bim 



3 5002 00134 1689 



Francis, George William. 

Electrical experiments; illustrating the 



PMYSIC- 



QC 

517 

F7 



i