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Full text of "The Magazine of Science, and Schools of Art"

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MAMCH 

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uBAAfves 




06905998 



8641^>:i 



PREFACE. 



yean barv now clcpsed naoe thia Mtgaxine first made its u^pesrwace. It has 
throagbrmt with care and mergy, Bud the uadiminisbed, oay increaMog 
it, w the hot crideaoe that oar endeavoars haTc met with approbalioa. 

Ilii* oontinoed proepcrUy of our uDABptnug little work caxioot be attnbuico lo lor- 
itoam circtunetanoee. The year of Uie pabboition of our lint volume, uideed« wm 
tmlmred Sd hy fsn^ endden, and imezpectcd diacovvriea in scicuee and art— Fhot< 

and the Daguerrcotrpe beiog among them. The aeeood Tolume, in Hke manner, 
•imnltaoAOiu with the Electro-type, Electro-magDetio movements of varioni 
<>ther oquanjr inteiTHtiag matters. The last ^nenTr oo the oontrory, has beeo 

in 4kcovme*. Hie meeting of the BhtiAh Association waa admittedly a hHure 

HiOvftl Society haa prodoced nothing o^ interest; the Philosophiciil Periudicols hai 

ino^ aAfraicful ; Mcehaaica] and Manufiictimng gemua has invooted little of pubti 

tano« ; the huasted German and Ruasian Electro-magnetie Machines are decided 

; and even the Acadetme des ScMOoes at Paris, that b genenlly «o mnch on 

mlert in mctcn of discovery, has been vapid and uninteresting. 

With bB tbeae discouraging eirenmstancca* attended by a complete stagnation nnd 

<t in the book trade, BtiQ we have steadily pursued our wonted course; and U it 

-NhtioA to reflect upon the steady support we b&ve contintially received from 

iuyrrj thmg new and really vihiablo we have maerted. and every thing, 

Tiuhiie iaquhy we have cvpltuned. Yet should our Friends have seen vttcli 

i«giaarr isventtonit in the public papers, tiui wondin^d why thoee aitictca faaive^ 

• - — 

d with na ; we can tell them, that paragrapbs in Works which ore iuA aciicntific 

>iys to be depended upon, thus we should oftcjitimes quote, and have tmmediAtaty 

to contradict. If such accounts are true in themsehrea, it^ is impoaaible that 

'tt timea procure the iniurmiitiun refinlsite to muke th^g^valuahlc'; inveotore kee^i 



7 ^^.iZi'aCE 

E'ttf"".-. '-.'^ ■- ■-. '.h«.rc are sor- c art.-? which we tc-x ibtu*!» Uttlc icfonaiitia:; is^ no ^v 
f .ctcry .Lcc'.'ii' 'jfin?" puM'-ihcd in our la:i</!r.LT ; for ejifamplc. Turaing, Orgwi Baiidaiir. 
■u:'i Acr^'^raphy. 

As fiir, however, ab tlie abov.; a't- are conrtrnci, ar.d s^me more, of wtijcb we hav;; 
rot iii'herto rreut; :i , wi: tj^ in wtli-ijroiiaded cxpcctoaon,. very k>oq, of rrc»ci:ring 
the tl-.-'^ei i.'ifurn .ition upoi., as wc!' a« of nunicrous otiitrs of more scncial intirvst, 
l)yeiii£r, oicacl'inp. Tli'jrmo-ma^etifna, &c. ; thus we Ir.ve do hesitation ia proir.i^ing 
iccrca-'j 'f H.*i:re»T to ci.r r/:xt vulunif. One ^re&t . iteration which we inttnc toi-.".pl 
i-. f- crii-T f. iricl>iri»'. into the b-xij of tht- text a srcat part cf the answers to Corr>:.-=p-i ii- 
<'"-rjt>, iio- tin-: ■ i. -Mr jnquiriefr in the ^-hapi: of queries, and sjiswering them a= Pi*xh, I -.;vii jr 
T^ . our 01*1*- ! Corrcsp'.mdents to send as other and better answers, if they can, as in tlio 'irel 
■vviiurue. 

The mo't pleasing duty still remains fur w= ; it is to tliaak those who have WindJr 
•. .ritnij.iV-ti iij!'».rn'-ition to our pairvs. Tu iiami; particiilar individuals would bo inV)iii»"*u?, 

• ■- coui.i w a-dicml^cr th^ra all; and imju^t did we not also express our scnu »•: 

• '■•':»,' :i^'. M t'- (ji,r norncrou- :itfn iuoiir I'rKud.-. 

'Ac IpJIcvc liiat wc hitve ancwcrtu idj letter^; received throucrhout the year, yet thc;5e 

• -. n.' h:ivt- Ijttn ail winch have l)t;ti. ficni to \xs\ foi while Currespondcnta wmd their 
:■ >:i !i'ii»!-;uiifinr. -lonic to the rubli-iitr, uthtrfc to the Printer, others even to our urmtr 

• - ; .i,'.. ':«.!••( vvliwrh v.L- iiuvt> now left for nmny moiithfe,) it is pet^sible, particularly in tlic 
'-.tU;r '•■.-/_', 'ill ' ;-.«iinc (.f Ihcrti Imve been di.lnvcd ui iust. 



THE EDlTOit. 



1 ,-'\ /. Hf^- 



THE 



AGAZINE OF SCIENCE 



^nb ^rtiool of ^r($(. 



\5J] 



8.\TL'RUAY AI'iUL. a. IMl. 



IHd. 




THREE-WHEELED ORRERY. 
Tb the Editor. 

Km.^l indoM for itiM-rtioii tn ^our Mnguini;, a 
|icrsprt:livc riew of the exttrnal arranK^iiiKrit of a 
three-wheeled orrery, which 1 invented iluihig my 
raideocc in Loudon, early in the year 1H37> 

The wheel-work, Ac, U inclo»«l witUiu a large 
oircnlnr frame of maliogany, of about eighteen inclica 
is diaraeter, E E, on the upper surface of which is 
carefully laid down the signu of the elliptic — the 
days cif the inontti, and hourf of tlic (&y. as de- 
lineated. The aim is repriMentcd by a ball, S, in 
the centre, ^Ided, and is six inches in diameter, to 
the right of wliich ia a small terreatlal globe, F, 
tiin* inrhcs in diameter, on wbitth are engravcji the 
■cTeml countrira of the world, with circles of lali- 
todr and longitude, and i» fiurmanded with a small 
engniTcn ecliptic circlf, K, and circle of altitude, L. 
The IniII, E, repri'$entiiii|; the earth, is iiirlmed at aa 
angle of aboat 23^", and is attachitl to on axle 
which asceoda from the wheeUwurk, and by virtue 
of which connexion it prraerrcs its parallcliam in \ta 
circular journey round' the- win, thereby familiarly 
^Ifthibiting the cafise of the rhonf^e of the scaMma< 
■nd differont tengthi of day and night throughout 
the year, &c. Immediately under the earth i« fixed 
a small circular dial-plate, on which i^ engraven the 
twciity-four tioori of day and night, which ie very 
■ervicesbtc in attaiuing the time of terrc^tial phe- 
iMnnena. Under Ibis dial-plMe i« another, which ia 
atationary, and on wliich arc rrigniTen the daytt of 
the moon's age ; and lastly, another circle is attache*! 
tb the wheel-wnrk, and on which is laid dnwn the 
dcgreoi. Stc. of the node:* of the nioon'i orbit. This 
rfng or circle is inclined at an an^lc of about 5^"^ 
to the plane of the frame, E E. Thia ring has a 
retrograde motion in the ecliptic in the space of 
18 years and 234 dnys, which is nearly the ptiriod of 
the nodes. Between the circles of the hour, at the 
foot of the earth's axis, and the circle of tlic moon's 
age, a horizontal arm extends from the wheel-work, 
and carrteH a [wrpendicular arm, H, which is partly 
hnUow, for tlie pnrpoitc of affording a vcTtical motion 
mitable to the mooD'tt dceliiuilion, ike. M is a small 
boll of about thrce.quartera of on inch in diameter, 
and is furnifitied with a black cap. which exactly 
covers from view one-half <if tJu* lunar globe, and to 
which is attached a kind of forked arm cxti-iiding 
upwards, and has a comirxion with the sun tliruugh 
the medium of tlie slight horizontal bar^ Vi, and 
joined to tlie sun at 1. In short, with this very 
simple orrery, the following vrr^- interesting astro- 
nomieal phenomena may be dif^tinctly ascwrtained, 
and which, so far as I know, U the first time such 
important results from such simple causes have been 
effected : — 

Phenomena a-hidifed by tht Neuf OrrHy* 
r. — The ime(|UBl lengths of day and njglit durinj^ 
the year, and hence the cause of the %'iciiwitudji 
of the seaaons. 
2. — The fun's place in the ecliptic, declination, Ac. 
S. — Tb« periodic and synodic revolution of the moon. 
4. — The moon's iliumal mtation on its axis. 
4. — Tlie aff)? and phases of the moon. 
8.— The morion of the moon's orbit. 
7. — Tlie motion of the apogee of moon's orbit. 
S.-^Tlif eclipttes of the sun, moon, &c. 

All the above being efiVetcd by a very peculiar 

WT'tngpmeqt of only three wheels and a pinion. I may 

«M th«t the moon goes roond the earth in the ma- 



chine in 29 days. 12 houn, 14 miiuitrs, 2^i M>randil. 
and romul its own axil in the same time. The eartli 
is moved by hand, ts aastuued to perform its journey 
niuiid the unn in^GAdays, 5 hours, 4B minutcff. nnd 
9 seconds. The moon's orbit makes a rrtrograilt? 
movement through all the sixns and drgrces iif tlie 
great ecliptic cirdc in G,7^B days, 1^ hours, aul 
that of the apogee iu 3,231 days, 18 houn. tn^tfat 
time. 

I gmerally exhilitt this simple orrery inmrutro^ 
nomieal lectures, and as it ^ves general satisfaetianr 
and as a number wish to have copies of its form* I 
send it to you, in mxler that (bey may see it engrnvtM) 
in ynur widely -circulated Magazine, of which 1 have 
b«en a subftcriber since* its commenctmient. 1 may« 
at farm future period, render you a description of 
the wheel-work of thlR instromcnt, as also of ■ 
variety of original aiift various aatronomiral ma- 
chinery, should the present be acceptable to yonr 
readers. s. uknoebsox. 



IMPROVEMENT OF THE DAGUERREO- 
TYPE. 
Till process of Mr. Wolcroft, an American, paj- 
tented in Englnnd by Mr. Beard, for quickening 
the acliim of tlte Daguerreotype, so a» to produce 
the eflVct in a few seconds, ia now carried intft 
practice at the Polytechnic Institution in taVing 
likenesses. The mom titted up for the pnrpofle Is 
at the top of the building in CaTcndish-aquare. 
Tlie roof is composed for the most part of Urge 
sheets of jtlate-gla^^, $tnined blue to soften the light, 
and this glois ruohng traverses so as to meet llie 
rays of tlie sun nt any part of the day. The sitter 
is placed on an elevated platform, with a support 
for the head, snd the camera obscura rests on ■ 
shelf ■ few feef distance from him. The constnie- 
tion of the cnmera itself, as thus applied, consti- 
tntea part of Mr. Wolcrofl's patent. Instead of 
using a lens to refract the rays of light to a focoe, 
he empIbjR a reflector, ahout seven inches diametef« 
By this means a much greater number of the rays 
issuing from the object are concentrated within • 
given space than could be otherwise accomplished, 
and the image is consequently the brighter. The 
speculum may abo be placed nearer to catch thfi 
rays of light than a lens, and this also affords aa 
additional increase of collected rays in the image. 
Tlie silvered plate, prepared with a coating of thft 
vajiors produced by iodine mixed with nitric aeidt 
or with bromine, so aa to quicken the action of tha 
light, is put into the focus of the reflecting mirror. 
The person whose likeness is to be taken keeps Mia 
face steady for a few seconds, and the effect on the 
iodine coating iiit produced. The plate is then taken 
away, and excluded carefully from the light until it 
has been exposed to the vapor of mercury, which 
sttacbea to the parts acted on by the tight, and the 
image becomes visible — a perfect fac-aimile of nature. 
Before the plate is exposed to the light, the iedine 
if washed off, and all farther cliooge is thus pre- 
vented by eipoaure. The time occupied by the 
process varies with the intensity of the light. Soma 
likenesses were taken in five seconds, others occa* 
pied twenty, according as the sky was clear or 
clouded. The difficulty experienced, is to deter- 
mine the exact time that the plate should remala 
exposed to the vapor of mercury, the requisite time 
is at present determined only by trial, and the judg- 
raenl of the operator. It must therefore rcqmre 
some pmottee to produce the best pouiblc effects. 



k 



MAGAZINE OF SCIENCE. 



ISTUIBUTION OP ANIMAI-S. 

6dal view, vegrluldcA aevm inorr lihun* 

taiioalc: fo contrirjr. huwevtrr, in litis lo 

the tperios of animals, when compnirtl 

ofpUiiU, may be coruiJerc*) in the pnt- 

1. Hence it fcllovr* that botHiiy 

«lih xool'>g7.i5a(erY limited study : 

Miilered in relatiou to uiwct» alimc, 

on in the number of the tpecJefl. 

oas plants of Britain have beeaes- 

roond oainbers at 1500, while the iniectji 

t already been discovered in this country 

M^y many haftdredssUil remain unknown) 

10,000, which 13 oKM-e than jl\ insecta to 

. It ia therefore obt-bui that tlie know- 

Dired of tKe geo^caphicol diatribation of 

n comparison with what is known of plants, 

■and antahsfactorj : it ia likewise attcndrd 

(culties inseparable from the nature of beings 

roos and diversified, and which will always 

oftoiparatively imperfect. It rarely hap- 

a nagle specimen of a plant is found lao- 

; )>otanist can therefore immediately amve 

. ooarlusious : if he if in a mountainous 

he isenabled to trace, without much difti. 

lowe«t and the highest deration at which 

iUr sp«cira is found ; and the nature of the 

^ m^j be considered the food uf the plant. 

But these advantages do not 

ist 1 his business ia with nu/n^roa^ 

while of the marice tribes be 

hope to be [acquainted with toure than 

t ponioo. The following obicr- 

therefore, be copudered aa merely an 

general lavs which leem to regntote 

y of onimaU. 

tbution of animals on the face of the 

be considered under two heads, general 

sr. The first relates to families or 

babit&Bg particalar conei, and to others by 

ftre represented in onother hemisphere. 

d mfcra to the local distribution of the 

any particular country, or to that of in- 

*es. It is to the general distribution 

a celebrated writer has well obserred, 

xoologist should tint direct hitt 

than to the locality of species. By 

Motwre in her higher groups, we discover 

n fnacLiofM are dereloped upder different 

w« begin to discern something [of the 

of |>rovidence in the creation of animals, 

at generul rmults, which muMt ))c fnr eror 

Ihoae who limit ibelr views to the habita- 

Bpedea, or to the local distribution of 

lis, like plants, are generally found to be 
in tones. Fabricins, in speaking of in- 
tbe globe into eight climates, which 
the Indian, Ettyptinn, southern, 
northern, orientiil, occidental, nod 
firvt he includes the tropics ; in the 
region immrdiatrly adjacent ; 
i« lontbem ; in <he fourth, the coun- 
!ng on the Mediterranean Sea, iochiding 
i«nia and Media ; in the fifth, the northern 
when; the cold in winter is intense ; in 
North America, Japun, and China ; 
eighth, all tltose moanuins whoee Ham- 
covered with eternal snuw. It is, hotvet-er, 
:eiTe. that this, though a very ingenious, 
artificial theory ; the divioiona ire vague 



and arbitrary, and we know Umt animals nf one 
country differ essentially from tliote of another, 
although both may enjoy tlie same dcgrwr of tenijw- 
rature. M. LntreiUe has thrncfure ottnnpte^d a 
more definite theory. His two primary dtvistnns 
ore the arctic and Uie antarctic climatrs, acci>rding 
to their sitoation above or below the eqiiinortial 
line; and Uking 12^ of latitude for each climoie, 
he oubdividei) the whole into tweKe. Uc^inntng at 
84** N. L., he han seven arctic climates : vix, the 
poUr, subpolar, superior, intermediate, supmtropi- 
cal, tropical, equatorial : but his antarctic rlimates, 
OS no land has been discovered below 50° S. L., 
amount only to five, beginning with the equatorial, 
and terminating with the auperior. He propose!, 
also, a farther itivijnon of Butfcliroatea, by means of 
certain meridian line*; separating thoA lltu old 
world from the new, and subdividing the former 
into two great portions; an eastern, beginning with 
India; and a western, with Persia. He proposes, 
further, that each climate should be considered u 
having 24*^ of Inngitude and 12*^ of latitude. This 
system certainty approximates more to what we see 
in nature than that proposed by Fabriciiia; yet Mr. 
Kirby observes K-ith truth, that the divmlon of the 
globe into climates by equivalent parallels and me- 
ndiana wears the appearance of an artificial and 
arbitrary syotem, rather than of one according to 
nature. 

Mr. Swainson considers that the geographic dU- 
tribuliuu of animals is intimately connec-ted with the 
limits of those grand and obvious sections into 
which the globe is divided ; and that in proportion 
to the geagrarbii:al proximity of one continent to 
another, so will be either the proportional identity 
or the analogy of their respective animals. Hecoo* 
aiders Europe. Asia, and Africa «9 agreeing man 
particuUrlyJn possessingcertainanimalsinoommonf 
whir.haeem excluded altogether, from America and 
Aostralia ; both of which gre not only i»ulati'd iu 
situation, hut tbcir animals have it difference of 
form and habit from those of the three continents 
of the old world. He considers that the animal 
geography of Asia U connectecT with that of Aus- 
tralia by the intervention of Borneo, New Guinea, 
and the neigfabonring isles; while that of Amcrira 
unites irith Europe towards the polar regions. 
These five great types or divisions will, of course, 
present certain affinities or analogies dependent 
upon other causes, arising from temperature, food, 
and locality. 

Vertebrated animals have a wider range tban'.in- 
vertcbrated animals, thus resembling mim, who la 
spread over the whole earth : the dog and the crow 
ore found wild in almost every climate; the swal- 
low traverses, in a few dayn, from the tempernle to 
the torrid zone ; and numerous other birds annu- 
olly i»erform long migrations. Nestto-lbe!*e, inserts, 
above all| the other Invertehriitcc, enjoy ibe widest 
range; the house fly of America and of Euiojie aw 
precisely the same ; and Mr. Rwainsnn hns observed 
in Brazil vast flocks of butlerflic*, whirh annuiUy 
mignitfl from the interior townnU Hie coft*(. 

Marine animals have, in general, a wider range 
than those strictly terrestrial. This may probably 
originate in their being more independent ef the 
effects of temperature. It is remarkable, that, with 
the exception of the crow and two or three nthrrs. 
the land birds of America differ entirely from thoee 
of Europe, yet that nearly all our aquatiit speetott 
are found both in the new world and in the aoulhoni 
cOKita of Africa. 



MAGAZINE OF SCIE>JCE. 



p 



Subordioate to the tivr frcogni^Jtic groups already 
notieerl, trm^erature mi; be ciineiddred the phnci- 
pnl rfgulritor of the statioa of Miioials ; it ha5 like- 
wike rtrmtirkable influeuce oa their cintbing. Many 
quAtlrvprds, inh&faiting the colder region*, appetr in 
their natural culora during Eumtner, but become 
whitr ta winter. The same rhuige takes place in 
the pluruage of sereralland birds ; b'jtis not obier- 
vablc in inficcta, or the other invertebrate grotipa. 
Temperature has llki-wiac a Rreat influence on the 
aixe aiiil colur of antnialii. The Sphinx eotiv<SlTuli 
of Etiro|>e i« found also in India, but of ii much 
■oialler ci/e and more discinctiy colored : tbtit ia 
usually the effect of heat upon nntmaU whose chief 
t^ti^t ia in temperate Utitude5. On those which 
may be coniidered intertropical, a greater degree of 
heat not only increase* tht brilliancy of their colors, 
but adds to their aiie. There are many birda and 
inaecCa common l>oth to Central Brazil and Cayenne ; 
but from the greater beaC of the latter country, the 
specimens are always larger and llieirplnmagemore 
beautiful. Temperature likewise affects the clothing 
of animals in respect both to quality and quantity. 
Thia ia more, particularly observed in snch domesti- 
cated animals as have been tranaplanted from their 
natural climates. The covering of awine in warm 
countries coniiists of bristles of the same form and 
texture, thinly dispersed ; while the same animala 
in colder climates have an additional coating of fine 
frizzled wool next the skin, over which the long 
bristly hairs project. The difference is very re. 
markable in the swine of northern Europe and those 
of tropicjil America, the tatter appearing almost 
naked : it may be observed in a lees degree in those 
of the south of England nnd the north of Scotland. 
Similar appearances present themselves among the 
•beep of warm and cold countriea : the ticece of 
tboae of England consiate entirely of wool, while 
the sheep of Shetland and Iceland possess a fleece, 
rotiLniriing, tie^dCA the wool, a number of lon^ hairs, 
wliich give it an appearance of being very course. 
{To be eontinutd.) 

.,■■■■■■■. MJ..!**. . ^. .. .»--■■.■.■■■■.■.■.■■■■ — .■■ -■ — — .»■■. — ■ Ji.. - 

GILDING ON STEEL. 
Dif4sDi.vB any quantity of pi\d or platina in nitro- 
muriatic acid (a^tta rrgia), until un effervescence is 
oociuioned by the apptic^iiion of hrnt. Evuporote 
the solution of gold or platina, thus formed, to dry- 
nest, in a gentle heat ; (it will Uien be freed from 
alt cAccsfi of acid, which is eaieotial)j and re- 
ditaolve the dry mass in as little water oa poasible : 
next lukc nn instrument which ia used by chemists 
for dmpping liquids, known by tlie name of a sepa- 
rating-funnel, having a pear-shaped body, tapering 
to a fine point, and a neck capable of being stopped 
with the finger or a cork ; which may contain a 
liquid ounce, or more: fill it with the liquid about 
one quarter part; and the other three parts, must 
be filled with the *ery best sulphuric ether. If this 
be rightly managed, the two liquids will not mix. 
Then, place the tube in a huriiontal poaition, and 
gently tarn it round with the finger and thumb. 
Tha ether will very soon be impregnated with the 
platina or gold, which may be known by its change 
of color. Replace it in a perpendicular position, 
and let it rcit for twenty-four hours ; having first 
stopped the upper orifice with a small cork. The 
liquid wiU then be divided into two parta ; the 
dvlust colored being underneath. To sepnratc 
tbtm, uke oot the cork, and let the dark liquid 
flow ou( - when it h.if diaappMred, stop the lube 



immedintely with Clio cork ; and what remains 
the tubeia til fur use, and may be Called the g))dinc< 
liquid. Let it be put into a bottle, and tlghtl; 
corked. WTien an artirle is to be gilded, a ve»i 
of glass or unglased ware mu«t he provided, of jos 
sufficient size to admit the article : it most Uien h 
filled with the gilding-liquid, nearly t<i the top 
The steel roust be very highly polished, and be en 
tirely frre from rust or grease. A basin, full 
clean water, mu.'it be ready at hand : the ai 
must be immersed into the gilding -liquid, and tl 
lowed to remain as short a time lu pofutihle ; 
be taken out, quickly plunged into the watef* 
well rinsed ; it must nest he dnrd with blntd 
paper, and be placed in a temperature of IdO'^Fah^ 
till it be completeljr heated throughout ; it may t' 
be polished with rouge and a soft leather ; or, iridc 
is better, be burnished. 

!t will be aa well to obaerve. perhaps, that 
muriate of gold or platina, formed by digesting 
metals in nitro-muriatic acid, muat be entirely 
from all excess of acid ; because it will otb 
act too forcibly on the steel, and cause the coa 
ing of gold to peel off. Pure gold must lieemploy 
The other most not be shaken with the muriaiK 
gold, as ia advised in chemical puhlicationa ; for 
will be sure, then, to contain acid : but, if the t«0 
liquids be brought into contact, by the motion de« 
scribed* the affinity existing between ether and g 
is so strong, as to overcome the obstacle of graTity, 
and it will bold tlie gold in solution. The ethei 
solution may also bo conrrntrated by i;entle ev. 
ration. Care muat be taken not to wipe thft 
until the heat has been applied. Thia gilding 
effectual protection against rust ; and is, at 
same time, very ornamental. 



OBSERVATIONS ON THE FORMATION Of 
MISTS IN PARTICULAR SITUATIONS- 

or MIfL UUMPURbY DAVT. 

All persons who have been accustomed to the ob* 
8er\'ation uf nature, must have frequently Hitncsatd 
the formation of mista over the beds of rivers i 
lakes in calm and clear weather after aun-aet ; aod 
whoever haa considered thc»e phenomena in rrlatioa 
to the radiation and communication of heat i 
the nature of va|>or, since the publicatioo o( 
MM. Rumford, Leslie, Daltoo, and >A'eUa, cm 
hardly hare failed to discover the true cause ^, 
them. Ai, however, 1 am not aware that any wof^ 
has yet been published in which this cause is fulhr, 

>n>i<1icalcU 



discussed, aod as it involves rather co 
principles, 1 shall make no apology for • ^ 

few remarks on the aubject to the Royal > J 

As soon as the sun has disappeared fium a4| 
part of the globe, the lurfoce begins to lose bat 
by radiation, and in greater proportions as the alty 
is clearer ; but the Und and water are cooled by 
this operation in a very different manner : the iqi* 
presaion of cooling on the land is limited to Iht 
surface, and very slowly tranEmitted to tlie ioteriori 
whereas in water alfOTe \yf Fahrenheit, as sooe tm, 
tbe upper stratum is cooled, whether by radiatim 
or evaporation, it sinks in tbe mass of fluid, and 
its plut-f ia fuppbed by water from below, and liU 
ilic tenifKTOivire of the whole mass is reduc4.'d U>^ 
ncnrly 40'^ F., the Kurface cannot bo the coulott 
part. It follows, therefore, that wherever watar 
eatsta in considirrablc mat^a, and has a temperatHTB 
nearly equal to that of tlie lond, or only a few de» 
grcM below it, and above 40° F. at snn-tttt ita 



MAGAZINE OF SCIENCE. 



ihirii>S 1^^ night, In calm »ncl cte^sr wmttier, 

be vumcr than tKat of tUe coobeuooa land ; 

thm air *bovw Ibe Uiitt will iieccaaarilj bo colder 

ihnt aSi[iv« tbe wuLcr ; auil when Ifaej boih 

i'.ic pntjtnrtion v( aquroui vapor. 

I of the ^oiind u surh as to permit 

ii the laud to mix with the narmer 

>trr. mUt or fog will be the malt ; 

iter in qnnntity. aa the 

M,^ the wat^r is higher, 

.. ,v mperature of the water, 

1 h thr quantity or atrengtb of 

it, grc«t«'r. 

<^'b«erTations nhlch appear to 
•ko' rirtt at thii Tiew. June 9th, 

lAtureof the atmosphere and 
cjieatcdly exitniinvd during a 
.. i M..^-. .-I'JD thia river (rora lUti«bone 
«im3 on eocfa of these daj-t, the sky being 
dev, the «pi>fvrance of miat above the 
the rrcntnf noifonnly coincided with the 
of Ih*" ti»mperaturc of the air from three 
Mefi hit of iLe river, and the dis- 

h: luuraing vritb the elevation 
l»H.fr. t,;.^,, of the air a&opc that of the 
Fk9» lUtiabone to Paauu. the tempcratare 
Dorabe waa pretty fair throaehuui the 24 
Iwittg highest, 6r F.| or 62^' F.. between 
«fi^ two o'clock, and about one degree less 
the temperatiiro of the air from 
during thr- day, and from BV to 
laj tiif uight. R^Jow pM^Mn, the Ion and 
iBtotht Danube. The Dauubewaa gretniih. 
bad • milky blurnna, the llz was perfectly 
: but from the rapidity with which the Inn 
its wkteri at Uiij spot give their tint to 
• nrfsce. On examining the temperature 
/i««ra at ax o'clock, a.m. June 11, that of 
was found to be ti/* F., (hat of the 
v., *ud that of the lie 5fi^ P. : the tern- 
40 the atmoapbere ou the banks where 
II Mixed, was 54^ The whole surface 
ibc w*s csTvred with a thick fog ; on the 
r» sraa a slight miKf. and on the II2 barely a 
»t LiKticsiing the deptwition of a very small 
of water About 100 yards bcUiw the 
the three riven joined, the tcmperatare 
part of the Danube wu 59' P., and 
qasttdty of mist was less than on the bed 
before the janctioo ; but about half 
r, tbfl warmer water had again found its 
ffvf«oe, and the mist was as copious as 
'^lUon of the three rivers. June 12tb, 
cloody, and thft temperature of the 
lfr«natned till after dark higher than that 
brTng, whtn the lost obKrvation was 
K, when there was not the slightest ap- 
Ttie Bky was clearer before sun- 
fHA. And the tbermofoeter immediately 
• >r above the river, stood at 
r uf the Uanube beioK 61^F. ; 
1 inmtUiaiely above the river ; 
i5S of vapor to eiclado the 
rlUiippcared ; and was not 
-urface ; and in half an 
1 c was perfectly trans- 

slofif tlir Rhine from Cologne to Cob- 

'SlftS. ' InA and 3rd. the nights 

cfce^i; phenomenon of the 

- ,. ..served, precisely under 

t but u 1 could examine the 



temperature of the air and the river only ctote to 
the banks, sod in two or three situations, my ob* 
servations were less precise and less nuuurous : the 
mist formed later in the evening, and disappeared 
sooner in the morning than on Ibe Danube ; which 
was evidently owing to the circumstances of tbo . 
atmosphere being warmer, and the river colder. ^H 
temperature of the one being from 60° P. to Z^'^ l^f 
during the day, and that of the river, where ^T 
examined it, from 50° to 00'' F. 

July 11th. I examined the temperature of the 
Roab, ncAT Kermond, in Hungary, at seven o'clock 
p.m., and found it G5'' P., that of the atmosphero 
being 72^ F. During the whole evening there «V^| 
some thin fleecy clouds in the western sky, wh^H 
being lighted np by the setting sun, gre^y inter- 
fered with the cooling by rudiatioo from the earth, 
and at half.past nine, the Uiermometer, in the 
atmosphere, was still 69*^ F., and at half-past tea 
G7^ P., when there was not the slightest appearance 
of mist. In the morning, before sun-rise, the tcm* 
perature of the atmDBi>Uere on the banks was 61° P., 
that of the river 64 P., snd now the bed of the 
rirer wss Ailed with a white thin mist, which en- 
tirely disappeared half an hour after sun-rise. 

I made similar observations on the f^avc, in Car* 
niola, in the end of August: on the Isouso la the 
Friul, in the middle of September ; on the Po near 
F^mra, in the end of September ; and repeatedly 
on the Tiber, and on the small lakes in the Cam- 
pagna of Rome, in the beginning of October ; and 
I have never in any instance observed the formation 
of mist on a river or lake, when the temperature of 
the water has been lower than that of the atmosphere, 
even when the atmosphere was saturated with vapor. 

It might, at Unt view, be supposed, that whether 
the cooling cause existeil in the water or the land, 
the same conaeqaences ought to result ; but the 
peculiar properties of water, to which I referred in 
thr beginning of the paper, render this impossible. 
Water in abstmcting bent from the atmosphere be- 
comes lighter, and the warmer stratum rests on Ifaa 
stirfiue, and its operation in cooling the atmospheri 
is extremely slow ; besides, the cooled atmnsphei^^l 
stratum remains in contact with it, and water caiin^H 
be deposited from vapor, when that vapor is risiof 
into an atmosphere of a higher temperature than ita 
own ; and the law holds good however great the 
difference of temprrature. Thus. August 26th. at 
sun-set, the dny after a heavy fail of rain, and when 
the atmosphere was eiceetlingly moist, I ascertained 
the temperature of the Drove, near Spital, in Ca- 
rinthia, and though it was U'^ P. below that of tho 
air, yrt the atmosphere above the river waa perfectly 
transparent. 

It mny be imagined, but without any reference to 
the cooling sgencirs of the air from the land, mist 
may form upon rivers and lakea, merely from the 
toas of heat by radiation from the air, or the vapor 
itself immediately above the water ; and that the 
phenomena is merely one of the formation of 
va|>or, the source of heat being io the water, and 
its dcpositioD, the source of cold, being in the 
atmoaphere ; but it is extremely improbable that 
air or invisible vapor, at common temperatures, 
can lose any conndersble quantity of heat by radia- 
tion ; and if miat could be formed from laoh ft 
source, it must always be produced to a great extent 
upon the ocean in calm weather during Ibe night, 
particularty under the line and between the tropics, 
which the jonmnls of voyagea suftciently prove is 
not the case. 1 hare myself had on op poitunity of 



d 



of making tcmc olutervatioiu which coiadde with 
tbU view. During a voyage to and froai Pola, I 
passed the ui)thu of Sept., 3rcl, 5th, and Clb, off the 
coast of latna ; there was very little wind on either 
of the oights, and from sun-vet till nearly midoi^t 
it was |>erfeclly calm in alt of Uiem. On the 3rd 
It WSJ cloudy, and the lightaiog was perceived from 
a distant thunder-atorm, and the vessel was neve^ 
far from the shore ; but on the 5th and &lh the sky 
vra& perfectly clear, and the zodiacal light, after auu- 
•Bt, wondeKully distinct and brilliant, particularly 
on the ith, and we paased, by the help of oars, from 
two to eight milea firom the abore. The tcnipera- 
Core of the sea at sua-iet was 76^ F. on the bth^ 
77*^ F- on the 6ih. that of the atmosphere imme- 
diately above it 78" F. and 79^ F. On the &th at 
midnight, about five miles from the shore, the (cm* 
persture of tlie sea was 74° F., and that of the 
Atmosphere 75° F. There was not the slightest 
appearance of mist od either of these nights on the 
open sea, or at any distance from the land ; but 
cioae under the hills of htria there was a slight line 
of haie rinible before can-rise, which was thickest 
under the highest land ; and ajs we approached, at 
ftun>rifte on the 7th, (lie mountains of the Kriul, the 
tops of those nearest to Trieste were seen rising out 
of a thick white mist, wluch had not reached a 
quarter of a mile from the stiore. 

After mists have formed above rivers and lakes, 
their increaae seems not only to depend npon the 
constant operation of the cause which originally 
produced them, but Likewise upon the radiation of 
beat from the aopcrficial particles of water com- 
posing the mist, which produces a desceudlog cur* 
not of cold air in the very body of the mist, whilst 
the warm air oontinually sends op vapors : it is to 
these circumstanoea that the phenomena must be 
ascribed of mista from a river or lake, sometimes 
arising considerably above the surruunding hills. 
I have often witncsKd this appearance during the 
month of October, after very stilt and very clear 
nights, in the Campagna of Kome above the Tiber, 
and 00 Monte Albano over the lakes eiistiog in the 
ancient craters of this extinguished volcano, and, in 
one instance*, on the 17th of October, before sun- 
rise, there out being a breath of wind, a dense white 
doad of a pyramidal form was seer, on the site of the 
Alban lake, and rising far above the highest peak of 
the mountain, its form gradually cJianged after sun- 
liM, its apcLi first disappeared, and its body, as it 
were, melted away in the sun-beams. 

Where riven rise from great sources in the inte* 
rior of rocks or strata, as they have the mean tem- 
perature of the climate, mists can rarely form npon 
them, except in winter, or late in autumn, or early 
in spring. In pavstng across the Apenniues, on 
October lit, 2nd, and 3rd, 181S, there having been 
much rain for some days preceding, and the nights 
being very clear, I observed the beds of all ttlf^ rivers 
in the valleys filled with mist, morning and evening, 
except that of the Clitumiuii near its source, in 
which there was nu mist, and this river rises at once 
from a limestone bed, and when I examined it, at 
half-past six o'clock, a.m., October 3, was 7}^ lower 
than the atmosphere. 

Great dryness in the air, or a current of dry air 
passing across a river, will prevent the formation of 
miat, even when the temperature of tlie water is 
much higher than that of the atmosphere ; thus, on 
the I4th of June, near Mautern, though the Danube 
at five iu the morning was Gl"^ F., and the air only 
^i'", yet there was oo mist; bat a strong cislerly 



wind blew, and from the rapidity with which watte 
evaporated, it was evident that Utis wind wu ta 4 
stale of eztrrme dryneas. 

The Tiber baa furnished me with a number of 
still more striking examples. October lOth, tU 
night having been very clear, on arrivine nt tht 
Ponte Mello, at half-past six la the m 
found 00 mist on the river, yet the tcnij" 
the air immediately above it was 48^ F., aa^ :.»■. ». 
the river ^6' F. i a strong north wind blew, whidi 
indicated, hy the hygrometer, a degree of dryaess 
of 56% and thij part of the river was exposed to H ; 
but the valley above, where the river was »hcltcn4 
from the wind, waa full of mist, and the mist la 
rising to the exposed level might be seen, as it weit^ 
dissolving, presenting thin striK whi<^ never reach«4 
above s certain elevatioD. and many of which diMkp- 
peared a few seconds after they rose. From the 
I3th to the 25th of October* during which time the 
tj-araontanc or north wind blew, 1 witnessed repeat* 
edly the same phenomena, and in the whole of thii 
time there was only one morning when there was no 
mist in the sheltered valley, and tlie cause was per* 
fectly obvious ; the night had been very cloudy, bs4 
tite thermometer, before snn-rise, indicated a diff^ 
nnoe of only one degree in the atmoBphere bsiov 
that of the river. 

It ia not my intention to discuss the general sul^ 
ject of the deposition of water ft'om the atmoaphcfv 
in thia paper ; hut merely to describe a locjil dUM 
of considerable extent and variety in its modificia 
tions, and which is not without an effect in (hs 
economy of nature -, for verdure and fertility, in hflC 
climates, generally follow the courses of rivera, aaA 
by the operation of this cause, are extended to the 
hills, and even 10 the plains surrounding Lhllr 
banks. — PhitoMophical TVonsacfi^mt. . 



ON SEASONING TIMBER. 

Tub premature decay of timber, and especially qf 
the oak. by what ia technically called the dry ro(, 
is a subject which has occupied no small share flt 
public attention. If we may credit all that we v% 
and hear, the immerRing of limber in Kyan''s m< 
curial preparation is the nearest approximation to 
the long wished-for desideratum. Still I cam 
conceal my doubts as to its general utility. Ill 
application to timber for lighter purposes may b« qf 
much use in promoting durability ; but ita octiim 
on the huge timbers of eren a third-rate man o( 
war will, \ fear, come inliottely abort of etpccta* 
tion ; and, indeed, I think it highly probsbU; tlul 
aftcr-rxpcrii'nce will prove that, from the cUima af 
a decided specific, Kyan's process must degenorsM 
to the rank of an expensive auxiliary. 

In all our attempts to arrest the progress of diy 
rot, there seems to bean obvious misdirection of tl^ 
quiry ; our investigations not having been yet directeJ 
to the more immediate cause of the maUdy. to 
organic bodies preventives are always prefembtc tQ 
cures; therefore, wherever detrimental effects pre* 
sent themselves, we uught at once to turn our sttfa< 
tion to the producing cause with a view tii its re- 
moval, rather than to the application of tem]>orary 
palliatives. That the appearance of precocionH de- 
cay in manufactured timber may be tmr- 
presence of nlburnaus matter, in iu Hii 
the aap vesaels, is a fuct generally admttt* 1 .. .tim 
an oak tree with its Vfgctatire powers in full opcrm^ 
tion is felled, the sap, or albumous fluid, nut havinc 
hecD perfin:ted, or converted by the process of fotiit- 



rfAXSAZINE OF SCIENCE. 



atjoD to' iti ultiiTute purpose, beoomes 
in ipeedily commrace*. and in 

binmunicatea witb, and conts- 
.^.,d*.t parts of tbe fibrous column, 
ins employed by nature in decom- 
_ ie matter do«a not appear to have 
doe ■hare of consideratton from the 
The agency of albamoan matter in ao 
ttate U allowed ; but, judging from the 

t subaisld between animal and vegetable 
re can only riew this an a secondary cause. 

ica, whether animal or vegftnble, whern 

OMuud to exist, it seems to be a universal 
an*, in the process of derompoiiilion, to 
e active foreign power. Self-deotructioD 
MftMe in the natural code; therefore we 
kSaored that there is aomething ebie in 

than merely tlie presence of ijmple albur- 
Animal bodies contain the seeds of 

within themaeWn ; the different fluids 

conntlr.u millions of animated beings. 

rital functions are brought to a close, 

tenants of the veins and arteriei com. 

I work of derafltation upon the more 
matter : the putrid mass eogenderi ani- 
rger dimensions, to gnaw the sounder por- 
}fnsme, and, shortly afterwards, the loath- 

of uniting farth to earth is accomplished, 
aible that the decomposition of vegetable 

is performed by meaDs not rery dissimi- 
it of animals. The germs of the dry rot 
nmnnicated to the fibrous mnn through 
xn of the secretive organs at the root. 
I Cfaealbamoas fluid is tenanted by legions 
Cttlet, the patrid recoains of which iirthe 
t may form a soil, or bed, for the deTe> 

of tJie embryo fungus. Immersion in 
Vublimate impsrts no additional strength 
ody Abre. it only destroys the ritality of 

in which the dry rot originates ; anff, if 
Kng remarks on the origin of the malady 

io truth, then we have within uar reach 
IaUj, or even more, effectife, and far Itfju 
, than corrosive lubUmate. If it can be 

ved, that unconverted sap in timber b 

of the dry rot, as already suggested, then 
needed recently ia the inventing of a pro^ 

'by the sap cau be completely extracted 
of almoit any size. By this process (the 

r the prrpanng of which onn be hnd for 

anywhere) 1 find that oak timber can be 
the up, and so seasoned, tliat, in less 
nnn aft^r being cut, it may be put into 

of the carpenter. It was my intention 
lui process to preventing the shrinking 
log of larch timber ; but I have not had 

oity as yet of matting the espcriuicot: 

X have Hcn of tta efleota on oak, bow- 

bertaiu the most sanguine hopes of aaccess. 

ttude to act on superficial evidence is a 

on to our nature ; and hence we are too 
Io mistake effert for cauRe. Preemptions 
dry rot, is an efTect, in my opinion, pro- 
most ^Instaaces by tlw very ({uvstiunablo 
> which oak tiuihtr is harvested. In 
It of the other epecies of hard-wood treei, 
variable practice to have them cut down 
nation is in its most inert state ; but, from 

aluo of its hark, the oak furuis an excep- 

most judicious rule. The process of 

only be performed when vegetation 

ty, and certainly it requires no argii< 




nent to show dut this, of all seaions la the year, 
is the most improper to frll timber of any sort, if 
durability is Co be taken into consideration. Oak 
bark foruis no contemptible item of our rnlnnd com- 
merce ; and to propose that alt oak-trees to be ap- 
plied to marine constructionft should- be cut down 
in the months of December and January, will be a 
startling announcement to some economical pro- 
prietor!) and stewards, as by such a course the value 
of the bark must be sacrificed ; but I propOK no 
such thing to them. Let it be remembered that I 
am writing with a view solely to the stability of the 
wooden wsUs of old England. I am not patriot 
enough to recommend individual sacrifice for the 
poblic good, wfaea there exists no necessity for tt. 
This is the nge for," compensation ;" and when, 
collectively, we cam afford to present the West India 
planters with twenty miltiotis sterling for performing 
one single act of jaoticc, snn^ly, when treating with 
oak-venders to furnish our timber depdts with 9onnd 
material, we can well afford to make an equitable 
allowance (or the bark, if it can be proved, as I 
think it easily may, that we would be gainers thereby. 

All timber, then, for the oae of the British navy, 
OQgfat to be purchased growing, with an under- 
standing between the contracting parties, that the 
vendor alialt be bound to fell the trees at such sea- 
sons OS may be agreed upon ; namely, in the months 
of December or January. Had some such plan aa 
this been adopted long ago by the officers of the 
public dockyards, It is my firm belief that dry rot 
would have been much less prevalent. Even the 
process of felling herein recom mended is susceptible 
uf Improvement. Where any large oaktree fit for 
naral purposes is sold, It might be Mmiiged that 
the purchaser should be allowed two, three, of 
more, years to remove it. In this interim, vegeta- 
tion might be gradually retarded, by severing from 
the main root, annually, so many of the principal 
lateral roots, until the foliage aU but refused to 
expand. Under this treatment the usual copioas 
flow of sap would be diminished ; and, by redudng 
the mediiiin of its a.<!icrnt annually, the libre would 
become seasoned, and would acqnire a rigidity and 
toughness not obtainable under the old regimen. 

CiuUe jsAb^. J. ucvno, 

PETRIFIED HUMAN BONES. 
Dr. Lund, now residing at Xjigoa Santa, In Brijil, 
states that upon a lote journey into the interior of 
firaxil, he had, for the first time, met with bumoa 
hones, in conjunction with the hones of acknow- 
ledged extinct animals, which must be of au ex- 
traordinary antiquity, perhaps the oldest human 
bones that have ever been found ; for they arc in 
part petrified, and in their preservi'd condition alto- 
gether corrpflpond with those of the extinct auimala, 
in connciioD with whicb they were found. They 
will, he observes, throw a light on the nature of 
the inhabitants of this part of South America, in 
times which go much farther back than our know, 
ledge of this part of the world. The formitloD of 
the cranium is extraordinary, ina-smuch as the fore- 
head does not rise in the same plnne with the face, 
but forms a considerable angle, by which pecalinHty 
they differ from all craniums of living races of meti, 
and resemble the depressed heads represented in 
the ancient drawings of the Mexicans. In con- 
nexion with the extraordinary hones, was found a 
hemispherical-shaped stone, quite polished un the 
under sarfucc, which had evidently betn used for 
rubbing. 



A 



J 



MAGAZINE Ol 



MEDICAL RECEIPTS. 

FOn TlIK TRKTII. 
Hudton'* Pmertatit>e consisU of eqiul parti of | 
the tintiture of birk, rojrrh, wid cmninioD, with • 
Utile f!um ftrtibio. , 

Hfwtie't ia mide by roUiinc 4 graioi of ehlori- 
nateil Umc ichloriJe of lime) with 2 drams of pow- 
der«l gum or red coral ; this is recommeDdcd as a 
sweetener of the brcsth, and to t^ke off yellowDCH 
from tlie tceth. 

Grfenovgh't Tmcturt. — Tnke 2 onnc« of bitter 
dmoiids. half «n ounce each of Draxil wood and 
cassia berries, 2 dramft of Florentioe orris root, 1 
dnm each of bmoialate of potass, &lam and cochi> 
neal, half an ounce of spirit of horse-rmdiah, and 2 
pints of spirits of wine. 

Green't Thoth^povrder.—Ttkt 1 onnce each of 
dried sage leaves, crust of bread, and chloride of 
lodiom. and 1 dram each of nutmeg and cIotcs 
powdered ; triturate and mix in a morUr, 

RuMiiai'M Tincture fvr (At 7>WA.— Take 8 ounces 
of Florentine iria root and rhaUny root, 1 ounce of 
cloves, 1 scruple of amber^Kriae, 2 grains of musk, 
2 pints of spirits of wine; make a tincture and 
apply it with a bit of sponge or ootlon. It ia not 
10 good as tincture of mjrrh. 

Dele*cotV$ Myrtle Opio/f.— Simmer 21ba. of 
honey with half a pint of rose-water in an eartheo 
Teasel over a alow ftre. for a few minutes, and then 
mix it with a tooth-powder prepared from myrrh 
utd Armenian bolr, into a soft paste. It is laid on 
with a brush and ia good for sweeteoing the t«rcath. 
Parisian Dentrifict. — Take 4 ounces each of pow- 
dered FloiWSoe iris and TeruTisu bark, 12 ouocea 
of prepared chalk, (whiting,) I ounce of myrrh, 1 
ounce and a half of roBc-pink.and IG drops each of 
the oils of cloves and of cinnamon. 

Barktr'a I'ootk 2Tintf/wre.— Take any quantity of 
alcoholic infusion of pyrethrum, (feverfew) and 
color witli tincture of red cabbage. 

Laennic's Remedy for r&oM-fleAe.— Mix 1 dram 
of creosote and 13 drams of spirits of wine ; to be 
applied on cotton wool. 

Mineral Metallic Cemtnt.—Ku amalgam of tin 
foil and quickiiiWeT, combined with iron filings, 
finely levigated for filling decayed teeth. 

Z,e Dray't Marmoretum. — An amalgam of tia 
foil with quicksilver, combined wilb some Tery finely 
powdered fitnt glus. 

Mallan'x Sncctdaneum ia nearly the aame aa 
Ihe tin-foil on the back of looking glasses. It may 
be made by rubbing together quiokaiWer and tin- 
foil in a mortar, or melting them together in aludle 
OTcr a iire, and applying them wbile warm. It 
grows harder by degrees as the quicksilver becomes 
•baorbed. 

Lardner'a Prepared r*arcoaf.— Chalk, colored 
grey with charcoal. 

Grorpenor'9 Tooth-powder. — Kose<pink Slbs., 
palvcnzed orris root ^Ib., oyster shells 31bfl., oil of 
rhodium 25 drops. 

Atiatic l}e»ti/rice. — Powdered red coral 6 ounces, 
Vrnctian red 6 drnms, red ocliro and pumice stone 
each 1 ounce, mu*k i dram. 

Hemet'9 Dentifrice. — CutUc fish bone fib., cream 
of tartar \\\3, orrts root 2 ouneca. 

Green Tooth-povder. — Dry asge leaves, toasted 
crust of bread, and common salt each 1 ounce, nut- 
mrg and clove* each 1 dram. 



I>£PlLATOni»»; 
OK, coarsMtTion to t*M on terKavtvucl ««l» 

Take of quicklime lib., orpirocnt ^rama, 
root 2 drams, saltpetre 1 dram, sdipw ^ljj 
aoap-lees half a pint ; evaporate to a pff^ 

sistence. 

Roseate Potcrfer.— Lime ]2 ounces, starO 
ouncefl, orpimcnl 1 ounce; mi« thtm ti>grthar, 
Boyle' M Depilatory. — Take equal parts ofool 
and quicklime, powder them separately and cfll 
them ia water tilt they form a thick paste. T 
laid over the part whence the hairs ;are to Ij 
moved, and afterwards wiped off with a wet d 
Strong Dejrilatory. — Take 1 ounce of g« 
and 1 dram each of orpiment, ant's eggs, Ul 
arable reduce to powder and make Into pastti 
vinegar. 

Turkieh Drpilatory. —Tmkt 5 onncca of i 
lime and 1 ounce of orpiment, reduce th*am 
ralely to fine powder, mia well and fift. 
strong add l-aeventh or 1 -eighth of starch pa 
form into a poiite with warm water, and ap 
before. 

Deleeroix't Depilatory, or Poudre SHbtiU 
Colley'M Depilatory, composed like the r 
quicklime and seaqni-snlphuret of arsenic (orp^ 
perfumed with orris root powder and ten 
with atarcb. 

[It is to be remarked that tbo use of all de 
riea ia attended with danger, aa it Is by the a 
tion of the very poisonous snlphurcl of areaol 
ihey produce the effect eipected from 



tbuu 



lIAin DYES. aie. 

Enenee <\f Tyre \m merely a solatioaj 
of silver, (lunar caustic.) 

Grecian Water, or Hajna»*t Djfe, 
of nitrate of ailver, colored with syrup of 
diom. 

Orjila'M Hair /)y«.— Plurobile of limf, w 
boiling for an hour and a quarter 4 parts oT 
of lead, with i parts of Klskod lime, ai 
of water, filtering the liquor, and 
powder. This, in a warm solotion, 
hair a fine black in one hour. 

f Ve'« Dye. — Dr. Ure recommends a 
by mixing litharge, sUked lime, aud bit 
potass, (pearl-ash) in various proporlit 
to the shade of color desired ; he all 
the salts of mercury, lead, bismuth, as mtM \ 
oxydes, blacken hair, by the formation, hk 
bably. of metallic sulphurcls. ^ 

Foi'» Cream for the Hair— Pot into 
ounces each of marrow pomatum and alrai 
melt gently by the fire, and while cooHng 
2 drams of oil of jessamine or bergamot. 

Rjou'landu Bstenrf of Tyre is also a A 
solution of nitrate of silver. 

Rovtand's .Ifaecusar Oil is made by 
any rancid oil with onions or garlic, to taki 
bad smell, and Bcenting with oil of roi 
coloring while warm with olkanet root. 

Note. — We intend to give each month a c 
oflittle-knoft-n and vjloablo receipts, si 
above. 



liiiju 



VoU. 1 and 2 (j/" ihi» Magazine art now rt^ 

ffontly bound in Cloth and Lettered, prie* 



l^vnnx rriDlMl by O. rii*ll«ia. C. Whit* H..r»» t*nt. M-U VIikI.— PublUbvd by W. n«ttiAiH. II. 1 -Icti 

C^titmiitiUsiioin, fwliJch ir* aaswaiwJ on ihe Wran*" "' ""■ Pa»U) u-lie sddrtmd to UieWiiw.alw.GraaU 




H\T)RAULIC ENGINES- 



csoiutldcird in a Conner paper tboic hy- 
pMm which ftct by the pressure uf the 
■noolf culled pumps, it ia ailvijablf* 
mttetttion to the most remarkahle of 
br mechanical meani only. 
ouc of the mcMt ancient, as well as one 
effcctire, was the tympatium. 
of 1 great hollow wltccl, composed of 
joined together, and well calked and 
Ltng, as itc name iniportu, a kind of 
dnxm, aad haTing a hurizoiital uXe on 
turru. The interior ia divided by eight 
into u many equal fpaoea or cells, each of 
an oriAce of about half a foot in the rim 
or wheel, shaped so as to facilitate the 
the water : there are, moreover, eight 
iiMiU running Contignoas to each other 
L — NO. U. 



and pondli'l to die aile of the wheel, ench corrrs- 
ponding to one of the eight large cells, throii^U 
which the water pasiCfl from the cells just mentioned, 
and after running along the channels to a convenient 
distance, escapes through orifices into a reservoir 
placed just beneath the axle of the wheel. Thus 
the wster is elevated t)irough a vertical space equal 
to the radios of the hollow wheel. When the tym- 
panum is used to raise water from a running stream, 
it is moved by means of float-boards impelled by 
the stream; but when employed to raise stagnant 
water, it receives motion from a foot-wheel placed 
on the same shaft, turned by men walking inside. 
Tlie chief defect of thi« machine is, lh:it it raises the 
water in the most disadranltigcou't jjitualion possible: 
for the load being found always towards the extremity 
of a radius of the wheels the arm of the cfl'ectiys 



^ 



10 



MAGAZINE OF SCIENCE. 



lorer which answcri to it, mn-cMcs through tUc 
wluAe ijufulniat Uie wftter dencribcK in [i.i.<!iing from 
the bottom of th(* wheel Co the altitude of it< ci ntrt- ; 
«(i that the power tduhI art in like manner u if it 
wprt" npplird at a winch -hanflle, and conAcquentlj. 
connot act unifannly. 

M. di" In Fnyc, to rrmrdy this defect, iIpv'hum) a 
machine which may here ht^ dftifrihed, logetho' with 
the prooTM of rvaNmui^j tliat led tn it. 

W'hrn we dpvcloj»r the circiunfermcc of a ctn-lr, 
a curvti is described (i. e., the involute) of which all 
tb« radii arc ao many Ungcnta to the circle, and are 
Ukeviee all respectively perpendicular to the several 
points of the cur%'e described, which hna for it* 
greatest radius a line equal to the (>eriphcry of the 
circle evolved. Tlie truth of whitii i» shown by 
geomi-tririans when treating of the genefiia nf evolittr 
asd involute cnrvea. 

Hence, hai-ing an lule whose cirnmifierpnoe o Uttlo 
nceetU the height which the water is propodcd to be 
elevated, let the circmnferenceof thonilebc eTolved, 
and make a cnrred canal who^e cunature shall <;'jjn. 
cide tlirouKhout exactly with that of the involute 
just fornied : if the. fiirther extremity of this canal 
be made to enter the water that is to be elevated, 
and the other extremity abut upon the Bhaft wliich 
if tamed, then, in the course of the rotAtiou, the 
water will rise in a vertical direction, tang:entia] to 
the shaft, and perpendicular to the canal in whatever 
poaitinn it may be. Tliua the action of the weight 
annwerihfj nlways to the eitrctnity of a horixontal 
radiufi, will be as though4t acted ui>on the invariable 
arm of a lever, and the power which nuaes tlie 
weight will be always the aame : and if die radius 
of the wheel, of which tliis hoUow canal ■erves as a 
bent apoke, is equal to the height that the water is 
to be raised, and conscqnently equal to the cir- 
cnmference of the axle or shaft, the power will be 
to the load of water reciprocally as the radius of a 
circle to itfcirciunfcreuce, or directly as \io 6i nearly. 
In M. de la Faye's opinion, the machine ought 
to be eompoeed of four of these canaU ; but it has 
often been conetrucicd with eight, aM represented in 
our flgurc. The wheel being turned by the impul- 
sion of the streiun ujHin the Hoat-boardii, the oriAccit 
1* L, Ac. of tlie carrilinejir canaln, dip one 
after another into the water which runs into them ; 
and as the wheel revolves, the fluid risea in the 
ctinula, C, C, C, C, &C., and runs out in a stream M 
from the holes at N ; it is received into the troogfa, 
and conveyed from thence by pipes, 

By this construction the weight to be raised offers 
always the same reaistanoe, and that the least 
possible, while the power iii applied in the most ad- 
vantageooa manner the circumstances will admit of. 
Ai in many eaaea water is to be raised higher tlian 
the radius of any wheel that can well be made, we 
shall dcHcrihe a machine called the Perttan tehee!, 
which, like the machine of M. de Faye, may be 
turned by means of a slreain of water acting upon 
the float boards of the wheel. It. had, however, 
tile disadvantage attending the tympanum, which 
ii, that it can only raise water to the height of its 
semi •diameter. 

Tlie buckets B C D E, dec. are Aunff upon the 
wheel by stroDg pins, Axed In the side of the rim ; 
which must be made as liigh as tlie water i» intended 
to be raised above the level of that part of the 
stream in which the wheel i* placi^d. As the wheel 
turns, the tuckets on the left hand go down into 
tiie water, where they are filled, and return up full 
on the right hand, till they come to the top at P ; 



wherr they strike ngninSt Uic end of tl*r fta4| 

tmugh O, bv wliich they art oven'-' * - --— '- 

the water into the trough ; from ■>• 

conveyed in pipes to any plan; it ' 

and as each bucket gett over tJie trough, it lalli uito 

a prrpcndicular position again, and so c-s ^nwn 

empty till it comes to the ^atrr at A 

Ailed as before. On each bucket if a s\n 

^ing over the top or cnjwn of tlie troujgii ^ 

the hotloni of the bucket above the IcvlO of its 

and so causcs it to emjity all its water into the I 

DISTRIBUTION OF ANIMALS. 
fRtrtimed from pagt 4, and twichideJij 

The particular or local distribution of antmali 
is affected by various causes whirh have little tn(1o> 
enoe on their geographic distnbutinu. I'hus tba 
jiurely insectivnroQS bird* nf the fairily sylrladK 
feed on all small kinds of ic<iects, without regard tv 
any particular species ; yet the sylriadte nf Ameriet 
and Those of Europe are each characterized by a 
pcculinrity of structure which invnriAbly designattt 
the continent to which they belong. The wrTnnft 
is represented in America by the oxyrhynchua 
tatns ; yet neither of these turd» if found to inhabit 
all parts of their respective continents : their rvogi^ 
on tlic contrary, is reguUtrtl by tetiiperature. food|. 
and other drcamstances connected with local dUr 
trilmtion. 

Prom temiierature originate all the caoses «l 
aJTect local distrihutioo, namely, food, situatUm. vA 
migration. Were the climate of this country «a 
nnchanging as that of Brazil, the insects which no* 
have only a single brood in the year might then pnv 
dace several, and the swallow woold no longer b« 
obliged to quit us as now, for food in oUier cUoifttja, 
at soon as our insect season was at an end. lMigr»< 
tion and torpidity arc eijually the effect of temper*' 
ture ; the tirtt depends npon the effect whkk If 
changes of the seasons produce in the abondaooei 
scarcity of food, whether animal or vegetabLc i thi 
Istter is a state of inaction during which the ncce^ 
sity for daily nourishment is suspended. 

The migration of birds and of fish is more cJctuo* 
sive than that of quadrupeds. The birds ol thi 
Polar regions migrate to Britain daring 
winters ; while those of .^.frica come to ■». in 
season when the southern beats are most intenvi 
but tha same species which is migratory in oo* 
country is in some cases slationary in another. U 
is stated that the linnet is migratory in Greenla&ili 
but that it is stationary in Britain. 

The torpidity or hybernation of animals is 
dently designed to suspend the necessity of laktof 
food during the winter ; althongh in some coses 
small stock of provisions is laid up,' most probaMf 
to serve for nourishment previously to entire to«^ 
pidity taking place. Several quadrupeds are snb* 
jcct to this partial luspenaion of life, as the dflP- 
mouse, hedgehog, bat, marmot, &c. It is said tbfll 
birds have sometimes been found in a simihr ttatsj 
but this is very questionable. Among insects, on 
the contrary, torpidity is very common, and a lar|S 
proportion, when undergoing transformation, piM 
a considerable part of their lives in this state. 
Situation hss an extensive influence on the 
distribution of animals, although it has little 
geographical diatribntlon of groups. Air, t\ 
and water, have their di»tinet iohnbitanU, vliich sre 
again restricted to certain situations in their 
spceCive elements. The higher regions of tbi itf^j 





HYDRAULIC ENGINES, 



lira eobaUervd hi a former paper those hy. 

""^ whtt:h set by the jircuure of the 

:iimnnljr caltpii pn[u|H, it is ulrisable 

' Atientlon to the most remorluble of 

iK't by uiecluuiical meuu only. 

one of the most andent, u well u ooe 

Tctive, wu the tympanvm. 

t great hollow wheel, comfKiaed of 
I'ined together, and well calked and 
:;;, afl its name iinportn, n kind of 
,,, and boring a horiKOUtal axle on 
torn*. The interior is divided bj eight 
Into as many equal spaces or cells, each of 
an oriflce of about half a foot in the rim 
or wheel, shaped m as to facilitate the 
erf the water : there arc, moreover, eight 
channels mnninj; eootiguoas to each Qtber 
lU. — NO. U. 



!CntBi 



and pArntlel to Eho axle of the wheel, enrh corres- 
ponding to one of the eight \arge cells, throiittb 
which the water passes from the ct-lls just mentioned, 
and after running along the channels to a convenient 
dUtanee, escajtes through orifices into a resorvoir 
placed jost beneath the axle of the wheel. Thus 
the water is elevated through a vertical space equal 
to the radius of the hollow wheel. When the tym- 
panum \s used to raise water from a running stream* 
it is moved by means of float-boards ioipolled by 
the stream ; but when employed to raise stagnant 
water* it re(x:ivea motion frum a foot- wheel placed 
on the same shaft, turned by men wulkin|^ inside, 
'llic chief defect of this machine is. tlut U raises tha 
watfT in the most disadvantngcoatt situntion t»o»sible: 
for the load being found alwaya towards the eztrrmity 
of a radius of ibc wbeelf tbc arm uf the effective 



Bbnk 



12 



MACAZISE OF SCIENCE. 



gmbfyo or Jtvmi*/ u visible — ibU cousItU 'of two 
ioAt$ or eotyiedoim, attached to eiich otbrr by t 
bmrt-iihaped buiiv, calleH the corcftlnm — the lowitr 
endnfwbirb, thti raHide, products the fature root, 
nod tb« upper rnd ox plumule the future atem, while 
the lobes jive the fir^t nounsbmeot to the jouni; 
plane. 

rttf. 1 Sulevlcwof ■ licMi. a EfUlvienofdlltP. X Th* 
umer'.rw.ihr cent ontw mhU bvLngrvmund. 4 Thf> Min« 
ufHrnctf, tltuwiiig 111* imo lobr*. the laillrlv (A.f um) tbr rila- 
mul* itlj 

In ffome leeds, betides the embryo, there i> ■ 
poftiuQ which when young is fluid or pulpy, and is 
iotendrd to nourish tbe seedling plant, in the lame 
manner as the white of an egg nourishu the young 
chicken, and which it therefore csUrd albumen. 
Sometimes the albumen in wholly sbiorbed during 
ike ri}N3nlng of the (teed ; in other cases it is found 
aftarivards as a nut-like, homy or mealy Gubstance, 
ll>u« nimott the whole of a grain of wheat is albu- 
men— lo is tbe hard ttone of the dale, and Che deah 
ofthe cocoB nut. In the last ioilancc part of tbe 
albutttrn remaioa flnid. which we know as the mitk 
of the fruit. A thin akin, called the membrane, la 
alto found Bometimes witbtii the tnta, as in the 
wslnut t and in many inAtauccs an extra coat onre- 
lopea it — this ia called the nrii. The bean sboro 
rtprescntcd has neither albumen nor aril. TTio 
nntmr^ flctrd baj both: the inaoe lathe one, and 
the mund aromatic part, commonly known as the 
xiutcnet;, U the otJicr — the embryo being exceedingly 
small. 

t)f the Tarioua parta of a seed the embryo is the 
jnoft ef4enti«l. as it is this which grows into the 
fulnre plant, and without which no seed is perfect, 
Iffiwcvnr well formed it may appear. The embryo 
i* sonii'tirnes erect (1) as in the dandelion and other 
componnd flowers j rereraed or hsngiii; by the 
upper (ud (2) as in parsley, and the rest of its order; 
wr boiiiftnliil (3) as in the prlmrote. Itjt particular 
atisfke varies materially: it maybe Htraight(l) — 
coiled up (j)'-apinil (6) — annular (7)— or bowed, 
b«nit, and plaited in Tarlooa ways. 




I. Kmfifjo rr Dondrllia 5. Ditto of Pnnlfy X I»U!ci 
of th* t'r.mro**. 4 I>Lilo nt lh« Anim. i. tU'.to of llici 
lta\\ a tittbi iiF Ihfl IKhIiIct. 7. Hlllo nf llio t.ycbuU. 
the S)itu»eh, and very mniiy other |;rt>cnt d planli. 

8uch sfrnU as agree with tbe above description in 
having two cutyledona opposite to each other ; also 
those few plunts which have more than two are 
called dico/y/ef/onDUf; but tliere are others which 
are never found willi morccotyli-dons than one, (or 
if thne are innre they are not opposite to each 
otb«ri) sacb, for example, as the grasses and the 
lilifi. T' '•'■■ -''..u arc called monorofi/hdonotift, 
while tl. I lantfi, having no cotyledon at 

all, are * fJonouM. It is in botany of the 

6rst necc»»ity to puy uttantjon to these three words, 
because the plants of the. one or other kind hava 
such Ytry uifftrcut cbar/tctcrs of leaves, stems, and 
general atruiiure, thnt the foaodatiun of the whole 
arrangflment of pbuta in natural ordcre drpvudt 
upon thcie differettcri. 



!n the color of secda almost every tint may li» 
found. Various shades of brown, red, and str«« 
culjr, are ronimon— black and white scarcely fcis 
BO. Brilliant yellowa, blues, purplra, and gteeita, 
are more nire ; but bright acarleta, crittiaf>«ts, and 
delicate flesh colors occur fi^qnently, whilo baay 
arc most beautifully mottled and speckled — an u- 
stani'c of which we see la tbe different vanciios of 
Llie French bcdn. 

The sh.i]te of seeda ia nu leM varied. Tbry may 
be globular, flat, oval, teur-tluped, and of almaa 
every solid form, at will be ie«a by tbe fuUowIm 
engravingi :— 

\ s s 4 a 6 

® % ^mfs> 

7 & 9 lu II 



13 



14 



IS 



IC 



I. 1 i 

17 \*mmi 




I. Heed of th« P«&. SI. Of Ui« Kt<)iifv > 
lV>n*Ulit pAluttn*^ 4. Of Uie Flaa. t < 
Wttrt. It ur Ifafi Tau»oy. 7. The h»irv 
fi- Pitted M'cd of Ibe Scuip-Dra^.in. 9. Of - 
lU. SbffU-liko need iif (he CiDque-rulL i 
r.illnn Plinl. illia Phyaoetcmon.j If. S.. 
Kilt. U. Th« riljbod»e*d ofibe tloMrnuu Dm 
rough H«d (A tb» Krog Bit l». Srnl i>r (be 
16. Sp0<1 uf OD« apecWs of lh« IxJViutUlfe 
i«ed uf Lti* tra-ni^k Stock. 

It will be seen from (he above bow the turlu»tf 
seeds ia variously marked and ronghejied — and, aa 
TD the rose tree, covered with hairs, la the cottoa 
tree they are enveloped in tbe fine, long, and whibs 
down, which is wo well known as cotton } and if «« 
consider still as secda, rather than aa seed-vesadk 
what are commonly called such — namrJy, tha 
produce of the grasses, the compound Aowvn^ 
the nmbellnte plants, and some others, we shall not 
only grcAtly increase tbe number and vnrircy of 
aha|tes which they aaatime. but have our attcntlen 
directed to sundry curious appeudages, by wtu^ 
the dispersion of seeda is in oumerons iii&iancet 
aasiiitcd. 

Tbe seeds of many plants have attached to tbem 
feathery crowns, called in the singular a pappia. tt 
the valerian it at first remains carefully coiled ^ 
but as the seed ripens it eipanda, and the tccd li 
carried away \ when it finds a moist spot ada[iliA 
to its growth this beautiful little crovrn fsUi «f. 
From the aeeda of the willow herb the crown of 
haire projecta like the feathers of a shuttle-cockt 
opening afterwards like a atar. In the dandelioo 
this pappns is supported upon a stalk, which de* 
vates it above tbe seed. In the goat'a-beard sot 
only is this the case, but each fine hair is itsdf a 
feather — forming altogether one of the moat elegui 
and perfect objocts. All these contrivances are !•• 
tended to catch the wind, tliat the seed may bt 
wafted to a distance. The same purpose is sccon- 
ptished in the feather gra«s, in the clematis, aad 
still more perfectly in the tilhndsia, a jilant of tro» 
picol countries, by a long feathery awn. Tbe 
of many of the gmsscs iirnl such like plants hav« 
tached to their lower cod, strong and hXXS br: 
called k*ta'. Theae pointing oil (.me way prevail 
the teed rt turning, when by any cause it has ororkel 



MAGAZINE OF SCIENCE. 



IS 



ig the ^ound, or tmoog the rlnda. Thii 

oftcD (X'CMsiotied by cbungr uf Jf7nrsi and 

l^kn tbeair. Tlte animated oat (ovcnafatan 

,) U a welMuiown example of H. If 

ftcerls be placed upon a shelf or window 

in^Mble weather, it wtlU af^rr the lapse 

Ibrre Jnyt, be found to hate crmwled for- 

« cAitsi livable dtstanco from its first sita- 

'fblloffft : — When the seed becomes damp, it 

' lengthena. 'A'hen the air dries it again, 

ahorter. but on accoant of its aetK, it 

turn ; therefore it draws the latter cud 

thiu aC every change in the weather it 

Ibrward. 




[Pxpmii of tfat Vklerlan. 8. Oitt* of the WillAw 

mm CirunndML 4. OiiOj oT lb* Ouidvllon. S. Ditto 

Wt Bcsnl. C. Fraihrr ot lh« Cl«mAlU Sre&. 

lh« Son^tit. ('f ituU Kuib. & tlainftf tbt Adi- 

i- Ann. <-r uwitwd brltU* of Um Barley OnM. 

the case too with the aim or beard of bar- 

rb<*t. which are set with tcetb like a aaw, 

ly the leeda of these plants, but the 

wiU crawl away from its pareoC, if broken 

" known to children, who gather the 

loa barley graw, and putting one 

;, at the wrist, soon find it at their 



admirable contrivancea for the dis- 
i re are many more to be looked 
nid peculiar formation of seed- 
ing ulten assist in accomplithing the 
Lbeir fur and wool catcbea the hooks 
tteedsof the goose-grass are provided ; 
[the mistletoe adhere to whatever may 

ioK to their clammineaa. It ii well 

ii that the seeds of numerous berries and 

it will grow, though tbey have passed 

bodies of the birds which bare swallowed 

toa we not only witness in seeds them- 

Bost admirable stracturea and contri- 

theirwH)-b«Mng, but the very hsbita and 

cf animola are made subservient to the 

lion of the vegetables upoa which 

Aooriihed. 

EVER-BURNING FLAME. 

« lately read at the Royal Irish Aca- 

Mr. G. J. Knox, ' On a Principle for 

•n Ever-burning Flame.' — " A belief," 

in the discovery of an ever-burning 

to have been prevalent in all agea ; 

informs us. that lamps have been 

where they hare continued burning 

■ thousand years, of which mention 

in the works of St. Austin, PlutArrh, 

lens Vivea, Bapttsta Porta, and Licttus. 

idans, who laid claim to the knowledge 

mystfrioufl, pretended to have re-dis- 

r-t fif lbeir construction, which was 

ive been buried in the tomb of their 

Dr. Plott, in a treitiae which be has 



written upon this snbject, alludes to a Ump men- 
tioned by St. Anstln in his book de Ciritaic Det, 
which was bung up iu the trrople of Venos ; and 
to another found in the tomb of Pallas the Arca- 
dian, who waa slain by Tumus in the Trojan war, 
whirh cootinard to burn after its removal from the 
tomb and eipoaure to the air — proving that these 
lamps were not aupphed from any bituminous source, 
or volranir fire. He considers the rc(iui«ites for an 
ever-burniag lamp lo be — a perpetual wick, which 
might be msde of gold wire, or asbestos ; and^a per- 
petual supply of fuel, which he imagines the bitn- 
minous springs of Pitchford, In Shropshire, or the 
inflammable gasea isaning from fissures in coal 
mines, would afford. That such coold fupply fuel 
for a flame, so long aa the bitnminons spring cxislrd, 
or the gu oootinaed to eibtle from the mines, is 
evident ; but it no more deserve* the appellation of 
an ever-burning Ump, than does a fire arising from 
any volcanic aonroe. The desideratum for such a 
IfiSDpis, that it should contain, within itself, a reno- 
vating principta, aach as, probably, dona the lani- 
nnu5 aCmosphrre enoompaasing the body of the sur, 
ftippoaed by Sir William Herschel to b« electrical. 
That electrteity was the principle upon which such 
a lamp could be constructed, having occurred to me 
some years ago, 1 reflected upon the ditfertnt means 
by which a constant light could be produced from 
this source, and concluded that, if by an arrange- 
ment of metals a thermo-electric corrent could be 
produced of sufficient intenaity to decompose water, 
the heat produced by the burning of the two gaaea 
arising from the decomposition, would be aufbcient, 
when applied to the alternate metallic junctiooa, to 
continue the electrical current of the thenuo-electric 
pile ; while the gases, which, in burning, become 
aqueous vapor, might be oonilensed by paaaing 
throngh a long tube, through which, being conveyed 
to the closed vessel in which tlw water bad been 
originally placed, th<*y would again undergo decom- 
position, recombination, and condeasatioa. Such a 
thermo-electric arraogoment has been discovered hj 
Professor Botto, of Turin, who has obtained decom- 
position of water from a series composed of a greater 
number of wires of platinum and iron. To prevent 
the apparatus from acquiring Jn time the aame tem- 
perature, the alternate janctions of the metals, to 
which the beat is not applied, might be connected 
with the pedeatal upon which the lamp is placed ; 
and the pedestal be either allowed to rest in a cold 
sitQBtion, or else be connected by wires with mmdc 
extensive cooling surface." 

CHARCOAL AS A MANURE. 

BY MK. LCCA8, BOTAKIC OARDEN, BCUMICH. 

According to my promise, I now lay before mf 
r««dcrs the experiments I have made in the applica- 
tion of charcoal to another purpose, via. using it as 
a mixture with various sorts of earth. It showed 
here alao the aame extraordinary effect; and all the 
plants that have hitherto been subjected to thia 
treatment have been as much distinguished by their 
luxuriance of growth, as* by the more perfect de- 
Tclopemeot of their individual parts, lliia waa 
particularly the case with tuberooa- rooted plants, 
which, besides their perfect develupement, had also 
n much longer period of vegetation ; so that the 
diffcrt-nce in thia respect, between those that were 
cultivated iu tlieir usual soil and those which had a 
mixture of charcoal, amounted to nearly two monlba. 
I was led lo thia by several trifling dreams t&ncca. 



A vcrj suitable trcAtment iatroduccd into thin 
botanic garden of plunging poU with bulbous or 
tubcroui-roated pUntj taken up PTfry year, for a 
fvw werka afier potting, or till tbey begin to shoot, 
in a moderate bol-hrnl, ccvcriog them «u inch dtep 
with earth, was applied the prevlotu year. A bed 
which bad been us«d for aowing the aceds of tender 
ptinta in pots, and in which charcoal uhea were 
need for plunging them in, waa appropriated to re- 
c«ire the newly. pljuitcd sprciu of ^4'mm, Begonio, 
Oitaerat GlosCnia^ and Scitambeec. The pota 
with these Cubera were plunged to the rim in the 
frame containing tbo chnrcool ashes, and then 
covered over with loose moold from a dung bed. 

Before I proceed further, I cannot refrain from 
recommendiDg this method, which, to my kooT-. 
ledge, has not been long known io German gardens, 
to all cultiraton ; for nothing is more contrary to 
the nature of thotc plants, than to set Ihem in tlie 
open greenhouse to make their first shoots, where 
they are cooaeqaently in a dry situation. Most of 
them, when treated with a gentle equable warmth, 
like that of a prerionsly-used dung bed, will be 
much more fine than if pUced in a higher and drier 
temperature. Watering the tubers before they be- 
gin to grow ia very disadvantageous, and yet it 
would be absolutely necessary if the pots stood in 
a greenhooM : we prevent the evil by making the 
earth in which the tubers arc to be set sufficiently 
damp, only slightly pressing tliem down, and im- 
mediately coverirg them with earth in the dung 
bed. Only wben the Intter begins to dry, it should 
be moistened all over with Uio watering-pot ; and 
this operation should be continued till all the tubers 
bare made sfaoots, and then each can be watered 
mngly. With reap«ct to preserving them through 
the winter, I have to observe that these tubers, as 
soon as tbey are taken in, should be placed in the 
greenhouse, not too near (he glass, and the earth 
covered with moss, by which they will be prevented 
from drying up too soon, and the neceaaity of 
moistening the earth obviated. By such treatment, 
waul of success in the cultivation of these spleudid 
omamentj&I plants can never be complained of. But 
to our subject. 

Theac tubers, plunged in the aabcs, soon ahot up 
ligorooaly. Aa they ought to be grown in a high 
frame In summer, bat which could not be im^- 
nediatcly prepared, they remained io tbls low bed, 
which waa only raised, dug up, and kept covered 
with earth. They absorbed a great dval, and re- 
quired watering every day. "When Ihey were taken 
np, moat of the roots, as may be snppoaed, had 
grown over and under the pota ; tb^y bad pene- 
trated into the charcoal, and grown so strong, that 
it waa abaoliitely necessary to re-plant the tubers 
in pots considerably larger in size. I. of course, 
mixed charcoal with the earth in which they were 
to be planted, in the proportion of rather more than 
half. All the above-named species showed estra- 
ordimuy Ituuriance under this treatment; some 
were particularly rich in their inflorescence, and tlve 
green of their leaves waa much more iDtense ; in 
others, the period of flowering was of unusnoUy 
long duration, so that while others planted in the 
usual soil had Jong ceased flowerins. these continued 
to vegeUte freely. Very small tubers, from which 
in the ftrat year no flower was to be expected, 
flowered very beaotifolly, as was the caae with 
OcMotra atrowinguinca. The AwtdcK, namely those 
with spotted leaves, such aa Caladium pictum, 
C bicolor, C. discolor, C. spl^ndens, C. poe'cile, 



C. bEmata»li^n)uui. C. verfticolur» iiwc., caciud out* 
versol admiralion. Several apeciea of Bkllb^igaa 
and TilUndaia, to which I also added charcoal, soon 
exceeded in luxuriance thoae that were growing la 
common earth. From what waa before said of tbs 
C6ctif it may easily be su^iposcd that Lhcy wooU 
flower well in a mixture of charcoal, which a- 
pcrience confirmB. Hcchtid, stenopL-tdla. whkdi 
rooted so quickly aa a cutting, has since tbritra 
equally well in a mixture of charcoal. Tlic iplendkd 
Mexican euphorbiaa, such as E. faatuusa and £. 
fulgens, showed a very considerable power of gnnrCL 
Orange trees with yellow leaves, having had a Itytr 
of charcoal laid on after the upper surfaoe of earth 
had been removed, soon recovered their greca 
color ; this was also the case with gardenias, W« 
need not be very particular oa to the quantity to be 
aaed, half charcoal may be used withoat injin; 
only care must be taken, as before noticed, that \M 
charcoal should be exposed for a time Io the infla* 
ence of the weather, and the larger pieces remoroti 
and watering should never be neglected, aa dM 
greater poroaity of earth causes it to dry up soour. 

A very interesting circumstance took place with 
an old and very sickly plant of the DoryantiMS 
excdlsa. After thia plant had been falling off tm 
two years, and in reality had no roots but one 4|d 
and decayed one. it was planted in charcoal, sad it 
the course of three weeks it began to shoot, and ft 
since perfectly recovered ; it is growing in a soQ of 
one-third charcoal. 

Fernfe sown on fine lifted charcoal germinsli 
quickly and well ; a number of species come a|i {■ 
the charcoal beds where seed falls, and not ooJr 
Gymnofriunma macrophylla, and PtiTis serraltef 
but other rarer and more valnable species. ^ 

A friend of mine in the neighbourhood of MqbI^ 
uses charcoal ashes for mixing instead of aand, aad 
he assures me that all plants, chirfly hothouse ooeS, 
and among the castas, particularly thoae with pis* 
nated leaves, acaciaa, bignonioit, 6cc., succeed a- 
tremely well, and have recovered wonderfully tetm 
their previous bickly state. 

My esteemed principal, the court gardener, M- 
Seitx, who acknowledges the importance of thi.'* use 
of charcoal, is now putting in practice a number af 
systematic experiments with different sorts af ehtf* 
conl, on all the familie'* of plants, and it will aotf 
be at the conclusion of these extensive obserratiQiili 
which in spring are to be extended to garden bedi^' 
that a well-grounded opinion on the nppUcatioa t$ 
charcoal ashes In general can be formed. 

Geaiin ZHtunff,Jbr 



CASSAVA. 
Casbata bread, cooaqne. &c.. are different 
given to the starch of the root of the mi 
(Jatropha ManiHut, Linn.) prepared in the 
ing manner in the West Indiea, the tropical 
of America, and upon the African coast, 
tree belongs' to the natural family of the 

The roots are washed, and rcdaced to a 
means of a rasp or grater. The pulp is pulj 
coarae strong canvas bags, and thus aubmiC 
the action of a powerful press, by which it 
with most of its noxious juice, ^used by the Ii 
for poisoning Llie barbs of their arrows.) 
active principle of this juice la volalili:. it is 
diKupated by baking the squcexed cakes of 
upon a plate of iron Fifty pounds of the: 



MAGAZINE OF SCIENCE. 



r, wlwetr distilled, nfftirH. a* ftnr. ihrw oanced 
% poteocMuc wftter, posKssiBic kn intolcrftbly 
:M»fr Ms>el| ; of wliich, thirty-fiTc drops brinjt 
ilattUrvd lo a 8U»e ron*lcted of Uie crime of 
cmaied UU death in the eonrae of tix 
ftmid horrible cunvulvtons. 
The pclp drletl In Ibo miinncr aboTC describet), 
iff^Ua tnio luspi, wliiob b«romc hard and friable 
•Wy cool. They are tlien brolcen into pieL*e<, and 
It is tbc aun to dry. In this aUte ifaej afford 
nutriment, tind are hRbilnallj used aa 
by tlie DefToes, ai alio by many white people. 
.ofutitiUe the only provisions laid in 
ri their voytges apoii the Amoxoni. 
vith a little beef or matton, tbey 
"nop similar to that of rice, 
^kes sent to Enrope, (which I bare 
««.ure-,^ are compoaed almoet entirely 
«>fti»« aloo^ with a few fibru of the tif;nrous 
U paay be purified by diffusion through 
-. p«MtDg the milky mixtnre thrv>righ a 
TTTtporating the strained liqaid orer the 
' nt agitation. The itarch dissolved 
rcns as die water erajmrates, bat 
luiTTil. it becomta granalatrd, and must 
'idried in* proper stove. Ita specific gravity 
of the other species of starch. 
Ifiuiuct abtained by this treatment is known 
under the name of tapioca: and being 
dcatIt pure, is often pniacnbed by phy- 
a aliment of easy digestion. A tolerably 
of it is made by heating, stirring, 
pa4«to ttareh in a similar way. 

juice of the root of manioc cod- 

Don a ?ery (i«e fecaU, which it de- 

tif itpoa the bottom of llie vessels. When 

Recantation from the supernatant liquor, 

ijKTcral times and dried, it forms a heautifoH 

vfckli creaks on pressure with the fingfrs. 

eipipa, in French Gaynnn ; it is em- 

br SMDT delicate articles of cookerr. es- 

ftttey^ as also for hair powder, starching 

lo«r, u imported, may be distinguished 

-ffOpt ftod other kinds uf Ktsrch. by the 

oC ita particles viewed in a microscope. 

afilwHcxl. all about UlOOOth of an inch 

and Asaociated in groups ; those of 

ftr« irregular ellipsoids, rarying in 

l«^0Oth to 1 -3000lh of an inch ; those of 

hjre th£ nme shape nearly, but vary in 

l-&00th to l-800th of an inch ; those of 

sepasmte apheres, KlOOOth of an inch. 



rUEL FOR &TK\M ENGINES. 

itt from St. PetcrKburgb gives some par- 

'if a sew foci for steam-engines, discovered 

ired by a M. Waschiuokotf, which 

ll U Asid* P^eat idrantages over coal. We 

r, besrd of so many of these wonderful 

~" oountrr, tbst we are a little 

)>« well to publish the facts 

'-xperiment msde, on a large 

,«iU tcttt toei, to which M. WasohinnkolT has 

lb« ftubc of rarbolein. was on board the 

itmmmr Syrias, on its last voyage from 

to Uoodun ; and the results are given aa 

•ooauiDptiun of-lilb. (English weight) 

is per bour, for every horse-puwer of the 

Uuitfwn revolutions per minute, 

■ speed of more thsn seven English 



miles per hour ; whilst, on the same voyage, wiUi 

ilb. of English rotil, of best quality, the wUc<>l i 
only twelre revolutions, and the vessel miuti 
more than f)\ miles an hour. The flaniA- 
new foci, sayi Captain Wjitera, who 
the Syrius, wai> so great, that they wert 
obliged to reduce it to one-third. — A cubic 
the best Newcastle coal weighs nearly S^itb., 
the same measure of carbol&n weiglis nearly .'iCt 
•t,4SO,0001h. of coal, the usual provision for 
vrsscls passing between England and the Uni 
States, occupy a space oi Hl.HSl cubic feet 
2,480,11001^. of carboliJin yielding the same i 
take only Dl. 094 cubic feet; so that the latter 
biistilile would effrct a saving of room to the e 
of 30.100 cubic fret, aviiUble for mrnhandii 
pasaeogers. The freight from EitgUnd to 
America, and vice versfi. I>t:ing at the ra(e of 2s. 
per cubic foot, makini; b». boLb ways, the 
economized, vrould produrr, for the two pi 
an excess of freight amounting, in value, to £'. 
deducting from this sum i643 (or the greater y 
of the corboU^in necessary for the two voyages 
coal, and allowing, bcsidet, jCl.^tO to the aco 
or any defiriency which might occur in filling 
the space aaved, with goods or paasengent, thl 
would still be a clear gain, at the lowest calci 
tion. of £3,000 by the use of the new fiiel.— 
AtAenatttm, 



MEMORANDA. 1 

Acthn tff Sulp/iur on Tron, — Colonel A. Evans 
has remarked that although sulphur has so strung an 
action on heated wrought iron, as immediately (o 
form boleH in it. yet it does not at all atTect grey 
cost iron. A plate of wrought iron, 63 of an inch 
in tliirkrieds, hrated to whiteness, and held against 
a roll of sulphur fi.lU of nn inch in diameter, was, 
in fourteen seconds, pierced through with a perfectly 
cylindrical hole. Another bnr, about two inches in 
thickness, was pierced by the same means in fif^cn 
seconds. Good steel was pierced even more rapidly 
than the iron ; bnt a piece of grey cast iron, wdl 
scaled and heated till nearly in fusion, waa not at 
all affected by the application of sulphur to its snr* 
face, not evenj a mark being left, A crucible wu 
made of this cnst iron, and some iron and sulphur 
put into it; on applying heat, the iron and sulphur 
soon fused together, but the cast iron underwent no 
change. — j^nn. de Ckim. 

Z^ad On in Glamargofuhire. — ^The Cambrian 
obierves— " It seems somewhat extraordinary, that 
in this speculating age, when such vast sums are 
sent to seek, and too often to sink, their fortunes in 
a far di«tant region, that our home treasures should 
be so disregurded, even our own county of Glsmor- 
gan. Leod ore, of the purest quality, which c&a 
even be scraped up by the sides of the road, in 
ditches, and abundantly a few feet beneath the 
face of the soil, still coniinues to be dormant 
science, capital, the gigantic power of the stea 
engine, all alike dormant. St. Hilary, Colrinsto 
Langan, Penlline, and other parishes, abound 
lead ore. Take up a handful of earth near any of 
the old pits, and it Is fall of lead ore. Twenty-iive 
years ago, it was asserted by tlie oldest pergmis then 
living, that the working of the lead mines on the 
PetiUine Court Estate was suspended (now from 
eighty to one hundred years ago) in conM^queoce of 
the overwhelming prcMure of water, years befu; 
the iteaa-eDgiue, with iU gigantic power, came ' 



ut 

i 




play, and Cfaat the mun vein of ore at Uie liine was 
Ihirijr-sPTen inchei in tlucknua. The ore waa then 
carried above half a mile to be waahed, and taken 
bark again to tbe Rmelting-honae, which adjoined 
the pita. Tbe iteain-engiae would now admit of 
the ore being washed U)K)n Che spot.'* 

GotJ, Sitver, and Copper dnn, — The folloffiog 
ia the number of pieces uf various sort* cuiiied at 
the Mint from the Isl of January, 1H37, to the 
31st of December, 1840 : — SoTcr«tgns, 4,395,373 ; 
half-Rovereigoa, 43-1, 77M ; — crowns, nil , — half- 
crowQi* 567.072 ; — ftljiUings, 9.74l,l}00; — liz. 
pence*, 7,524,000 .—fourpcncei, 6,070,680;— (the 
(otalQumbcroffourpcneesiaaucdbciitg 10,325,320 ;) 
penoe, 174,720 ;— halfpence, 1,075,200; — and 
£arthinga, 10.913.280. 

Coat Dust a* Manure.— Mt. W. H. B. Webster, 
Surgeon, K.N., of Ipswich, baa paid aome attention 
to this subject, the details of which may be found 
in tbe last part of the Transactions of the Society 
of Arts, London. The analogy twtwecn the con. 
atituent priuciplea of coal to that of oily matter led 
Mr. W. to conceive that it might be advantageously 
employed as food for plants. Tbe complete insolu- 
bility of coal dust aeems to be the Inwparable 
objectioD to its utility as ii raanure. and Mr. W. is 
inclined to beUeTc, from a long conitnued series of 
'observations, that tbe slender fiUmeutous radicles 
of plants (in other words tpongeoUtt) liave a power 
in all reapects equal, if not niperior. to small electro< 
galvanic wires of low intensity, which, by slow con* 
tinucd action decompose most substances that are 
presented to them, end among others that of coal 
dttst. Mr. W. also further states, that, whatever 
the Tital principle may bo, a lower grade cannot be 
aasigned fur it in the scale than that of electro- 
galvanic infloeoce ; and we are not, says he, 
Msuroiog too much for tbe TiCal action of the 
radiclea, when we -claim for them a power etjual to 
that of amatl galvamc wires, which can and do 
effect a deconi position of coal dust. He then pro- 
ceedfl to demonstrate the fact, that coal dust is not 
inimicat to vegetation, and this he accumplishes, by 
filling a series of garden-pots with fine cotl dust, 
and planting and sowing b variety of plants thrrein, 
as potatoes, onious. Sec. In all of them the vegeta- 
tion was estrejnrly vigorous and luxuriant. He 
also filled hyacinth gUsscs with coal dust, and put 
bulbs therein, supplying water as required ; and the 
result, when compared with tliose without tbe coal 
dust, was very marked and evident ; large, healthy, 
strong plants being produced, and admired by many. 

Animalculen contained in CAaro.— Thuret has 
observed in the interior of the anthers (globules) 
of chara mtgarii and C Hitpida, AexuoHc. Iriins- 
jiarent, chambered filameuta of unequal length, in 
which are containtd animalcules at fimt niotionlL-ns, 
but after a time they move and struggle to release 
themselves from tlidr prison. In this they do not 
always succeed, although their twisted position 
attests the eflbrts mode far disengiigement. Tliey 
appeared like a spirally-rolled thread of three to 
6ve curvea, with two appendages, briitUes, or ten- 
taeuU of excessive tenuity, which the animalcule 
incesuuilly agitates with great rapidity.— A/icro- 
Bcopic Journal, 

Air contained in Snov. — According to Dalton, 
the quantity of oxygen in the atmonpherc diminishes 
in proportion to the distance from the surfHce of the 
earth. Gay-Lussac, however, did not find this to 



be the lesult of hia experimenta — foi\ir whidilM 
obtained at a height of upwards of 2U,0Oi> i-^'-t r^ 
taincd the same proportion of oxjgcu n- 
cured from tlie nrighbuurhoud of P*its. 
singauU has found, iu common with oUicrt, lu*; «r 
obtained from snow contains 1cm O-tygen th«n tiiat 
of tbe atmosphere. Bat this holds good with rcfarl 
to tbe suow of the Andes, as to thitt of I'siii. U* 
admiti, however, that this may not be the composu 
tion of the air as it eii«ts in tlu: luuw ; bcesuse, Ui 
onlur to obtain this sir, it is iieceasary to mill ttut 
snow ; the gas of Cht- flask coiuea in contact with tbi 
wattrr, little if at all impregnated with air n-«nluttf 
from the melting, and it is wilt kno-->' 
such circumstances oxygen ditt&ulvcs mur- 
water than tlie asote, and that thr -•' 
water is saturated is richer in a\> . 
the atmosphere. M. Duinai and ' . 
are at present examiniug the cunpoailiou of atma* 
spheric air. — j4Mcn(pum. 

Briti»h Muttum. — The numl^er of ^i 
mitted to view the general collections fr< 
mas 1H39 to Christmas 1840, amounts u> ^\.,j,j, 
being 32,921 leas than in tJie previuui: yenr. TU 
number of visits made to the reading room*, im 
the purpose of research or study, during the fotf 
year, amounts to 07, •'i42, being 1,G74 less than hi 
the year before. The number of visits by artists 
and students tu the galleries of sculpiure. for the 
purposes of study, amounts to 6,354, being uk 
increase of 1,013 to the previous year. Tbe num- 
her of visits made to the print room, in ImQ, 
amounted to 6,717. The total number of additioui 
to the zoological department, by parcliaac ur othn- 
wice, 21,976 specimens. — Report, Houie qf 
ntons. Match 8, 1641. 

itff/eoric Paper. — TTie microscope has 
empluyt'd by Ebrenbef^ to determine the oo 
tion of the meteoric paper of lOliG, and w 
states is a product of eot\femm and ii\fu»orwat 
existing on our globe. According to this 
tbe substance known by the name of meteoric 
and which fell near Rauden, in Curlond, in 
is formed of ^laments of cortferva critpat.. 
matted together, Wwix remains of a noal^j 
nine well-prntcrved kpecifs of infusoria, miu 
cosca of dapfmia pitlrjc. Vf the twenty-nine 
soria eight only have aiUcious lorictt ; the r 
soft coverings. In the meteoric psfier of 
seoberg, Ehrenburg found eonferra eapillA 
punctaliit and otciltaioria timota^ along with 
distinct species of infasoria, tec. In a mass 
in Sweden, (Edogomum ceMtcatum (Link) loi 
and the- potten of some couiferte were discovi 
Microtcopie Journal. 

Preserralion of Meat. — At the last roeeci 
the Academy of Sciences, M. Gannal presen 
important essay, which is hkely to produce a 
derablo sensation amongst the public as well 
the scientific worid. M. Ganoal bos been for 
years occujiied with the idea of preserving mi 
injection. Thus, 4tb. weight of saline mixturff 
jected into the carotid artery of an ox penetrates 
■ he vessels, and prevents a putrid decompotil 
M. Gannal presented two 1^ of mutton 
two years since by this plan, and which i 
to be perfectly sweet. M. Gannal eraploya for 
purpose muriate of alum. This discovery is 
sldered ns valuable in prcaerring provisioua for 
nsTy. — Timt9. 



Lowmiw^PrinK'l by P. rsAHOk. fi. Wmt llono Lai>«. MtlP Eud — I'uhlixheil tiy W lUirrAi^. 1 1. raWratN«i»f Hi 
Cuinni4aitrsli«>ua. (»ltlch are 4iMntfivU uo Iht W(d)(|>cra of ibe I'artfj to hi adilrcueU to tlie k:ailc>r,a[ S^,(i(«a1 1'rruvtl 



AGAZINE OF SCIENCE, 



Unt School of ^xts. 




18 



MAGAZINTS OF SCIENCE. 



THE GAS METER. 

Pom (be invention nf this niftrhiae wn arc indchtrd 
to the innenaity nnd tolrats of Mr. Cltq^, mad ua- 
doubtcdly trf all the uiiprovefneut* wilb wbich the 
art uf prvcoring light hu been enrichctl, there ia 
none which has been attended with reralti more 
bencAcial to the inierat both of the nuuitifactartr 
Kod consumer of coal gia. 

In thin nischint! we Me coDibtocd ft itandard or 
cheek on the cutidiict of the workmen, which enabled 
the monufhclurer of coftl gv to BMore himself of 
nhtJiiuin^ at lUl timet the ^reate^t poacible produce 
firom bis estahliKhment ; s me«5Ure by which hr raui 
deal the ^bm oat to his costomers in whaCerer qnan- 
titu* they may reqoinc it, and an Index which re. 
psters the exact qnantities fornished, and tfauj serves 
u an infallible account of debtor and creditvr be- 
tween the seller and purchaser of gas. 

Tlua machine, therefore, perfoima at onoe all the 
dntim of an overaeer, meter, and book-keeper, and 
performs them all an mnch more effectooUy, thai ltd 
operation is not dependant on mattera ao onceruuu 
aa tite care or iDtCffhty of aervonta, but on onerring 
priociplea, whit^ are fixed and incapable of any 
hidden mifl«ppUcati(m. 

Rg. 1, representa a perpendicnlar section of the 
gaa meter. It eooiisti of a hollow wheel or cylinder, 
made of tlnn ixtm plate, revolving upon an bori. 
■ontal axis, in the manner of a grindstone ; thit 
wheel b hiclosed in a cast iron air-tight case con- 
taining water. 

The cylinder, or whed, is composed of two cir- 
cular channels, concentric to each other. The larger, 
or outer channel, is divided into tfanw equitl com- 
partmenta, by partition plates, marked, aa »hown 
in the design. The compartmeuts are proviHedwitb 
hydraulic ducts Of valves, mode at the upper port of 
emy pwtitioD plate A, A, A. and by meona of them 
m oommimication is formed between the larger con- 
centric channel and the outer case in which the 
wheel revolves. 

Similar valreii are also placed at the foot of each 
partition plate, they are aeen near the other letters 
A, A, A, and by thia means, a communication is 
rstjihlishcd, brtwcm each compartment or cliaiuber 
of the larger concentric channel and the smaller in- 
terior circle of the wheel. 

On ioffpecting the dt-sign, it will be seen that the 
valves are situated in o|iposite directions to each 
other, hence there can be no communieotion either 
between the inner smaller concentric channel, and 
the larger compartments of the wheel, nor between 
the latter compartment, and the exterior caae, in 
which the wheel revolves, except through the valves 
A, A. A, Ace, which form thf oom muni rating ducts. 
It will be aeen also, that theae valves are carried 
from one chamber of the machine into another, but 
in opposite directionti ; the entry into one chamber, 
being in the oppoeite direction to the hydraulic 
duct, placed in the other clumiber. 

Prom these particulars the action of the machine 
will be obvious. 

l^t ua suppose that the outer case (which is 
marked in tlte sketch by a black tint.) in which riie 
wheel revolves, be filled with water, to about on 
inrii above the axis of the whcd, and that gas is 
conveyed into the interior small cliiunel, by n piyte 
passing along the axia, so as to allow the wheel to 
turn freely round, and that the pipe is turned op 
at right angles in the inner chamber, and projects 
A \'tt\c way above the mrfarc nf the vrntcr, as 



ahoam in the design. Hie gaa then ma] 
into the interior rhamhBr of ihc wheel nbi 
surfane of the water, and Dtn%t prr»a ogaiiiat 
jacrut partitiuD ; it will therefore cau>e tli 
to turn round, and in coiis»jucnoe of thia 
the next |uirtttiou plate will prra« the gaa 
the surface of the water, and i-auj-cr it u> pua 
the hydraulic opening, in an r<)itnl i{uanttty 
which is introduced into the exterior * i.:>.nlii.| 

This alternate tilling , uiid diat). 
contenta of each chamber, will ih-. 
during every revolution of the wjjfil. 'uj r,. 
number of tttuea each particular ch.in.ir l 
hlled, and emptied of ga», may be ku'.s u. 

In fact thit maciune perfurms the t-lliri- n 
revolving gas holdera, tuni on an ) 
and moving in a dateru. which is li 
the machine. One gas holder, or l>[j 
of the machine, is olway* in the act of li| 
filled with gas, another is emptying ltd cootdj 
the outer c««e, from which it passe* into thjl 
voir, where it is to be stored up, or to Cht 
where it is to be burned, and the third compl 
is stotioaary, or in on equilibrium. The W 
any situation will* therefore always have one 
receiving, and one of its discharging toIvci 
and consequently it will revolve. 

Now to ascertain the quantity of gas dim 
by one revolution of the wheel, we need ( 
know the capacity of the chambers, and ad<i 
together. Let us for example BUppoae, ihi 
chamber contains 576 cubic inches, then on 
lution of the wheel, discharges a cnbic foot 
To register the total number of revolutions 
the wheel makes in a certain time, a train of 
work is connected with the axis of the m< 
LtiiuctKti of a pinion impelling a common t 
wheel- work, comfio«ed of any number oi \ 
The pinion on tbc axis of one wheel, 
circumference of the next wheel, an 
ference of tlu* wheel being as ten to v. 
whilst the meter makes 1.0UO,OOOrt-^ 
sent-* consistx of »ix wheeln, the lu>t 
series will only have mode one re\ • 
axil of tlie wheels is provided with a i 
plate, divided into ten parts, therrforv on) t. 
of nn-olutions may be read oif at any time 
apcctiou betwixt 1,000,000 ajd 1. (See Fig. J 
The velocity with whiiih the meter acCi, 
counse in proportion to the (|nantity "f cr-* i 
through it. Thus snjipose there it .- 
lamp connected with the machine, ol 
city Ughled. which consumes four Cuba fc«c 
in an hnur, the gaa mctt r perfnrms foor reto 
per hour, not exceeding the number wtuch ti 
chine is calnilated to supply. 

To render the contttrurtion rf the gas 
more obvious, we have ot Pig. 4, ethibiled u 
verse section of the machme; K ti tlw nuto 
of the machine in which tlie wheel revolves, 
the outer or larger concentric chamber. M tbt 
or smaller concentric chnmber. I) the index 
axis, which passes tlirough a stuffing box m ft 
the mochuu*. A Is the inlet pipe for the | 
enter into the machine. The gas passes di 
the pipe C, and ^om thence into the curvu 
D, into the interior chamber M, nf the I 
The pipe H, Is surrounded by a second p4 
which has a small aperture nt X, the office oif 
is to act as a ^phon, in order to preaer 
proper level of the water, which is poured M 
innvhtne through the funnel at tlie buftj 




MAGAZINE OF SCIEXCE. 



19 



ice f{p« A. Y is a flout, which stopi the 

lAQoe of ttw m^-trr alto^ethrr, if a fraudulent 

ipt sbould \te nittde to »tap the retnsteriiij^ of 

meCcr, by drnwiug off the watrr with which it 

iJirKed. In Fiff. 1, C ii the inlet pipe; D the 

pipe of the )^u. 

► GaM GoperMur.-^Viff. 6, is an instmnaent 

ited br Mr. Cleif]?. fnr rej^lntinn the inequnlitien 

«n the irreinilur prPAsiireofthe ;ft5-bnl(lcr«, 

tbftt from th^ {itiTtinK out of tlic Ug^hU nt 

tH-HnH.i f.f the night. This contriTiincc 

CMotnettT of sufficient weight 

[Dirptl pressure ; the interior of 

;t t-\iu\itiunicAtloii with the pipe tbroagh 

gti pitymm. This prwiomrter is connected 

rntvr, sn thftt when the pre«snre 

I, the gmomctcr risc!) and con- 

and, cm the cuntrarf, if the 

I the guomrter (altx and inereaMtM 

everjr case, the aperture is always 

tth the demand, presrrvint; the flame at 

height. Ita purposes are more eflertually 

»hnl by placing one, on a small sode, in 

hotiMT ; but one on a large scale, placed at the 

nutlet at the ga:9 works, will eqnalize the 

prr»are, and sevnis to be absirlately ne- 

iet.^«. -nremors are not indfridiiftlly used. 

-acting machine, and requires no 

■I once adjusttrd. The following de- 

m will probably render it intelligible : — 

6| is a section of the governor, and A B ex- 

jter ease ; this is made of sheet-iron or 

the top and bottom dosed, and bnth 

and nutstdi^ are al^o japoimcd. C shows 

'm tif the small giuometer. D the pi|« by 

the gKi enters ; and E the pipe by which it 

out. Tlie conical valve attaclied lo the 

uf llu: npright spindle I, risi^ and fnlls, so 

or enlarge the aperture G, as the 

nceiuls or deiicendfi by the entrance or 

of the gas ; and H is a short hollow 

eeji, in which the outer caae is fixed ac 

;of Its ha5«. 

has made some improvemenL<- in the 
. of the governor for regulating the supply 
owlet of the works, %o that, by its own 
pii'nure is increased or dimini.«ihcd with 
I Oni; of the modes he em- 
irtion of the small gaMmcter. 
».''>, iiy making an experimental gas* 
a small scale, ami requiring; luiifonn 
comparing the intensities uf light, in- 
a compeiisaiion chain, which it is not 
free from friction, he found that he 
the fiune, in a more shnple way. by 
giMHoeter leas in diameter at the Cop 
biHtom. Hence, by incrcjuiuE; this 
ice. tJir gwometer may be made to vary its 
Jo any required degree. He also effects 
irpo5e by employing a gawmcter of the 
instruction, making the necc*-!Qry com- 
tneans of a cycloidnl whfel.over which 
■-wriirht is itiapendcd. This wheel ia 
■ pegs for varying the curve, 
■ uro to any required variations. 
nioiiinrationB of the governor, Mr. 
I ftlmdy rendered it capable of regulating 
r.f .r*. fVom a portiible gas vessel, so 
i-tment of the valve, the flame 
from the beginning, tlirough 
of preanire, from thirty atmospberea 
of conimon gaaoiuetcra. 



The Oat Renter is a simple and iHgeninos in< 
strument for Indicating and regirtertng the impori* 
ties of the gna, and which, at the Mme timCt denotes 
the periods when they occur. 

The arrangement of this apparatus conftitts of a 
circular card placed upon an axis, which commoni- 
cntes with a time-piece. Upon tliis card tliree 
circieji are described which are divided into 24 divi- 
fions by line* drawn from the centre, corrospoDdiDg 
with the hours uf dny and night. The two largest 
cirrlex, {\ B, Fig. .1.) which arc of equal breadth, 
otrcupy the marginal ipace at the outer extremity of 
the card ; these ore coated with the usual solutions 
or tests for sulphuretted hydrogen and ammonia, 
and a very small jet of gas, from an oritice adapted 
to each of the circles, is made to pUy constantly 
over them. The inner circle being divided into 
.•ipacett that are marked from 1 to 12 fnr day, and 
1 to 12 for nigliK, hence, as the axis of the time- 
piece performs its revolution with the card attaclied 
to it, the impurities, and the time when they happen, 
become exactly registered ; and by changing theso 
cards daily a perpetual register is obtained. Tlie 
principle on which it acts renders the managing of 
it readily attainable ; and ita utility U obvious. 

Specie Oraritt/ Apparatut. — Another valuable 
addition to the apimratni reloting to gas, for which 
the public is indebtcil to Mr. Croaley, is a very 
simple and efficient cmitrironce for ascertaining the 
Mpeeijir tfrwity of corbnretted hydrogen gu* which 
he has acoomponied with an appropriate table for 
rendering the calculation easy and concise, at dtflcrcnt 
temperatures and hai-ometricat prcasures. Fig. 5, 
is a figure of the instrument, and the description 
annexed is copied fniin Mr. Crosley's, 

The specific gravity of carburetted hydrogen goa 
being one of the lending tesU uf iu illumiuatiaK 
power, the following easy method of ascertaining it 
is submitted for the use of thoae who are engaged 
in the management of gas-light estabUahmentft:-^ 

The figure represenU the form of a flaik, with 
an opening and cap at each end, which may be 
completely dischargNl of tlie air, and filled with 
gas, by placing one of its ends upon a pipe or coclc, 
of the same size, and passing a current of gas 
thrrmgti it in the following manner:— A projection 
is placed on each side of the flask, by wliich it is 
intended to be held iu the hand, so that the tempe- 
rature of the gas or air within may not be increased. 
Previously to the flask being filled with the gas 
intended to* he weighed, let it be freed from foul 
air, or gas, by taking off the caps from each end, 
and passing o current of fresh air through it, until 
the air within is the same as without ; this may 
be easily eflected by moving it quickly and repeatedly 
to and fro, endways, in the air ; the caps nmy then 
be put on, and the flo-ik arcHrately balanced; this 
being done, take off the caps, and past a current of 
goa through it during about ten seconds of time ; 
then put on the cap at the upper end, and, at the 
instant of disengaging the bottom end of the' fla&k 
from the pipe or cock, put on its cap, and im- 
mediately weigh it again, when the diminution, or 
counter- weight, required for restoring the balance, 
will give the specific gravity of the gas. 

TO OBTAIN PURE PLATINUM. 

Platinum is found in the metallic state, in small 
grains, in South America, confined to alluvial 
straU, chiefly in Brazil and Pern. It has alto been 
found in the proviaoe of AuUoquio, in North 



I 



■Ok 



tf 



MAGAZINE OF STTENCE 



Anirricit; ami in eoiuiderable qiuntiticj in the 
tJrnltan tnouotaiiu of Siberin. The grains, bnides 
piNtinum, rontnin prnrrally gnid, iron, le«d, psUa- 
dinw, rhodium, indium, ftnd cMmium, utA often 
flitdt* of titaniam and chromftte of inin. Roandcd 
raB5*pft of the ntiHal, howrver, ncrnsionaUy occor 
among them, and are tnrt with in mineral col- 
ffftions ; thr^ are rnrcty larger (ban a small nuirbic, 
tbouj>h some huvt been found of tbe size of a 
pi|;con'i e^ and upwards. 

The pure metal may be obtained br diasoWing: 
crude pUtinnm in nitro.roariatic acid, and prc- 
cipltatini; by a solution of rnuriate of ammonia. 
Thtr firit precipitate \» heated, re-dinsolred io nitrn- 
nuirinlicanid, and sfrsln precipitated h% before. Tbe 
icc*ond precipiute ia heated white-hot, and pure 
plntitium reniainii. It if a wUite metal, rjEtremely 
difficult of fusion, and unaltered by tbe joint action 
of heot nnd air. It Tarie? in density from 21 to 
21.5. According to tlw dci^rre of niechaniral com- 
prcsBsion which it has nu^taincd; it ia extremely 
durt!Ir, but cannot be beat«n out into itucb thin 
FeavcA on gold and icilvrr. 

The follnwins: details respecting the mode of 
puriryiiijn; plnlinuin, iind renderini; it nialleable, are 
t'ikcn from I>r. WoUa'«ton's hitc^t pnptT upnn this 
subject, published in iha Philosophical T^-aiiaactioTiM 
for 1829 :— 

*' Tbe Ofual method of giriof chemical purity tn 
this metal, by solution in nqua rcpa and prvcipi- 
tatioD with tal-ammonioc, nre known to every 
rhemlst ; but 1 doubt whether sufficient care Is 
ti>uiilly tftlcpn to Rvutd dixsoUini; tht iridium con- 
(..;. ...I ... I, ,> oi-p^ jjy ^jyg dilution of the coli-ent. 
I .t which I (p»ve in the Pfiiiotitphicat 

T V for IMO-I, of n new metal, rbodium, 

contained tn mide platina, 1 have mentioned this 
pre«:Aution, but omitted to state to what degree tbe 
acidfi should be dilutnl. 1 now, therefore, rccom- 
luend, that to every measure of the strongest 
riiurintic acid employed, there be ndded an equal 
nipj»*nre of wnler ; and, that the nitric acid used 
be what is called •' sin|-le aquafortis ; " as well for 
ttie suke of ubtAinitiff a purer result, as of eoouomy 
in the purchase of nitric acid. With rt-frard to the 
prnpDrtions in which the acids are to be used, I 
may nny, in rrmnd number*, that niuriiitic acid, 
C<)(iiralent to l&O marble, together with nitric ucid, 
e«|mv«lent to 40 marble, will take 100 of crude 
platinum ; hut in ordi»r to avoid waste, and render 
the snhition pnrer, there should be in ihe menAtruum 
n redundnnre of 20 per cent, at leant of the ore. 
The acids tfhould be allowed to diirest three or foar 
riaya, with a heat ^aduHlly raised. The salulion. 
bein^ then pourrd ofT, should »tand until a quantity 
of fine pulverulent ore of iridinru. suspended in the 
liquid, haA subsided ; nnd Bhould then be mixed 
with -tl parts of flaUammoninc, disftoked in about 
five times their weight of water. The first pre- 
cipitate, which will thus be obtained, will weigh 
about Ifift parts, and will yield about 6ti parts of 
pare platinum. As the mother-liquor will still 
contAm aboat 11 partif of platinum, tbe^te, with 
some of the other metals yet held io solution, arr 
to be recoverwd, by precipitation from the liquor 
, ..;. ..I ,.. v..^j ^ vroTi, and the precipitate is to be 
i ill A pro|Hjrtiunn1r qnnntity of aqua 

r'_ , I ir in lU eomjuisition to that bIkjvc 

dtm^trd : but in tbiu case, before addioi; sal-ammo- 
niac, abimt one part by mcanurc of strung muriatic 
acid ahouhl he ntixed with 32 parts by measure of 
the nitro-murutic solution, to prevent any pre- 



cipitation of palladium or lead aloag with tk« 
ammonio-muriate of pUtinum. T^i- t.Hi.^v Tire- 
cipitate mnat be wpII washed, in '<? U 

from the Tarioua impnrittcK «hirh n^ . i<i b« 

contained in the coroplir-ittcd ore in queauon , and 
must ultimately br well preflinrd, la order to remove 
the lost remnant of tbe washings. It ia oeiC to b« 
heated, with the utmost caution, in a bUck-I«Sid 
pot. with so low a beat as just to expel tbe 
of the sal-ammoniac, and to oceasloA tbe 
of platinum to cohere as little aa poasiblc; 
this depends the ultimate ductility of the produrL 

" The grey product of tbe pUtinum. when tarmd 
out of the rntrlhle, if prepared with due cautioa« 
will be found lightly coherent, and roost tbra be 
rubbe<l between the hands of the operator, in order 
to procure, by the gentlest means, a> wuch u CU 
poftHibly be so oVitained. of metallic powder. M. 
aa to pass through a fine lawn sieve. Tbe 
parte are then tu l>e ground lo a woodro bowll 
a wooden pestle, but on no account with tay' 
material, capable of burni«biug tbe partiele* 
pUtiutim ; aioM every degree of boroisbiiig »iD 
prevent tbe particles from rah^ring in the further 
stucfs of the proccM. Sim.-e the whole « 
tn br well wAshcd in c)e)in water, the < 
the Utcr stages of grinding, will fm'i 
facilitated by tbe addition of water, m order so 
remove tbe finer portions, as ^<oiia m they are nfi-^ 
cicntly reduced to bo AUipendcil in it. 

•• Those who would view this aubjeet arientlfi- 
cally, should here con^-ldcr. that ai» platin' 
be fused by the utmost hmt uf our furi 
consequently cannot be freed, hVr ■•' 
frnra itA impurities, during igneous ' 
nor be rendered boitioneiieffus by h 
mechanical diffosioD through water .sho 
mode to answer, as far aa may be, the ; 
roeliing ; in allowing earthy matters U> c 
surface by their superior lighlness, and 
tbe solvent power* of water effect, oc far 
hlc, tlR* purifying powers of borax mad otbtfl 
in removing Boluble oxides. 

" By repeated wafibing, shaking, and 
the finer parts of the grey powder of plstinnm' 
be obtained aa pure u other meiak are ti 
thf^ various proceasea of ordinary metalli 
if now poured over, and allowrd to s-. 
clean basin, a uniform mud or ptilp will 1 
ready for the further prtweaa uf casting. 



DIMINUTION OF TEMPEKATURB 
COASTS, SANDBANKS. Ae. 

In the third number of the Journal of 
the Arts, an extract of n letter from Dr. D»< 
been published, eoniainini; some obscrti 
the temperatnre of the ocean and atmosphi 
the equatorial regions of the globe. Amoogitj 
philosophical remarks, those by which be eofl 
the conclufion of Mr. Jonathan WilUama, an4j 
observers, that the teinpfratmc of the 
lalls in sbiuil wiiler, ;ind that the thrrmomct 
be made a useful instrument in Da\iga(ioo» 
to be very important. 

Mr. Witlinms attribate« th*- effect npoa the 
mnmeter, on tite approach of land, to the 
power of the land ; but this n»son will DOtil 
to the effect of shooU in the oc«tan, or to the 
i?a1 climates. M. de Ilnmbold, in bis 
Narrative, seems to couaidci it us restillili| 



rflte 



MAGA2INK OF SCreXCE, 



21 



[ciM cnmnka Mow the suif&ce ; bat 'm kii work he 

,jioc cuter into my miriule details: nor did he 

it ftjiy turtber, thui to mautiontng thiv gnne- 

ihtioti Dr. Dary hu merely noticed the fnoC, 

ier«l Uw ; bttC hju not ipecukted u(M>n tha 

tof it. 

raya produce very little heat, in paistng 

eir; hot during their trarismiuiun 

body M imptrrfci-tlr traruparent as water, 

am Im no dmi1)i thnt th« sane oaaie which 

loos fth>aa "• !"■'■* —n^t cororounintc ui etTect 

sf bCBl;. Hid ccM the i^mtejit heat inuat 

laeed at '. nf the sea, and it muat 

ulty diminiah, as the rays penetrate deeper. 

itt heal of the aurface of the ocean most, at a 

:diJlaocn from land, depend upon the ahiwrp- 

the witar rwy«. xhr eooling of thi« surface 

.ind upon evuporatlon. 

'■nn»Iiictor of heat ; and 

-e .«. -r ...- „. W of Fahrenheit, its 

terreaaed : when cooling af^nciet act 

^vnfiltliomable ocean, the atrata of water 

'^Vlnk Ant of the reach of the surface, and 

inrtniinre the tempernture of Ihia <iurfnre; 

ioUd]^ aieencies act npua a shallow part 

I, the couled strati accamulute and up- 

■r the Hurfacf, and cause the tcmjiera. 

ocean, bt \ti surface even, to be nearer 

tmpenttnre of day and night. 

shallow water, close to the shore, the 

be heated ; and durinir the day the 

dose to the shore, will be higher than 

ocean ; but in tlie night, as the land 

than the sea by radiation, the air, haTiiig 

tare lowered by contact with the cooled 

down upon the sea, and thuii will deKtruy 

the hot watrr flowing from the extrente 

at a L-t-rtnin moderate distance will 

a diniiriuliun of temprrurure, as will 

oomprnsate for the heat prodaced by 

bot land. Hot-air and water, witbin 

i»2^ always rise ; water cooled below 

Its ; therefore, by whatever cause cool 

arv kept near the surfuce of the ocean, 

will dimimsh the general temperature of 

[Mrlboc. 

snpposed by M. Perron, and other 

tt tee may exist at the boUooi of the 

simple physical reaimns show thnt this 

tuibit:, itoless the temperatnro of the surffice 

vvc^n in below 40"^; lor water at 40^, is hca- 

^tltaa at tlie frceiin^ point. Ice, as Count 

lias shown, olwBjrs forms at the surface; 

at tbi' txittom of soy part uf the ocean, must 

ttii Itisw, when the temjKTBturr. of the aurface 

40^; fur hot curreols then descend, and 

riae. 

ir caoM must always operatCi when the 

ke snrfdce of the ocean is above 52*^ ; 

these circumstaoccs, whether in the equa- 

polar, or tropical climates, Und or sballuiirs 

•|v4fa lower thr tpmpcr.«turc oi the ocean : 

li latitudes, if the heat of the surface 

ti'' 11 Co 4U'^ oiily, Uie Uiermomcter will 

ifunKri iir .1 gnide of land tn the riBric;Htor, for 

if hearier at 1 7". ihaa at the freezing point 

hat such ao occurrcooe can only happen in 



HOW TO STUDY CHEMISTRY CHEAPLY, 

BT jaMcs HKantaT cookk. 
It is a common opinion, that in order to study kdj 
acience practically, a per^nn mast ofCfManly incur 
a great txpetiae ; thnt this in, to o cnruiin orient, 
correct, cannot be drniird. nn the hi^htr branches of 
every science frequently reiiuire tnitrumeots of ■ 
delicacy snd einctness of construction far beyond 
the akill of the experimentalist himself, and which 
cannot be procured without coniiderable expense ; 
at the same time, however, a person may, with hut 
a trifling expenditi»re, make himself acquainted with 
all the chief facta of a science, snd even pursue it 
to a considerable eitcnt, with the aid of such appa- 
ratus as he may contrive, by a little ingenuity, or 
procure at hat little cost : this is peculiarly tbe caae 
with chemistry, which may be studied with little 
ex|>en9e, to a greater extent than perbapi any other 
science. 

The advantaget to be derived fr^m a thorough 
knowledge of chemistry, (which can only be no- 
qaired from experiment,) are very great, as well as 
every other hrnnrh «f s.rience as well as art, is more 
or less dependant on it. and many of them owe 
some of their chief facts to the chemical knowledge 
possessed by the di»C0Trrie« of them ; neTCrthelesa, 
chemistry it: fur less studied than Its Importance 
deserves, the generality of people either knowing 
nothing at all about it, or, at beat, resting in a mere 
theoretical knowledge of some of its prinoipid faeti, 
under an impression that It rcfpiires loo large aa 
outlay, to be follovcd by any but those whose pro- 
fession recjuires it. Thta idea is, perhaps, strength* 
ened by attending chemical lectures, where, as the 
lecturer generally makes a point of cjthibiring aa 
much apparatus as possible on his table, the unini- 
tiated are apt to snppase that oil this display of 
brass and mahogany b essentially necessary to the 
atndeut — than which, nothing can be more errone- 
ous. Another, and perhaps a chief cause why che- 
mistry it) not more atudied. la the extravagant price 
charged by the philosophical instrument makers, 
their charges acting, iu many coses, as a complete 
prohibition of the use of their instruments, to per- 
sons of hut limited means. 

The object of these papers Is to show to the 
young liow they may study chemistry with most 
profit to their parses, as well as to themselves. 
I do not profesa to advance anything new, but 
simply tn e]i|]]ain tha constniction and urc of such 
articles of apparatus as will supply the place of the 
more expensive ones usunlly figured and described 
in chemical works; many nf thrm are thr invention 
of persons whose names stand high in the annals of 
science, sud as all of them have been used, for a 
long time, and with success, by myself. I can con- 
scientiously recommend them. The use of cheap 
appnratns has at all times been supported by the 
example of the first philosophers. Dr. Priestley 
used, for several years, no other pneumatic-trougn 
than a small washing.tuh, and made some of hia 
motit bnltiant discoveries with it, and It is well 
known how economically Franklin proceeded, Of 
late years, much has been done with the prq/ienutt 
intention of benefiting the catue of science by tlie 
inln-iductiou of surae very pretty, French polialied, 
brass-bound, mahogany chests of apparatus, tests, 
^c, under the name of " portable laboratories,'* 
which, however, are, apparently, more for ornament 
than use ; if for use, it is decidedly the moet ex- 
jwiiaive plan of proceeding Uiat the studtiut can 



.GAZINE OF SCIENCE. 



Aua they conUln may be 
Mifonrxl) the price chari^ed 
V AIT lew in qoBDiity than 
for specimens ; thcr nre 
It would be reallj useful, 
wUlies Uf study with as 

of inttractiTe ezpfvi- 

tuftl routine or mntiipitla- 

roun^ studeut a fair Rlart, 

to proceed in acquiring 

|m« one of the most useful 

jjlle circlr. iht^rcby opeoiiig 

IliuKtible fiuurce of iostruc- 

bet will provp of in6iute 

iCvery-day transactions of 

(very path in life, gtvra its 

biority over those who are 

toqnired by the stadent are 
ii ipirit Imap ; 2. a Eanip 

tmakiag gases ; 2. pneu- 
; G. evaporating dishes; 
ii funnel ; 9. blowpipe. 
^ is a small lamp iuteiided 
if provided with a wick> 
Vnt loss of fuel by evspora- 
Qasks, evapornting dishes, 
nble heat, without smoke. 
be msy be made in the fbl- 
Uhort glRJU bottle that will 
W, and will stand steadily ; 
^'0( the neck, witli jiincers, 
lirith a tile, ur on a land- 
sound cork, or ^tituU bung, 
t middle of it, and fit it 
&c bottle, to which it may 
Old cut it olf level with the 
ii|) may be made cither of 
B of a phial, cut off with 
d fit closely over the cork. 
I plate, about 2 inches long, 
irith a rim or ledge ^ of an 
) which rests on the neck of 
tde enough to cover the top 
K from the flame. A larger 
Iced by pulling up or push- 
|f wick-holder. Wicks may 



in balls, about Gd. each ; 



pf wine, bat nsphthn will 
ply two- thirds of the price, 
^of a stroni; and disagree- 
trill be found equal to any 
9i cost more thaa 6d, 
to the spirit iamp, when a 
il is to Ix heated, is a tin 
^OTcr the lamp nnd shout 
jMfTcral arched openings cut 
jlr ; when the lamp is placed 
t^e steady, protects it from 
^ time causes s current of 
leirculflte round the bottom 
p vessel, thereby heating It 
than could be accomplished 

i 

0ed to "mpport vessels orcr 
Sowing will answer the pur- 
ttiiy cduhtructed: take three 
'. brass wire, each 1 H inches 
^Ibe figure of a squarestaple; 
together at the angles and 
B copper wire, so that the 



sides of eacb may (nrm a trtanicte, eacb side bebfg 

4 inches long, stan-'i"' nn Mif- i'— ^ '■>« !■ " mr-k-t 

lon^ ; when the ' 

atniid on the In ■■ 

twisting together the ends nf liirce sbart pin^«a iti 

wire, may be plsred on the lorire one ; in «»n!rf to 

apply n greater or le« drgrc^i of ' 

should be adjusted at different he'. 

vessel by means of pieces of wood <- 

nessrs, of which several should be ] 

3. Appara/uf for genertiiing go 'ni 
rc(|uire heat for their eitrication, 

Florence flAsks, which can be obi ■ 

roan's for \d. each; they must be .v *UJ 

pcarlssh and hot water previntts (o ; a 

glass tube passed through n cork, is r^ 

neck, tu conduct the t(as to the jais intei.< 

reception ; the tube should be atjtiut '^0 m--.. 

and \ of an inch wide, and shnuld 1>e brnt 

angle, about three inches from one enrt, by 

of the spirit lamp and blow pipe, u will he b 

explained. 

For making hydrogen, cnrbonic nrjd, 
gases, where heat is not required, noy ' 
a bent glass tube passed tlitough the coi»., -r .i i^ 
to the flask, will answer tbc purpose ; it ihi>uld atil 
hold less than four ounoe;*. 

4. A pntvmatic trough is • large t< 
with water, for collectiDg gufs, and prw . 
a perforated shelf to support the jar^ while 
a wiuh-h.-iDd bdsin will aii^wer the stndrnt^s pi 
Tery well: for a shelf, take a U ox. c 
a hole \ of en inch in diameter thr- 
with a large noil or nny Bocb lv/< > . >^<.vi., 
pincers, make an irrhed opening in the edge, 
} on inch wide and \ of an inch hiijh ; tb«M 
turea may be finished utT with a file ; thll 
inverted on the bottom of tlie basin, wlitcb 
with wnter, (he apparatus is ready for use. 

b, 6'iu Jan. — For collecting snd experxn 
with gases, 4 oz. phinis may be used ; a bo 
will hold half a pint or more, the bottorsr 
with a red-hot wire, is useful for many exp 
the phials will cost about 3^. each, and i 
chosen B» wide in the neck as possible. 

fi. Evaptiratiny ifiifhrx. — Vessels for tv 
are generally made of Wcdgewood ware, hat 
is expensive, and not absolutely nt-< 
experiments on cryittallixslion, Sec. 
u«F I'ominon gallipots, which he «im •>.>•> u; 
S9 vesiwls of ten times the price ; they msy 
of vtirious sizes at nbout Is. per dozen. 

7. Tcft glaatea, tx'c. — Vessels for testing, p 
tations, &c., may be replaced by wine gla 
tumblers : when a precipitate ts to be 
or champagne glossca are preferable 
their depth ; glass rods for stirring t 
be bad in moit towns, nt from Iff. to 
where they cannot be procured, n 
window-glass msy be used. 

8. A fflaJcM funnel, for filtering. &e. ; 
inches diameter will cost 6</. ; filtering 
sola at the druggists at 2r/. per sheet. 

9. A blow pipf. — This is a small ins 
used in coiijunctioa with the spirit lamp for 
on intense hcnt on a small m'Me : a common 
ing tube will answer the student's purpose 

This li^t includes nearly every thing re<|uir<d 

the Btndent ; a few misc^laneons articles, sudi 

dedagratiug spoons, &:c., will be described wbcrn 

come to the experiments in which they tre 

(n be cOHtinued.j 



MAGAZIN'E OF SCIKNCE. 



23 



THE EXPANSION OF ARCHES. 

aiuion of DoliJ*, which b«8 esrftotl Ihn 
of mnUtctciaticiLiiii since ttte inrestigatiuns 
ire, in t6t^8, qii a rod of iron, ik uf (lur- 
portanc« in Uic eonwtrurlioD of bridges, 
which majr be mtfecifA by the djlatu- 
ction conici^uent od change* of trtn. 
todic&l mottunA, rtferotilc oul^ to 
pemture, were observed by Vicat. in 
built o»cr the Dordogne, aiSouilUc, 
frequently b«ea ootit^fd in atructurea of all 
The ttiffL-rent cspinitibilitiea of stone aud 
t been coniidered an objecti»n to the use 
Iroa pilUr« id connection with stone, to 
the fronts of huildingit ; but the experi- 
' Mr. Adie, of Edinburgh, led him to tht- 
n th4C no danger is to be apprehended 
ibange of temperature affecting cut iron 
ne In any grrac degree, as their expan- 
Ikr N« rrgarda buildings, may be considered 
Ar){uu>enU from this source were em. 
piinat the archrij of Southwark-brid|;e. and 
tHtncnta act furth in this cominuiitcatiou 
icrtakco with a riew of aaccrtAioing the 
temperacure on these arches. Three sets 
menta were made, the 6rfttin January, 1318. 
Siain ribs and diagonal braces rcated on 
and before any of the spandrils and 
a had been put upon them ; the second in 
d Senietnbcr of the same year. The rise 
nircd by ihe injiertion of email wedges, by 
t rise was ascertained to about one-fortieth 
inch. The aioiit extensive set of expcri- 
Im made on the eaateru arch. Qreat care 
I in obserring the thermomctere, of which 
i ikret : one in the open air, another aroon^ 
«wl Uie third inserted in the iron of the 
It result of nine ciperiments gave, as a 
of one-fortieth part of an inch for T F. 
ti of changes uf teroprraturc were also 
la the stone bridge over the Thames, at 
^'V.r r|,.. arches had obtained their full 
.-■i were obaerved in the joints of 
iiately oter ihe spriugtni^ of the 
Bad a diatortioD, or sioking. of the uppn* 
the para|>ets. A wedge was inacrtcd into 
tiuwi opeoiogs, and the lowest point of its 
in the month of January, marked. The 
were carefully inserted CTcry week 
, wbcQ they would no longer enter, and 
me firmly closed. At tbia period, 
tots immediately over the crowns of 
b bad, doriag the winter, been quite 
opm. From these facts It follows, as a 
consequence, that iu winter the arch con- 
, and the spaudri] joints opened : 
tha arch expanding rose, and closed 
jind opened those at the crowns. 
of the parapets, which were made 
of granite for the whole height, 
od imiicatora of the change of tempera- 
hdd al»u been observed iu tlie Waterloo 
ca, that, joints made good in the 
an ccmwt, were found cmabed in 



LIQUOR FOR ACIDS AKD 

Ai.KAL1ES. 

ta of the Society of KrU hare been voted 
MsTkb, of the Royal Arsmnl, Woolwich. 



for his communication of the foUowiog new teat 
liquor for acids aud alkalies. 

The infusiDn of thit common red cabbage has 
Iwen long in um; in Ute chemical labomtory, aa a 
test to diiitinguish acid from alkaline bodies when In 
solution ; and, althouKh posiwssed of great delicacy 
in this respect, is still subject to au objcTtion, on 
nri-iiutii i)f its becoming so exceedingly ulfensive in 
it» smell, after baring bet-n prepared n ffw months. 

In order to obviate this objection, Mr. .Marsh 
undertook sdehc experiments, about two yenrs ai;u, 
on the coloring matter of the dark red hol]yht>ck, 
the purple radish, and the dark red beet>root; bat, 
during his experiments, he found many objectiona 
to all. The beautifdl blue color of the dark red 
hull) hock, obtained by alcohol, is, however, worthy 
of notice ; but Mr. Marsh's attention was forcibly 
drawn to the beautifully colored infusion obtained 
from the dark varieties of the dahlia, each aa the 
Conqueror of Sussex, Sir Edward Codriugtnn, Sir 
Edward Sugden. Alman's Splendissima, Parson's 
Rival, Brown^s Ion, Holmes's Rival. Sussex Lima. 
MetrofwUtan Perfection, Pasha of Egy]>t, Robert 
le Didble, and Sambo — these being the rarieties 
mostly employed. 

Thi« infusion is easily obtained as follows : — Into 
on infusion pot, or any common earthen vessel, let 
89 many of the petals of the above-named dahlias 
be lightly pressed, and then boiling hot distilled or 
good roio-wHCer, sufGcient to cover the petals about 
an inch, be introduced. T\\e best method of keep- 
leg them down is by means of a piece of pUte-glasv, 
or the foot of a broken tumbler, or even a piece of 
common porcelain will do very well. The whole 
may be kept on the hob of a common fire-place, 
simmering for two or three hours, covered over 
with a piece of common paiier, to keep out any dirt 
which otherwise might fall in. The liquor is then 
to be poured off the petals, whicli vrill be found 
almost colorless. To every pint of the infusion, 
add lialf an ounce of salpburic acid, keeping the 
whole slowly stirred with a slip of glass. When 
quite cold, add to every pint of Ihe mixtura two 
grains of corrosive sublimate disiolved in a portion 
of the liquor : filler the whole through a piece of 
coarse cloth, and bottle it up ; and it is immedtatelx 
tit for use. 

When wanted for use, the liquor is to be carefully 
neutralized by ammonia, which gives it a kind of 
olive color, and in this state it may he used liquid ; 
or bibulous paper may be dipped in it, and tiien 
dried. Either the liquor or the paper will become 
green with alkalies, and red with acids. 

Being desirous of turning to account some of the 
qualities of this class of flowera now so much coU 
tivatcd and so generally admired, and also render- 
ing them useful as well as ornamental, Mr. Marsh 
hns made several attempts to fix it na a dye-stuff on 
ctoths, &c. ; but has not yut succeeded in his 
attempts to his owq satisfaction. 

This test liquor has bc»n approved of and adopted 
at the Royal Military Academy and Royal Inatitu- 
tion. — ^Vansac/iorur iff the Society of Arts. 



MISCELLANEOUS EXPERIMENTS. 

Watch G/fl**e# — The art of making watch-glaasea 
depends npon the employment of caloric, as a power 
which expiindi gloss unequally. A glass globe is 
blown of sufficient sure to permit five glasiet beln; 



24 



MAGAZIXE OP SCFEXCE. 



cut from it. Whrn the globe is cold, a red-bot 
(obscco- pifw, or iron-wire, is nin roaod the 
model of the watcb-glnss drawu upon it ; Uie crack 
foIlow9 (he point of the heated wire or pipe, until 
tlie circle is described, and the watch-glus drops 
out of itfi place. The other four ore done in the 
lame way. This contrivance is admirable, consi- 
dering that it arose from wliat ii generally supposed 
to be a bad property of glass, viz. fracture by heat 
too Suddrtily applied. 

ffnbg/itufir Jar a Cnpying Machine. — Write with 
common vrittog ink in which lump sagar has been 
distotvrd, in the proportion of four scruples, or a 
drschm and a hnlf of sugar to one onucc of ink. 
Moisten copying paper, (a paper which is sold at 
the BfHtioner's for Is. lOrf. per quire, for the use of 
copying machines.) by paasing ■ wet soft bronh 
OTCr it, lUen press it gently brtween sofl cap paper, 
to as to arooothen it, and absorb the superabundant 
moisture. Put the pnper ao moistened upon the 
writing, and both between cap or other smooth soft 
paper, placing the whole on the carpet or hearth- 
rug, one end of whirh is to be falded over. By 
vtnnding and tresding upon this, an impression will 
be taken, equal, if not superior, to what would have 
been taken by a copying machine. 

TVaeinsf Deal. — Let a frame be made sufficiently 
Urge for ■ square of crown glass to rest upon it, 
BUpporteil by a ledge at the bottom |iArt ; where, 
by two hinges, it may be fastened to a drawer of 
the same dimensions, which may be dirided to serve 
for pnper, pencils, tec. To the top of the frame, 
fix two stays, by which the frame may be raised or 
depressed, as occasion may require. Thr fnune is 
to be used thns : — lay the subject you intend to 
copy on the glaf«, snd fasten a sheet of fine white 
paper upon it, with some wafers or paste. If you 
work in the day-time, place the back, after you have 
nised the frame to a proper height, agatnst the 
window ; but if by nigh^t put a lamp behind it, and 
you will see every line, which you muy copy accu- 
rately, and finish as you think proper. If it be a 
soUd piece you intend to copy, then filace it behind 
the desk, and having fastened your paper to the 
&ame, put the lamp so as to produce a strong ahade 
on tlie object you have before you to draw, and you 
will plainly see to trace the lines with a black lead 
pencil : aftrr which, fill up the shades in the manner 
it appears without the desk. 

Optical Ejrjierimentit. — .\ffix to a dark wall a 
round piece of paper, au inch or two in diameter ; 
and a little lower, at the diitauce of two feel on 
each vide, make two marki; then (dace yonrseJf 
directly opposite to the paper, and hold the end of 
your 6nger before your face in such a manner, that 
when the right eye is open, it shall conceal the mark 
on the left, and when the left eye is open, the murk 
on the right : If you then h'ok with both eyes^to 
the end of your finger, the paper, which is not at 
all concealed by it from either of your eyes, will 
nevertheless disappear. 

TtHy at the height of the eye, on a dark ground, 
m imall round piece of white paper, and a little 
lower, at the distance of two feet to the right, fix 
up another, of about three inches in diameter ; then 
pUcs yonrself opposite to tlie 6rst piece of paper, 
ud, having shut the Irft eve, retire backwards, 
keeping your eye still Axed on ibe first object ; 
when ;ou are at the diHtmce of nine or ten feet, 
the second will entirely disappear from your nght. 



A Simple Btavmtier. — Take n oommon 

bottle, and cut off the rim and p'"-' ■:■■* '' - 

This may be done by a piece of ■ 

whipcord, twtitcd round it, and pi: gl 

a sawing position by two persons ; one ot nliOB 

holdi tbe bottle firmly in his left hand. !f '-itc-J u 

a few minutes by the friction nf tb' thsn 

dipped auddeoly into cold water, i; 1) bv 

decapitated more easily than by n tns 

Let the phial be now ne<ariy filh maa 

pump-WBler, and» applying the fini, • "> 

turn it quickly upside down ; o j 

finger, it wilt be found that only • 

escape. Without cork or stopper of aii v 

water will be retained within the VmMH 

pressure of the eitcmal air ; th' 

without the phial bcmg to much i 

of the small ijuantity writliin it. >•<'» . 

lope be tied round the middle of the 

which the two ends of a firing may be ot' 

OS to form a loop to hang on a nail ; let it t>e \%m 

suspended, in a pcrprndiiMtlar msauRr, with (kt 
mouth downwards ; and thia ia the barcnmlv. 
Whrn the wvather ia fair, aad inclined to be aa> 

the water will be level with tlic seeii " * 

or rather elevated nbore it, and lu: 

surface. "When dtspotted to be wt 

appear at the mouth, which will enlonge t^ 

Olid then another drop, while the hnmi<lr. 

atmosphere continues. 

How to prepart Parthmtht Jhr Ptrinfin^. — IVIv 

about a yard and a half cf li«t, on* 

tight in a circular form -. then take ■■ 

dered white pumice-stone, put tlic 

rub it over the parchment. Tlii-> 

simple and very common, aimwers ' 

If you wi*h it to take water colnrw \^ 

choose tliat whit^ is not spongy an- i 

olum-WBter with tbe colors when you mis Utcni 

use. 

Ea$y Method of taking Imprtmona ftviu "." 

Cohtx, 4fc. — Boil B quantity of iainglas> 

brandy, or other spirit, tilt it is in a 

liquid state to pour upon the mrtoJ, &c 

may be mixed with this composttton ; 

be poured in a liquid itate to the mixtnral 

best to m\% the color with the spirit. 
Artijiciel Rain and Hail. — Makf: 

der of wood ; let it be very thin at ' •! 

eight or ten inches wide, and two or turcc iwi 

diameter. Divide its inside intu 5vc eqwd 

by boards of five or six inch^« ••■■'•' -•»■* i*' 

be between them and the wC" 

about one sixth of an inch. ^ 

boards ohUqncly. In this cylinder put fnur 

pounds of shot tluit will eustly pass through 

n|>eDing. When turned upside dn^i 

the shot going through the varion 

resemble rain ; and if you put lorgp in'jt. fi 

produire tbe ^ound of hail. 

To make n Ring tuapend by a THrtad, q^ 

Thread hnt b&en Awmeflf.— Soak a piece of tb 

rommun salt and water. Tie it to a rinc not 1 

than B wedding ring. When yon i> 

of a candle to it, it will burn to ashv 

tain the ring. 



Votit. I and 2 of this Magaxine are nov rvad^p^J 
tianiljf tivundin CJa/kandhtitfredtprictHt, 



LoMuON-^Prlnicil hy t>. thMHet*, S. Wlille Horse Urte. Mile Fwl - rgliliil.i.iJ hy W WaiTtAi*. H. l*atwi*^>Bt»v 



26 



MAGAZINE OF SCIENCE- 



raftftietic forre of this coftcnt opernting cm the 
compau* needle would Aefitet it out of iia Bintral 
direction ; and after a few oKtUationo ii would t^ke 
ft new atationary poaition. 'lltia new position ol the 
oerdle would not be at ri^t anglra lo ibe plane of 
the coil, became of ita etill bciog under tlte iti- 
Haenrt* of terrratrial raa^oftisru, b<i well as under 
the Killuencc of tbe flectro-mag^uf^tic force ; bni it 
%vould form on sngle with the meridian Uue of the 
oompass-csrd, the extent of which would depend 
■pon the extent nf the Utter force; or, if yoa pleaae, 
npotj tl)0 iiit< iisity of the electro .dynamic action, 
which krj't lilt: itLi'dle from reiomii^ to lia terres- 
trial hue of rcpOM;. 

If now we canbider ihmt the deetro-mag'netic 
fcrce ia ef(aAlly dUtributed orer every part oif the 
wire forming the coil, it ia obviotu, that by paaaing 
tbe wire once round the romposa-box. directly over 
and under the meridian line of the card, this forcv 
woald be brought into piny both on the upper and 
lower sidea of the needle : and theae two incre- 
meiiU uf force would conspire, and auatain tbe 
needle farther from the mcridum line thoB either of 
them aloDP would do. 

To fuiiiiltnrize the action which tends to the pro- 
duction o( tbia fact, Jet na suppose the circles to 
repreacut troiuvcrse aectioM of the upper and 

919 



tover portiona of the wire ; and thftt the aouree of 
electric action is a sinf^le pair of cop{ier and zinc 
platoa : then Hcctirdingly with what we have already 
shown, the rurreot would (lov/roni the end along 
the wire, (which imagine to he bent oTcr the farther 
edge of the conip8»s-box, behind the paper.) and 
return by the oth<-r end. This being undcriitood, 
the right lines with cross heads will show the diitri- 
hation of the polar line« of electro- magnetic force, 
due to the adranrtng and returning current. Hic 
north poles of the two )X)rtion& of those lines which 
are situated immediately between the upper and 
lower yarXs of the wire, will be observed to be di- 
rected towards the spectator's right, and all Uie 
mnit/i poles of those lines, towards his left. And 
M tlir needle N S ia placed between the upper uid 
lower iwrttoQs of tbe *ire. it is influenced, princi- 
pally, by those coimpiring furcea ; and is sustained 
out of \hp magnetic meridian by their joint action. 

In puraning this illastration, we mny now readily 
Imagine, that by passing the conducting wire once 
rouud the compnjs-box, the electro-maenetic action 
on tlie needle would be double that which would be 
due to either tbe opper or lower part of the coil 
alone. This being admitted, two such colls would 
be productive of (our tiniea the single lorce, and 
three eoUa would multiply the force six times, ond 
•0 on ; and hence the mime multiplier being given 
to this instrument. By this mciuis, nn ehwlric 
current. whoAc force in one strand of wire alone 
would be too freble to prndmie a perceptible motion 
of the magnetic needle, may easily he detcctird ; 
Mmetimrs by deflections of considerable extent. 

In^trtjid of employing ■ rompAss-box in the con- 
■tniction of a galranowiter, it ii now usnol to ouko 



fta open oblong coO of Uiin copper wire. previOMfy 
covered with sewing ailk, in ih" 't<-'>t>-.r it, .r t,..(inrt 
wire i* covired. This silker I'd 

as an msulator, to prrrent thr ■ -mm 

poaaing laterally from one cuu^^olutiuti tv kiiother. 
Tbe number of convolutions in each coil «aclea 
with the different viewa of the ronfrivrrs, from Can 
to more iboQ a hundred convolutiona. For gwamt 

purposes, perhaps about eightech or * *- "^*u» 

lnliona are qoite toffldent. The > «r« 

uatially packed cloae together, an>i ><^ 

Tertically on a board; and each extren'i 
wire frequently terminates with a small c>< 
purpoae of holding mercury, which ia : 
useful for connecting the instrument in lii 
or other electric circle. The r. 
shape the experimenter thiul 

long thin icwing needles, witJk .... , 

cut ofl*, answer as well aa any. One of tti 
magne^tized, may be sunpended in the cri' 
coil, by means of a silken fibre, wbii 
through an opening in the upper side, > 
fig. 3, or else supported on a pirot, a?> 
A deep groove is usually cut in the bat*' ' 
place the lower edge of the coil in, and a ^ 
card for measuring the angles of deflt 
pasted to the surface of the board over tlir ^ 

When the electric forces to be etamineii 
feeble, it will be better to employ two necdlea* 
their like poles in opposite directions, 
scnted in tig. 5. The advantages drrivrti t\ 
arrangement are, that wheu the nvedles are 
power, they will counteract each other's 
tendency, and obey the influence of an exci 
alight electric action : and in consequence 
positions, with regard to the coil, they ; 
orged in the same direction, by the 
electro- magnetic forces to which they ai 
The needleji may be inserted in any light 
OS a thin straw, a piece of dry gla»», r>r 
slip of card; and sustained by a silken ' 
tbt- figure. This is called the astatic rl< 
oouieter. Tbe angles of dcdectiuu ure n: -. 
veniently read off, when the graduated cardu 
on the upper aide of the coil, the dipper 
serving us the index. The astatic > 
vention of the late Italian philosopti> 
Leopold Nobili. 

As the electro -magnetic force is known to 
cline with an increase of dist"—- (• — 
dncting wire, auuther Importu 
in the construction of theae :< 
tended either for the detection, or tQe • 
ment of feeble eleiTtro -dynamic acliun. 
upper and lower Hides of the coil ah 
farther asunder than is necesaary for the 
of the needle between them ; and the up 
should be adjusted so as to move as clonic as 
to the coil. To prevent undulations of the 
disturbing the needles, the galvanometer a 
covered with a glaid shade. Although the ap 
galranuineter is nsually given to sit the 
forms of .Schwetgger's multiplier, mony of 
obviously very far from being deservinc; nf 
tied title ; and are of nu fxtthor u^ than 
iodicatinj^ tlie mere exiMtenry of an dL-ctrie 
Such instruments have ■ometiinecbeeu calh 
nobcopen. 

Dr. Ritchie's Torsion galvanometer, we 
not grueraily known, and as it posfeesaes 
culianties, a description of it will, no di 
interesting to many of oar readen. Tbe 



MAGAZINE OF SCIENCE. 



S7 



tiie Doctor'* own worcU^ «a wc find it in 

tmai n/ the Rttyni fiuMuiifm q^ -Oveal 

\Ji>r Ortnhrr IS30/' 

pnprr whtrti appcarrJ in thft firnt ]iirt nF the 

thiotU TranBACtinns for tH30,' I invejti- 

eJrtsticity of threaila of glt^s, and applied 

;y Co tlie ronntructian nf a ddirAte fral- 

Tbr instrument then desrrthed, thou^^h 

for moft pBr|>o»r«, reqaires «ooic mndi^- 

adapt it lu p^Tscnrcbea of f^itrtoio dclicacjr. 

»n of Ibe instrument, in it< more per- 

a few of it* namerous niiplicaliuntt 

ibject of this communirntion. 

^rirneiilal rcjiearches in rltvtrn-mD^ne- 

ettremcif useful to havr ronstantljr at 

of copper wire, of different degrees 

' Miith senlin^ wax. Tlie inost con- 

^ttf giving tbc wire thift coatinit; in the 

tch the wire between two itiipporta. 

\y, from one end to the other, with 

>irit lump, and continue rubbing the 

|Ui a etick of sealing-wax ; the wire 

»c coatin/;, auffirient to prcvetit me- 

rhen portions nf it are pressed to- 

mitruction of any piece uf electro- 

tus. 

v^re thus coated, beat it slightly to 

wax cracking, and form it into a 

shape, ronsiHting of lix. eight, ur ten 

of the wire, acci>rding to the delicacy of 

tent required. The upper «idc of the 

'Viuat then have the wires separated into 

' portion*, bent round a snial) cylinder, anil 

lued Htraight, so oa to kavn a circnlar 

the middle* about one-third of en inch 

The a»o of the circular ojiening in (he 

U to albw a BlendiT axis, carrying the 

lies, to fOMs through it, in order to ia> 

p<»iBvr of the iastrument, and render the 

needle aitatic. Portions of a brass Inbe, 

tnch looK, are to be soldered to the ends 

Firrt furmini; the rectangle, for the purpose 

a aniall quantity of mercury, to render 

contact complete. Fik*. G and B, ex- 

licel »C(<tion of the rectangle, and a hori- 

rtf ita upper side. 

ire» forming the rectangle are pressed close 
'-il by a waxed acwiog thread, 
tliem. The rectangle is then 
,r.r box, having the upper side 
idiDg panes of window gloss, for the 
ig up the needle from the agitation 
beh pane has a small semicircle cat 
of the edge, by means of a round file, 
a oircnlar opening directly above that 
\t. Venom rontrirances for suspend- 
ncedle might be adopted. The 
ipa the roost convenient : — Into a 
e or base, f\x two npright sop- 
feet long. A amall stage at the 
Ivided arcle on its opper side, end 
r eleratrd or depressed at plcainre» 
' frame of the instrument. The stage 
of the same stse as the supports, and 
distance, with two small screws pausing 
op|«»iite the centres of the open- 
)Ose of fixing the stage securely at 
A small cytindrieal wooden key 
a «man bore in the axis, for the pnr- 
iving the end of the glass thread, passes 
centre of the divided circle, end is 
«aail)t« without mncb frictioiL. 



'^Aftar numerous trial*, the following appf«rv to 
me the best moile of preparing tlie tliicnds of glass, 
so ef to bare tlirir extremities somewhat ihirk ead 
tapering', for the purpopc of sernring them iu tho 
Tnrvion key, and in the an is which carries the mag- 
netic needles. Take a *olid rod of glass, or a piece 
of a clean thermometer lube, having a fine bore, and 
draw out one of its ends as in fig 7. Direct the 
very )>oint nf the flame on the thick (lortinn, and 
pull it out, bKwrrn tbe two handjt, to the proper 
length and ftnencA$: nt the first trial, it wiU be found 
necessary to dr»w leveral, end select the one boat 
adapted to the parpoM. 

"Two slender darning needles, of the best sted, 
nrv then to he selected, the eyes to be broken off, 
and the ends tiled to a point elmilar to th« other 
endtf, und then strongly magnetized iu the usual 
way. 1'he needles are then to be fixed transveraelf 
in a piece of straw or other light sobsiance, about 
an inch lung, and at the dtfttance of alinnt bolf an 
inch from each other, with their corresponding 
poles in opposite directions ; — the one needle in- 
tended to be above the upper side of the rectangle^ 
and the other below il. One end of tbe gloss thread 
is then to be secoi-ely fixed in the end of the straw, 
or light axis, by means of strong cement or sealiog 
wax. wbihic the other extremity is fixed, in a like 
manner, in tUe centre of the Torsion key. A single 
fibre of silk, having a small weight attached to it^ 
is filed to tbe lower end of the axis, and made to 
pass through a small hole near the lower side nf the 
rectangle, for the purpobc of keeping the axis carry- 
ing the needles (n the centre of the circular opening 
in the coil. The upper needle has two pieces of 
fine straw, several inches long, fixed on its ends* 
BO that the slightest dctlcotion may be readily ob- 
serred. The extremity of one of the straws is 
made to oscillate between tw;o upright piecea of 
glass, to prevent the needle moving over un extensive 
arc. and thus lengthen the tinu necessary to com- 
plete un ubscrvution. The M-bulc will be obvions 
from the simple inspection of Ag. 4, in which A B 
is the rcrUngiilar coil of wire ; N S tbe magnetic 
needles; C the stage witb^be divided circle and 
Torsion key ; and G the glm thread. If instead 
of the glass thread tbe needle be susjiended by a 
single fibre of silk, tbe instrument beeoiura a gaU 
vanoscope of cxCronu delicacy. Tbe /oUowjng 
experiment aifords a strikiog illustration of the ex- 
treme sensibility of the instrument with this modi. 
flcocion : — File off a few grains from n piece of 
sine and cop)ier, by means of a coarse file ; place 
two «f these near each other, in the bottom of t 
clean watch glass, bring tbe clean ends of two fine 
copper wires, connected with the cups of the galva« 
nometer in contact with them, and then drop over 
them a small quantity of dilute acid, and the com- 
pound needle will be deflected several degrtcs. 

"The instrument by which 1 aaevrtaincd lin* esist* 
ence of a voltaic current from this elementary hnttrey, 
c-onsistrd of a greater number of coils in the rec- 
tangle, and tbe needlca were light acd stfongtjr 
majtnetixed." 

Gahanometera vstd *y Dr. Faraday —T^a gal- 
Tanometers, which have lieen employed in a great 
-variety of important eTprriments, are described aa 
below, in the rath and 205th articles of Or, Fare- 
-day's " Experimental Kosearcbca in Electricity." 
Phil. Trans, for 18.12. 

Article 78.— ** The Galvanomeler mm r«u«U)f 
made, yet sulSciently delicate in ita indicntuHia. 
Tiu! wire was td copper £orerfid «itii ailk^ azulj 



^8 



MAGA^HNE OF SCIENCE. 



ftUlMB ar eighteen ^oiivolutiuru. Two sewing 

nrriHiH \>frc luagrirttitnl Aud |i»»«vd tbrou^b > picCB 
• - parallel to each other, but in oppn. 

fi u'^, and about h«lf on inch tpsrt ; thU 

*y«tcm n^M fUfpentlcU by a fibre of urit^^mu talk, to 
thAt the luvrrr nrctlte flhAuIil be bctvi'ra tli£ eonro- 
li. ' ' ' ' ' , :iJi(l the uppt^r ahovf tbpm, 

'J :jo mcrtt powerful tuagncf. 

ku^. fc. .. - .,..,..... ■-. Lion to the whole. 

Articlti 205. — ** To ubtuixi perfectly BatiafM-tory 
results, ■ new galvanometer was convtructe^l, con- 
■ifdii^ of tvo independent colli, each cunuiniDg 
18 feet of ailkcd cop[>er wire. Thete cotU were ex- 
nc^Xj alike in sh!i[>c and number of turns, and were 
fuel &ide by Bide with a email iaterraJ between 
them, in wliick a double needle i-ouid be hune; by « 
filirc of iitik cxutly afl in the former iustrumt'nt. 
When cleotrical currents were Knt throoj;h them in 
the same direction they acted upon the needle with 
the aum of their power*, when in opposite direction 
with the ditferenee of thdr powera.*' 



CRYSTALLIZATION OP BISMOTB. 

BiBMrra tndti at 476", and if allowed to cool 
■lowly, it crygtalltzcfl in parallclopipcduns which 
jctin or rnther meet at a right angle and are enve> 
loprd in one auother lilie tlie turni of a volute, 
•ueh ao are trrmed MaGrecque, because the Greekt^ 
have often employed thii form iu areliitecture. In 
order to obtain this cryBtallisation, wc must wait till 
the bismuth is fixed at lUi surface ; then f>erforate 
the cru*t nnd pour off the fluid pordon, not in order 
to leave a space sufficient for the regular arrange- 
ment of the molecules as Rome de Lisle imagined, 
for the crTfltaU are formed in the midst of tfae liquid 
motiil like the saltA in their solutlan, bat in order 
to Iat hnre the crystals that are already formed, and 
not ititTer them to be inclosed in the whole of the 
fixed metil, M. Pongct haa actually obserrcd 
that when the solid crust formed at the surface of 
the fu*ed bismuth is taken away whilst the lower 
part is still liquid, tliis crust exhibits well-formed 
rryatals beniuth. Of i) the metals this cr^BLaUizca 
10 the most regnlsr and Msy manner. 

Dr. Reid ol>»cnfcf, " melt some bismuth In a 
crucible when the surfncc becomea aolid. and while 
the greater pNrt of the melal is still melted within, 
make a siiinlt hole in the middle and inrert the 
cruci*j!e til) all the liquid metal hss been poured 
out. On breaking iulo the hollow mass Oiat is left, 
tti internal surface will he foond studded with oryi- 
iala of luetaUic bismuth/' 




Another method U tn melt the hiamutli in on iron 
ladift, vwdlng the botWui by immersing it in culd 



«Bl«r before breaking tht Croat iborc, 
care put lo«ttow any water to toll apoa 
nietil, least some Of H should be throwa 
explosive viol«io«. 



PRIMING AND PREPARING CU 
THE ARTIST. 

PftOM the time that the restorBtion of 
Italy commenced, down to the dnya 
panclf were always lued for pninting 
when the works were to W fixed to i 
place. Canvasses nnited the Advsntagef 
new and easy removal. The latter, thrrej 
n preference ; and after Rsff'^ul's tic 
longer painted lai^ pictures on wood ii^ 

In the Low Countries Uie use of panel 
much longer. Even in the ttuiR of R] 
was, at Antwerp, a celebrated manufoc] 
the panels were prepared of ^re4t dim< 
after the death of the chief artist of t 
school, the artists painted osilj easel 
wood. 

The Italians preferred pojilar wood I 
pose. In Flnnders oak was used ; as iC 
dom injured by worms. 

It is natural to suppopc, that pnn^ 
of several pieces glued together, might 
uuitrd by the changes nristng from 
moisture, to which pictures are alw«] 
less subject. To prevent these occideota, 
care was taken in the earlier timea, 
these precautions were neglected \ b«n| 
were glued upon the joining, and even < 
they covered the entire surface of the 
black tanned leather; the gluring on of 
is Bttnljuti*d by Vicwaii to Marshtritun^ 
in tJie twelfth century, but it ws* knowi 
time, for the practice is described in * 
treatise, Dv arte Pingendh it was prol 
into Itoly by the Greeks. 

In the commencement of the art thft 
were prepared like the panels with 
grounds \ and generally the pictures of Pi 
were pninted upon such primed cloths. 

The practice now is, to prime the rli 
cobr, changing the mode aocordiug as 
is of a closer or more open texture. 
cauvBSs is very open, and lets the coU 
it must be saturated with siie mode of gU 
laid on with a Isrije pnlette knife or trow 
of which should be blunt, and as stralgl] 
thnt the couch of size may be lud 
pod&ible; when tltc priming is quit*' dry^ 
rubbed with pumice stone, to make it, 
lumps I then with the knife, a conch 
applied ; when dry this is obo pumi 
couch is then put on, and sometimet « 
Caia « perfectly even surface. 

ijjnncrly. the first priming was 
red. mlied with umber, or with pure 
some sixty years since, it was suppposn 
drying of this color wonld be quickened 
it with litharge ; hut it has been dii 
pictuiea painted on these aorta of prejiarl 
a few years have their surfaces covered wit" 
titude of little grains like sand ; and 
that the litharge was bctdly prepared. 

At the present day, the artists are 
in such cseeoLiai matters } and the 




MAGAZl?^ OF SCIENCE, 



29 



[lliar own ffiikn^ atr txrUte^ to prepare their con- 

«.-« tviiii tv.M^r ..tr.-Mti for any uruhijrfioe Lu 

1 rutii Chcir trade. 

.r tnring, ought to he of 

.itul nicHC evrii tcii'irp ; in this respect 

fwnuUarlv ad^untkijrouf ; for tLioueh at 

■ I to l>c faiitl of a much trreilcr width 

yul, if thp TnaTmfirNirerH foand h 

thcjr, Tio doubt, wontil nmke it up 

'- diuieiuions. If the cloth ia not 

juire three or four couches of color 

in eren nurfnfe ; »nd before « new couch 

' time mwit be allowed for the former to 

'i to be rubbed with pumice ; this it 

-loth requires, in prepanitiati, two 

>" in furnmer, iind t'lve or vlx io the 

lirrd for priming may be shortened 

..Aing the ftrst and second couches 

. and AS soon as they are quite dry, 

-a on eren surface, let the UaC couch 

iuch has become viscous by exposure 

will penetrate the distemper, and 

pliant. By the former method. 

•■ i jtr <> irquircd to dry the cloth. But by 

au>dr, OS ROon as the oil is absorbed, they mny 

n»llcil lilt liVu waxed doth?, with perfect safety. 

of these clothfl de)>rads upon tbe 

> of the oil with the diste^mper. the 

. would be greatly fncilitated by using a 

iiize, mixed with a little oil, and a good 

of BDuriln^e of limred meal, or the latter 

•loue will do if well boiled. 

..^.-i... .,f ground may be made in four or 

will economise tbe time consider. 

I rri-tendtrd that a picture may )>e 

ly unoo one of these grounds 

ff«^> -ltd that the colore will change 

IflK tliaii they do when used on a welUdried 

; but such is not the general opinion : for the 

oil lurd in the ground, and to which the 

rca its ptiaiicy, dricii but slowly. Hence the 

l.rinr left too long eiposctl to thc chcmlcal 

1, are likely to undergo a change. 

umstances compel artists to point 

lud when fresh, they woald do 

11 ' rtrong couch of white chalk with 

i!/r in It, to absorb the excess of oil; bat 

lu such a case, be still better to paint on 

groand. 



lid. 



tMPROX-ED PAPIER-MACUE. 

CLn has published a rery interesting 

oo the origin of papicr-mAchr, thc cauicA 

ovfiment, and its re-iutru<luctiua for the 

of tbe interior and exterior of booses, 

pplicstion of steam-power, and the rast 

nt. of recent date, in all branches of 

tlcasl >cimoe, bare enabled Mr. Bielefeld to 

• SBsterial similar, in name only, to tne 

" ' ' vi the last century : its biird com- 

rtrmctb. imperishable nature, ligbtnexx, 

'"tf, (if luch- an expression may be 

(iw (uality and quirkness with which it 

yvcparcd, pot together, and filed up. nnd, 

cheapitess, are qualities which emiuently 

iU bat which cannot, perhaps, be fully 

, rsc«ptiiig by those who hare had pro- 

ptrUucti in its application. Amuni; the 

architect, builder, and hou*c>dccorKtor, 



the most extensive opportunities are ofTi're*! fior tbe 
employment of Mr. Hielcfeld'i pnpier-inuchi> : Inos- 
much as not only all the forms of ornament com- 
monly in nse may be executed with it, in evrtry 
way superior to that with any other material, but 
its particuiur qualiciea are such as to e:it«!nd the 
field of inventiun immeasurably beyond (he limits 
to which it hab hitherto been confinrd. To assert 
tliat whatever hns been attempted in stucco may be 
■oeompUshed with the greatest fodlity in papier- 
mtLcbe, would be very inadequately expresalng its 
capabilities. Whatever the genius of Grinlin Giblrana 
IndoctM] him to attempt in wood, may be etfectively 
performed in papicr-milchc, with oo leM sharpnesSf 
DO less relief, no less lightness, and much less Ua- 
biGty to injury; papier-m&ch^ haWng this great 
advantaga orer wood, that, although as bard, it is 
tougher, and is wholly wiihoot the grain In wood. 
which gives it a bios or tendenry to chip ufT in one 
direction ; bnt with papier-iciich^ it is wholly dif- 
ferent ; no matter io what direction a blow faUs;« 
nothing but destructive violence will damage it. 

In arcliitccture and interior decoration, papier* 
mjichi' is advantageously used. Nothing can pos- 
sibly be more to thc purpose, in cases where an old, 
plain, plaster-ceiling, has to be rendered ornamental 
by the application of panels, jmteras, &c. ; without 
disturbing the ground of the ceiling, every kind of 
enrichment can thus be applied to the surface ; and 
so trifling is the weight of these ornamental addi- 
tions, that old laths and ceiIing>joists can receive 
tliem with perfect safety. A. new cornice, dry, and 
ready to color, can thus be fixed up against an old 
ceiling, without the delay, rubbish, snd dirt, attendant 
on running a plaster cornice ; indeed, without the 
removal of a aingle article of furniture, on old ceiling 
can, in a very few hours, be made, if desired, to 
asaume an entirely new aspect. By the Kama 
meanF, old pbiin stuccoed walls can be paneled, or 
otherwise enriched, with equnl convenience and 
deipatch. V\hen, from the Iaj»«e of lime, or other 
cause, the enrichments on an old atucrocd or can-ed 
ceiling have fnllen to pieces ; or when, ss is sot 
unfreqnently the case in works <rf even recent date, 
plaster ornaments have dersebed theroselres from 
the ceiling by merely the operation of their own 
weight j the injury is repaired in pspier-miVbe with 
perfe-ct success ; ornaments of great bnldnms and 
projection being thus applied to tbe face of the old 
work without the least risk, and when, peHiaps, the 
timbera ere so slight ss to make heavy plnsttr orna- 
ments highly dsngeroufl. In the completion and 
decoration of new bnildings is a further unlimited 
range of ornomentol ))arposes to which papier- 
m&chc is applicable (.'olumns of every order and 
degree of enrichment, including not only thc capi- 
tflls and bases, but the entire thafta. whetlier fluted 
in the claislc atyle, or fi-etted over with arabesques, 
ns in tbe C'inque-Ceato ood Eliiabethan styles ; 
caryatides, termini, and chimera ; are all produced 
with great facility snd bnt slight cost. 

Ceilings, especially, are wholly within the mas- 
tery of tbe manufacturer : those at the Pootheon, 
in Ojcford-street, snd Grocers* Hall, near the General 
Post Office, in London ; the vice-r^al state rooms 
of Dublin Castle, snd others, which may be referred 
to, display, in some roeasorc, what may be ftchieved 
in pspicr-miicb^ : yet these, superior as tbey ore 
in general effect, are specimens of bnt trivial sig- 
nificance in comparison with the powers and cajm- 
biiities of the material in the gorgeous details of the 
rasgnificCDt ceiJinge of tbe age of Louis Quaturxe, 



hM^ 



MAGAZINE OF SCIENCE, 



which cjm be fuUy and pcrmanentljr ei«mt«d ; and 
aft thtre U ntjibliihed endrnor of the diimliility ot 
|iftpier>iiuu-hr tn the 0|irn air,, it <tf courxr follnw*, 
that in all interior decorations its indratructible 
qoality may be still more tmpUciUy relied on. 

Pur jcaUcrj-fttmti, &lur-picccs, ur^un-ca^L-^, and 
othiT omamenUl parts of ctmntbea nihI rhiipels, 
pftpicr-niArh^ has now becomr fcnernllY minpt«d ; 
nor ia itA uso confined to thp.5« more inaportant 
work* ; many buDdreda of patvms or fluWRrs &re 
annually hand up on critiiigft of thf smaller class of 
jirivate dweULngs, in almunt every town of tb« king- 
dom. Flowcn are, further, cxtrnMVfly employed 
in covering the apertures for rentilution in tht eril- 
ingi of churchev, chapels, nnd places of public 
resort : piaster flnwi-rs hcinp only with much diffi* 
cully, and often timfs with danK:f^r, fixed up in these 
situations. Tbr wn-athn, or enrichrd baiuU. which 
/rcipirntly rncirclr these Howcrs, are also moat 
clfectiTely and elegantly formed of papier*rouch«. 
Another Tery usual mode of giving eohciuuent to 
roomi in the modem style, ia to connect with the 
cornice Home ^uilluche, or fret, upon the face of the 
ceding* and. where still more effect is retpnred, 
adding a frieze under tbe cornice, againut the face 
of tlic wail. Aa in funning Ihesc enrichments, the 
ground is firat finished plain, and the fohage in the 
papirr-mfiche then laid upon the face, it is olivioufl, 
to the prarticnl man, that a clear relief and distinct* 
ness of outline is tlierehy obtained : fjuite unattain- 
Hhl[! ill plaster work, where tlie enrichment ta cast 
wttlt the ground. 

Brncket^. consolec. and cantiltvers. in numerom 
and tasteful Tarietics. ore mode of this substance ; 
and indeed, one ol the earliest applications of 
Mr. Bielefeld's improved papier-mache to architec- 
tnml purposes, was the formation, on the accession 
of William the Fourth, of several large consoles and 
ooniioca. in the state apartments of St. James's 
Palaoe. Since that time, similar enrichments bare 
been supplied, by the manufacturer, to Groeera* 
Uoll ; King's College, Slnind ; tlie Carlton Club, 
aiui the Oiford and Cambridge Club Houses, in 
Pall Mall; tbe Briush Mnwum ; the State Rooms 
in Dublin Castle ; tbe Grand Mnsooic Lodge, Prce- 
inasons' Hall; the Corn Exchange; and other 
public buildings. 

Nor need its application ho limited to interior 
docoratiooa. At Paria. the Carton-Pierre, a suh- 
Btaucc analogous to pupier-mucht', but in every 
reapeot inferior, especially as rcgarda durability, 
being very abaorbeot of moisture, and, conse<iueiitly, 
liable to bacome aoft, is largely used for exterior 
ornaments, even in buildings of the most sumptuous 
and important character. Not oo tbe pnpier-muche 
of Eugliidi manufacture ; as even that uf the last 
century is found, on inspection, to atford abundant 
proofs of its extreme teoacily in exposed situations. 
The papier-mitcbe which enriched the fanciful nrchi- 
tcoture at tbe back of Sir William Chafflhera's 
house, in Berne rs Street. Oxford Street, now nearly 
three-fourths of a century old, is still in perfect 
condition. Mr. Bielefeld's improved papier^m&ob^ 
is of too recent introduction to afford a reference to 
any example of its adoption in txU'riop work beyond 
fourteen years ; but seventj sbop-rronls in the mc- 
tropulid, fitted up of that material, have at this hour 
their papter-miiche enrichmenta as sound, sharp, 
and perfect, aa when 6rst tuned out from the 
mould. 

Another and most important use to which the 
in\proved mdche may be applied, is that of render* 



ing ID duplicate forms tba emautioM of iW smlp- 

tor's skill : for whdst any piece of »*-iilitturr rifi *n 
insde ill ffkc-siuiilc wttli iwrfcet tiu 
is scorooly oue-slxth tbitt of pUsler, 
to injury or fraclur* i* in no way -rnl 

with copies or repetitions in eith« ' w, 

or woud ; Mliilst tiie economy of {>ii<><- pi;xc« (ha 
papier-m/iclu- ixprcimeiis bcvotid «U rrai-h of rlMlfy( 
as all being finished with equal mmuteni*«a and an, 
they have only to be colored in repreaentaboD af 
the marble origiiuli. 

Papier-miiche is applied by the cabtnet-mshaf 
and nphoUterrr, with surprising elTerl. to HV 
euncticd cornices of book*easea and caV>mpiai Iv 
the mouldings, comers, and centre arnauiriils a( 
paneling on their dnors and addes ; to the tiutuiuA 
scroll lega of rabinets. and pier tMl>ti<«. in thiiidd 
French style ; to ornamental brackrU fur cloekli 
busts, vases ; to the enriched borders of roonA 
hung with silk or paper ; the ornamental parts tt' 
picture and glass frames, however rurvtd nnd Ha« 
borate In their form ; and. also, to window-cart^ 
cornices, the canopies of bedstead*. &l-. 

With regard to the mode uf tixmi; papter-Mftdii^' 
ia cabinet work, the simplest and mc>»l mrrr..-' mU 
is. to treat it as if it were wood, and fa' 
means of brads, needle-points, or glue, t- 
cnt with a saw and chisel ; and may he U*At- b 
Rteam or beat, pinned, and rleanrd up with 
paper to lite smoothest face, and tn the An 
if required. The larg^ objects, such as bri 
and canopies, can l>r made ritber with a wood 
or wholly of papter-muche : in either case 
three screws secure them in their i.lti.-. 
fixed, the work can be painted an^l 
any previous prt^paration ; and, in :. 
face of the work is better adapted u> ; 
gold than that of any other material; mw 
expense and delay osually attendant on the p 
being tiicreliy saved. The aamc nhscrration 
to silvering; and, tt may be addr<> *)>- 
leaf continues untarniahed on pa; 
greater length at time than Ob other 
may be proved by the speclmeoi at C 
llotue. and other houses of the nobility.— 
Jirom the Literary Worlds vol. l&i. 

GLAZING EARTHENWARE AND CHI 
Thk glaze usually employed for common 
eartbeiiwarc is compounded of litharge of 
ground Hints, in the proportion of ten 
weight of tlte ibrmer to four parts of the 
Cornish granite is sometimes substituted for 
and used in the proportion of H pnr 
tharge. Tins method oi glazing i^ ' 
account of the injury which, notwi^ 
preeatitton that can be taken, it '.-■ 
apphc'Jitiuii, to tbe health of the worLj 
who freqnently are seised vrilh paralyaia; 
caose the lead, which is soluble by means of 
and higbly poisonous, renders vessel* thus 
improper for preparing or rootnintng Imman 

The mixturea just mentioned are called 
glazes : their employment is coovenieiit to the poU 
ter because of their cheapness and exlr-'-- '"■*- 
bility. Flint, which remains unafTccied in 
of the most powerful lens, is, when cont'. 
lead, melted nod vitrified at a cetnparativriy 
heat. The mixtiire mast be well stirred, thi 
powders may be always ke]it notformly hi 
throighoui tlie fluid. Tbe pieces are Arst bnuM 



1^^ 



MAGAZINK OF SCIENCE. 



31 



irm from dust, anil then mcrrty dipped 

^uiit Riid withtJniwn, when Ihey must be 

idly about in «lt dirrrlioii*. tli<t the ^Uxu 

qu&tl; over the whole siirfitcc. The su* 

quid h«%iiig hecn aUowrd to drnin off for 

da, and ihc pieces having bceu set oo u 

D^ A fvvr minatn, thry are ready for 

the for n are. 

Ill his '• Chemistry afiplied to the Arti/' 
a pniress for forming white enamel, 
ers well for gluing the tapenor kind»of 
and tender porcelain. Etpial parts of 
tin are kept in ftuioa until completely 
The powder thus fo^m^d ii ground with 
|inipnritic» Are removnl by repeated wash- 
being dried it is kept for use. The 
fa are then cho^pn, and fu«ed with car- 
ta^b, the latter being in »uch propor- 
flint, that the mixture will be soluble in 
the solution of flint thus made, muriatic 
from time to time, be added, until no 
pitation occurs. The precipitate thus 
pare silex, which buing washed and 
fit for um:. If then one part of this 
One part, of the metallic oxide, bo added 
of carbonate of potash, and the whole 
a crucible, the mass need only be re- 
fine powder to prepare it for use in 

m Rose, of the porcelain works at Coal- 
kropshire, apcaks in commendation of a 
ikrd porcelain which be baa used for some 
wbicV biTing been ex\mioed by compe- 
At tfae reqnest of the Society of Arts, 
rted on very favorably. Mr. Rose's 
mpoffcd of 27 parts of felspar, 18 of 
Lynn sand, 5 of nitre» 3 of sods, sod 5 
day of Cornwall. This miitore ia 
and ground to a fine powder ; 3 
oed borax being added previously to 

porrcinin and the finer kinds of earth- 
■n!!T made with white lead, ground 
|[|i lass, and comnioa salt; Lynn 

ll^ -oda.as a flux, being frequently 

' '-nti just mentioned. Almost 
|u li^ca a peculiar glaze, the recipe 

k Is ki:[>: iccrct by him as much as possible, 
I idea of )t3 superiority compared with that 
I by hi* competitors, so that it ts not pos- 
[glatti pruportioDS with accuracy. The 
pr.-viiiTi ni.ikers hare given the compo«i- 
kr ide by them, which are all said 

:■', groDod porcelain, and crys- 
gypsum, in the following diflerunC 

tin. I. Km, 2 Nrt. 3. 

. . . 8 pts. 17 pu. U pts. 
... 15 16 18 

tad gyp»um 9 7 12 

to vary the compofition uf tile 
Ibt to suit the diflcrent materials that 
ly of Che ware, since that would be a 
one mixture of earths, which 
1 propriaCe tx> Another, jiroving 
«., ^ ^..d being liable to crack. Before 
glaxtf in CDDJuuctioo with a particular 
, ic la most prudent to make trial of it 
aculcr in order to prove the suitable- 
bodies (0 each other, 
ia the competitiou among potters in tiie 
', tiiat meaoi which are injuriuus to their 



real quality are frequently adopted for mideriog 
their WBres leas costly. Some makers are hence 
tempted to the eniploymt-nt of nisteriuU that will 
enable them, at a moderate price, to furnish arlirlM 
oppanrnlly good, but wliich will apeedily prove de- 
fective when brought into one. The saving which 
the manufacturer i^ able to effect, through ibo adop- 
tiou uf an inferior glaze, consists uutso much in the 
■ctunl cost of its component parts, an. in the smaller 
quantity of fuel required fur its viiriAcatioa. and ia 
the shorter period of time demauded for its coo- 
veraion. 

The earthenwares ofiered, at low prices, by hawk* 
eri and pedlers, and at inferior shops, arc mostly 
composed of clay that will not bear a proper degree 
of heat in the oven, and arc covered by a gloso so 
tender oa to craze after a few cleansings with hot 
water. If exposed to a high temperature, or if 
acids be applied, the glaxe will be dissolved, and Uie 
vessels conftequrntly rendered useless. The quantity 
uf lead which enters into the compooilion of the 
better kinds of glaxes is so small, that the deterio- 
rating and pernicious effects which attend upon Ihc 
usv of raw glaze need not be apprehended from 
their employment. 

Ai alkaline substances are so powerfully instru* 
mental in promoting the fiiaion of intractable bodies, 
it may he thought, that by increasing their pro- 
portion when combineil with felspar, gloiva might 
be formed that would fuse at a beat sufficiently 
moderate for any description of earthenware, and 
that, consequently, the use of oxide of lead, which 
is so pernicious, might be altogether abandoned : 
bat onother serious evil which would then be ex- 
perienced prevents this substitution. The glaze, If 
it contained bejrond a certain portion of alkali, 
would not undergo the same tlegree of expsn^ioa 
by heat as the body wbcreon It is laid, and would, 
as a conaequence, crack to such a degree as, when 
brought into use, would allow any greasy matter Co 
penetrate through to the body of the wore ; and 
this would speedily destroy its coherency. 

The qnalilies which it is the object of the manu- 
facturer to give to porcelain of the finest description, 
are density, wliiteness, trmnsparenoy, and fine tex- 
ture of the glaxe. These properties are estimated 
in the order wherein tliey arc here enomcrntcd, 
compactness of body being the point which it is con- 
sidered most desirable to attain. The glaze, as scoq 
in the finished porcelain, should not put on a lus- 
trous appearance ; hut while beautifully smooth to 
the touch, should present to the eye rather the soft- 
ness of Tclvot tlum the gloss ot satin. This pecu- 
liar semblance will only be produced wiili glaxe 
tliat melts with difhculty, and when the hoat has 
been raised preoisely to, and not beyond, the point 
that is necessary for its fusion. 

The glazing: of common red ware is effected by 
the decomiwsiliou of common salt thrown into the 
kiln, at or near thi* conclusion of the baking procre«. 
Other gUzea o^ likewise employed for many orti- 
cka, and, acconliug to the usual system, the par- 
ticular oomponenta of the^se arc abo veiled in 
mystery ; groond glass is, however, understoo<l to 
be the basis of all. 

The diiferent colora observable on the outer aur- 
face of drinking jugs and other articles, is owing to 
the partial use of a ftlaze, the part to which this 
is appUed becoming dark in the heat of the kiln. 
while the gloxing of the light colored portion is 
cauaed by the introdaoUon of salt. 



mmk 



39 



MAGAZTNB OF 



NOTBS ON THB 



'^^^^ ter;:2,rKr.i;;3:f' 



RatsBaaoji. 

Dnuii . . . . 



Me I 



30-02 
WS85 
SO -061 






0794 
1&I3 



Ts thii mnnth BntmaU of alt kindi are in full vigour. 
Tbe bcASlB enjof dieroselvej in the fresh pastures. 
The grovci resound with the loni;! of the feathered 
race. The reptiles and donnant animali, as Che 
acaaon progrewea, and the air becomes warmer, 
break trota their winter'^ torpidity. Trees and 
pools swarm with inncct life Ptsh again become 
active, and fill the stre-ams with tlieir spawn. Trees 
bioftftom, vegetation rapidly proceeds, flowers enamel 
the meads and hedge-rows, and all nature seems to 
smile, Mun finds his spirits improve, his vigour 
increase ; his ogrti^ultural labours occupy his at- 
tention, and he returns to them with renewed 
atteutiuQ and xest, urged on by the united stimu- 
lants of health, proAt, and pleasure. 

ANIMATED NATURE. 

Lererets and young Rabbits are now first seen 
gamboling in the copses and among tbe young crops 
in the fields. 7*he Cnckoa is heard early in the 
month. The Chimney Swallow, tbe Swift, the 
Martin or Mortict, and others of the Swallow tribe 
rtttnm to us again. The Corn Crake and the 
Nigbt Jar make their discordant noieea. The Tic- 
lark sings. The Goldhuch. the Blackbird, nnd the 
TliriLih make the groves re-echo with their varied 
melody, and towards the end of the mouth the 
Nightingale may be heard in the forest. The Dove 
and PtJgeon coo, the Redbreast, the Willow Wren, 
the White Throat, the GrasNhniiper Lark, and the 
Goatsucker return from olhiT climiia, to spend their 
summer with us, and towards the end of the month 
the Great Bat flutters in tbe evening. Reptiles, 
the Frog, Snake, Eft, and Lizard ore, if the weather 
be warm, tempted from their winter quarters, and 
lay their slimy spawn, tbe first in ponds, the rest 
mider dunghills or warm walla. 

Fish sport up and down the streams, and find 
abundance of food in the larvie of numerous in- 
sects nnd worms, and shelter for their spawn amidst 
the young and growing wuter-planLa. Snails and 
Slugs Appear in the gardens. Earth-worms are 
abundant. The Cockchafer or Mayfly abounds on 
tbe trees. Tlie Lihelhilnr or Dragonflies sail over 
the pools. The Ladybird, or Ladycow, the Green 
Aphis, and the White-cabbage Butterfly are of con- 
stant recurrence in the gardens. 

VEGETAULK Llflt. 

In the fields, the Botanist will see many of bis 
Isvorites appearing again, while those of winter 
an not yet over. The Mosses are still in perfection ; 
indeed for most of them this is the best season. 
Tbe Brynma ore now particularly fine ; so are Che 
Gymnostomums, tbe Tortulas, the Poljtricbums, 
and the Fhoscums. AlgB are nSfr in vigorous 
growth, but not yet fertile. Lichens ore decaying, 
or rather becoming dormant till the damps of the fol- 
lowing autumn shall agoin urge their farther growth. 
Fungi also are nu lunger abunuant, though many of 
the Polypori arc yet to be found, and indeed mime* 
roofl otbm on decaying plants in damp situations. 
Flowering plauLi arr leeu every day to put forth 
frc^h blo^tiomi, though it is not till the end of the 
moiiLh that ihc rciU ht'auly of surouicr is fully esta- 
bliahcil. In the tarlicr part of the month VMrious 



MONTR OF MAY. 

of the Dead Nettles, tbe PHcwovt, T'- '^' 
Palustrijt, the Daisy, the D«ndHio«, il 
Ivy, vorioua of ihe early Spfcdwellt. i 
thorn, and tbe Shephrrd's Vursc, vc almost 
only common plants. Towards the lattrr port 
the month, the collection is greatly increased 
in number and in besnty. The trees are in 
greatest perfection. Tbe Sycamore and Maple 
Chestnut, the Hawthorn, (emphatically calli-d tl»e 
May,) tbe great tribe of the Willows, [the Fi 
the Pine, and Fir, the Poplar, the Borberiri 
Iris or Cora Flag, the Ijly of tbe Vallfy, the 
Rose, the Columbine, the Buttercup, the Plaintlfa^ 
the Wallflower, the FOTget-mc-nol, the W 
Violet, Milkwort, and numerous others, f^ome 
these, though indigenous in our islandt, are broMgbt 
into our gardc'Df, where they flourish, yet not with 
greater beauty than in their native wilds. Th^ 
garden at this season is still in its infenry, yrt 
begins to put on its summer dress. The liur^ 
Ancmonles, Ranunculus, Anricolas, and the Pbly- 
anthna tribe ore now in i>erfec(ion. Peouies, the 
Crown Imperial, the Tulip, the JooqaU, and nume- 
rous other bnlbs. are in full flower, and aided tiy 
tbe Aisles, tbe Fruit Trees, the Early Heaths. lh« 
Ilorse-chesnut, the Tulip Tree, the Drabs, andthf 
Aubletia. and other no less beautiful trees Moi 
plants, make the garden gay long before its seed* 
lings and the majority of its herbaceona pliats ibov 
any signs of beauty. 

OAKDENINa OPCIlATIONfi FOR TBS UONTI. 

Pruning and Transplanting of Trees and &bnbi 
is now over for the season, and the gooenl Sunour 
Crops are sowed and planted ; the digging up of 
the borders Is completed, yet much rematn» tor 
the gardener to attend to. Weeds at all timu srt 
to be eradicated ; and if frosts prevail, as they 
do in tbe early part of the month, the y 
tender Radishes nnd Lettuces must be diftn 
strow or other matting. Sewing and I 
Culinary Vcgctabli?s is still to be contiQu> 
vols to obtain a succession of crops. Sow ar mM- 
vols of a fortmght. Spinach, Radishes, Small Sabri, 
Peas, and Besus ; Carrots for Ute drawing; Bors- 
cole. Dwarf Kidm-y Beans for a main crop, CsoK^ 
flowers. Onions, Savoys. Stc., may still be soind> 
Strawberries transplanted. Their numers must te 
nipped off, and the suckers of all trees and b 
except Raspberries, rooted up. Sow Ci| 
and Tomatos on warm borders ; and 
Melons, Cucumbers, Stc in the frames. 

In the Flower Department of tbe gvden» 
of the more hardy Annuals and Biennials 
have been sowed under glasses, may be 
planted — such os Ten-week Stocks, Chitin 
TobacoD, flfc. ; snd tbe sowing of the yn< 
of border flowers be continued for a st,. 
crops daring the summer, such as M 
Virginia Stock, Indian Pink, Poppies, Coot 
and others. Such bulbuua snd tubprooa 
still remain out of the grounds must b« pi 
early as possible, such as Dahlia, C »mrnf'll 
In the Nursery Grounds, tbe &l 
should be sowed— of Wallflowers, • 
Rocket, various Stocks, &c., and uuutciuusof 
Potherbs, and Flowering Plants and Shnib^ ma; 
propagated by cutting or parting tJie roota. 
young plants now springing up will require 
ing If the weather be dry, and the corlli 
luoBtned. 



■t^. 



about' 



LtfSMOf ^PiialcU by D. rsAjccu, fi, Wbtta HurM Laue, AlUe £ad.— t*at>Ii»be<l by W. BsinAin, 11. Paicroottrx Koc, 



i^ 



rik 



34 



MAGAZINE OF SCIENCE. 



DORPAT TELESCOPE. 

Toe late Joseph Fmunhofer, of Munich, b most 
akilful artist Bnd eipcrimenter in optics (whose de- 
anise in I82C, in tbt: prime of life, was a great Inss 
to science), construrted a tna^jtiificcnt refrartiog^ 
telescope for the obsen'ocorr of the Impriial Uiii- 
vrrvitj at Dorpat. It warn rccrivctl by Prufe»or 
Strtivp, in the Tear lH2a, and has Mnoe been found 
to fulfil mont Autisfactorily hi* expectation and the 
intentions of the maker. A* this is one of the most 
mn^iiticcut iDstrumenlsof the kind that has hither, 
to been conktructed, and described by a figure, we 
hsvi^ given an engraving of it. copied from U&e ** Me- 
moir of the AslronoDiical Society.*' 

The (thjtN't-glass of this telescope is about 9J 
inches in diainetCT, and its focal length about 14 
English fei;t. The main lube is 13-H feet ; and, in 
addition, there is the smatl tube which holds the 
eyepieces. Of these there are four ; the least 
itiafrnifying power is 175, and the greatest 700. 
JUter the telescope was receiTed at Dorpat, a per- 
fect micruraetrieal appaniiaa was ordered to be 
made for it. This was to consiit of fonr annular 
micrometers, of which two were to be double ; a 
Ump circnUir micronieter, with four eye-pieces; a 
refracting lamp net micrometer^ with po&itioa ^cir- 
cles, and fnureye-pircea. 

Tbn frame-work of the stand la made of oak, and 
the tube of deal, Tcneered with mahogany. The 
wholu weight of the telewope and iu coanierpoises 
jpi sup}>ortvd at one point, namely, at the common 
centre of gravity of all th« poiideroaa parts. Tliesc 
weigh 300U Russian pounds, of which the frame- 
vrork contains 1000 ; the rcmainmg 'iOOO are so 
balanced in every position, that the telescope may 
be turned, with rapidity and certainty, in CDCry di- 
rection towards the heavens. 

The basis of the frame is formed of two ctom 
benma, each 9 feet 7 inches long. The ends of 
these are seen in the figure at A, B, C, D. They 
are braced by four smoUer bars, farming a square, 
one of which i» seen at E. This braced cvosb is 
fastened to the floor by eight screws, 6 of which 
are teen in the figure. A perpendicular popt, about 
6 feet high, and 7 inches square, is fixed over 
the centre nf the cross, and is propped at the north, 
east, BTtd west sides by three curved stsy^, denoted 
by O, ti, G, whii-Ii arc fixed at their lower ends 
tu tilt bcsma of the cross, and at the upper to the 
verticiil |K>st. An iurlincd beam H of the snme 
thickness rests on the southern side of the meridian 
fieam of the croas, and is alLsched to the Tcrtical 
beam in a position panillel to the polar axis, lliis 
uto, shown in the figure at I. is ■ cyliniler of steel, 
30 inches long, and ]>raportiona1ly thick. It turns 
In two colltrs, and itn lower end, which is rounded 
and poliithed, revts uu a Mtcel plate attached to the 
bearing piece K, which is secured to the inclined 
beam H, and has. therefore, very little friction, the 
wt-ight being supported by friutioa rollers near the 
common centre of grarity ; and a coanterpotsc L is 
applied, to support the axis in any position. There 
is a circle, 1.1 inches in diameter, graduated tii mi- 
nuu8 of time, fixed to the lower end of the axis, 
niid tiirnishrd with vcmiers. The axis of vertical 
iiv-tlon of the telescope, which baa nearly the di* 
ni< iiMons of the polar asi£, paasea throogb a brass 
ti.li' III right aneleft tu the latter ; the tube, which 
j^ i-^-'-n ut M, forms n part of the frame, and is fas- 
tened at the upper end of the polar axis by twcWe 
•crews. This Axii L&rrics the L-irclc of decliDAtion, 



which is 19 inches in diitmctci. and ii dh 
every 10', with a vemier rruiling 10" o( 
estimation. The tube of the telescope ia ! 
the frame-work nearer to the eye end ibaad 
die, and has two connteriioisea attacbed to 
which balance the tn'o ends, and prevent th« 
tendency of the longer end to bend. TH 
frame holding the two axes appear* on tbi 
clomped to the tube by two strong ring*, 
each end of the centre of motion. A bcu 
carrying the weight O, embraces, by a douh 
the near end ot the axis of the declinalioi 
The axis itself carries another weight j and 
and the weight O It ta coanternoised. T 
motion in altitude it given to the leIeaco| 
joint applied to the screw of the clamp, wll 
a spring urging it against a atrcmg iron bu 
uchcd to the end oif a cylinder M, that 1 
stop to the circle ; and a slow equatorial nu 
given by a aecond joint taking hold of aa 
screw, acting with tbe racked tdgit of th* h 
cle, while a spring pressea it into actktt wM 
and a lever ia ctnployed to ralac it out of d 
when necessary. Tbe bandies UUng hoU ( 
screws extend to tbe reach of the obaervflr. 1 
thus point hia telisacope in rifcht aaccnsioo j 
clioatiun with the same certainty aa the ba 
dian instrunwnt. 

A regular sidereal motion ia communiflatw 
instrument by clock-work, which kcepa a i 
parently at rest in the centre of the 6eld d 
and there ia a contrivance by which the \ 
can be changed into a solar, oIm Io a lOMT 
motion. 

This almost invaluable instrument coct 
flonns (about 950 ponnda sterhng). Tlu 
altbongh it may appear coostdersbic, yei 
covered the cxpensea of the workmuishi]! 
constrnctian. This relinqoishmeut of the y 
trade difia great credit to tbe ingenioua and 
minded artiata, PrannhoCer, and Utzcbneid 
chief of the optical establishment at Munich. 



THE TIDES. 

One of the most immediate and remarkaUl 
of a gmvilating force external to the earthl 
alteruate rhc and fall of the surCscs of < 
twice in the conrve of a lunar daj, or ti 
50 minutes. 28 araoods of mean aolar (uac 
depends upon the aetioD of the san anS oux 
classed among astronomical problems, of i 
is by far tbe most difficult, and iUi explanal 
leoMl antisfactory. Tbe form of tbe sur&OM 
ocean in etiuilibrio, when revolving with tfa 
round its axis, t3 an elUpsoid flattened at fbl 
but the action of tlie sun am) moon, fcpo) 
the moon, disturbs the eqnilibrinm of ibe 
If tlie moon attroctcd the centre of gravit] 
earth and all its particles with equal and 
forces, the whole system of the earth and lb« 
that cover it, wonld yield to these forcn 
common motion, and the eqoiUbriam of tl 
would remain undisturbed. The difTcrvnai 
forces, and tbe inequality of thetr direcuou 
distnrb tbe equilibrium. 

It ia proved by daily axperience, as «iil 
strict mathematical reasoning, that if a nw 
waves or oscillations be excited in a flidll 
fbrcnt forces, eadi parsnea its eoum, md 
effect independently of tbe rest. Now, ia t 
there are three kimi& of oscillations, tlcp«all 



MAGAZINE OF SCIENCE. 



35 



Uid prodaclni; tbeir ttCuctt inile- 
-t> other, which may therefore be 



I of the first kinti, which arr very 
r itiiiciii-n<lcDt of the fetation of the earth ; 
fT ilrpenil upon the motioa of the iltsturb- 
m its orbit, thej are of long periods. 
md kind of OHcUtations depends upon the 
of the earth; therefore thrir luiriud is 
day. The osciltations of the third kind 
■n an^e equal to twice the angular rota- 
be earth, and confequentlj happen twice in 
brar hoam. The tint afford no particuiar 
ind arr ritremcly Kinall ; but the difference 
inierutive tides dependi upon tbe second. 
ne of the solstices, this differcnci', which 
be very greitt, necarJtn^ to Newton's 
hardly lensible on our &hore«. La Place 
n thai the diEvcrepaiicy arises from the 
the aea ; and tliat if the depth were ooi- 
rv would be no difTercncc in the conaecu- 
bat that which is occatiioned by local ctr- 
K9. It follows, therefore, that a« this dif. 
eitremely fmail, the sea, considered in a 
■t, mnat be nearly of uniform depth ; Uint 
•here is a O-Ttain tnran depth from which 
|)oo it not preat. The mean depth of the 
Icean is supposed to be about fuiir mites, 
be Atlantic only tlirec, which, however, it 
Evrtarc. From the formiilte which deter- 
difference of the consecative tides, it ia 
hat the precession of tho equinoxes, and 
ft of the earth's axis, arv the same as if 
rmrd one solid mass with the earth, 
ftions of the third Idnd are the scniidiurnal 
vmarkable on our coasts. Tbey are ocr«- 
the combined action of tlie sun and monn ; 
affect of each is independent of the other, 
' be considered separately, 
jrtides of water under the moon are more 
Plhen the centre of gravity of the earth, in 
ffae ratio of the square of the di<)tauces. 
ey have a tendency to leave the earth, but 
fed by their gravitation, which is diminished 
lendenry. On the contrary, tlw monn 
he centrt of the earth more powerfully 
Ittracta the particles of water in the hcmi- 
Iposite to her ; so that the earth has a 
to IrsTfl the waters, but is retAined by 
I, which is again diminished ty this ten- 
Thos the waters irnracdinlely under the 
drawn from the earth at the same time 
krth ia drawm from those which are dia- 
'opposite to her; in both instances pro- 
elevation of the ocean of nearly the same 
ive the surface of ec|uil)brinm ; for, the 
I of the gravitation of the particles in each 
almost the same, on account of tlir dii- 
te moon bring great in comparison of the 
n earth ■ Were the earth entirely covered 
I, the water thus attracted by the moon 
the form of an oblong spheroid. 
Ktrr ni« would point townrds thu moon, 
f :" water under the mocn and in 

It ncally op|rosile to her, are ren- 

Mitrr It] ( Liiikequence uf the diminution of 
fixation ; and in order to preserve the equi> 
axr» 9<>' distant would be shortened. 
Ion, on account of the smaller spoce to 
confined, is twice as great a«i the 
because the conti-nis of the eplieroid 
the aame. IT ihc sralcra were capa- 




ble of tmuraing the form of equilibrium inslantane- 
ously, timt is, thn form of the •tpheroiri. tU Fumroit 
would always point to tlie moon, notmthitnhding 
the eaiih'f rotntion. Itnt uti account uf their re* 
sistanoe, the rapid motion produced in them by 
rutatton, prevents them from assuming, at every 
inntant, tlie form which the eqailibriura of the 
forces nrring upon them requires. Henee. nn 
account of the inertia of the wilers, if tbe tides he 
considered relatively to tbn whole earth, and open 
tea, there is a meridian attout 3U^ eastward of the 
moon, where it is alwuys high water both in tbe 
hemisphert! where the moon is, and in thut which 
is opposite. On the west side of this circle the tide 
is flowing, on the east it is ebbing, and on every 
part of the meridian at 90'* distant, it is low water. 
7*his great wsvc, which follows all the motions of 
the moon as far as the rotation of the earth wiU 
perihit. Is moditlcd by tbe action of the sun. the 
cfiVctK of whoae attraction arc in every respect like 
those produced by the moon, though greatly leas in 
degree. Consequently, a similar wave, but much 
smaller, nused by the «un, tends to follow hia 
motions, wliich at times combines with the lunar 
wave, and at others opposes it, according to tbe 
relative iwsitions of tbe two Inniinnnes ; but ns tbe 
lunar wave la only moJilied a little by the solar, tbe 
tidra must uecessority hiip)>eo twice in a day, itnce 
the rotation of the earth brings the same poiut 
twice under tbe meridian of the nwon ia that time, 
once under the saperior, and once under the inferior, 
meridian. 

In the semidiurnal tides there are two phenomena 
particularly to he diatinguifilK-d, one occurring twice 
in n montli. and the other twricc in a year. 

The first phenomenon is, that the tidca are much 
increased in tbe syzlgics, or at the time of new and 
full moon. In both cases the sun and moon are in 
tbe same meridian ; for when the moon it new, tliey 
are in conjancUon. and when she is full, lliey arc 
in opposition. Jo each of these pabitiouK, their 
action is combined to produce the highrst or spring 
tides under that meridian, and the lowest in those 
poinU that are 90" disUut. It is observed that the 
higher the sea rises in full tide, the lower it ia In 
the ebb. The nei^ tides take plaec when the moon 
is in quadrature ; tliey neither rise so high nor sink 
so loiv OS the spring tides. Tho spring tides are 
much increased when the moon is in jterigc*:, becausB 
she is then nearest to the earth. It is evid<*nt that 
tbe spring tides most hippen twice in a monrh, bince 
in that time the moon is once new and onre fiUl. 

The second phenomenon in the tides is the aug- 
mentation, which occurs at the time of the rqni- 
noxes, when the aun's declination is zero, whii'h 
happens twice every year. Tbe greatest liden take 
place when a full or new moon buppens neur (he 
equinoxes while the moon is in perigee, The in- 
clinRtion of the moon's orbit to tlk; eHiptie is 
y 8' i7"'9 ; hence, iti the equinoxes, the action of 
the moon would be increased if her node were to 
coincide with her jMiigree. For it is clear, tlial the 
arlioii uf the sun oitd moon on the occmn ia nio*t 
direct and intense whrn they arc in the plnnr of 
the equator, and in the i>ame meridian, iiud when 
the moon in conjunction or opposition is at iwr least 
distanre from the earth. The spring tides which 
happen nuder all tbcve favourable circumstances 
mTwt be greaU»t posuible. The eiiBiftoctiaJ gales 
often raise them to a great height. Bosides these 
remavkablc variatiuns, there arc others arisi/ig from 
the dodinjLlion or angular distance of the sun tod 



AA 



zn 



MAGAZINE OP SCIENCE. 



moon from the plane of the equator, which have s 
grent influc-nce on the ebb and flow of the waters. 
The iun and moon are continoalty making the 
circuit of the heavens at ditTerentdtRtances from Che 
plana of the equator, on arcuunt of the oMiqutty of 
the ecliptic, and the inclination of the lonar orbit, 
'flic moon takes about twenty •nine dayi and a half 
to vary through all her declinations, wfairh some- 
time)) extend 28f degreee on each side of the oqiia.- 
tor, while the sun requirei nearly 365} days to ae* 
com^lish hia motion from tropic to tropic through 
abo^it 23^ degrees ; so that their combloed rootitm 
rau«e« grent irregalaritiesT and, at times, their 
attractive forces connteraoc each other's effects to a 
certain exCeut ; but, on an average, the mean 
aoonthly range of the moon's declination is nearly 
tha same as the annual range of the declination of 
the SOD : coDsequently, the highest tides take place 
sfithin the tropics, and the lowest towards the poles. 
Both the height and time of high water are thus 
perpetually changing ; therefore, in solving the 
problem, it is required to determine the height4 
to which the tidM rise, the times nt which they 
happen, and the daily Tariations. Theory and ob- 
ifervation show, that each partial tide increases as 
tha cnbe of the apparent diameter, or of the parnllax 
of the body which prodnees it, and that it diminiiiheB 
u the Bqoare of the cosine of the declination of that 
body. For the greater the apparent diameter, the 
nearer the body, and the more intense iti action on 
the sea ; but Uie greater the declination, the less 
the action, because it is less direct. 

fTW be continued.) 



THE GONIOMETER, 

The instruments which are used for measuring the 

anglrs of crystals ire termed tjoniomeiert. The 
iplest of these consists of a protrsctor or semi- 
!ular scale of degrees, A A, and a small pair of 

compasses or nippers, BB,CC, destined to recesve 

the crystoL 




The eentiv of the pair of compasws ic made 
moveable, like thtne of the common proportional 
compaaaes, so as to |>crmitthe legs BB, and CC, 
to be considerably lengthened or shortened, when 
the two pieces are applied to each other. The fised 
leg BB, is represented as beneath the moveable 
one CC. or radius, raessnring 90*^, and the lower 
end of the centre. pin, which could not be shown in 
the wotid-cnt, is made to At the hole or crntre in 
the protractor precisely at the same time tliat a 
■tud or projo(!tmg piece of brass, being admitted 
into the long perforation of the leg BB, the piece 
becomes steariUy attached to the protractor or Krui> 
drde, oi is seen in the figure. 



The appUcatioQ of this instrument b obviotiA.— 



.) h 



n the 



The crystal to be measured is appl 

compasiCB, which being thus srt, ai 

protractor, and the value of the an. 

ofFat theedge of the tegCC, It i>. v ..;.«4. 

dom that accurate resulta csn thns *'■ <^'>wh.1. te 

the surfaces of crystals are generally too sraaJl or 

too im{>crfcct to admit of sack method of measw^ 

meiit. 

'ITie reJUctivf gouiomeifr^ invented by Dr. Wol* 
laston,. is a more useful and perfect iasirumtmt. It 
ensbles us to determine the angles rven i*t minnlc 
cr)'staU with great accuracy i a ray of ligbt rrfl«<rtrd 
from the surface of the crystal being employed • 
radius, instead of the surface itself, Mr. W . IMl' 
lips has given the faUowing deacriptiiMi and prac- 
tical details for the use of this iaflrameitt, ia kii 
" Introduction to Mineralogy.*' 




A is the principal drcle-t graduated on one 
to half degrees, and divided, for couTcnienf^, 
two ports of iHO'^each. B isa hrosa t>lat' 
upon, snd supported by. the pillar C, » 
oted as a vemirr. F is the axle of the <-irri<- .<., 
and passes through the upper part of the two paUsil 
C £, tlie other ends of which are iascrt^<t >i>t<^ & 
wi3iiden hflsc. G is an axle, enclosed wit): 
earned by means of the smallest circle \ i 
communicates a motion to all the apparaluk 
left of ]. without moving the priocii>at circle 
K is u circle, to which is attached the axle 
prinripiU circle. l(, therefore, we would n 
Litter, it wiU be done by moving K ; and as 
of the principal circle includes that of the ap| 
on the left of I, we necessarily give a motion 
whole instrument by moving the circle K. 

These two movements b^g understood, 
now suppose tlmt we want to meosare a 
rhomboid of carbonate of lime for tnaltnce. 
D be the rhomboid, attached by means of 
one end of a plate of brass H ; the other end 
plate being placed in a slit in the upper part 
circular broas stem O, which posses thi 
tube, to which it is so adjusted as to sllow of 
moved cither up or down, or circularly, by 
of the nut. The tnhe is ftxed to the curved 
plate P, which is attached, but so at to 
motion, to another curved ptate Q, by Deoni] 
pin. the other end of the latter plAti> being coi 
with the concealed axle G, to which a mot 
given by turning the little circle U. By mi 
the pin and the tube, therefore, we have 
tions, in addition to the two before describeil 
longing to the axles of the instrument. The it 
axle, however, may be said to be the ccntcv of tU] 



ions* It wilj, therefore, be of adT«nU^ 
rhdmboid of Ciirtfunaic <»f time should l« 
I nmrly on a line vUh that asle ait [(n*»i- 
I will be «u(Rdr»|ly adjuicetl by meoaa of 
O. Hhich Hdmiu of txAug nwed.or dft- 
tt )ili»sure. 

thin inttrument depends on the re- 
of tbc ]iolish on tbe natural pUnra, 
nrfocra of mineraU ; and Ihul this U 
ca rcry powerful, any one may convince 
looking upon a rcry brilliant plane, held 
IB eye, with its edge nearly touchiniy the 
ind not far distant from a window; ha 
obKTvr the rrflectioD of the btrn very dU- 
Urt oa then luppoic the goniometer, aj 
niKoted. to be diatant from a window 
to twenty feet. Let there be. then, a 
f (the uae of thia ia eaieatial) drawn on 
cot between the window and the floor, and 
parmiitt with the horiiontal barv of the 
If. then, the eye be placed olmoit clo6e 
>aibotd or crystal, a reflection of one of 
lUl ba aeen on one of ita planes. Ixt ua 
hi reflectioa to be in the direction of the 
ted line on the plane ; and it will be clear 
fanot be parallel with the bar of the wia- 
Vmag even with the black line. If, how- 
fa reflection appeara to be like the upper 
e, that ia, parallel with the black line, wo 
; conrince oorselrea that it ia to» limply by 
; tbc crjalal a Utile, by meani of moring 
circle JJ, ao aa to bring the reflectioa 
Aloe* iine. Thia being adjuatod, which 
fl precisely, we then torn the crystal, 
the httle circle H, ontil the reaectioo 
*«r b« seen on the next plane, perfectly 
" amd i^MMi tAe black line. Howcrer, 
Bf the aecond, wc may disturb the lirat 
By perseverance it will be found that 
be AdjUflted hy means of one or the other 
ffttocDta, or by the help of both, and a 
Mieooe will do away the chief difficultiea. 
eetioDa being precise, we are now, by 
circle K, to turn the principnl circle 
arrest«d by a stop on the pillar C ; it 
J found that 180 on the prindpal circle 
With cipher on the remier. In doing tliia, 
Iwc may slightly disarrange the reflections 
pne of crrstol, which may be rr-adjustrd 
moring the little circle !, which will not 
! principal circle A ; we must be certain, 
Aaf mo fjit ii fonnt a tine with cipH^ on 
, at tht tfime time that the rtftection of the 
1 cifmg thi black line. One movement 
, the measurement will have been made. 
irde K, keeping the eye almost close to 
id< «ntil the reflection of the uame bar is 
«<^}oiidng plane precisely upon the black 
--—=■->»:, and the opcratiuu i» cum- 
II be observed what proportion 
-c has been moved, i^ppose 
it« tpc now on a line with cipher on the 
» the vaJge of the on^le. But sup- 
a litll*« more thun I0:>, and leg» than 
twt then be observed vhicA line f^f the 
''•rtitM bat one line vith, another 
drrlf; ; 4U|ipOBi; It to be 5 on 

., is then lOJ o', which is the 

the obtuse angle of a rhomboid of car* 
tit. 




POLARIZ\TION OP LIGHT. 

The foUowinji valunble paper on the polarisation of 
light is by Mr. Goddard, the iuventor of t p^iUri- 
scope and other apparatus on this subject. 

The beautiful phenomena of colors produced by 
the transmission of poUrized light through doubly 
refracting crystals, the Tsrious bands and com-eotric 
rings, composed of rII the most brilliant nnd drlicate 
tints of the solar spectrum, and the diHWrnt forms, 
changes, and modifications, that Ihcy may br msde 
to undergo and cihibit, are ao numerous nnd varied 
Bi to furnish a display of the roost splendid e«|>eri. 
ments within the whole range of science ; whiUt 
their value and importance in the sciences of mine- 
ralogy and chemifttry, from the deep insight which 
polarized light afibrda uf the minute ftructure and 
coDititQtion of transparent bodien, wbidi appear, 
upon every other mode of exunination, to be per- 
fectly homogeot^oua, yet. when viewed in polarised 
light, exhibit the moat cxqnisite structure, (as la 
seen in the extraordinary configurations of apophyU 
lite, anolcine, and many others, displaying the influ- 
ence of laws of combination, of which it is irapoa- 
siblc, by any other means, to obtain the least know- 
ladge.) renders an exhibition of these experimeoti 
not only interesting, bnt most desirable and im- 
portant. For this purpose, after having tried nn- 
meroos eiperiments upon the different methods 
now in use, I have constructed a poUriacopef 
adapted to Mr, Cary'a hydro-oxygen microKope, 
which is capable of exhibiting, upon a disc, on a 
highly msguified scale, all the beautiful and curiona 
pbenomena of this interesting brant<h of science. 

But, previous to describing the polarizing appa- 
ratus, and the effects that may be produced by 
means of It, It may be as well to give a abort and 
popuUr explanation of what polarized light is j 
and, to do this, we must notice the principal hypo- 
thesis upon which the lluygenian or nndulatory 
theory of light is founded, at least so far aa relatea 
to the phenomena under consideration : but la bo 
doing, I beg that I may not be understood as advo- 
eating this theory in opposition to any other, but 
merely using it as affording a popular explanation, 
which those who give a preference to its rival will 
have no difficulty in understanding, and can, if ther 
plemse, substitute the language of ita rival, the cor- 
puscular theory. 

The following are the principal poatulata, accord- 
ing to Sir W. J. Herschel. upon which this, the 
undulatory theory, is fouudi-d. 

1. It is supposed that a rare, elastic, and Im- 
|>onderable medium, or ether, filhi all space, and 
pervades all material bodies, occupying the intervals 
between thdr nM>lAealei, and poasesaing inertia, but 
not gravity. 

2. That the molecules of ether are susceptible of 
being set in motion by the motions of particles of 
ponderable matter, which motion it communicates 
in a similar manner to adjacent molecules ; thus 
propagating it, in all directions, according to the 
same mechanical laws which regulate (he propaga- 
tion of undulations in otlier elastic media, ns air 
and water, according to their respective constitu- 
tions. 

3. That vibrations commanicaled to the ether, 
in free space, are propagated, throuf^h refractive 
media, by means of the ether in their interior, but 
with a velocity decreasing with its inferior degree of 
elasticity. 

4. That when regular vibratory nwliona, of ft 



da 



MAGAZINE OF SCIENCE. 



jiroper ktndt are proptgited throagh the ethfival 
tnedis, aud pau into our eyrs, And rtuich and agi- 
tate (he nenrra of the retina, they produce in ni 
the sensation of lifht, in a manoer more or leu 
Anulogou« to that in which the TibniCions of ike air 
affect our auditory nerves in producing soond, 

5. That aa, in aoand, the fre({uency of the aerial 
Ttbrationi, or number of excursions of each mole* 
cnU of air, deternoinea the note, so. in U(;ht. the 
frequencj of the Tihrations made on our nerves, in 
m given time, by llie ethereal molecule, determines 
the color of the Uf;lit : and that, hh the extent of 
the vibrations of air determines the loudness of the 
sound, so the extent of the vibrutions of t)ie ethe- 
real molecule determines the intensity of light. 

To understand how waves are produced, by the 
vibrations of the particles of an clastic mcdiutn, we 
have only to atudy the waves produced upon the 
surface of a pond of water when rain is falling ; it 
will be found that the particles of water driven down 
by a single drop of rain force the adjacent ones 
upwards, the nlr above, in coDse()uence of its being 
more elajitic, yieMing sooner to the pressure exerted 
by tlir difplaced particles on those surrounding the 
point of disturbance. Tbtis a wave is raised round 
this point by the momentum of the falling drop, 
and, AH sDon as such momentum is spent, the effect 
of i^ravity draws the raised particles down to the 
common surface nf the lifjuid ; the momentum, 
however, which they have acquired in this desoeat, 
carries them below the level, or point of rest; and, 
in descending below this point, they cause, among 
the adjacent particles of still water, ■ motion similar 
to thnt by which they were themselves actuated by 
the falling drop. The second wave thus produced 
will, in its descent, cauae a third ; and thus a series 
of waves, decreasing in height as they increue in 
breath, will be produced in rings, vibrating up and 
down, as is easily proved by placing a cork upon a 
smooth surface of water and producing a series of 
wives, when the cork will produce the same vibra- 
tiona AS the particles of water upon which it flouts. 
Such Tihrations present the appearance of waveir 



as the motion is commnnicflte6 from or 
thoM odjaceot. as u reprc*ented by 
we may suppose to be a section of tbttl 
water at tba time of the appearance oti 
the dots being the separate porliciea. 



j'AAa 



donhb 
ofH 

le ^1 
d. agl 
Co hai 

e rti 



Dr. YouD^F, in applying the undulah 
light to the explanation of the v: 
nomena. while considering tlic rcsulta «f 
Brewster's researches oa the laws of donhb 
tion, first proposed the hn'^tliMii of 
vibrations, which hu since been sbci 
necessary consequence of dynamical pi 
is most importiint to tlie explanation of 
These vibration* he illustrated by the _ 
of undulations along a stretched cord, agl 
one end. which, supposins a person to had 
huud, and, by moving first quickly op 
wave will he produced, which will run olc 
to the other end ; and then, by a aimilarj 
but from the right side to the left, nnot 
be produced, which will run along the 
former; but the vibrations or undutatiMii 
will be in planes at right angles to each oU 
dependent of each other, one being in a i 
plane and the other in a horixonta] plai 
according to this theory. Fig. 2 maf be i 
represent a a ray of ordinary or anpoli 
I have chosen this representation of a a 
ordinary li^l, which is a drawing of 
Woodward's beautifully simple card ce 
conveys at nnre to the mind a distinct D 
planes in which theribrations take place. 
light we may therefore concdvr to cona 
cesainn of systems of waves following 
with immvnee rapidity, and comprtstog 
number of rays, the vibrations of whie 
farmed in every possible plane. 




CTa be coniimei.) 



ELVDORIC PAINTING. 

Tbis method of painting, called elydoric, was in- 
vented by M. Vincent, of Montpetit. It takes its 
name from two Greek words, denoting oil and water, 
both these liquids being employed in its execntion. 

Its priucipal advantages are, that the artist is able 
to add the freshneaa of water colors, and the high 
finishing of miniature to the mellowneu of oil 
painting, in such a oaanner that the work appears 
like a large picture seen through a concave lens. 

The following is the manner of proceeding : — 
A piece of very fine Uocn or white taffety is sized 
with starch in the most equal manner possible, on 
pieces of gloss about two inchca square, in order 
that the cloth may be without wrinkles. When 
thcfe ore sufficiently dry. a layer of white lead, 
finely ground in oil of pinks or poppies, (the whitest 






that can be procured,) is to be appQ 
with a fwllet knife. To this la^er, whea 
to admit of scraping, more is to he 
cessary. 

A,s it is of very great importance for 
vstion of this kind of painting, that the 
free from oil, that they may better imbt 
laid on them, it is nece^ary that thi 
mode very smooth, auil that it be very 

The ariijA is next to procure a oir«i< 
about two incites diameter and one-foo 
in height, extremely thin, and painted 
inside. This circle, is to contain the 
surface of the picture. 

Water distilled from rain or snow la 
any other ; ordioary water, on account 
which it contains, being pemictous tu 
painting. 



MAGAZIVE OF SCIEKCB. 



99 



be finely IrvigBted betvcea two 
i-fiilly preserred from dtiat, and 
)U of p«>ppiea. or any other cold 
rhicb thoiild be as Umpid as water. 
r« being grouod, arc to be placed in 
m a piece of glaas, end covered with 

lU beiD^ thus prepared, the subject to 
to be fiuDtlj traced with a black*Iead 
it the piMM of cloth above- menliooed. 
tbm to be formed on the psllet from 
M nnder the water; and the pallet 
nl, ia the left band. The picture Is 
wecu the thumb and forefiugcr, aup- 
D reuldle finger, and the necessary 
lird and little fingers. The hands reat 
of a chair to giTe a full liberty of 
rork nearer to, or remuriag it far from 

kg made the rough drangbt with the 
lab, the circle of cupper, which is to 
pricture, is to be fitted eiactly to the 
tilled water is then poured wilhiu this 
Hi to thr height of onc-cigbtb of an 
•ye is held per]>endicular over the 
third Anger of the right hand, while 
lid rest ou the internal right angle of 
The work ia then ;to be re-touched, 
hv oolor and softetiiug as be finda re- 
leon as the oil swims on the top the 
hft off, and the picture carefully covered 
l^au. and dried in a box by a gentle 
dry enougb, it is to be scraped nearly 
i knife, the artist repeating the former 
tit latiiried with hia work. 
k period that the advantage of this 
wrlictdariy shows itself fur the purpose 
c» the water pourrd on the picture 
ry fault of the pencil, and gives the 
ecting Bud perfecting it with certainty. 
iiork is I'misbcd it is put aoder a fine 
birii the eaternal air is excluded, and 
ncaas of a gentle heat. 



Ktri 



lICITY OP STEAM. 
To Iht Ktiitar. 

■ the opportunity of mentioning, in 
be subject of the electricity of steam, 
« which occurred to mywJf some time 
■oakiDg an experiment, in which 1 was 
a gas-holder, the gas and steam which 

off from two retorts containing re- 
r and water. 1 was very much sur- 
irre, shorlly after the commencement 
meat, the diichnrge of at lenat two 
cs from the top of the glass tube which 
•eertaining the quantity of gas by the 
w^ter contaiued in the Tcssel. My 
the roommt being otherwise occupied, 
heed to the circumstance, thinking it 
t this manifestation of electricity was 
DC pecnliar chemical action resulting 
|m of the gaaes. The accidental dis- 
letrieal phenomena in ateam genented 
imntt, inclines me to thinli otherwise 
vUl b« much the beat judgt* whether 
ton of this circumstance will assist, 

•0 feebly, in the elacidation of the 

S. U. TAYLOa. 



ON MANAGING BALLOONS. 
7b M« Editor. 

StB. — A taggestion having occurred to me to 
render balloons more manageable, I beg to submit 
it to your scientific readers, it consists in baring 
a fire in the car, and a tube (open at the top) from 
the fire or stove to pass through the balloon, (firom 
the boUom thnragh the top.) bat not so as to touch 
the gas, the hole through which the tube pasBM 
being intended to be closed up with cloth, so thit 
if the labe were removed, it would havi; no aperture 
for the gas to escape, as the rJoth tabe would be 
left in the cavity. This tube must have a valve in 
it near the bottom which can ahut or op«a the pu- 
sage at pleasnre t and it is by meana of hot slam 
or heat pMoed thraogb it that the balloon is to be 
coofed to ojcend and deocend. When wished, then, 
for it to ascend, the ralve must be cansed to o^n 
the passage, when the beat passing through the 
balloon will dilate the gas, and the balloon will con> 
aeqocntly rise. For descent, then, the valve must 
be closed. But tbe balloon must not be nearly 
full, otherwise it could not expand, but most burtt. 
No hBllo.iit will, it is presnmed. be required, and 
probably some progreasion might olso thereby be 
obtained, by employing a sort of nearly horisontat 
sail and inclining it one way or tbe other, as tko 
balloon ascemls ; and the rrsihtance of the air woul4 
then, it appears, cause the ballooon to progrest. 
Suppose, then, the oeronaat wiahed to go eastward, 
he must let a current of hot air pass through the 
balloon, and at the same time incline tbe cast end 
of bis soil opword. and then close tbe posasge sn as 
to let the gas cool (or, if any method should occur, 
be may send in some cold air.) and as tbe ballooa 
would thereby descend, he must turn the eost end 
of the Mil downward, and tlie balloon would go ia 
the coDtmry way. 

But tbe car ought to be fire-proof. It does not 
seem impossible to produce the same effect without 
Are by means of an apparatus in tlie car to con- 
dense snil exbsust the gas : but then the tube maat» 
instead of passing through the balloon, open into 
tbe bollooa itself, and this method would be tctj 
laborions. 

But with respect to ballast. 1 am obliged to con- 
fess my ignorance why any it ever required, as it 
seems that the only reason v^hy it is adopted is 
because too mach gas is put in the balloon, wliichf 
if not fall, most eipand as it rises into a more raro- 
fied otmosphere, as, the more the qniwdc air be 
rarefied, the more so will l>e the gas within ; and, 
if the batluoii be full before it rises, it cannot eipottd. 
but may burst. 

The machine Utely exhibitpd at the Polytcthnie 
luatitation of a cross sail applied to a ballooo. 
fteema to be the same as was invented by me, and 
also by another person, signed '* Volitor.** several 
years ago, and. which, on being turned round, roi 
in the air. (Sec the rhiloMOpAical Maffustne^^ 
1814, and the Afec/Mraics' Jommat, £(e.) 

L. OOMPKnTI. 
Oral, Kemti^gtoa. __ _ 

"^ form Pignreu in lUti^ on an Ejf^.— Design 
on the shell any figure or ornament you please, with 
melted tnllow or any other fat oily substance ; then 
immerse the egg in very strong vinegar, and let it 
rrmaio till the acid bos corroded that port of the 
dhell which is not covered with the greasy maUer : 
those parts will then appear in relicC exactly m 
jon hove drawn them. 




40 



MAG/VZINE OP SCIEXCi:. 



MEDICAL RECEIPTS. 

SNUFFS. 

Tax baM of all rauITi is, or oaght to be, gmnnd 
tobaceo, the part of the pUnt tt6«d b«iag the ttalka 
of the plant. 7*he following are general directions 
on the manufacture of it : — 

Perfitirwi Snuffi. — The tobacco being groand 
and sifted, aa the wented snuffs do not require mueh 
pungencf. it may be mixed with maboganf tawduat, 
or that from rose-wood, or else the pure Ivbacco pow. 
der may be soaked in water, (the woUr being 
serriceable to steep cabbage and lettuce leaves in to 
make "penny Havannaba;'') then pressed nearly 
dry, then dried, afterwards moistened with rose-water, 
or orange flower water ; and finally sufficiently dried 
for sale — a htUe oil of tartar being put into all the 
moist snuffs to keep them damp at all timea. 
Fr«oeh innff is scented with the root of calamos 
■romaticas. 

Macouba Snuff" owes ita flavor, and perhaps its 
sedative powers, to theprevious fenneotatioD of the 
tobacco leaves by moi6t<ming them with cane juice, 
ond probably producing iu this way an acetate of 
the narcotic jmuciplt; of the tobacco, if such exist, 
M there is reason to believe there does. 

Lundjcfoot't Snuff, which has a burnt odour, 
somewhat like malt, is prepared by partially torri- 
^ing the materials, and is imitated by moistening 
any light colored snoff with empyreumatic oU. 

Bye Snuff. — Triturate and mix together, in a 
marble mortar, 5 grains of sulphate of mercury with 
2 scruples of liquorice root, powdered. Grimstone 
and others disguise this by various ingredients. It 
is a powerful errhine in producing a diacharge from 
the nuae, wheo snuffed up in small pinches, bat it 
is not Kafe. 

Cephalic Sniiff. — The following are various re- 
ceipts recommended for this snuff: — Mix together 
oqoal parts of tlie leaves of asarabacca, marjoram, 
mod of the lily of the valley, dried leaves of asara- 
bacca 1 ounce, flowers of lavender 2 drams, dried 
leaves of asarabacca 3 ounces, leaves of the dock 
■nd flowers of lavender each I ounce, sage leaves, 
nsemsry, 1Uie« of the valley and the tops of sweet 
marjorum, of each 1 ounce, with a dram each of 
asarabacca root, lavender flowers and nutmeg ; 
pound and sift it very ftnely. 

VeUoiP Snuff.— \ei\ow ochre the sbe of an egg, 
add chalk to lower tlie color, grind with half an 
eunoc of oil of almonds till tine, then add water by 
degrees, and two i|>oonsful of the mucilage of gum 
tragacanth tiU you have about a quart, mix tbia 
vidb pDrified snuff and dry it ; then aift it through 
a veiy fine sieve to remove the color which does 
sot adhere to the snuff, and moisten it afterwards 
with any aceoted water that may be deainible. 

Taltac {Snuff) Perfvme aux Fievrs. — Put orange 
flowers, jasmine, common or musk roses, or tube- 
lOMa with the fcuuff fur a dny and a night, and sift 
them out ; rc|)eat this as often as necessary. Snnff 
doea not heat with the flowers. .Snuffi are also 
scented with musk, civctte, ambergris, the essence 
of bergamot, rose-saCer, elder-flower water, itc. 



Cones ffoid 



KINDS OF CAUPIiqH^,, , 

AowpA Camphor. Ijinrtl Camphor^ Csmphora, — 
Obtained frum the routs and shoots of the Laurua 
camphnra, L. cinuamouinm, and Capora cunindu. 



by dTstiltation with water 
Jnpan. 

l^ryobaimm Camphor. — Very littie ol 
pbor comes tu Europe, it beiog carried 
where it sells for aboat thirty times 
their own laurel camphor. Obtained 
spUtting the Dryobahinns camphora ; 
this tree containing camphor mixed 
camphor. It cumea from Sumatra and '. 
Refined Camphor^ obtained by subtil 
one-sixteenth its weight of lime in a ^ 
beat. Camphor is stimulant, narcotic 
retic, in doses of 5 grains to 1 scmple, I 
bolus : too large a doae occa^aa vonntil 
rnlsiona ; its effects are eooateraeted by 
msybe faapeaded In liquids, by means 
yolk of egg, or almonds. Camphor 
boxea to keep insects from them, and 
fireworka ; it renders copal soluble in 
tJal oils. 

lAquid Oa^kor, Oil (/ Campkor. 
liguida, Oifum cwmphara, — Prom 
camphora, by piercing the tree. 

Rofemary Camphor. — Obtained fwU 
a careful redistillation, without additi 
third of thr oil ; the reaidunm affords 
camphor ; on separating which, and re-J 
remaining oil two or three times, the w 
camphor, amounting to 1 ox. from 10 
may be obtained. 

Sweet SfarjttrHtn Camphor. — Obtaa 
manner, nbout 1 oa. from 10 of the oil 
tile ; when act ou fire, it soon goes 
Cttmphfir, 1 or. from 8. 

Latmder Camphor, 1 ox. from 4, e 
of oil. 

Thyme Camphor. — Crystals cnbica1,d 
a liquid solution either with nitric or sal| 
is precipitated from nitric acid in a glul 

Soap Camphor. — Obtained from 
tion in water, adding muriatic actd, 
curd, wothiug it with boiling water, ani 
to separate the liquid rialne. It is i 
Btearic and margaric acids ; used to m 
which ore very white, aa neat aa wax i 
give a brighter light, bat do not last ao 
Turpentine Camphor. — Obtained fs\ 
turpentine, by passing muriatic gai 
by which means it will yield about iti 
of a kind of artiticial camphor, not 
dilute nitric acid, and when dissolve 
nitric acid not separated by the additic 
Cilrrm CatHphor. — Obtained from t1 
tified oil of citrons, exposed to miuiat 
absolves 286 times its bulk, or ne 
weight, and yields about 9-lOtha of 
It will be seen immediately that 
are muriates; the first, or that from 
the muriate of cumphogeu, or artifld 
oamphogen being the iupposed bate ol 
while the citron camphor ia the man. ' 
citrene being the new name of the oil 

Common Camphor ia called the proto 
pbogen, and conaistji of carbon 10 pal 
8 parts, and oxygen 1 part : by di 
nitric acid it absorbi 4 parts more of 
becomes camphoric acid, 

Voii. 1 oiuf 2 qf Ihit Magarine art noi 
jfontly bound in Cloth and Jjetttrad, 



U>NOo}< ;— PrUUcil by I). k'sAMCW. 6, Whilo UoiMLaiK.Uileiiad.— I'uOUftbcd by W. BsirrAlu, 11, Vi 



THE 



lAGAZINE OF SCIENCE, 



^nd ^tbool of Stm. 



.0.] 



SATUBDAV. MAY 8. I&4I. 



[l^rf. 




42 



MAGAZINE OF SCIENCE. 



FILTERING MACHINES FOR WATER, 
Tnc Approach of summer, ind the Tut amount of 
ftnimaj .-intl vcf^etible life which it gi^ra rise to, co&. 
taminating no mncb the wiiter of ponds and streams, 
induce n» to offer this week a few remarki onjl/trr- 
mg, with the view of directing our rejidcrs to a 
kaowledge nf the construction of some simple filter- 
ing machines. 

The first of these machines which we sh&U notice 
ii Messrs. While and ATeline's '* artificial spring," 
in which the water is made to filtrate upwards by 
its pressure i^ninst the under side of a stone, the 
quantity filtered depending upon the area of the 
atone, and the height of the reacrroir from which 
the water descends; but with a head of 35 feet, 
which can be obtained in most houses in l^ndan, 
a stone of 10 inches squsre will filter nearly 30 gallons 
per hour. Tlie engraving. Fig. I, exhibits u vertical 
•ection of the apparatus. A is the cistern which 
reecircs tbe water in its impure stat« : it bos a ball 
float and lever to keep a constant head of water 
orer the pipe B* and likewise to prevent any air 
])assing down it. Tlie pipe B is shown broken 
off, that the space between may be considered as of 
any required length. To the lower end of the pipe 
there is a nozzle C through which the pipe passes, 
which causes the water to shoot up against the under 
surface of the filtering stone F. Through this stone 
the water oojtes with great rapidity, leaving the 
■ninialculic and other impurities in tiie lower part 
or boMD £ of the marbinL*. from whence they are 
drawn oB* occasionally by the cock G, and carried 
away by the waste-pipe H. When the filtered water 
rises in the reservoir above K, to a certain height, 
the filtration i* stopped by the rising of the float L, 
which by its lever or rod N, shuts a cock O in the 
supply pipe. When the stoue has become charged 
with a deposit on its under surface, it is capable of 
being cleansed by the scraper S, which is turned 
round by means of a handle shown st the bottom of 
the reservoir K, the luia paBiiog tbrongh the stone; 
provision is thus nade for reviving the filtering 
properties of the stone whenever required, and with 
Tcry little trouble. 

A very old coutrivance for filtering water, but 
which has been the origin of moat of the more recent 
ipporatas for the purpose, consists in nearly filling 
the two legs of a pipt^, formed either of metal as in 
Fig. 3, or of wood as in Fig. 4, with washed uand, 
leaving merely ■ ajiace at B and B to receive the 
turbid water, and another at C or F for the filtered 
water to run off by. The chief objection tu these 
machiDes is, that they soon become foul, and con- 
sequently useless, until restored by cleaning, and 
this task, OS gcnt'rnlly performed, issuch alsboriouSf 
tcdinu<t, and alopping one, that these filters are 
mHunlly abandoned in a abort time. 

The engraving, Fig. 5, represents an apparatus of 
a convenient form, by Mr. James, of Knightsbridge. 
It consists of two vessels, A and B, of stone-ware, 
placed upon a strong stand C The upper vesael, 
which is covered, recelvea the impure water in a 
chamber D, at the lower part of which there is a 
large aperture, stopped by a sponge E, which de- 
tains the grosser impuritie* : henre the water passes 
through a finely-perforated eartbeuware plate into 
a layer of six inches of prepared charcoal, through 
which the water filters, and is thereby purified from 
any noxious smells, as well as any (Inatiog im- 
poritic-s ; it then pa5&es through another perforated 
plate G, and is received at H into the separate 



vetiael, which is b ttone-ware cask, from whitA it 
may be drawn off at pleosnrc by the cock. 

A very simple method of freeing water (rom As 
impurities by means of the capilUry ottractiasi af 
fibrous sobftances is represented in the at * 
engraving. A ia the reservoir. H the lowe 
partment. C an open tube soldered into tke 
of the reservoir, in which is put a wick of 
or wool, (the latter is best.) with one end im 
in the bottom of the rrservoir, whilst the otlm 
end hangs down a liuLe below it, forming a kind 
of syphon. The water in rising by ibe capillary 
attraction between the (ilamenta, deposits tha 
gross matter floating therein, and desccnda in a 
comparatively pure ttate into the Teasel B, or iiU 

• j«g- ^ 

The engrtrlDg, Fig. 2, repreoents an npperMn 
contrived by Messrs. Williams and Doyle, fcr tho 
pnrpoec of separating the salt from eea^wster, fcf 
merely causing it to percolate through « body flf 
sand under mechanical compression, and thua to 
render it fresh, Conld this object be obtaiii«d bf 
such neons, the invention wontd doubtleM be bM 
of the utmost importance to navigatioa, ea it woaU 
render a store of fresh water unneocaoory, thefrf^ 
affording additional stowage for provisions or cargo; 
but we ore not aware of any experiments provf«( 
that substances diaeolvedr and rhemically rombinei 
with a liquid, ean be separated by filtration ; «c 
therefore apprehend ihot the apparatus wonld he 
ineffectual for the object the inventors had in view, 
ntthough it may prove very efficient io freeing water 
from any impurities floating or aaapeoded in U* 
Hie following description of the eogrtLving (wUek 
represents one of the several modea of cooatmrtoQ 
pro|MMed by the inventors,) ia derived from "^ 
specification of their patent. A ia • psrt of ' 
supposed to contain sea-water. B • tube 
ing therefrom, made fast by bands to tbe 
apparatus D D, which ia a atroof aqvarv 
of wood, lined internally with aheela ( 
which are cemcntfd together to prevent the 
sition of water. TTiia part of the apparatna 
in section, that the construction and 
may be aeen at one view. E is the lower 
where the water u first received. F is a rtn 
of open frame-work, supported on fifc M 
F F. Over this abort frame ia nailed • 
of copper, pierced with naiuerou5 small holes, 
the perforated plate ore eereral layers of 
cloth, or woven horte-baJr, and abo«e 
body of sand, filling up the entire 
the top is placed a sliding cover L, which ia 
upon by a strong acrew M, working throagk a 
nut N, which is supported by curved iron 
tending from opposite sides of the trunk. Thei 
having been curopressed, by the ogenej of 
screw, into a more dense and compact mMi 
vented from rising by the pressure of tl 
which percolating through the minute Jntei 
regain its level, deposits its salt, and rax 
the pipe O in a freim state into a vexseJ P pi 
receive it. When the sand bu become sal 
with salt, it is to be removed by taking 
screw and the pressing-board L; the nun 
R R may then be opened by uniscrewiog the 
when the other materials may be eooily siAed. 
matters being completed, a fresh quantity of 
may be taken from the ballast of the ship, am 
process of filtration continued aa before- 



tr«ak. 



MAGAZINE OF SCIENCE. 



rO STEEL OF DIFFERENT 
(SITJONS AND (DUALITIES. 

f rtn t).,- innnafacture of rut itecl st Si. 
I J maDufactory of iwordi lad 

n .' Houttieni part of the Ourat 

l^oloHcl Aiiuof detcribes thn prooeNM 
b*( rasnaToctury to produce the tteel la 
pbl<« bj the fnsioD of b»n of iron ind 
(Bi of blut fiimace«. The peculi&ritj 
hm consbts in tliii ; that ima n put 
iifalet covered wilh charcoal to submit 
If ttnaeatetion , whilst in England iteel 
tmenlcd is empioyed. In other respects 
liaf new in the method adopted, but it 
*v1ceBble to atate, briefly, the toeaoi 
the author of the memoir of obtaining 
brent TArietiei in its compositioa and 
I*h0 foUowiuf arc hia observationa on 

leam idopted for the fobrication of 
IBdeat to ifaow the principal cauies 
ID vary the «faa1itiea of this metal ; aa, 
the quantity of carbon absorbed by the 
iBAtore of the iron itself. As the firaC 
tn Buy be regulated at will, it requires 
1/a, and the second need not now be 
I will therefore confine myself to the 
ksTC formed, which are the resiUta of a 
r of experiments. 

p purer the iron, that is, the more free 
W Ribitincet, the better will be the 
Bflnm H ; but the cementation will re- 

IbDC. 

'qualities of tofl iron are not to be pre- 

Ittle iron ; for if the hardnens of the 

ted by the carbon it conuins, it is prc- 

iroo, of the same quslities in other 

of the iron to be converted into 
on the quality of the iron ores 
the preparation of the iron. For 
i ium procured at ZUtnnnst, from the 
I from the Tearoincic mine, is preferred 
,theother mines in that net^hboorhood ; 
iCrom the iron works of Tugikk pro- 
ji fuperior quality to that from 

eiipgnngi from the sworda made 

piwhice cast steel of a quality 

to that of the ehppings of iron. 

bar* of iron which have been baried 

fer some time produce steel of a 

>r to that obtained from iron which 

Illy manufactured. This fact wa^ 

|a in the most ancient time, but Euro- 

Ifoi^otton the leasoun of their roaaters in 

kvc been in arrear of those natiooft, not 

H of making the be&t steel, hut also in 

^ of the slfpis by wliich the perfect 

I ,»-miux,\y atcertoined. If we are well 

cutler at least. Mr. Weiss, 

i.iii. v 1 the superiority for making 

^B^ haa remained a long time tmder 

f aleet is of better quality when the 
i ore hofDOgeneoos and of equal sise. 
i ftoel is softer when tlie ojteniitg in the 

trz 



or pieces of iron which have 
■d to the air produce worse 



presauR of the iron be equal up lo the tine the 
lid is put un the crucible. 

" 9th. If the workman have neglected lo put the 
lid DD in time, he may reader the steel of good 
quality by adding as much iron as is necessary to 
raise the metal to the proper height. 

" lOtb. If at the time of tlie final proof the steel 
does not send forth sparks stitficirntly bright, the 
evil indicated by this bad sign may be remedied by 
introducing throuf^h the opening of the crucible two 
or three pieces of iron of the weight of about half a 
kilogramme, 

" Uth. The fusion of the steel mixed with pow- 
dered charcoal or soot in determined proportiotiB« 
and in a closed crucible, as proposed Messrs. 
Mushet and Urcan, mi^bt, indeed, produce steely 
but ita dei^rec of hardness would be moeh Ifln 
certain than on the plan 1 have described. In fact, 
if the charcoal be in excess the ateel will become 
too bard ; if there be not eoougfa, the metal wiU be 
difficult to fuse, because a part of the charcoal will 
be vohitiliaed. 

*M2tfa. The addition of other metals, such as 
platinum, sih'er, or gold, in the proportions of I '& 
to 1*2 per cent., aoraewhat Improvca the quality of 
the steel, but the more pure the steel is, the lesa 
advantageous do such additions become. The effect 
of the addition of these metals consists principally 
in making tlie steel more easily forged, the propor- 
tions of carbon and iron being eqoiU. 

" As to brittle metals, their mi^iture with ateel is 
always more or le.4« injurious, and this becomes 
more apparent In proportion u the quantity of the 
alloy is increased." — Afonttfur Industriet. 

BOTANICAL NOTICES. 

ROOTS. 

The root is that part of a plant which grows away 
from tlie light. Ita use is to absorb moisture for 
the support of the rest of the plant, and generally 
to fix. it to whatever it grows upon. 

The root la called ttrrtatricl^ if growing in the 
earth, aa the generality of roots do ; pmraxitie If 
attached to other plants ; thus the raialetoe growa 
upon the thorn without contact with the soil ; 
aquatic if suspended in water, as in the duckweed 
and numerous other water pUnts : this kind of 
root does net fix the plant to any particular Rpoi, 
not being itself attached to an immoveable sub- 
stance. 

Roots differ from stems in not bearing regnhir 
buds upon them, and in growing downwards : t))ey 
consist sometimes of fibres only — at others of vari- 
oasly>Bhaped fleshy portions, oiled the body of the 
rooL This latter part is intended as a storehunso 
of food, and to eqnaliae the supply to the stem, 
when the other parts are impeded in their forniathm 
and re-gular artioa by drought. The fibres are, 
however, most esseotial, and alonf! ran be considered 
the true root, as it in by meann of tht-in only that 
moisture is drawn from' the earth and L-onveyed 
upwards. Their curious and beautiful structure is 
apparent in the first germination of a seed, in a 
vigorous and young root when removed from the 
earth, and in the fibres of a hyacinth growing la 
water. In each of these cjuea the end of every 
fibre will he found to terminate in a delicate, white, 
and spongy point, called a spongiolc, and which la 
more than any other part capable of rapid ah&orp- 
tJon. Owing to it« extremely tender nature it ia 
not adapted to long-continued action. The spon- 
giolea, therefore, and often the fibres which boor 



*^ 



44 



MAGAZINE OF SCIEKCE. 



Ihem, die ava; at the close of each growing seaaon. 
being rt'jploced by fresh uuci when the pUnU 

jeTITC. 

The fibivwi roet ii of three virietief. In the 
tinrt It contiftlaof simfilc uobranched fibre*, iit the 
duckweed it is fine like & thread, (I,) — in the 
Jiyaciuth Bud the orcbiftes like strings — and ia the 
acrrw pine so thiuk b8 lo resemble stout and ittroog 
poles, sometimes two inches in diameter. In the 
second variety, the hbrc» arc more or Iras bnuicheii, 
(2,) as we se£ io ordinary plants. In the third 
case, the Abrea are thickly clothed with long dowDi 
(3,) so as to present a shaggy appearance — this is 
ohfterved porticulArly in those gnusca and Kdges 
which grow upon n sandy shore. Tlie fourth vaneiy 
exult in trees, where year after year the fibres 
become changed into a woody rabstanoa, increasing, 
spreading, and strengthening ; antil at length they 
form a mau anderground, similar to the stem aod 
branches above, not merely ia vppearanw, but 
general structure, (4.) 




Ill I 

The tap or Juf\form root ; a fleshy root, thick at 
top and with the lower part gradanlly tapering down- 
wards ; it ia attended with but few fibres, and these 
are abort and branched. Carrots, (1,) parsnips, 
■nd radiahes, are examples of tap-rooted pUnta. 
In the turnip, (2,) it takes a rounder form. If the 
root perish at the lower extremity, so as to end 
■bmptly, it [a called a pnemorK or bitten root (3.^ 
The plaintain and the devU'a bit, (scabiosaauceisa,) 
sreof tUikiod. 




^ I 3 

The knotted or htiiercuaUd root is extremely 
varied, in the dahlia it consists of a number of 
fleshy taperiof* bodies united together, (1.) la the 
dropwort the fibres of the root are loaded with 
spindle-shaped knots, (2.) The roota of some of 
the orchis tribe consist of two finger-Uke portions, 
(2,) or else of two solid bulbs, (4,) one of wliich 
diea away each year, while a new one ia being 
formed : in a few these bulbi are ai a distance from 
each other, (5.) In the bird's-nest orchhi the root 
4»nBists of a mass of fibres, interbdng each other, 
(6i) and iu the coral root, (coraUorhixa innata.) it 
resembles the branching of a piece of coralline, [7.) 




Tlie aboTC are truly roots. The following an la 

reality under-ground stems, but as fl— * iiOl 

lately been comddered roota by bot tst 

still called such by otlier persoos, thi , ^^zn 

classed. 

The tnitbaut root is • root to which a bulb b 
attached : it b divided into the wolid butb, oa t9 sco 
in the crocna, (1) — this is often calkJ a carmm. 
The coff/rfif bulb, as in the onion, (2.) The •rmif 
bulb, nbich consists of a number of thici: lesrves 
folding over each other, as is wcU knowu to be Ihfl 
case with the white and the ycUow lily, <3.i Aa 
aggregate bulb consista of a number of bulbs uaitad 
together, u in the guiic (4)— ewih of tlieM sru- 
rately is called a dote. Roots of this dcsi-ripaoQ 
are in their nature correspondent to tlt^ luf ait4 
flower buds. The; bear from tlicir cecire upwi 
mostly a aingle nnbranciied flower stalk imd n 
lesTCt, with numerous simple fibres ^m the 
part. Also during the progress of their g 
small bulbs grow around the lower end at the 
one ; these are called off-teh, and beiaf se|ii 
grow into other plants, exactly similar eren 
their shades and stripes of color to the on 
It is by means of these that tulipa, orocuMii 
cintha, &c. are propagated. 

flr^ ^^^ iJUJBk 

I 9 2 

The granular root is one ia which the main , 
of the root are attended with a number of 
grains like bulbs. In Che white meadow snii 
(1,) they are brown and shaped like on onion. 
the pUewort, (2,^ like grains of wheat both in 
and form ; and in the wood sorrel, (5.) rei 
green, and formed of fleshy scales foldini; overi 
other. The root of various grasses m knotfied! 
a necklace, (ij^tbis farm, however, ia ool 
atant, but ia Uie result chiefly of waul of 
moisturt. 

I 8 S 4 

The inhertma root is one which has flfsiiy 
attached to It. These tubers remain perfcet 
the root or %tem which bears them h.: 
being fumishrd with ffudx or eye», B' 
they sre cnpablr of growth ; each n. .;:« ..^..«t 
year producing a plant similar to that whiefa 
them. Tlie potatoe, (fiG;ured below, "l EUid the. 
salem artichoke, ore examples 




The crerping root, (aoholea.) is a dud 
which £row8 horixontally &nd quickly, 
mostly jointed, throwing out fibrr* from its 
joints downwards, and one or more shoots uj 
whenever it arriTcs at or approaches the 
This root is so tenscioos of life, that if brokeal 
small pieces each of these will Tcgetate, pi 
as mtoy pltots ; heace the diffioultjr thcrv is Ib 




MAGAZINi: Of SCIENOK. 



45 



the eoDcb gnus, (1.) the brtlbinc. and 
which have o cteeping rout ; henoe also 

cxteaaiun and grovtb of lucb pUnti as 

^w, the mint, (2,) the cott'flfoot, &c. 

aria, (3,) the root appeara jagged at the 

cat into teeth. 




^Mn^ or rAJxomd — a thick, fleshy, and 

p>ot, gm^tng: occasionally apoo, hut more 

rjuBt un<ler the aurface of the ground — 

nying at one end aa U increases at the 

M furaUhed at irrcgalar interrala wtth 

. which each year afford freah leaves, 

The orris root, the ginger, and the 

n eumplea of the rhiioma. 




bIiat function of rooti to supply moisture 
of the tegFtiiblc. is rendered evident by 
var manUtstcd by plants to increase and 
roots according to their wants — thus 
aa ^rovr la dcaerta, on dry and hot 
naked rocks, hare asoally very long 
fibrous roots, which extend to a coo- 
below the Btuface, whence more 
attainable. Orchideous and other 
throw out fibres from their Htema into 
if in search of more food than their 
oan famish ; a pUut or tree distorbed 
iteee of growth, and injured as to the 
roots, will iofallibly die, unless it can 
w oat others ; a fact well known 
ho, in tranapUntfng, are obliged to 
that tbeae delicate and essential 
be ai little aa po«nble diatarbed. 




► 8TUDY CHEMISTRY CHEAPLY, 

«Y JAUKI^ HERBERT COOKS. 

(RerHmtd from page 2 1 .) 

deaarib«d the inatnunent required by the 
i now remains to give directiODs for their 
ipnlstion, with a few experiments, in 
iie an insight into the general manage- 
enucal processes. As theee papers are 
!d as an introduction to the science, I 
10 fonber cxpUnatioD, than will suffioe 
e rationale of each expcrimont well un- 
for other information I refer the student 
td't » Elements of Chemistry," or to any 
r poUMwd work on the subject^ 

UAMPULATION. 

/Atf 9j)irit-lamp, tripod-atand, ^c. — 

l-lanp is used to give heat in erapora- 

lUtion. preparation of gases, and in all 

rtiment^ where a moderate heat is to be 

t nntities of any subatance ; also, 

1 ' nding and working glass tubes, 

fliuk CT eraporiting vessel beiu^ placed 

the lamp is adjustcrd by means of the 

, to a height beneath it, pruportion- 

c of beat mtended to be applied ; — 



^M 




when the tin ryltnder is employed, care must be 
taken to leave sufficient space between it anil the 
bottom of the vessel, to allow of a free ascent of the 
heated air, otherwise the draught will be stopped, 
and the process much impeded. 

f7«e qfjloikt, Sfc. — Flasks ore osed for distilla- 
tion, preparation of gasea, solution, digestion, &c. 
For the dtsrillation of water or alcohol, take a clean 
flask and lit a cork to it, bore a hole through it 
with n red-hot wirr, oad enlarge it until it will ad- 
mit the shorter end of the bent tube, which is jwased 
just through it ; four or five ounces of the liquid is 
then poured into the flask, which is placed on the 
trii>od ; the other end of the tube is paaaed (with- 
out a cork) into another flask placed in a Tsssel of 
cold water ; the liquid in the flaak is now made to 
boil by the application of the lamp, and the steam 
coming through the tube into the receiver, Is thera 
condensed, by the cold water in the veasel in which 
it is placed ; this water sboold be withdrawn by 
means of a syphon, when it gets warm, and the 
vessel refilled with cold water. In distilling acids 
and other fluids, whose vapours would corrode the 
cork, make a little plaster of Puris into a stilT paste 
with water, and spply it to the end of the tube, in- 
stead of u. cork, fitting it to the neck of the flaak aa 
before ; the neck of the receiver should also be par- 
tially obatrooted with tow, as the nneondensed acid 
fumes are very disagreeohle, and even dangerous, if 
allowed to escape into the apartment. 

For the preparation of gases, the bent tube is 
fitted by a cork, to the tiask containing the mate- 
rials from which the gas is to be extricated, the 
other end of it being pasaed under the arch in the 
shelf of the pneumatic trough, which must be filled 
with water ; the phial intended to receive the gaf. 
being oorapletely filled with water so as to exclude 
all Btmospherir air, dose the neck with the finger 
and invert ou the shelf of the troogh, over the hole 
in the bottom of it, the gas then ascends into the 
bottle, displacing the water ; the portion of gas that 
cornea over first should not be collected, aa it is 
always contaminated with atmospheric air; when 
the phial is fall of gas, remove it from the shelf and 
cork it onder water, immediately replacing it with 
another, previously filled vriih water : the jar of 
gas ahuuld be preserved until wanted, inverted, vrith 
its neck under vreter, in a wine-glas* or gallipot. 
Gaaea prepared withoot beat are collected In the 
same way ; chlorine roust be collected over warm 
water, aa it is absorbed in large qoantities by cold 
water. Some gases may also be collected by dig- 
phetment, which consists in conveying the gas, if 
heavier than air, by a bent tube, to the bottom of 
the receiver, so that it may gradually drive out the 
air ; if the gas is lighter than air, the receiver must 
be inverted over the bottle in which the gas Is 
generated, and it is conveyed by a atraigfat tube to 
the Qpper part of the receiver ; this methotl may 
be adopted vrith those gases that are absorbed or 
decomposed by water. 

Some BubstaDces that are insoluble, or nearly so, 
in cold water, dissolve readily when boiled, or 
heated in it ; sometimes a snbstance is heated in a 
liquid for the purpose of extracting some soluble 
matter from it, which is termed digestion ; both 
these processes are carried on in a flask, vrith the 
aid of the tripod and <tpirit-lamp. 

Vte tif tmxporating dixhn. — When a substance 
has been dissolved in a liquid, in order to recover 
it, we have recourse to evaporation, which is con- 
tinued ^ either until cryBtalUiatioa takes place on 



dl^ 



46 



MAGAZINE OF SCIENCE. 



}liiig. or until the substance i« \rti dry in the 
e1 : for cryi-talluin?, tbc general nile i?, to cun- 
tinue the evapnratioo until a pellicle ar Rkin formi 
the surface of tbe liquid, when the Tc&sel should 
»e removed and set aiide, that crjstal* may form, 
which will geaeraHy take place in a few hours. 

fjKr of tfti gloMMM. — A teal '« any known chemi- 
cal body, which, when mixed with an onknown 
aabirtance, produces appearonceB, which enables as 
to judge of ita nature and propertiea: thus, if s 
solution of ferrocy&nate of potaaa, when added to a 
mineral water pnjdnces a blue color, we know that 
the water, under rxaminahon, contains iron, be- 
eaoBe a bine compound U olwaye formed when this 
•alt ia added to a aolutioa containing iron ; the 
cobsUoce formed is termed a precipitate ; its form 
and general appearance are aluo to be coniidered, 
as the color aloue is not always sufficient to dcter- 
nune Its nature ; sometimes a precipitate baa to 
undergo a more parlicuUr examination, as to its 
solubility, &c., in which caie, we bare recourae to 
filtration, to separate It from the liquid io which it 
was formed. Wine-glasses, \c. used for testing, 
or precipitation, should be quite plain and free from 
cutting and ornament. 

Filtration. — In order to collect a precipitate, to 
flree a liquid from dirt or impunity, it most be made 
to paaa through a filter uf porous paper, which re- 
tains all insoluble matter, and renders the liquid 
dear, 'after passing through it ; to make s ftlter, 
take a piece of filtering paper, five or six inches 
■qaare, which will be Urge cnongh for the funnel 
U-forc described, smd fold the opiwsite comers to- 
gether twice, so as to form a conical bag or cup, 
which is to be placed in the funnel ; the funnel 
may be supporteil on the tripod, placing a vessel 
nndemcalh, to catch the filtered Uquor. A preci- 
pitate may be remorcd from the filter by means of s 
knife. 

f/»e (if the blowpipe, — The blowpipe is one of 
the roost useful instruments the chemist possesses, 
as it exerts sll the effects of the most powerful fur- 
naces on a small scale, and thus ensblea bim to per- 
form qualitative analyses, and go through many 
other experimentit, that could not otherwise br ef- 
fected without considerable expense end trouble ; it 
is also of great use in the laboratory, in bending 
and working glasa tubes ; it is used to convey a 
csonatant current of air through the flame of a lamp. 
whereby it is converted into a horizontal jet of 
flame, and an intense heat is excited near the point 
of it : to keep up a continual blast is generally a 
matter of no small difficulty to the beginner ; be 
may, however, overcome it by attending to, and 
practising the followini; directions. First — Breathe 
freely tfaroueh the nostrils, keeping the lips (-lo!<ed. 
Second—- Pill the chuektt with air, breathing as be- 
fore. Third-^lntroduoe the moath-piece of tlie 
blowpipe between tbe lips, nnd force the air from 
the mouth, by the action of the muscle of the 
dieeks, supplying air from the the lungs as the 
dieeks become empty ; all this may be soon &c- 
compUihed by a little practice ; llie student shnuld 
avoid blowing too hard, which is a common fault 
in begionerv, as very little more force is required 
than will suffice to bring tbe flame of the lamp into 
a horiioncal positioa. 

To bend a glass tube, bring the part to be bent 
gradually into tbe blowpipe-flame, and keep it con. 
stoutly lumiog round, nntil it is at a uniform red 
beat all round ; then bend it a little with the haods ; 
apply the heat to the adjoining parts of the tube, in 



like msniMr. and bend it again, repeating Uiis oper. 
Btiou until the bend has arrived at thr reqairrd 
angle: by tliese means, you itis^ v...:. . ^^^ 
round bend, free from wrinkles, wli ^s 

efl"er(ed if you bent it at once ; coru - ikm 

not to remove it from the flame too •<>)> lU . nr it 
will be very brittle and liable to criiik. inrrw Jifdi, 
when heated; many kinds of elass, when hronglLl 
into the blue inner part o{ the flame, receive « per- 
manent bUck stain ttota. the redoctinn to ihe me- 
tallic state of the oxide of lead they contain : this 
may be avoided by kwpiug it near t' ■■• ■'■>■■» • f tbs 
yellow part of the tlsme. In ordn i^lh 

hands at liberty during blowpipe \ ttw 

jet-pipe of the btoHpi^ic may be pa»>Fd Ifarondk a 
small staple of wire. 6ied iu the top of a bloa of 
wood of tbe proper height for the lamp. 

It nisy be nseful to add a few words on tbe ofr 
ce&Hity of order and cleanliness in 0|>eratiof $ •!' 
buttles and other vessels should be cleaned sadjut 
in their proper places after an experiment, that OMf' 
may be ready for use when wnntcd again ; 
care should be taken when experimenting wnlh 
and other corrosive fluids, not to spill, or sailv 
any to run down the outside of the bottle \ no bottle 
or box should he suffered to remain without a pop- 
per label. An old tea tray should be placed on <k« 
tabic when operating, and will be fouiui very ascfiU 
to save it from tbe accidental apilUng of liquid 
and the wear and tear that always accompaxiia 
chemical experiments. A due attention to the dk 
rections, will odd much to the coovcnienoe sntf 
comfort of the student, and will prevent much mot* 
tification and loss, from the failure of experimentA. 

In conclusion, I would advise the atudc ' 
no article, either of apparatus or msteriat- 
actuolly wants it; by this means he wili ... ..~ . 
great deal of unnecessary expense, for articles tbst 
he may seldom or never want; for this reasao«i 
have not given any list of chcmifats, &e. to 
vided, as is generally done in adentihc 
may, however, be necessary to state, Chat 
should be preserved in bottles with glasa stO| 
all other materials may be kept in comJDoa p 
well corked, or in pill boxes. 

(iSi be continued.) 

OBSERVATIONS ON BUGHT. 
Blight is a term generally misunderstoed, 
cially among those whom it more particuUrIf I 
cems. The knowing horticulturist wiU Cell 
" There is blight in the air to-day ;" and 
daya or weeks he will see the web of the 
or the yellow tail, or the ermine, on hu whilr^ 
hedge-rows ; or the caterpillars of the di 
head hawk moth on his potatoes; or tho<> 
terfliea on his cabbages ; and then be will 
a toss of his wise head, and utter, with 
quite in keeping, " I knetr there would h- 
this year ; 1 saw it coming in the air." rrrriar 
liowtrver, be may find a good many snails eitinf: 
woll-fniit ; or may, perchance, trrsd on two 
three great stag beetles while perfDrminr tbrir 
evening pcrambuUtion along his gravflU'd walks { 
and then, " he knew it would be either a blight or 
a sneg; but it's more of t sneg this year.** 
Further than this, the horticultorist has nut pr»k 
greased : webs and soft insects ore blights ; m 
and hard insects are snegs. Warm south- 
winds produce the first ; cold north-east windc-t 
lost ; and yet the saraa man would laugh in 
face if yott were to ssy serioasly. oa ■ cold 



MAGAZINE OF SCIENCE. 



47 



'* There will be a riae in the Tunds (o- 
un Bce it in tbc air." I maioUiu (hat 
urdljr be a grcftter semce performed to 
l«gmniltiinies, than by pointing out to 
pitnre and habits of their in8«ct enemies ; 
llaqB;bing at xa in the fint instance will 
I repaid by tbeir thanking as at last. 
loDfidcr, scparatRlj, tome of the insects 
^ the name of blight. We will, in the 
DC, uamioe the upple>trce. Cider ii an 
article of manufacture, as well aa con- 
in many of our counties ; and, con»e< 
tcTcr tends to inoreaae or diminith tlie 
jU to be deemed by the ffrower worth 
The apple-treo hu manj assaiUnta : 
are the wecriJ, the voollj loose or 
ight. and the moth. I will describe 
Uwse, and its mode of proceeding. 
J cramintng the hark of an apple-tree 
you wiU occuionalty find a pretty 
in the cnicka, which, directly on being 
I dead, and drops on the ground, 
will not, without great difficult, dis- 
account of the groat timilarity of ita 
mast, therefore, hont till yon find 
%Ib time, as soon u yoa lee him, place 
flow him, then touch him lightlr with a 
stick, and be will drop into your open 
own scheme for self-prescrvution will 
Now nil hira into a qoill, or pill. box. 
In home. Place him on a sheet of 
ler ; you will soon see his shajie — the 
bhed with a trtink, from which, on each 
I a feeler, bent at right-angles forward, 
r trunk altogether looks to be three- 
EC a trideut. The thorax and wing cases 
beaatifully mottled ; and an obliqne Uoe 
bting towards the suture or meeting of 
■cs, is much lighter colored, and gires 
MIb an appearance of having a letter V 
■Iked on its back. Its size altogether 
I than a bcmpseed. 

I first sanshiny day in March, these 
» their winter quarters, crawl up the 
long the twigs, perch themselrcs so as 
be full benefit of the sun's rays, and 
•elves with their legs and feet all over, 
all, juat in the same manner that a cat 
lace with her paw ; they then stretch 
at a time, cramped, no doubt, by the 
t ; they lift up their wing-cases, 
two large transparent wings, which, 
le as long af) the wing-cases, were 
>p and hidden under them, and then, 
cmseiTes into the air, they go roving 
ehards and gardens, tbeir little hearts 
r of frticdom, and love, and happiness. 
; before ea^ finds a suitable mate : no 
i objections ; and the nuptials are con- 
Now 1 will allow the gentleman weevil 
f in quest of new loves and conquests ; 
WU time 1 will observe the conduct of 

the female is ready for the important 
■Jtlng her eggs, the spring has con&i- 
lAcc«l. the apple-buds have burst, and 
Irhcs of blifflsom arc readily to be dts- 
The weevil soon finds oat these; and 
lloxsom cTcry way to her mind, com- 
V The beak, or trunk, before 

at iU extremity with short 



L 



tceth» or mandibles : with these, she gnaws a very 
minute hole into the calyx of tbc future blossom^ 
and cootinncs gnawing until her trunk is plunged 
in up to her eyes ; the trunk is then withdrawn, 
and the hole examintd with careful scrutiny by the 
introduc^tion of one of her feelers, or onttT prongs 
of her trident. If it seem to require any alttralion, 
the tnmk goes to work again, and again the feelers ; 
at last, being fully satisfied that the work is well 
accomplished, she turns about, and standing with 
the extremity of her sbdomcn over the bole, thrusts 
into it lier long ovipositor, an instnimetit composed 
of a set of tubes retractible one within the olhcrf 
and deposits a single egg (never more) in the very 
centre of the fiitore flower. Another czamioatitm 
with her feelers now takes place ; and when she la 
thoroughly satisfied that all is right, away she Ales 
to perform tbc same operation again and again^ 
never tiring while she has an egg to lay. 

The bud continues to grow like the other bods ; 
the little perforation becomes invisible. By anil by 
the egg burets, and out comes a little white maggoty 
with neither legs nor wings, which, directly It ia 
hatched, begins to devour the young and teadw 
stamens : next to these, the style is atUcked, and 
eaten down to the fruit, the upper part of which is 
qnickly consumed ; the maggot a then full fed ; 
it casts its skin, becomes a chrysalis, and lays per- 
fectly still. Up to this time the blossom has con- 
tinued healthy, no trace of the enemy being to be 
discovered without ; but when the neighbouring 
blossoms are expanding their petals to the genial 
breath of spring, those of the mutilated bud remain 
closed, and retain the arched balloon-like appear^ 
once of a bud about to burst. For a few days they 
presem) their lovely pink color ; and tbea, by 
degrees, fade to dingy brown. lathis state they 
remain until the other apples are well knit ; and 
then the damaged blossoms, by their decided con* 
trost, appear very conspicuous. On opening tlieso 
brown, or rsthar nist-colored blossoms, about the 
lOth to the 15th of June, tbe chrysalis will be found 
to have changed to a perfect beetle, similar to ita 
parent above described, which, hod it been left to 
itself, would, in a few days, have eaten its way 
throagh the weather-beaten case of dry petals, and 
left its prison-house, flying about to take its plea- 
sttre, until the chilly winds of autumn should drira 
it to ita winter habitation under the bark : and in 
the next spring, the wliole round of oporstions, 
through which we hare watched its parent and 
itself, would be performed with the same unvarying 
unerring instinct. 

The cloudy misty east wind, in which our farmera 
and gardeners see the blight, ia tbe very weather 
of all least favourable to the propagation and in- 
crease of these weevils. The fine, clear, raany 
days of March and April are the moat fkvoorable 
to them. The tomtits, sparrows, boUfinches, and 
other birds, which, at this time of year, more par- 
ticularly frequent orchards and gardens, and which, 
also, at this time of year, are persecuted vdth re- 
lentless hostility by Uie former and gardener, live, 
during these months, solely on these weerila, and 
similsr tittle insects ; and, consequently, are the 
only check ou their increase which we possess: so 
that, in the first investigation of blight, wc see bow 
a little prejudice, superstition, and ignorance, tend 
to increase the injury they dread. 



48 



MAGAZINE OF SCIENCE. 



MEMORANDA. 

The Pcrit Telegraph*. — There ire in Pari* live 
tcle^nphs, vie, the centrtl telegraph in the Kne 
lie riJoircraiti-, which is about to be tranaferreil to 
the Miniiilry of the Interior ; the telegraph at the 
Ministry of Marine, which corresponds with the 
line of Brest ; the telegraph on the church of 
St. EustAche, for Uie line of Ulle; and the two 
uj>on the toven of St. Sulpice, onn of which (the 
north) corresponds with the line of Strueburg, luid 
tlic other (the south) with Lyons and Italy. At 
the oentnl station accounts are recciTed from 
Calais in three mioutes, l)y a line of 27 telegraphs ; 
from Lille in two minutfn, hv 22 telegrapha ; from 
Strssburg in six minutes, by 46 tele^phi ; from 
LyonK in eight minutes, by 50 telegraphs ; and 
from Brest in eight minntes, by 80 telegrapbi. 

Oh Making Bone Gbte. — The French have of 
late years made a considerable quantity of glue 
frova bones, which they consider as BDperior to the 
ordinary glue made from the skins of animala. 

For the pnrpOAe of making this gtun, thry use 
the refuse boue of the table knife-makers, and the 
skulls of oxeo, from which the teeth hare been ex- 
tracted. These materials ore soaked for aboat a 
week in water rendered very sour by the addition of 
a liltJe spirit of salt ; in which time they become 
quite flexible, and may be bent with ease. Being 
taken out of the acid, boiling water is ponred on 
the bones, or rather glue, to separate any %ttmt, 
and also the acid that adheres to it. The pieces of 
glue are then wiped, wsfihrd in cold water, and 
dried in the shade. S^'hen this glue is to be nsed, it 
is boiled in water to a proper consistence. 

Mineral Tallow. — This rare substance, which 
was discovered in Finland, in 1730, has lately been 
found in a bog on the borders of Uwh-fyne, in 
Scotland. It bos the color and feci of tuUow, and 
is tasteless. It melts at 118 degrees, and boils at 
290 degrees. When melted, it is transparent and 
Golorlss ; on cooling, it becomes spongy and white, 
though not so as at tint. It is insoluble in water ; 
bat soluble in alcohol, oil of turpentine, olive oil, 
and naphtha, while these liquids are hot, bat it is 
predpiiated again when they cool. Its specific 
gravity, in Its DftCural atate, is 0,607H ; bnt the 
Callow is full of air babbles ; and after fusion, which 
disengagu the air, the specific gravity is 0,9H3, 
which is rather higher than that of tallow. It does 
not combine with alkalivs, nor form soap. Tlius it 
differs from every clafs of bodies known — from the 
fixed oils in not forming soap ; aud from the vola- 
tile oils and httnmcns, in being tasteless and desti- 
tute of smell. iLtt Tobtility and combustibility are 
equal tu those of any volatile oil or naphtha.— £<f/ii- 
hurgh rhilosophical Journal. 

EjTjierimenU on Human Hair. — M. VaagneUn, 
the celebrated French chemist, discovered from 
acme experiments wliich ho made, that black hair 
is formed of nine difiTereut substances, viz. animal 
nutter, a. white concrete oil, anotlter greeniah grey, 
one which is very abundant, iron, some particles of 
oxide of manganese, a phosphate of lime, carbonate 
of Umc, silcx. and a considerable quantity of sul- 
phur. Red hair contains red oil in place of a 
greenish black kind, and white, or very Light hair, 
difleri from all the olhcro. as the oil is nearly color- 
less, aud it contaiiu some phosphate of magneaia, 
which is not found m the others. 

Ga»from PyrtiUpneonx Acid, — U has lately been 



diftcovered thst when vcood arid ts mi 
through an Iron tnbe heated to ignil 
Nciil allowed (o enter the tube by di 
aucces«ian, gas of a very excelleot. 
talned. This fact wai Arst obser 
of this city, whilst pursuing ex| 
purification of pyroU^neoos acid. — 1 

Steam Enginet. — The value of the at 
to this country may be estimated from 
which show that the number of steam. 
England represent the power of 
which ia equal to that of 1.920, 
being, tn fact, managed by 36,000! 
actually to the power of our populatioii 
men. This Is wholly independent of I 
railroad locomotive engines. 

Cotuffarattre Magnitude of Plamet*.^ 
the earth to be 12 inches in diameter, tb 
is 4 ft. 5 in. Saturn 10 feet, Jupiter II 
diameter. Therest of the planets, nhich 
than the earth, bear the following relative ■ 
Vcnna 1 If in., Mars Gi in.. Mercury 4l 
3( in.. Jono 2| in., Ceret 1^ in., and ▼ 
in. in diameter. The comparative dianqi 
sun is 111 ft. B in. and the moon 5| incl 

Horticulture. — D. Powel, Esq., of 
EsMX, recommends the following inetl 
caring sdons when fitted to the stock i] 
spread the grafting wax in a melted atatc 
shMta of moderately thin brown paper, 
cold cut It into slips about } of an inch 
one of these slips with the breath, and bi| 
the atock and acion, pressing it gently 
hand, when it will be found to adhere tt 
totally to exclude both nir and moisture, 
may be prepared by melting U^ther lib 
lib. of resin, ^Ib. of beet' -wax, i^Ib. of 
and ^Ib. of turpentine. By placing the 
in an earthen pan over boiling water, it ni) 
in such a state of fluidity as to be easily « 
the paper with a brush. — TYtiuartiOHM % 
dun Horticultural Society. 

Fishing through the fee. — At Hudsoi^ 
rivers near the sea. and in lakes of a 
than ten or twelve feet, fishes are cai^ 
winter, by catting boles through the 
the water, and putting lines and hooka 
But in taking them with nets, thry cat 
in a straight line the length of the net. 
the net with a stick fastened to the bead 
hole to hole, till it reaches the utmost 
what fishes come to these holes for air, an 
in the net ; and these fish, at «oon 
brought into the open air, are inatanllj 
sUiT as stock-fish. 

A Sauing Mill in 159S.— Between R« 
Alatat, near Dantzyke, is a mill which, il 
ion is very rare ; it is driven by a river, 
out the help of hands saweth boords, one 
iron wheele, which doth not only drew I 
booketb in and tumelh the boonla to 
Moryaon'a TfateU, 1593. 

The Navigation qf the Alhf^*-^ '•■' «'- 
1838 ridiculed as an impoasib 
accomplished; in 1840 vesaelF 
Britain and the United Statea as 
twecn London and Leith ; and in 
Utcd thst there will be 42 steamei*; 
burden of 56,260 tons, employed fai 
alone. — Mechanic*' Attfuiimck. 






l.i»!«»«j>i — I'lUi'-fJ '■) 1>. f ^A.■i^.n, *, \MLi'.c lljtii l.-iiie, Mi'c KatI — Pu'jluijpJ '•) W BauiAiy, II, l*^»l«a 



THE 



AGAZINE OF SCIENCE, 

^nti Retool of ^rtsE. 




50 



MAGAZINE OF SCIENCE. 



DAVENPORT'S ELECTRO-MAGNETIC 
ENGINE. 

Trk property of electro-ma|cnelism, lo product ft 
strong and rapid rotAtory mmtun of a iiroperK-irrin- 
slrui-'icd a|)|iBijUuj^, t* thuttgtit capsblt: of afforduig 
a tnoviii^ puwrr which may, wlit^ii brought luperfcv- 
tkrtii, siipcrwdc U)C steam rngiae tUclf. both in tco- 
Quaiy, CO m pact n CSS, and facility of manageiuetit. 
'['hut «nch will evtrntuslly be the case in rxtremely 
l^'t-obuble. The models hitherto constructed have 
alrcjidy nccomplitbed much ; Professor Jacobi has 
workrd by this meatiK a ?iix>oarrd nutter nith cou- 
sidemble speed. Mr. Sturgeoa expresses his opinion 
of the ca|wbllily of applying tbe power to locomolive 
carriages on common roads ; and we have ourselves 
■een its lacceuful application to the grinding of 
cofTee, the turning of foot-lathes, and other light 
marbines. The attention of the scientific world was 
first turned to Uiis important subject by tl)e electro- 
motive machiitc of Mr. Davenport, an American, 
who obtjiined n patent for hi:^ invention in the year 
1837* This patent, however, «\aiU hut littlr, be. 
cause it is so esitreniely easy to modify the apparatus 
into a ditfereiic form, and in reality to give it greater 
strength ; thus numerouii uiachineAof the same kind 
Lave been invented, and although Mr. Davenport's 
is therefore disased, yetlieing the 6r»t of any mag- 
nitude, and that which first colled forth the inven- 
tiODS of others, it is proper to take notice of it, 
which wu do in the words of the specificalion, tjiken 
irum the" Franklin Jouraal,'' of November, 1837; — 

"Tlie innchinc for npplyingthe power ofmngnct- 
isro, and riectro-magnrtism, is described as follows: 
The frame AAA may be made of s circular, or any 
other figure, divided into two or more platforms, U 
and C; upon which llie apparatus rest8, and of a 
flise and vtrength adapted for the purf)otie intended. 
There arc two conductors, II and I, one from the cop- 
per, and one from Llie zinc end of any galvanic Iwttery 
leadti>(; to. and in contact with copper plates. K unJ 
Xj, pliii'ed upon the lower platform. These pliitr«, 
or conductors, are made in tlie form of a segment 
of a circle, corresponding in number with the arti- 
ficial tnAgnetK hrreinafler dnscribed ; they are placed 
around the sliaft. detiu'hcd from one another and 
from the fboft, having a conductor, leading ftnm Uie 
cupper-pUtt of the battery, to one of the i^aid plates 
on the lower piritform, and another conductnr Icrut- 
iitg from ibr zinc-plate of the batter]^ and so on 
ftlternately around the circle. 

" The gaUauic msgnets, M, N, O, P, are con- 
structed of arms, or pieces, of j>u(t iron, in tbeihnpc 
of a Atmigbt bar, horse-ahoe, or any other figure, 
wound with copper wire, tirat iniulatcd with Mlk 
coils ; these arms project around it horuiootally frnm 
the centre of a vertical shaft R, turning on u pivut, 
or ]>oint, in the lower platform ; the siud cupprr 
wires extending from the arms parallel, or nearly 
so, with the abaft down to the copper-plates, K and 
L. and in contact with them. 

'*Th6 ortiticial magneta S, T. ore mode of steel, 
and in the osu:d manner. They roay he of any 
number, and degree of strength, and fixed on the 
upper plHtfurni, being segments of nearly the laine 
circle as this platform ; or if galvanic magnets are 
used, (which may be done,} they may be made in 
Ihe form of a crescent or horse-shoe, with their poles 
pointing to the shaft. 

** Having arroDgcd these artificial magnets, on tbo 
lop of the u])pcr circulitr pUtform, there will he a 
corr espobding number of magnetic poles — the north 



marked D, and the south pole E. Now we wfll 
suppose the machine to be in » quiescent UmU 
gulvanie magnet O. being opposite the south pott tt 
the artJtii^al magnets, the galvanic-maguet P. wfll 
of cour*e be opposite the south pole E, and the gtl' 
vsnic uisgnets. M and N will be opposite each otbct. 
betweeu Ute poles just mcntiuned. 

"There being a corrrspondingmftnber olcoppa 
plates, or conductors, placed below tb»' krufidol 
magnets around the shaft, hut i\'- < it, 

as well as from each other, with «)■ : ir 

the galvHnic msgneln to these platea. and in 
with them, as before described, these vires » 
stand in the same position, in relation to the coppai 
plates, that the galvanic magnets »taud to the artA* 
rial niagnetf, but in contact with tlic pUtca. 

" Now in order to put ibe macbioeln mot^va. 
galvanic magnet M, being charged by the galvaldi 
current passing from the copper plate of the btf« 
tery, along the conductors and wires, becomes • 
north pole, whilst, at the same time, the umgnet K 
is charged by the galvanic current poe.&ing from tW 
line plate of the battery, and becuinrs a sooth p9^ 
of course the south pole of the galvanic ma^nCt. 
will attract the nortli pule of the galvanic 
and will move it a (|uarter of o circle ; the 
pole of the galvanic magnet N, being at ihtt 
dme attracted by the north pole D, causes 
magnet M. alrio, to perform a quarter of a 
the momentum of the galvanic arms will carry 
past the centres of tlie poles D and E, at 
time the several wirca from the galvanic 
will have changed their poftitious iu relation 
copper plates, or conductors : — Kor ins 
north pole M, having now become a south 
reason of its wires being brought in cooi 
the conductors of the sine plate, and N ha' 
like manner, become a north pole, ita wine 
changed its position from the sine plate to thtj 
per plate, the poles of the galvanic magnets 
course, now repelled by tiie [>oles that 
tracted them ; and in this manner the opri 
continued, producing a rotatory motion in the 
which motion is conveyed to machinery* fat 
purpose of propelling the same.*' 



DECOMPOSITION OF WATBB 
GALVANISM. 

Trk chemical powers of the voltaic pil«, or 
hnttcry, were lirvt observed in reii;Mrd lo the 
position of water by Messrs. Carlisle and Ni* 
in the year 1800. These were thrr, 
investigatrd in 1803, by lliainger m. 
in 1807, Sir H. Davy commuuicntiti ui 
lecture " On suuieChemicfll Agencies uf Elect 
tothr Royal Society, in wbidi the cit-ctro- 
powers of the pile were eluborately exsminf 
which (ornied the groutiu work of thr brillij 
cuvcries to which he was soon ofterwards lead 
prosecution and eitension of bis researches, 
were, however, many imiKirtant p! 
especially those connected with lb 
electricity by chemical action, and ••... ^■. 
of eleclru-cberoirnl decomposition, which 
Davy and others, who8<; researches have enli| 
thin dillicult department of tleclrical science, 
lefl unexplored, or insufficiently and unsatii 
evplained ; these have lately engaged the atl 
of Professor Furaday, and his " KipcnmenI 
searches in Electricity," published first in 
cession of papers in the " Transactions of the 



maga;:ine of sciknce. 



51 



lately in « diktinct volume, contnn the 
Ubors in reCercmce to ibis branch of 

I 

i eondoctiDg vim from the extremes 
ic pile or bnttery, ire brought near to 
^ rrrtnin liquids, each for infUnce is 
Uine €Otution» . or in other words, when 
I make part of the electric circuit, lo 
frent of the electricity pMs«i through 
ire d^eompoaed : thai )«, they yield up 
its Bi obedience to certain laws; water 
b rMolved iiitt> hydroffen and ori/ffen. 
■a I!m elements appear at the potfs or 
^t indiscrttninately, or inditferctitly. 
ka is devt^loped at the anodf, or xurface 
ff electricity cnlen the water and the 
I the etttHthht or larfaee by which the 
|bt leaves the body under decomposition. 
the manner in nliich water is decnro- 
^ , ,.f,,i,.. f the optnition with neatness, 
t(ty. many coutrivancea tnay 
1 ' ing will illnstrate tlie subject 

rli two plates or strips of platina foil, 
llh the ends of the voltaic battery, be 
* to each other in a Rlaaa of water, a 
^ frill issue from each, which, in an 
(Dilar to rither of those represented In 
I be collected, and submitted to rxanii- 

kvaenls the glass of water, and the two 
!>•, each incJosrd in a ((lasR tube. The 
Ubcfatfd, will asL'end the tubes, and 
in theoi. Fig. 2 rcpreKent* ■ mor*: 
itiLS but one ui which t)ie librrnted 
Itained in the «iiine tube. Itcon- 
Ithed gla^s, wtlh a fuot tu it, and 
eaoh aide. In the necks are fixed, 
the two wires, the outer ends of them 
^ with mercury cups, and the inner 
I op, made to pass through a cork, 
'an inch or two abOTo it. The glaM 
U to catch the gas is fixed over the 
y - - -■^ntation of ^ far superior 
I :c of which will be readily 

] : _ utily that the two glass tubes 
ft hra!i» plate which 6tJi ou to the top 
tower glaM. 

i»baerved, that twice the rjnantitr of ga« 

ie negative |iole, or calliode of the water, 

I with that at the positive pole, or at the 

\ water. When a single tube is used, 

bul lo contain n niiitnre of oiygen aud 

■Of, Ui ,the pniporlion of two volumns 

pr 10 one v( the latter. If a lighted 

paght to the montb of the tabn, thn 

^ explode and disappear, rp-produciog 

^tiry of water decomposed. In using 

ftbed apparatus, it will be iteen that twa 

i_ J jj^j gjj^ voluron of oiygen 

<1 m the tubes invi-rlwl over 

-- ; , .live wires. L'pon the approach 

ir byflru((c;o gas will burn quietly with 

flame ; and the nxjgcn may be rc- 

lerving into it the gloning wick of 

dft. taper, which will mstanlly kindle 



OF THE ATMOSPHERE. 

ipts have been made to ascertAin the 
the atmofphcre is extended ill 
These commenced soon after it 



^iftfa. These 



was diacoverad, by means of the Torrieellian tube, 
that air is o j^ravitatitif: ituh^ttnnce. Tint* ir aUo 
became known, that a column of air, whose ba«e is 
a square inch, and the ht^ight that of the «hoI« 
atinuHphere, weighs ir> pounds ; and that the weight 
of it is to that of mercury at 1 to 10,800 : whence 
it follows, that if the weight of the atmosphere he 
sufficient to raise a column of mercur}' to the height 
of 30 inches, the height of the aerinl column must 
be 10,)400 times aa much, and conseqaently a little 
more than five mllfj hi^b. 

It was not, however, at any time supposed, that 
this calculation could be just ; for, oa tbe oir is an 
elastic fluid, the U]>pcr parts must expand to an 
immenae bulk, and thus render the calculation 
above related e.\cecdlngly erroneo\i9. By experi- 
ments made in different countrieiy it bos been 
found, that the spaces which any portion lakes up, 
arc reciprocally proportional to the weights with 
which it is compressed. Aliowaoces were tn be 
made in calcolatiug the height of the atmosphere. 
If we suppose the height of the whole divided into 
innumerable equal partii, the density of each part of 
which is aa its quantity ; and the weight of tlie whole 
incumbeut atiuotipherc being alao aa its quantity ; 
it is evident, that the weight of the incumbi:nt air 
ie everywhere as the quaattty containpd in the snb- 
juccnt part ; which innkea a difFcrencc hftwf;^ the 
weightu of each two contiguous parts of air. By a 
theorem in geometry, where the difTerences of rosg- 
nitudea are geometrically in proportion to the mag- 
nitudes, these magnitudes are tn Ronlinual orilh- 
metical progression ; therefore, if, accrording to tbe 
Bupposttion, the altitude of the air, by the nddittnn 
of new parts into which it is divided, do rontmually 
inoreaac in arithmetical proportion, its don»iiy will 
be diminished, or (whinh is the aam? thing, \ln 
gravity decrtmsedj in continual geometrical projKrr- 
tion. 

It is DOW easy, froni such a series, by making 
two or three bommetrical observjitions, and deter- 
mining tlie deofHty of the atmosphere at two or 
three different ktatiuiiH, tu determine iti absolute 
height, or iti rarity at any afi.4igiiable height. Cal- 
culations accordingly were made upon this plan; 
but it haxing been found that the barometrical 
observation by no mcanfi correapoaded with the 
density which, by other experiments, the air ought 
to have bad, it was suspected that the upper parta 
of the spherical regions were not suhjix-t to the 
aame laws with the lower on<^. rhiloiophrri. had 
recourse to another method for determining the 
altitude of the atroofphere, viz., by a calculation of 
the height from which the light of the sun ia 
refracted, so as to become visible to us before he 
himself is seen in the heavens. By this method it 
was determined, that at the height of if* miles the 
atmosphere had no power of refraction ; and con- 
aequently beyond (hat ditttaiire wia either a mere 
vacuum, or the octt thing to it, and not to be re- 
garded. This theory aoon became very generally 
received, and the height of the atmosphere was 
spoken of as familiarly aa that of a mountain, and 
reckoned to be as well ascertained, if not more so, 
than the heights of moat mnuntaina are. Very 
great objeclioos, however, which hove never yet 
been removed, arise from the appearanct; of some 
meteoiY, like large globes of fire, arc not unfreqoently 
to be seen at vast hcighta above the earth. A Terj 
rrmarkahic one of this kind was observed by 
Dr. Hallry, in the month of March, 1719, the 
altitude of which he computed to have been between 



MAGAZINE OF SCIEN< 



69 lad 73i Englinh milrs ; its dinmft^r 38(H) jnrd*. 
or upTnffls of n mile •nd « U'llf; nnJ itn vrl.wity 
■bout :i50 milr* in a minotc. Othcri^. (iDparenil/ 
of the ftmv kiitil, but whose eltilude and vwlooity 
were etill gmitrr, Jiiive hecn ohicrvrd ; particuUfly 
that renntrkiiblp one. Augtut iHlh, 1783. whose 
distAmrc ftotn tl.<» rirOi could not be lew (Kin 
go toilf*. anil its dmmrtcr noi Km than iUc farmer ; 
at Ilie saint- lime that its velocity was ctruiiily not 
le» thao a thuusaitd uiilee in a QiiDute. Firc-ballc, 
ill N)ipesranc« «tmilar to ihfse, though T&Blly infe- 
rior iu aize, have been sometimes obaencd at the 
surface of the earth. Of tJiis hind Dr. Pricitley 
mentions one seen on board the Montague, ibe ■lih 
of NoTembcr, 17t9, which appeared as bi; M a 
Wkc iiiilUtor.e, and broke with a violent explosion. 
From flii»logiL'ftl rca*onin(j, it seems very proha- 
ble, that tiie meteom nhich appear at such threat 
heighU in the air are not essentially different from 
those which, like the flre-baU just mentioned, are 
met with on the surface of the earth. The per- 
plexing circumsUnces with rej^ard to the former 
Are, that ut the great hrichts above mentioned, the 
atmufejihere ought not to have any dcDfeily suflScient 
to support flame, or to propagate sound ; yet these 
meteors are commonly succeeded by one or more 
eiplo<>ions — oay, arc sometimes mid to be accom- 
panied with a Liesing noise as they paas over our 
head*.- Tlie meteor of 1719 was not only very 
bright , insninurh that, for a ihort =pace, it turned 
night into day. biil was attendwl with an explosion 
bnitd orer all the inland of Britaia, occaaiouing a 
TJolunt eancuanion in the atmosphere, and seeming 
tOhhakc the earth it»clf. That of Kb^alw, though 
much hightr than the former, waa succeeded by 
ezpIosioDs, and, according to the tejitimony of 
sereral people, a hissing noise was heard as it 
pasiSL-d. Dr. Hallcy ockDOwledged that he was 
unable to rcranrile these circumstancea with the 
receive*! theory of the height of the stoioapberc ; 
as, in the rccions in which this meteor moved, the 
air ought to have Ixeii 30l».,*VnO limes more rare 
than wh.tL we breatht-. and the next thing to a per- 
fect vacuum. 

lo the meteor of 1783, the difficulty is atitl 
l^^ter, as it sppenr* lo have been 20 miles farlhcr 
np in the air. Dr. Hnlley offers a conjecture, 
indce>l. that the roAt magnitudes of such bodies 
icigt.t comp^nMte fur the thinnes^ of the medium 
in which ihcy nmved. ^Tiether or not this was 
the case cannot indeed be ascertained, as we have 
lo few data to go upon ; but the ({reatest difficulty 
is to account for the brightucw of Uie light. 
Appearances of thin kind are, indeed, with great 
probability, attributed to electricity, but the diffi- 
culty is not thus removed. 

It appears that the ubsoiute height of the atmo- 
sphere is not yet determmcd. The beginning and 
ending of twilight indeed show, that tbc hcigiit at 
which the atmosphere l)eKin8 to refract tlie sun'a 
light, is about -14 or 43 English miles. But this 
nay not improbably be only llie height to which 
the aqueous vapors are carried ; for it cannot be 
ihouglit any nnreasonablc supposition, that U^ht is 
refracted only by mcen* c)f the aqueous vapor con- 
tained in the titinosphere -, and where this ceasea, 
it is still caj>rtblc of supporting the electric fire at 
least as bright and strong as at Ihp surface. That 
ft dof» extend much higher, is evident from the 
meteors already mentioned ; for all these ore un- 
doubtedly carrie«l along with the lUrroephere : 
otherwise, tliat of 17H3, which waa aeen for about 



a minotc, muit have been left 10*" 
westward, by Uie enith Ayinfi out 
annual coarse round the sun* 



COMBINED ZINCING AND TIN 



I 



A r*Ti!?rr hsf hwn jrai " 

Messrs, Summer and N • 

improvement in the proct 

vent it from rusting, and aI*o to oh 

veaienec of zincinf iron, which iin- 

muiished malleability. The invcotiui* i* "n w.. 

proveroenl o« one for ainring iron for which » 

patent was granted, in 1*37, Iw M. *^ 

aficctJication of their invention th* 

that having become proprietor* ti^ 

M. Sorfl** patent process, in carryii 

pracrical operation they found that i 

of sheet-iron is much impaired by giving tt « 

ing of line in the manner directed t»y M . Sofrij 

and that, iu consequence of this dim ""^ 

bility. such prepared sheet iron ' '• 

many cues, lo be applied to the pm jMi^r u. 

ing the roofs of houses, or to be otfaerwrlsv 

where it is required lo be grooved smiiir. 

any way suddenly Iwnl. Thi* im, 

gists in a process by which this diffi' 

nbitst the line is st the same time ao appln J " 

itg galvanic action on the iron to proun it Trew 

oiidation. Their mode of prorecding ii 

deacribcd : — " Wc take sheets of iriwi, and 

them with tin, or with an alloy of *• ' 

adopting m thi.s process the mode ui 
in the well-known raanufaclure of - 
of iron into tin plate. After having 
this operation, we submit U»o sheets oj 
prepared to a like process, with the mV ' 
sine for tin. or an alloy of tin ; the — 
forming which does not differ fn>iii tbr' 
prt)cei>)« known under the name of tiimiug- 
tho« treated, Ihe plates or sheet* of irun pi 
tlieir mnlleahility unimpaired, and may be 
otherwise worked as easily as before they 
oeived such coating — a result which appears 
due to tbe interposition of the coating 
between the sine and the iron, by wbKh 
pohitiun the chemical combit»ation ot the 
zinc is prevented, ^"hcre it ii not 
iiae pbtles of meUl of a larger si>« thim 
iihoetA of tin plate, we take that RAteritl' 
comes from the manufactories, and have 
to give to it a coating of line, to rrrp 
doea not require any particular ; 
the Utters patent granted to M- 
posed, sometimes to add a coating "T nu 
of the xinc. for the purpose of giving to thei 
mode n hrightrr appearance, and as an 
ment also iu culinary vessels ; but our pt 
tbe reverse of tiiiit, unJ the end attuned 
altogether different from that above pi 
at the same time, our process prodoer* a 
useful result. What we claim, < 
invention, and as an improvement 
M. Sorel, is the preserving the m 
iron, wliilst it is protected (ron 
gtthnnic action between it and the 
ner above set forth — namely, by tirdt tinnuic 
said iron in the ordinary way, and aftcrwardll 
giving thereto a coating of zinc above thr rio.* 



MAGAZINE OF SCIENCE 



5.1 



CTHUS. OR MOtTNTA-IN FLAX, 

M elude mineral lubstiincc, of ■ stlvm- 
Df gtrrnuli nAar; lu«tre gllininerinj^, of 
r Mlkf-n n|ip*MMin(.i:. ll h pnft enough to 
td hj the nnti, nnd mniJrtrrHbtjr rInHttc. 
loft and soEDfvrbat ffn-nsy ferl ; — sp«!dAc 
pot 9.100. This mtnrral ia naQolly ravt 
pacA in rucks oC serpentine, but it in found 
Ij ia the strata of irou ore, soinelimos 
f an inch in dinrr.f*ter. It ii found 
nut, Elb'i, und (Vomica : in Francr, 
and in the Diouiitiiin« of Arcadia ; 
parts of Great Brilnin, but pnrticn- 
Igrlesrn in Widea, and Aherdfcnsbire in 
Thr Tsrentaiae amianthai from Savoy 
bcautlfal. 

to the actioQ of tlie blow-pipe, the 
amianthua fuse* into an opaque aub- 
I di'ifiUra quickly in borax and micro- 
hot rrTcrveacex with carbonated »oda. 
nal amis hove a very feeble ai-tinn on 
It appears, from Uerifinan, tbatniusUc 
brda the meanit of dUs/rlvin^ this aub- 
Mb he effivted by tniiing equal parta of 
Mrbonated potash, anil charcoal, and 
1 for two Ilount, by which he obtained 
wai perfectly aoluble in uitro* muriatic 
parta of the Tarentai»e aroianthua 
BDording to Bergman, sulphated barytea 
OiMted time 6.9 : carbonnted magnflaU 
iae 3^ ; »ilu 64.0 ; uaide of iron 1.2. 
fllltty of man, tvro thouaaDd years aince, 
«tion of a peculiar kind of cloth 
ta of this trjitniordinnry mineral ; 
wonderful quality of beiug iocon- 
When the cloth became dirtied or 
usual to throw it into a bright Are ; 
thua burnt out, and the cloth pnri- 
d of a drizzling whiteness. Pliny 
bflen an eye witness to this opera* 
times of the Roman em|>ire^ 
aed at an enormous prire, for 
pping up the bodies of the dead. 
On the funeral pile ; the ashes of the 
M preaurred unmixed with those of 
Of the rciility of this practice there 
t a (toubt ; in 1702 a skull and other 
, together with a quantity of aebes, 
at Porta Nievia at Rome, which 
in amianthus doUi ; which intr- 
antiquity is now prrsen'cd in tlie 

y- 

nf burning the dead becoming dis- 

niaoufacture of amianthus cloth was 

and (he art was lost in Kurope. It ta 

rhe art ia slitl preserved in the 

employetl by the TarLara in 

T of the d(r;id. 

tampini, of Rome, published the 
of mjfnuf.ti;tnnng this ini:om- 
"he amianihua is to be firat laid 
tank for some time ; it is then to 
divided by tbe hands by gentle 
the rxtrancims earthy matters will 
ord and washed out. which, in tl.c 
t arrre to bind thu hltrrj logettirr. 
to be repeated several times by 
water, nnd opetiinit and squeezing 
the water runs otf quite clear, 
be left but long tlnx.like fibres, 
lo be laid in a sieve and dried iu the sun. 



It is then to be carded (or combed) on fery ftne 
cards, and the long filaments are to be steeped in 
oil to render them more flcsible. It !s then to I»e 
plnecd between the cnrd in such a manner thiit a 
portion of it may hang nut at the tides, 7*litt 
Rptnniug of it is performed by fiaing a atnall red 
with a little hook at the end on the same bench as 
the cards. The red is to be wound orer with white 
thread, which twisting about the thread plaa^l in 
contact with tbe amianthus, Uic Utter, by the 
assistance of the thumb and fore-finger of tbe 
operator, is wonnd up and twixtftl with it into one 
thread. A conCinuou$ thread being thus produced, 
it is carefully woven into clulb ; placed afterwards 
in a clear charcoal fire, both the oil and the tbread 
of linen or cotton that was combined with it in 
the spinning and weaving are consumed, and there 
remains a pure tissue of white amianthus. Thla 
method being, however, very tedious, another hai 
been recnmmended ; which is to place a quantity 
of flax on 8 distaff, and taking three or four fila- 
ments of tite amtanthuft between the fingerv, tbey 
may be easily mixed and twifited along with the 
flax. Tbe thread thus spun will be much stronger 
and more durable than that made by the obove- 
mentioned jprocesa ; the carding will alio be anne- 
ceisary, by which mauy of the filamenta are una- 
voidably broken. 

Tbe abort filaments that remain after the washing 
or carding of the atone, have been made into paper 
by the ordinary method of manufacturing that sub. 
stance, except that a larger portion of size is em- 
ployed. .\n it would be worth while to preserve 
documents of great Importance by writing on the 
amianrhus paper with an indelible ink, that wuutd 
also resist the effects of fire, the following ret^eipt 
baa been given for Ihnt purpose : — To one part of 
of sulphite of iron add two parts of alum, which 
having dissolved in hot water, add pearlaah as long 
as any precipitate takes place ; the mixture is nejit 
to be boiled, then Altered, and the precipitate well 
washed with wsrm water ; distilled vinegar is then 
to be nddrd to the precipitate, which wilt dissolve 
it. and form an indelible ink. .\mianthn8 paper 
being written upon with this preparation, the cha- 
racters will be preserred after combnation, of • 
brown color, and perfectly legible. 

Threads of the nmianthuf ore fometimea naed as 
perpetual wicks for lamps. Amianthus h frequently 
confounded witli the more flexible kinds of aabestos. 
By some writers the terms are used synonymously. 
Others divide tbe asbestos into scTcrol Tftrtcties. of 
which amianthua ia one. 

THE TIDES. 

Tnn periodic motions of the waters of tbe oe«n, 
rtn thp hypothesis of an rllipsoid nf rerolntioiis en- 
tirely covered by the eea, arc very far from accord- 
ing with ob8er\-Dtion. This arises from the vrry 
great irregularities in the surface of tbe earth, whieh 
is but psrtially covered by the sea. from the voriely 
in the deptlis of the ocean, the manner in which it 
is spread out on the earth, the position nnd inclina- 
tions of the shores, tbe currents, and the reststnnre 
the waters nii-et with : causes impo^nihle to esli- 
male. but which modify the oscilUlions of the great 
mass of tbe ocean. However, amidst all these 
irregnlaritjea, the ebb and flow of the sea maintain 
a ratio to tbe forces producing them sufficient to 
indicate their nature, and to veri^ the law of the 



54 



MAGAZINE OF SCIENCE. 



■ 



•Unction of the sun and moon on the »ea. Lb 
Ftace observes, that the inrehiigition of bucli rtlt- 
tiomi botwrc-n aiu»e and effect, is no lir>w uiefal in 
natural phil(U0[)hy than the direct Mlution of |>rn. 
blems, either to prove the existence of the caasest 
or to trace the taw* of their effcctt. Like the 
theory of probabOltieft. U is ■ bappr supplement to 
the ignorance and weaknea of ibc huoiLin miud. — 
Thoi the problem of the tides does not admit of a 
general solution. It is indeed nccesaAry to analyse 
the general phenomena whicli oiii^ht to mult from 
the attraction of the sun »nd moon, hut thette must 
be corrected in each particular caw by local obter- 
YationB modified by the extent and depth of the 
sea, and the (irculiar rirrnmBtancea of tiie place. 

Since (he ditttuxbing notion of the sun and moon 
can only biH!Ojne sensible in n very great extent of 
water, the t'licit'ic Occ4[i mast be one of the prin- 
oipal Boarces of our tides. But, in consetiuenre of 
the rotation of the earth, and the inertia nf the 
oecan, high water doe* not happen till some time 
after (he tztoon'a southing. Ttie tide raised in that 
world of wBten is transmitted to the Atlantic, from 
whli;:h sea it rooTca in a northerly direction along 
the coasts of Africa and Knrope, arrtvme later and 
later at each place. This crcat wave, however, is 
modified by the tide raised in iho Atlantii-, which 
ftDmetlmea combines with that from the Pacific in 
niaingchesea, and somecimea ia in opposition to it, 
no that the tides only rise in proportion to their 
difference. This vaat combined wave, reflected by 
the shoret of the Atluntic, extending nearly from 
pole to polt!, still roming northward, poars through 
the Iriih and Uritiah Chatincls into the North Sea, 
ao that the tidei in oar porta are modified by those 
of another hemisphere. Tfaas the theory of the 
tides in each port, both as to their height and the 
ttmeA at whidi they take place, is really a matter of 
ozperiment, and can only be i>erfect1y determioed 
by the mean of a very great number of obserratioos, 
including sevBral revolutions of the moon's nodes. 

The height to which the tidea rise is much greater 
in narrow channels than in the open sea, on account 
of the obstructions they meet with. The sea is so 
pent ap in the British Channel, that the tides some, 
times rise aa much as fifty feel at St. Malo, on the 
coast of France ; whereas, on the shores of some 
of the South Sea islands, near the centre of the 
Pacific, fbcy do not exceed one or two feet. The 
winds hare great influence on the height of the 
tides, according as they conspire with, or oppose 
them. But the actual effect of the wind in excit- 
ing the waves of the ocean extends very little below 
the snrfice. Even in the most violent storms, the 
water is probably cnlm at the depth of ninety or a 
hundred feet. TUir tidal wave of the ocean does 
not reach the Mediterranean uur the Baliic, partly 
from their poaitioa and partly from the narnjwneM 
of the Straits of Gibraltar and of the Categat, but 
it is. very pera^ptihle in the Re<l .Sea and in liud- 
aon'a Bay. In high latitudes, where the ocean is 
leas directly under tlie influence of the luminaries, 
the rise and fall of the su. is considerable, bo that, 
in alt probahitiiy. there is no tide at the poles, or 
only a small annual and monthly tide. The eb)) 
and flow of the sea arc perceptible in riverx to a 
*^ great distance from their eatuories. In the 
SCraiti of Pjiuxis, in the river of the Amazonn, 
more than five hundred miles from the sea, the 
tides are evident. It requires so many days for the 
khio to aacend this mighty stream, that the (rtum- 
iag tides meet a succession of those which arc 



coming ap ; »o that every possible ri 
at ioioe part or other of its flion-. k-.tI, 
nitude and time. It rrqui;e« - 
of wntcr to accnmnlote the '\w\' 
moon, so as to render Oieir inrtumcc Mrti 
tluit actiount the tides in the Mcditen 
Black Sea are loarccly prrcepCiblo. 

These perpetod cooimniinni in the 
occasioned by forces that bcor n very smi 
tion to terrestrial gravitation : the fun's 
raising the ocean i« only Uie l-3t444KOO(> 
tatioo at thr eartliV aurfNce, and the Htiii 
moon IS little more thsn twice as 
forces beinK in the ratio of 1 to ^'1 
sua and moon are at their mean dii 
earth. Prom t}it8 ratio, the 
found to be only the 1-75 part of tl 
Had the action of the »un un the 
octly equal to that of the moon, 
been no neap tidea, and the spring 
been of twice the height wbirh the 
the sun or moon would have prodat 
a phenomenon depending upon the 
the waves or nndulations. 

A stone plunged into a pool of stil] i 
sions a series of waves to advance aiong^ I 
though the water itself i* not carried fo 
only rises into heiKhts and <(inka into h< 
portion of the surface being elevated and 
in its turn. Another 5tone of the a«me six 
into the water near the first, will occoaioii 
set of undulations. Then, if an equal 
wave from eadi atone arrive nt the Mme ap 
some time, to that Che elevation of tb« oi 
coincides with the elevation of the otl 
united effect will produce a wave twice 
either. But if one wave precede the ott 
actly half ao undulation, the elevation ol 
will coincide with the hollow ot the other, 
hollow of the une with the elevation of the 
and the waves will so entirely obliterate one 
that the surface of the water will remain so 
level. Hence, if the length of each ware 
sented by 1. they will destroy one anolla 
tervala of 1-2. 5-2, 5-2, tScc., and vrill 
their effects at the intervals, 1, 2, 3, fce< 
be found, according to this principle, 
water is disturbed by the full of two em 
that there are certain linen on the suKao 
perboHc form, where the water u 
sequence of the waves obliterating ei 
that the elevation of the wntcr in the 
corresponds to both the waves united, 
spring and neap tide«, arising from th<> 
tion of the simple doli-luuur wn. 
is the joint result of the coro' 
coincide in tirue and place ; ami Uir 
pens when they succeed each 
tanral, so as to leave only the ef 
eoce aeosible. It is, therafore. 
solar and lunar tides were of the sami 
would be no difference, consequently 
and the spring tides would be twice as high; 
sepamtrly. In the port of Batsha, io 
where the tides arrive by two channela, 
corresponding to half an interval, tliere 
high nor low water, on account of the 
of the waves. 

The initial stale of the ocean bos no 
the tides ; for, whatever it« primitive 
may have been, they most soon huve vai 
the friction and mobility of the fluid. 



othor! 



MAGAZINE OF SCIEl 



[Able circomsUocet in the theory of the 
urnnre Cbnt, io coiiitrtjucnce of the 
be tra bruti^ only otip^tifth of the mcAn 
Ike earth, And the e&rtb ixjteii Lncrra&ing 
>wartU the centre, Ctie stability of tbe 
of the uoean never can be aubvcrlej by 
t cause. A general inundation, arising 
I initabilit; of the ocran, is, therefore, 
A variety of circumfUnces, however, 
iuce partial rariatiuus in the e()uilibriu[u 
which is restored hj mean* of currents, 
the periodicaJ melting of the ice at the 
ioD temporary watcr-countcfl ; bttt bj 
t important cousea are the centrifu^ 
td by tbe velocity of the earth's rotu- 
riatioiM in the density of the tea. 
riftigal force may be rMoWed into two 
pcrpeodkular, and another a tangent to 
nirface. The tangential force, thoogh 
BtcieoC to make the fluid particles within 
rdea tend towards the ecjiuitor, and the 
much increased by the immense evapo- 
«qtuitorial r^oott, from the heat of the 
ifiitnrbs tbe eqoilibrium of the ocean. 
f ftiso be added the superior density of 
near tbe polei), partly from their low 
, and partly from their gravitation be- 
uni&bed by the action of the sun and 
that of the seas of lower latitudes. In 
of the combination of all these cir- 
^ two great carrcot« perpetually set from 
iwards the etjaator. Uut, as they come 
dea where the rotatory motion of the 
earth is very much less than it is be- 
fOpics on account of their incrtiB, they 
ately acquire tbe velocity with which 
irt of the earth's surface is revolving at 
ial regiom) ; from whence tt follows that, 
ty-Ave or thirty degrees on each side of 

ocean apj^ars to have a general roo- 
Ut to west, which )■. much incrcMcd by 
)f the trade winds. This mighty mass 

waters, at about the tenth degree of 

lie. is tamed towards tbe north-west by 

H America, runs through the Gulf of 

it, pasemg the Straits of Florida at thi' 

miles an hour, fomis the well-known 

■' Neam, wliich sweeps along the 

V 'I, and ninfi norlliward as far 

L _. ..^ .. ;uiiodlQnd, whence, bending to 

wt Qows piut the .\zores and Canaty 

■ It joins the great westerly current of 

uboot latitude 21" north. According to 

pboldt. thix great circoit of 3800 leagues, 

r f The Atlantic are perpetually 

1 ■' purallels of eleven and forty- 
o.iiude, may be accomplished by 

rticle ill two years and ten months. In 
fi this rnrrent is situated the wide Aeld 
■c«-we«d. called the grassy sea. Be- 
there ore branches of tbe Uulf-itream, 
sy the fruits, scrds, and a portion of the 
the tropical climates to oar northcni 

nl westward motion of the South Sea, 
iih lii^ Ennth polar carrent, produces 
V in the Paci6c and Indian 
the one or the other prevails. 
vi Uie Pacific, causes currents lo 
■Ide of Australid, while the polar 
along the Bay of Bengal -. the westerly 
becomes most powerful towards Cey- 




lon and tbe Maldives, whence it stretcltea by the 
extremity of the Indian peninsula, past MadagnM-ar, 
to tbe most nonheni point of the coutincnt of Africa, 
where it mingles with the general motion of the 
seas. Icebergs ore sometimes driAed as far as the 
Azorea from the north pole, and from tlie south 
pole they have come even to the Cape of Good 
Hope. But the ice which encircles the south pole, 
extends to lower latitudes by 10° than ttiat which 
surrounds the north. In consequence of the polv 
current, Sir Edward Parry was obliged to give u^ 
his attempt to reach the north pole in the year 1827, 
because the fields of ice were drifting to the south 
^ter than his party could travel over them to the 
north. 

As diilinct coirents of air traverse tbe atmos- 
phere in horizuutal strata, so, in all probohihty, 
under ctirrcnta in the ocean flow in opposite direc- 
tions from those on the surface, but it is nut easy 
to prove their existence. It is supposed that an 
under current from the Meditemuieaa seU in 
through the Straits of Gibraltar. Tbe surface 
stream flows the contrary way. 



HINTS ON THE MICROSCOPE. 

Tt> the JiiUtor. 

Sift. — If you think the following remarks worthy 
of insertion in your very valuable and interesting 
journal, you will oblige me by inacrttng them. I 
am sure they will prove interesting to many of your 
readers ; there is nothing original in them, but I 
think, perhaps, the generality of your readers may 
not have met with them — they are all relating to the 
microscope. One very interesting subject is, the 
examination of the pollen tubes, or boyeaux of dif- 
ferent plants; I believe Dr. Aldhdge. of Dublin, 
in au elaborate memoir, first showed the meciiud uf 
obtaining them in the same state as that in which 
they perforate the stjgmatic tissue. They are 
readily obtained from auy pollen merely by acting 
upon it by dilute acids, nitric ( 1 to 7 of water) ia 
perhaps, the best ; if a drop or two of this be pUced 
Qponoue of the glass alidea, and the pollen «p rink led 
upon it, or what is better, if the atamens of a 
flower be touched with the slide, then the dilute 
acid dropped upon it, in a few minutes, by the aid 
of a very moderate microscope, the tubes will be 
seen shooting out beautifully. If they do not 
readily conic forth, heating tbe slide very slightly 
will produce the effect. Dr. Aldridge lays they ore 
eliminated upon the »tigma by the acid which he 
aayt is always found there. 1 have not been able 
to detect this acidity of the stigma my»elf, but, per- 
haps, it may prore interesting to yourst^lf or your 
readers to experiment for themselves. Another 
very interesting phenumcnoa is the production of 
tbe Torulo, and mycoderina cercvisiar, as described 
by Dr. Maudl, In his " Traite preetique du Micro- 
scope ;*' these are readily seen by putting a small 
portion of yeast into some weak lyrup, and allow- 
ing it to remain there for two or three days; when 
elongated, filiform, jointed bodies (the above named 
vegetable productions) will be seen springing oat, 
if these are alluwed to remain they will imu-eose to 
a conaidernhle size. Theoe and several other ob- 
jects (such as are spoilt by drying, but are prepared 
by means of water,) arc best preservetl as men- 
tioned by Dr. Maudl, by making some very thick 
syrup, and preparing them with this in tbe same 
manner as we use Canada balsam. Spiral veSficU, 
stomata of plants, and pollen lubes, Sir., are beau- 
tifully preserved thus. — Tlie syrup should be made 



5« 



MAGAZI 



IF SCIENCE. 



in the ordinary wijr, mn Id inedietne, ouly it ihould 
not be ctirred till cold, as by allowing tt to »tiind 
any f.xaen of »ugiT ii jirf^tpitAipd in cryftals, which 
mi^bt tske place in tiie slide of our ubjrct. utilr» 
avoided tbns : — wbco objects are pruerrpd in ihi* 
manner, they should be subjected lo consiilerahle 
prcMure until they are thoroughly dry, and then the 
sbacci exti^tioe WtwLfn Xhc gliua plate abould be 
filled (by capillarity) with white bard spirit v'orniah ; 
ill thti niELnner they are benntifully and permancutly 
preaerved. Spiral vusels are Tcry easily obacrved 
in any pbiEnogaoiona plant, but the conical tenniaa- 
tiona are very djtbrult to procure m the ordinary 
way : we are directed to boil the bulb of a hyacinth, 
then dissect out the ipiraJ vcaitela ; but the easiest 
plan is to take the flower of a hyarinth, put it into 
■ome wtt water, let it remain until the water be- 
cotnea slightly putrid, when the flowers will be 
found almost exactly like a jelly, the rpirol vessels 
ore very easily separated, pick off one of tbe seg- 
ments of the periiinth, press it tirmly between two 
glass tides, when towards the apci of the segment 
the terminationK will be readily and abundantly seen, 
or they may be disaerled trom the macerated seg- 
ment very easily, as they are so few in number ; If, 
after being laid between the glass isUdes, the slides 
are kept pressed firmly in a small pre^i?, and thtn 
the spaces between the glasses Ailed, as mentioned 
■hove, with white hard varnish, tliey may be per- 
manently preserved unaltered. 

A beautiful example of cellular tissue is seen in 
the fronds of Hymenuphylliioj Tunbrigensc ; they 
have panicles of green matter in their interior. It 
requires a very perfect microscope to define the 
green particles, but they are the most beautiful ob- 
jocU 1 ever saw. Thick gnm is sometimes em- 
ployed instead of the syrup, but it is not so good. 

J. w. o. 



MISCELLANEOUS EXPERIMENTS. 

Take a imall phial about half full of cold water, 
grusp it gently in the left hand, and from another 
phial pour a tittle sulphuric acid very gradually into 
Ibe water. A strong tertJtation of heat will imme- 
diately be perceived. This, by the contiaoed addi- 
tion of tlie acid, may be increased lo many degreea 
beyond that of boiling water. 

Dissolve one ounce of qnicksilver, witAout heat, 
in I of an ounce of strong nitroua acid, previnu-ily 
diluted with one ounce and a half of water. Dis- 
solve also the same weight of quicksilver, fty meanM 
tffhtat, in the same quantity of a similar acid, and 
then, to each of these colorless solutions, add o 
colorleits solution of ammonia. In the one case 
the metal will be precipiutcd in a hlack, in the 
other, in a ichite powder, affording an ciamplo of 
the difference of color of metallic oxidea, arising 
from different decrees of oj-itihement . 

Writ* with acetate of cobalt, or with a muriate 
of cobalt, previously purified frgm the iron which it 
generally contains. When the writing is became 
dry, tlieae letters will also be invisible. Warm the 
paper a little, and the writing will be restored to a 
beautiful hlHf. 

Put a Uttle fresh calcined magnesia in a tea-cup 
upon the hearth, and suddenly pour over it as much 
concentrated sulphuric acid as will cover the mag- 
nesia. In an mi>tant sparks will be thrown out 
and the muturewill be eom plrteti/ ignited. 




Pat a little oxymnriate of potAss *i 
phosphorus into on ale filass, |R>ur some 
upon them cautiously, so as not to cjifi.^i|| 
Now take u small ghiss ttihii, and pdoi 
some sulphuric add ; then place the C 
the upper orince, and, in this state, wj 
tube, which muat bo inslanUy imam 
glass, so that, un rcmonng the thoml 
msy be immediately conveyed upon the 
This experiment ik an example of a v 
phenomenon, cttmbuMtion untler water. 
Proceed, in all revpcctji. as in Che 
ment, and add a morsel of phosphuret 
Uere. be&idca the former appearance, we 
eomlfuntton aUn on the surface of the ir. 
MijL one ounce of litharge of lead with 
of pulverized muriate of ammonia, and i 
mixture to a red heat in a dein tobacco 
itMrcase of temperature will separate thj 
in the form of gas, and the muriatic acid 
bine with the lead. When the compo 
melted, pour it into ■ meLilUc cap» 
have a true muriate oj lead of a bright yel 
the brilliancy of which may be much hei, 
grinding it u usuoj with oil. la tliis 
the color called patent yettow. 

Take one ounce of red-lead, and half 
of charcoal, in powder, incorporate 
mortar, and then 611 the bowl of a tol 
with the mixture. Submit it to an intcfl 
a common fire, and, when melted, pouf 
slab. The result will be mettJOc lead 
revived. 

Take a little red-lead, erpose it to 
heat in a crucible, and pour it out when 
result will be metallic glass, and will for 
ample of the ftitrifieatiim ofmetaU. 

Boil equal parts of auoatto and com; 
in water till the whole are dissolved, 
produce the 2»ih rethluh Anff so much ii 
sold under the uame of nanJireert dye. 

If muriate of tin, newly made, be added 
tioQ of indigo iu sulphuric acid, the oxyl 
indigo will be absorbed, and the solatioa 
converted to a preen. It is on the same 
that muriate of tin is employed in 
loured leather fiirniture ; as it absorbs 
and the leather it rtstored /o iff natural 
Write with dilute nitrate of rilver, w 
dry, will be entirely invisible ; hold the ^_ 
a vcasel containing sulphate of ammonia^ 
writing will appear very distinct. The li 
shine with the metallic britliancy rtfttUtr, 
Write with a solution of muriate of cd 
the writing, while dry, will not be perorpi 
if held towards the Are, it wlU then wni 
come visible, and if the muriate of tx>b«lt 
in the usual way, the letters will appear ol 
gsnt green color. 

Take two grains of oxymnriate of poti 
three or four grains of flour sulphur, and 
ingredients very well on paper. If a Utdi 
mixture be Ukeu up on the point of a k 
dropped into a winc-glflsji ronttuning somei 
acid, a beautiful column of Jiame will be p 
the moment the powder comes in contact 
acid. 

Take a small phial, in one hand, coo 
pulvcrixcd muriate of ammonia ; ponr a lii 
upon it, and shake the mixture. In this 
a Kcntation of cold will immediately be fd 



V Ijjd — Publlilied by \V. BsinAix. U, t'aicwi 



GAZINE OF SCIENCE 



^nO ^cttool of ^r». 




S9 



MAGAZINE OF SCfENCE. 



CRANES FOR RAISING WEIGHTS. 



Cbjink* are cctUin nimpltr tnuchtncre in which citbrr 
Ute wLccI onil axir, or wbeol and pmiuD, are intro* 
ducrii, to elTect ihe raUing of heavy loadt, such af 
the loiiditit; or unloading of ihipping at tlic 4uay9 
or whiirfs, or the raisin)^ or loweriotf goods to and 
from chambers or warehouses. 

Various modcfi have- been adopted to turn the 
nheelt ur that pare of the machine which b applied 
to the laiue purpose, hy iutrodudDg ioiif; kt^tvea 
into tbe «x1r, by which it acquirer the name of a 
capstHDt or windlass ; or by a rope possinK over the 
wheel, and potting it and the axle in luotioD by 
fricCioo. Oiber methods have been adopted, soch 
as fonuiag the wheel holluw, aad causing it to re- 
toItb bj means of laborers iuaido of it, walking up 
iU side, which cotiicquently descends beneath their 
wsight ; or by fomiiug it into a platform, lyiuK i» 
» alanting direction, and tbe laborcrH pushing 
ftfainst a fixed arm. which forces the platform or 
wheel round under their feet. 

Moat of the cranes couainicted with the whecH 
an4 aals occupy too oiach space, which is of im- 
portance, and, consequently, where cranes are in 
j^euemi use* have becu superseded by the wheel and 
piuiua, wbtiJi is uf a more compact and convenient 
conttnictioa. The wheel and pinion is generally 
accoDipanied wicba raichei-whecl and pall, or some 
other method of lockini; the handle, ao that, should 
ihe Inborer draiAt from his exertion, the load may 
return to the place from whence it has been 

tht frame-W(rt-k. or that part of Ihe crane which 
dbes nut imiucdtiiifty oprratr to nuso the load, is 
divuleH into three part*, tike post, the jib. and the 
Stay. Tbe post i<t the upright ptc<x, almost nni- 
«eisally made to turn uo a centre; the jib ia the 
•TV cjitendiii^ from the upper part of the post, and 
Ml aoine atsca is horizontal, but more frequently at 
an angin to the horizon ; and tbe stay is that piece 
which sup]Mirt9 the jib, reaching from the lower 
jKirt of the post to nearly the extremity of the jib. 

The must simple furin uf the cruue is tiuttcom- 
mouly used in dtone and timber whaKii for unluad- 
ing TCMela. for which purpose it is well adapted, ita 
power beii)^ Very great. U has a frame consiAting 
of a strt'ng bvam supported horizontAlly at 10 or 12 
feet from the ^rLMind, on the tup uf several vertical 
posts vpry (irtoly lixcd in the ground, and securely 
braced with ftoys in every direction. At the eE- 
trciiiity of the buriccmttil beam the upjwr |*artof tlie 
jib tft supported, the lower pivot resting on a post 
is the gruund. The jib, ur gibbet, as it ts called, 
Iroco a rtisemblance to that machine, i» a triangular 
IhUDe ot wood, one hidi: being pcrjKndicalar, and 
ivppOried uu pivots at the top and bottom, so that 
the whole movt-s round on these ai a vrrtical aii« 
of motion. Near the upper end of tbe perpen> 
dicular post, a beam piuceetU, furmin^ the upper 
nt\e of a triaogle, whila the thirii oidc is a brnce, 
extendrd from the foot of the perpeu dicular, to sap* 
port the upper piece. From the extremity of the 
latter, the burden ifl suspended by a, rope passing 
over a pulley ; the other end of the rope ts coiled 
rouoda vertical roller, or capstan, tumini; on pivots, 
Ooeiuppottcd by the horuonUiI btMm tirat men- 
tioncj, and tbe other uu » post in the grooud, Tbe 
capstan is turned round by means of long hon- 
stootal levers lixcd to it, at which a great number of 
men may be employed to posh tb»ti round, or, in 
Mjuo outcSf UiL-y arc drawu by borsos. Aa the 



Irvrn admit of a very great Icoylli in proporliOft MT 
the diametrx of the windhus on which tht* mpc ooila, 
the pmrer of this simple crane is very c^oMderabla, 
and may be doubled by a pair of hloeks or pulUta 
at the jib. When the harden U raised la n *iitB- 
cient height, by turning the capstan, tbe jib, b^taf 
swang round on its pivots, wilt convey the load into 
a cart or woggon placed on tfaorc by the side of tbe 
crane. 

Another kind of craac. whieh is eqaally comi 
with the above, bnt used for lighter burdens, 
the same jibs, as indeed rooi>t cranes have ; but Ar 
windlass, or barrel for the rope, is placed faorisoa- 
tslly, and has a large vertical wheel fixed apon 0. 
lliis is made of two wheels fixed on an axia at a 
distance apart, and united by boards, so as to form- 
a large hoUow cylinder or drum. Several men fd 
into this wheel, and by constantly walking nnwirU 
on the inside, give it a tendency to rev 
wind up the rope on the barrel. It is su : 
that so imperfect, this should have been so uutci- 
snlly adopted as it was, till within these few yrara. 
Kven when the wheel is sixteen feet in dlameiVf 
the laborers within cannot walk so far up it, tea 
tbe perpendicular, as to have any effective 
to tarn it round ; tbongh tbey a»c always ex\ 
to danger, and frequently meet with the most shodt- 
ing and fatal accidents, from clipping down in tktf^ 
wheel, or from being overpowered by tbe Ifwr) : in 
this case, the wheel runs back with an ac 
velocity, and tbe people are thrown aboi. 
most dreadful manner. Prom tbaae defect oi uif 
common construction, skilful mechaciciaaa hum 
devised cranes that are not only more safe, bat non 
powerful in their operation thnn the common walk- 
ing crane. Some of these wdl be described in Ite 
present artidc, 

A crane is to be cooaidervd as if cottoiating of t«» 
distinct parts : — that which comomnicntea modM 
to the rope or chain, to which the weight ia at- 
tsched, and that which cuabka tke force to act 1« 
any required podtioo or coavetdent dtslance. Il- 
will be eccn, by the consideration of the next 
that we ahaU describe that the Utter part ii 
always necessary, especially when tlie only 
to drag the weight towards it. 

Fig. 1. Represent* the cellar or portaUe 
One side of it only is shown, the other nde k«fl|| 
the same framework, and a similar handle t^$»^ 
winch ; the wheels only being omitted. A B ii 
iron framed side ; B. tJte handle tnma the 
which works in the large wheel IK Around 
axis E, of tbe large wheel, one end of the rapt If' 
coiled : the other end holds the weight to be raised* 
Tbe action Is so simple thut it is not neoessary |ada> 
scnbe it, except to remind the reader thai the 
will be in proportioo to tbe size of the twa 
Thus, if two men apply together Ihf" power 
hundred weight to the winches, and the small wl 
attBchtd to their spindle be of six teeth, while iW 
large wheel has sixty teeth, Ihry would be ablf tt 
raise tea butulred weight — that is. fupponag Ut 
drum or axlei rouud which the rope cotls, be s^b 
to the diameter of the large wheel, but if tlusbe<f 
one quarter the size of the large wheel, m fartSnr 
advantage of four to one is gained, jiti ' '' *- ■ ti* 
would be able to raidc two tun^ i'l 
weight. If a greater power b« req-; 
wheel may have attnched to it a - 
teeth, and if this work a third whe- ' 
ibo rope being attached ' 
the power «uuld be in. 



MAGAZINE OF SCIENCE. 



lA nin tha weiglit vonlil be in the 

p f opoftiun looffcr. 

Manf iKber pnosiracttons o( -nhecl-H-ork are id 

for crjtirs. Wbcii tbcy arn tumrd by a 

wioA it i» [WttpTT ifj Mppty • lly wheel to thr cad of it, 

m i» trikTvannted in h|r. 3, both to e^u&lixt the efforts 

Ike labsrvn who turu tt, rbiI in case be acci- 

itaOf lct« gQ Use bitidlc. to prerent the load from 

down Ki qnickly a.<t tn codanKcr anythioj^. 

Thm rrm««, Ag. 2, is adiptrd not tnrrcly to lift up 

wicbts, but. bjr having n lateral motion 

ft ee&tre, it is capable of depoeitiog them on 

■C a certain distance ou rjtber Hide of it, 

m mmj bv nqoired. A ii « strong jrun pillur which 

tiitf whole of the crnnc abore it. Thia it- 

m m Wliow cfaambcr brlow the grotintl, rnt- 

}f tm a pi«ot belotr, and partly on a broad 

id MctMM ball at D. CC u the jib. formed 

or iron ; B u the faandle and amall wheel, 

«<arka the lar^ wheel that bears the drum for 

{ F M a fly whed attached to the winch ; 

— Ihat u, a strap of iron, which, beio^ 

Co the fly wheel by holding the handle, 

• suffideat fnctioo when the i;oods are 

i H uhI I are guide wheels or puUica for 

to work in. 

BrmBah*s m^mtotu hjrdrostatic principle of 

■ fmU power is applicable in several ways 

lag of heary weights, and has been fre- 

iffUntd in poverfnl cranea. In these the 

iv M« «bcuaed by wheel-work, puUie*. or 

ordinary tnecbftnical powers, but oo the 

of the eiperiment called the hjdrofttatic 

«hWb has been known for ages ; but the 

«i iu powers to mefnl purposes it> due 

Bnaak. 

form if, for a macliioe to raife a 

■ m amall height. A metallic cylin- 

lUf stronf, aad bored trnly cylindrical 

aolid piston httrd into it, wbicb is 

fohvtlj water-tight, by leather parking 

edfe, Ar other means used in hydraulic 

^he bottom of the cylinder most be made 

' drBay with the other parts of the sor- 

" the greatest strain which can OTer be 

to ix. Jn ibe bottom of the cylinder is in- 

ttitt c»i uf the siDJiIl tube, the aperture of 

Bnsas«nicates with the inside of the cylinder, 

tmdncKB water or fluids into it ; the other 

A* pipe eonunuucatcs with a small forcing' 

bf «ldd> the water c«n be injected into the 

its pUton ; the pump has, of 

to prevent the relom of the water. 

the diameter of the cylinder to be 

id the diameter of the piston of the 

or injector, only one-quarter uf an 

prnportioiM between the two surfaces or 

[^■^to* •■id piatun? will be as the squares of 

MUa, which arc as 1 to 24 ; therefore, 

*fll be as 2 to 576; and supposing- the 

space between tliem to be tilled with 

If ether denae and jaootnpressible fluiil, 

lUffl to the until piston will opernte on 

Iba above proportion of 1 to ^70. — 

MuU piston, or injector, to be forced 

In the * • ' ^ or Injecting, with 

■ JO rwt . L*4sily be done by 

'*lf*g ieici. L..., ,.i....,(i uf the ^reat cyliii- 

Chan b« moved np with a force cquol to 

"by Af6. 
Mpmmta a crnns constroctrd upon the 
' poaciplc, tbalia, by lh« iajacUon of 



water from « small pump into a larpi cyUn 
which if ftttf'd with a pifton, linvin;; « rack iittaol 
CO it, for Che |iurposc of lurnin); a piui«>n upnn 
aii» uf a Isrgv drum-wheel or barrel, round 
the rnpe is roiled, and from thence posses tn the 
The figure A A represents the jib, made of i 
and supptirted npon two brackets, projecting from 
the wall of the warehouse in which the crane is 
supposed tu be erected. The rope posses over tbe 
pulley I, and down through holes in the bmckets, 
then turns under the pnlley L. and comrs to the 
lower side of the great drum-wheel B. Thu pinion 
C is fixed on thu same axis with this, and its gud- 
gvons turn in small iron frames, bolted down to the 
floor of the warehouse. Tbe pinion C is acttisted 
by the teeth of the rack D, and a small roller pi 
sea against the back of the rack* to keep it6 
up to the pinion. The rack is aitaclied to the pii 
D of the cylinder, in which the poww for working 
tbe crane is obtained. Tbe piston passes Cbruu|g 
tight collar of leiither, on the top of the cylindo 
£. which does not admit of any leakago by tbe 
of it, ond llicrefore if any water is forceil into 
cylindor, it must protrude the piston from it. Tbe 
cylinder is supported in a wooden frame FP, and 
has a small coj'prr pipe proceeding from the lower 
end uf it, communicating with a small forctng-pa 
at H ; this stands in an iron dattm, which coui 
the water, and sustains the standard, for the ccn 
of the handle G, with which the jiamp is worked 
by one or two men. The upper extremity of the 
standard guides the piston-rod of the pump, to con- 
fine it to a rerlical motion ; nnd there is a weight for 
counterbalancing the handle G of tbe pump. F 
what we have said before, the opi^ratiun ui this 
chine is evident ; the power uf the cylinder iSf 
proportion to its sixe, compared with the siEC of 
pomp ; but, ss it only acta ilui>uf!h short Urn 
the pinion and drum B are necessary to raise tbs 
weight a sufficient height. 



list^P 
king 

i 

The 
and 

.DWOC 

it^l 
cnql 

rked 

the 

con- 

'. for 

i 



STEEL PLATES POR ENGRAVING. 

For several years past sheet steel has been used 
large quantities, instead of coppor-pUtes. by 
engravers. By this fortuuntc application of 
darsblo snd, it may be added, so economic.^ 
material, not only has a new licld been discovri 
admirably suited to yield in perfection Llie ricl 
and finest graphic productions which the Ingeni 
of modern art can accomplish, but to do so through 
an amazingly numerous aeries of impressions, wii 
out percepcible deterioration. Tbe art of engrai ' 
on iron or steel, for purposes of ornament, and 
for printing in certnjn cases, is by no means s 
covery of modern times ; bat the substitution 
the latter material for copper, which has in*itrd 
superiority of tlic British burin to at^hievciu* 
hitherto uoattumpted by our artiatSi is entirct] 
modern pmcUce. 

In the year 1810. Mr. Dyer, an American me^ 
chant, residing in l«oiidon, obiaincd a patent "Afl 
certain improvements in the coustruction and ia^| 
thod of using plates snd presses, &r..'* the prin- 
riplrs of which were communicated to him by li 
foreigner residinc abroad. This foreigner was i^M 
Jarob I'erkitis, an iiiscenious artist of New Eugls^H 
and whusc name subsequenltr iKcame m exB^^ 
sively known in tliis country*, in connection with 
roller-prrsit priiitiui; from hardened steel plates — 
Tbe plates turd by Mr. Perkins were, on tho sver- 
agc, aboui five-eighths of an inch thick ■ they «4te 



» 



cither of »t<el, to tirnpered iw t« Bilmit of Ihr ope- 
ration of the iraTcr, or, as was more generally the 
rase, of itrel decarbonated, so an to become very 
purr soft iron, id which case, after they had re- 
ceived tlie work on the surfaoei tbey were case- 
hardened by cementation. 

The decarbniiiitini,' process wai performed by in- 
closing tlie plate uf cait steel, properly sbiiped, in ■ 
enst-iron box or case, filled about the plate to the 
thickness of nbout an inch, with oxyde of iron, or 
niHty iron filings. In this state the box is lated 
close, snd plsred in a regular fire, where it is kept 
at a red heat during from three to twelve days. — 
Generally about niae days are sufficient to decar- 
bonise R plate (ivr-et^faflu of an inch in thickness. 
When the engraving or etching has been executed, 
the plate is superficially conTerted inln steel, by 
placing ic in a box, as before, and surrounding it 
on all sides with a powder, made of (K|ua1 parts of 
bnmed hones and the cinders of burned animal 
matter, such as old shoes, or leatlier. In this 
state the box with its contents, closely luted, must 
ht exposed to a blood-red heat for three hours ;— 
after which, it is taken out of the fire and plunged 
perpendicularly edgewise into cold water (which has 
been previously boUed to throw off the air) ; by 
this taeans the plate becomes hardened, without tl^ 
danger of warping or cracking. It ts then tempered 
or let down, by brightening the under surface of the 
plate with a bit of stone; after which it is heated, 
by being placed ujion a pieet; of hot iron, or melted 
lead, until the nibbed portion Ao<|uirea a pale straw 
color. Fnr this purpose, however, the jiatenlee 
r.\preS9ed himself in favor of a bath of oil. heated 
to the temperature of 4G0^, or thereabouts, of Fah- 
renheit's scale. The plate being cooled in water, 
and polished on the surface, was ready for use. 

In 1924, the large gold medal of the Society for 
-the Kni^ouragemfMit of Arts and Manufactures, was 
pre»4mted tu Mr. Charles Warreo, for the com- 
munication of a pnper on improvements in the art 
of engraving on steel. The death of Mr. Warren, 
in the interval, bt^twcen the adjudieation of the 
medal and the d.iy of annual distribution of rewards 
having prevencetl the society from receiving such 
details as were expected from the inventor himself, 
the (Committee drew np a report on the subject, from 
wlilrh, along with details communicated by Mr. 
IMiclps, and others of Mr. Warren's personai friends. 
the Account published in the Society's Transactiona 
-was coinpile<l. From this authentic source most 
of the following particulars are derived : — 

Some of the earliest specimens of engraving oa 
'Steel, for the purpose of printing, were produced by 
Albert Dnrer. There are four plates etched by tliis 
artist, impressions of which exist in the British 
Museum, which, in all book« treating on the subject, 
are recorded as having been executed In steel ; of 
these, one has the date 1510 inscribed on it. Since 
that time attempts have been made occasianslly to 
employ steel instead of copper, w a material to en- 
grave upon, but apparently with little success, on 
account, principally, of the great hardness of the 
material, which in a short time blontcd and de- 
stroyed the tools which were made use of. 

^•teel, as is well known, exists commonly in two 
states, the elsstic and the brittle, the former being 
eonuderabty softer than the latter; of the elastic 
steel, a saw-blade may be considered as an example, 
and, in fact, pieces of saw-blade were the material 
upon whieh nearly ail the earlier attempts have been 
made, of late ye>r«, to revive a practice which, if 



sttccrft»fnl, offered so many advaoLtgea to ih^ 
and to the public. Mr. Raimbsch. a ft-w \c,m afOv 
executed au engraving on a block >iy of 

steel, but met with ao many dm i iLe 

execution, that his experituent remained iu4uUl«4, 
and produced no sensible eircrt un the art u( t^- 
graving. 

Mr. Warren, io bis early youth, was intich o^ 
ployed in engraving on metals, for the nee of calus 
printers and gunsmitha ; and the expcrieooe Ihos 
acquired, induced him afterwards to turn bis attcDttoa. 
to the subject, with a view of applying it to the ins 
arta. It was suggested to him by Mr. UiU, oms of 
the chairmea of the committee of mechamci., ihol 
the method employed by the artificers of n^rmiog- 
ham in the manufacture of ornamental aoulliera aii 
other articles of like description, is, to aobjeeft At 
cast steel, after having been rolled iuto sheets, tt 
the process of decarbonisatioo. by means of whiob 
it is converted to a very pure soft iron ; being Klua 
made into the required instrumeot, or other arCish^ 
the omameoted work is engraved or impressed M 
the soft meuUic surface ; after which, by 
tion with the proper materials, it ia case* 
or again converted, soperficisUy, to atoel, and tial 
rendered capable of acquiring the highest polish. 

In the attempt, however, to apply this proremi to 
plates for the engravers' use, two opposite '. 
occurred: a plate of steel, of the samr 
as that of common copper-plate, when 
decarbonised, and thus reduced to the ctate 
flofl iron, yields readily to the graver and ol 
and, especially, ia susceptible of the p 
knocking-up: this consists in scrftiiing ovt 
with the graving tool, and aftarwmrds 
underside of the plate with a punch an 
in order to raise the eaviCy lo the general 
tbns allow the artist to take the error out 
occasioning any onevenneaa of the enpmd 
it was found, however, that plates of Che 
requisite for this operatioo, and of the naoal 
ficial dimensions, were very liable to 
last or re-carbonising process, and were th* 
capable of giving perfect impreasions. If, 
to avoid this disadvantage, blocks, or pUUs, 
or four times the ordinary thickness, warn 
uac of, the warping indeed was prevented 
the same time the process of koocking-np 
impracbcable, and it was necessary, in order 
move any error or defective part, to grind 
Burfaoe, or to drill a hole from tlie under » 
almost through the phite. and then, by forcing in a 
screw, to raise that part of the face which was ia* 
mediately above it. This Utter proeesa, however. «iS 
so tedious and difficult, as exeeedingly to 
from the advantage of substitnting steel for 
In this state of things it became a very in< 
object of inquiry, to ascertain how many imp: 
might be taken from a plate of soft or decarl 
sleel ; and it was found that audi a plate, 
aeoording to Mr. Warreu's process, was oS] 
affonliog several Chonaand oopiea. without u 
going any sensible wear. In proof of this, the ooa- 
mittse of the Society of Arts, tec. state, that is- 
preasions were laid before them by Mr. 
from two plntrs of decarbonised steel 
him, thr one for an edition of Mackenzie's 
published by Cadell. the other for an 
Beattie and Collins, published by Rtvington 
pistes exhibited, both in the landscape Ukd 
figures, the most elaborate and delicate work 
thousand impreaeions had been Uken fnoa oaa% 



rart«M 



cap^J 



Warns. 



MAGAZINE OF SCIENCE. 



61 



td {rem the. oUier ; und jet between one 

id unr of (he Intit Imprruiouft it wu 

lie to perceive »ny difterencc. 

r- WErren hid rarried nn bii experimentx 

rorking by btmself till lie bad bronght bis 

Lpfcrfccrlion, it la probable Uiat, at the period 

"t, the evidence of the great importance 

rery wouM by no mr«ns have been so 

it bctn&lly «ru : nnd the renull of hia 

It hsTc been lost, to the i^reat drtri- 

>fp«flion, and of the fur fame of thii 

'wtift. Bnt selfishnrftt and aecrecy in any 

ieh related to the impro^einenc of the art 

he wa.4 attached formed no part of his 

; and all his discoTeries, both those re- 

the pnsparation of his pUt«a. as well as 

LCh had reference to the eneraving upon 

aDTMcmdly and gratnitously commnni- 

Gooseqoence of Uiis liberality wan, that 

plates of Mr. Warren's own engraTing 

hefore the committee above mentioned, 

of portraits and other suUjecta cngraTed 

steel were shown, demonstrating 

►,000, and eren 25,000 impreftnoDs 

off steel plates, before their respective 

them for the prodvotion of their 

^uren's original process for decarfaoniain^ 
'^htet consisted in procuring a box or case 
id corcrini? the bottom of it with a mixture 
lings and ponnded oyster-shells ; on tlits 
t* is Uid ; another bed of the mirtarc is 
and so on alternately, till the box is 
cire that a bed of the compoflition ihould 
^«pper a« well as the lower layer. The box 
' was then placed in a furnace, and kept 
hours St the highest beat which it wonld 
It melting; after which, being allowed 
Inally, the pUtes were foond to be re- 
the mo9t part, to the state of soft de- 
ft copprr-plate maker,* having been 
'Mr. Warren in his process, and find- 
steel did not always tnrn oat bufliciently 
soft, (particulariy for the purpose of 
in menotinto.) imagined that those oc- 
were owing to a deficiency of heat 
process; accordingly, he snbsti* 
oven of refractory clay, for the cast- 
'leti applying a considerably higher 
the cast-iron box would have endured 
iritkig. WHS ennbled to obtain plates so 

night be bent over the knee. 
»hf|: the cfest superiority of steel-plate over 
^rnrkf that require a considerable 
n<i to be taken, there can exist 
iD^Mi^h the use of the graver, and of 
frt)uirrs more time on steel than on 
[h the process of re-biting has not 
to the degree of perfectiun in the 
been in the latter, yet the texture 
'•neh, as to odtnit of more delicate work 
; and (he hnrst and most elaborate 
of the flrt, which on copper would soon 
to Frduce them to an indistinct smeary 
to uudrrgo «rarrely any deterioration 
mtn the marks of the burnishes arc still 
bhle «ft«r sereml thouband imprcMiona. 

IB Shr« Ltfttf . [fOmloti. wh«rB erery nrticU re- 
■ip«<Kf may be porrbkiod, nd of woellenl 



ENCAUSTIC PAINTING. 

The art of paiutiiig in encaustic Is a manner of 
painting which is executed with the operation of fire. 
Ancient authors of\en make mention of this speiHcs 
of pninting, and which, if it had been dt^scribed 
(.imply by the word eneaustic, which signifies exe- 
cuted by 6re, might be supposed to hkre been a 
specie« of enamej painting. Uut the expreauons 
eneawUo, ptngerc^ jtioiura, -enctaittiea, eerit pin' 
fftTP, fitcfutom, inurere, by Pliny, and other ancient 
writers, makes it clear another species of painting 
is thereby ukauC. We have no ancient pidarea of 
this drHcnption, and, therefore, the prccisw manner 
adopted by the ancients is not completely developed, 
though many moderne have closely investigated the 
8abjectf and described their processes. At whac 
time, and by whom this species of painting was first 
invented, is not determined by antiquaries, although 
it appears to have been practised in the fourth and 
fifth centuries. Count Caylus, and M. fiachclier, a 
pointer, were the first of modern times who made 
experimeuls In this branch of art, about the year 
1749. Some years after this, CouDt Caylui pre* 
sented to the Academy of Painting, at Paria, his 
ideas and experiments on the subject of the ancient 
manner of painting in encauatic. In 1754, the 
count had • head of Minerva painted by Mous. 
Vien, after the proceiis described by himself, and 
presented it to the Academy of Sciences in 1755, 
This success induced Mons. Bachclier to recom- 
mence his experiments, in which he succeeded bet- 
ter than formerly ; but bis manner of painting in 
encaustic differed from the ancients, as described 
by Pltny, and, therefore, be was uosucuwful, iuas- 
much u he did not discover the rtai ancient man- 
ner ; after thia he made some other expcrimenta on 
the same subject, differing from the process as de- 
scribed by Cajlos and others. 

Plmy, in a passage relating to encaustic pointiDg, 
distinguishes tlircc species :— First— that in which 
they used a style, and pointed on ivory or polished 
wood (cfxlro in tbott) ; for which ])urp(ise they 
drew the outlines on o piece of the aforesaid wood 
or ivory, previously soaked or imbued with soma 
certain color ; the point of the style or stigma 
served for this <^eration, and the broad end to 
scrape off the small filaments that arose from the 
outlines, and they continued forming outlines irith 
the point till ibey were finished. Second— The 
next number appears to have been, wliere the wax 
previouftty impregnated with color was spread over 
the surface of the picture with the style, and the 
colors thus prepared were formed into sutoll cyliu- 
ders for use. By the side of the paiitter wa» % 
braxier for keeping the styles continually hot, with 
the points of which they Inid on the colors when 
the outUni* were finished, and spread tlicm smooth 
with the hroflii end, and thus Lhey proceeded till 
the picture was finished. Third — The manner was 
by painting with a pencil iu wax liquified by fire ; 
by this method the colors contained a considerable 
hardness, and could not be damaged either by the 
heat of the ouu or the deleterious effects of tlie aoa 
water, it was thus that they painted their ships 
with emblems and other pictures, and. therefore, it 
obtained the name of thip pttiniing. The Ust pro- 
cess was to smooth and polish the picture i^-thns 
far the aucieuts. 

Few, of late years, have made mora experimenta 
in thia mode of pointiog than the ingenions Mrs, 
Hooker, of Rottingdeon, in ;tbe county of Susses^ 



^.z^:.^ :j science. 



'■- -■* = ■'-* =j^-^-.'. ::^.i-s :—_■::»-- ■»-=t Isz^ *!--«• ^er toem ; but it in less troub 

-"■^~ ~ ■ -"' "-~ -r — .-„ ■- — : — * n *.-oaff T-ii^f- wh*n the colors ire obsrrve 

- * - ■ -- ' '- .•". •-• -' T-T-sa «-- .1 1 — it-j:^ irr. In ptinting with this con 
'" ' T--^-- -^ -^ - _-— j^ :_ I.M.Jx.»e'T--r -a* -currs ':>ad vithoat di£GcuUy when 

--' " _-:_-::_ .z^^ k. — ar « irzran *-■« wi-a cry the tints may easily b< 

- - ■ - ~ -^- » "== *'*Tr'^ i 7-Hsar-:ini^ -hr :- -oioza zi & bniih and a very smitU qu 
"■" "■- " - '--- * ** Irxx m^^f^ J r*^%jn::. vcrr. ^'■••z. the painting is finished, p 
'^ -" ■ ■=-=-:— ^jz -: ^-3 =r--T:T:(^.j- t -i^.^ ti.":* -ru 11:3 a clued earthen vessel ove 

- '-- '"-" '-=-: TV riii- a, =i- --iT '.**-!. riw ir^- ia»i »btfc, Kclted, but not boilini^, wit 
T -;. . » ----! -i .' -- »Ti^ * -n*TiB9 IT "3^ ivLti x'w lie pamtin|[ with the wax, a: 
^~- -- j: - » X— .1 :.- : — -^-jc - -z:: irzx. — v;ii u** k =odera:cly hot iron, such as is 
. ..s . ■,-rsL,^ TS—r -- ■: ::- « .-fjr- » h:?!!-"?:- -ir -j _r^a. i=.'i *o cold as not to bias if 
i:t - . :_T '—as - CT- -*-.iz ~.-it a zae n«am- t-^ i=.i'i -z we:, azd draw it lightly over i 
-rr^-.- ^- - -r_;r^ — - a-. iz'^leFXiT' u;>: T"!- i ."r.-.z *— VP'^s'' ■• if **"***■*" ■*"1'^"' 
s-T. i™r*:"r*. = ac "^tt .-"T e^i^ i -Vroiir vls *s<i vK:^T«r Mi'^tance the picture is 
--»iia;zi.-ic-'H X =r '*«n«!'" T -2e -— RiT rf If: aj«:.T. its zerxjt.t cold ; but if when so, tt 
tarn i^ir tit— «n?rr-2rrnT3 i^— rr- nifog sor; J14 ucLd z:z a^-ptar sufficiently clear, it 
"Z^iS. ':r r :: Hf c^ "a _- — ' '•'-«. Smc^'ixs icui 3«::r; xzt trt kt such a distance as 
UBi^-i : :-- :'^Lr:.=4. izx^ei^; »■ laa -nux'^ :3d vai iw: vly : lt :be wax may be melted I 
■^TTRi --crar^ -»=^ *i.ar-»rs..» Tw ^iiitiwin: jur a i:« pc^Tr a: such a distance as t( 
^ -i^ a ag V3-.--?* "ac "-*^"» rr -n.* ji-j"* ■ r*~j rs'i.-y, «Kca_.r over such parts of the pi 
vrwBVU^BMb o ~ar •^-v:s-~- W2u.--. "s i<.i!*:r T Wtuaui ace apwu- soificiently transparent 
ler 3:rw.Ti±r«* r— -3. ci ir-^aiss a -o:^ rzr-.- -ijaz - ::c ix Mi^iT heat ii applied to the 
•t* " ^i T 1 :^ TTw r*. r-tTLit :e ^ — j ne "ue rrsvr w-J,l b« tos traofparvncy and b 
i^«*»r«-ui =jur 1 !!»-sueC-* ratT:-.:; -C >a:L:---:i^; S-: tie contrary effect would 

"\tf2i •». n wg fc. - zg -.3C r^r — r-^ i .-•inr»rn T-.-e xasfi J tx> f^cicn or 100 great a degree o! 

TT -^i-^^ n TEiTa-a-tt re i« Otris^is .--*=at K:o<fi. :r f:-r ::-o lon^ a time, as it will c 

yi T— ^j - « w^ K 'a^t :▼ 'v.'v S-v^r- wax »o =:3C^ to tLe surface, and may 

7.. — . . ••-v^ -vi:-^ -i^!««s. HUT .-«=:*.-» mi .Tk:^ :x rdiai. Sh^sld the coat of wax ] 

i jn; - — j=' X-,- . mri -irt nc5«* .^ M^ i =K :a:ri.^ waca r.L.jhfd appear in any i 

^~. • ■*. T-:^«r- •: - -srr^ •-B.'y wst-: *::« *«*z. U ray a* rtzEeti^ed by drawing a mu< 

-^j y . ■*^.^-.— 1., *:r n *-^r -Hmr-f .1 rt.-n «.=^ tx l"::i -Tjf ;i a^am. is before mentioned, 

r *. < -: .-'» ^s— E ««i*v*£. jyv:. r.Ltr'i u: r» fcr-ij.-j tts wn wi:h a knife; and shi 

>hric "^-r ?«• re fwsK^ -ruv. .-vaaaxiTrs zxe ■'ai- '} ::o cr--^: ^t too loni^ an application 

jvcarnhj'' «-"-ts^ i:i.~3; :i." :-:r".rs *t particuLv places, byo 

<««N«. n rmsr v a ~^ c^f i^s^ied. cr even a tobacco-pipe m; 

s lai^isfrrv^ >.-i£<^^ :^.f :i::l^ v-_1 subside; or such defects 

-?*.. ?w."iJ VL-.-ic^f -r=: ri :j iriwai* anything hard over t 

. ,.; .1 ,ni»st *• HXTi i» iZA > w:_^:.t».' ri .'4(; any sm^II cavities. When 1 

^ w«. I- -. . ■. •- •««»■ aaw v»4:oi »» ."f:? --ir: » ,"i*i. r>5 sc «:th a fine linen cloth. 

^^ t^ . :^^. V.iw -V iXTs ■-• 3* tr- Mil t*^ 3C» =i? :< ei«:i>d in this manner upo 

,^^-» - - r .t.: >--^--i ---^ml ^wws^ «rr- w-ii :>: f;«w of wood let in behind 

—^ ^ww •- - T. rwi -'. ---t.. -".;-"i!tn& ^.vi*^^r■ lie ^n::2 c* ■^■e wood. ii> prevent it* warpinj 

. ^ ,... ^ ^, -».-.» «.>*. ^^ lae. vutM thn «wk --ari. -v plasser of Pari*. The phuter 1 

-I o, v-^-^^iiv^ -i :h fj~ » ?wu:iT? £ -siii^-r» >.' ,-:i*r prtpar»tion than mixing sc 

.-v' *...-««^» %v^^ iM^'i inr «v. jmi s*uscfc « Tatj in powder with cold wat 

._, . ; , .. ..^ ^ ,^.; Mf::«^v.> *:>^ ^issT. : 3;^ri3e« -f' a cr;ix : then pat it on a I 

../ .it-iC-.w 3. :fc.-i-r >^f U' irr. saU -: | *•■*»- iiT-^a; ar« miue a frame of bees wax 

. -X .=il ■ 'Jvt -.'sae^, t ^x.*!.^ >f 3»wstt iiri , a.vit:a*-*^J«#- the form and thickness of wli 

«n. • ». !* s.-t »«*»*.'« hftiiin; xt*.i »*ca '.- -y 

AV"*" * '"'• '• ■<>"-*«™ ALttfwiniirf ,f' .v.*i »rr-^ 

*^f ;h.'! -i-«ii -:*tf .TrtttjcKtA-e. « *:«* ^r: 

« . i-vt •^.■. .■» -K' t»in w^cv-J. ia*i t« X :s^J 

v "4- • •• 1 w » J'^ ■^.* -"rtOTK wi« a-ifti w::h ::. 
i^ vim^-v* ..- •■■ ^ A. rsf -swcioi .'t wi=£ :: :* 
^ u \ • • -h.- A-«^%iK=-- arv'3 *-. ei.-t=en 







•«: 



f.. V « v.v * .* :v .^' .-.-^ »* :»* nro^ier ;*ew of 
:j»,.' **,.*: .v-'--> - ■-- .-; >^^. -vV-^ : ti« I«in* ^* i 

rv *v»KV^ wSw^ ^- ^'-^ •■■-■ t^' c-.-aTposmoTi. 
,^, S- -w*i '■'■« *^*-**«' »^'*'^ »" '■"•■•• " ***• •"'"* 
«v«r »«Sv\-^v -'« •> '^^J* *c\vu3: :"• * »-v's-:v5^ti.>n i> 
L— , »i*jui; L<T\*-:> » V'v «:iv i\vr:vj;.<r rrans" irir.'y 

ILf, 5w#.'. :: '•'■f ^v:.-r» «t Wd on thiA. a* iVey 
*"!11. ;N' M'-.- KK- of the ^^^*h as if painting 
TTw-M* .v:or». and th* *sv.e bm*h,>5 *# used in 
TL ^"^ cvU'c*. if swwn dry when mixed 

•J" Am. »** be uKd by potting a 



wuitJae plaster of Paha to be. and when d 
ic iS. and there wiU be a very amooth sni 
paint upon. Wood and canvass are best 1 
w.th fome gay tint mixed with the same cc 
taoo of gum arabic. gum maslicb, and wax, 
the same sort of colort as before mentioned, 
tbe dengn is be^gnn, in order to cover the | 
tr.e wood or the threads of the canvass. V 
alM may be done in the same manner wit 
gum water and gum mastich, prepared th 
way as the ma»tich and wax ; but instead of 
seven onnces of maatich. and. when boiling, 
live onnces of wax, mix twelve ounces of gui 
rich with the gum water, prepared as mentii 
the first part 01 this receipt ; before it is put 
nre, and when suffiL-tently boiled and beaten, 
a little cold, stir in. by degrees, twelve oun 
three quarters of a pint (wine measure) < 
spring water, and afierwards strain it. It w< 
equally practicable to paint with wax alone, di 
in cum water in the following manner, 
twelve ounces, or three quarters of a pint (Air 
sure) of cold spring water, and four ounce 



MAGAZINE OF SCIENCE. 



63 



arable. paC them loto a f^Uxed cartbeo 
wben ttie |>um ia tliiiAolved. add ei^hc 
white WM. Pat the earthen veaael, with 
raCcr lad wni, upon n *\ow tirr. and ttir 
^Um wax is ritisolvcd and has boiled a tew 
tben Ukc thecu uff tUe tire, and tlirow 
■ baiin, ba, by remaining in the hot 
Hwlt the wu would beoomo rather hard ; 
Kum water and wax till <iuitc cold. Ah 
ia but a imaU proportion of water in compa- 
Co the quantity of (nm and wax, it would be 
Mf7« in mixing tbia cooipoaition with the 
I, lo put also lome fair water. Sboald the 
Mition be so made aa to occasion the ingre- 

I to acparate in the bottle, it will become 
riceaUe if ahaken before lued to mix the 

very Mmceable quality in the vehiale 
nw diacovered by Mrs. Hooker, which 
composition wluch had reinained in a 
the year ]792« in which time it had 
n4 booome aa aolid a aabitance as wax, 
a cream.like ooaatatence, and became 
u proper a st^te to mix with colora aa 
was first made, by putting a little cold 
upon ttt >nd duifenng it to rrmnin on a short 
" 1 aUo tatelj found,*' says this iogcnious 
** aome of the mixture coropused of only guns 
jiraCex, and gum moatich, of nhioh 1 bent a 
to the iiHiciety of Arts, in 1 792 : it waa 
r. and had much the appearance and con- 
bom. 1 found, on letting aome cold 
lOrer it, that it became as fit for paint- 
M when the composition was first prc- 

fTobt rmtinu*^ j 

FBESERVATION OF MEAT FOR 
FOOD. 

BT M. UANNAL. 

ting is a traofilatioD of an abstract of a 
id before the Royal Academy of Sciences, 
\, Iky M. Gaunol, inveittor uf the well-known 
iwafrnibnUning, 09 given in this Compte ReJtdu 
ttnAk 22, The author commenced by recapitu- 
( msae of tlte incoovenicncea presented hy the 
eonnDonly employed processes for preserving 
I fa« rrinarkctl that, whaterer substance he 
0y«d. great advantagea result from its being 
AMud by ibjection, iuatead of making it iiluwty 
tme, aa in the ordinary process of salting, by 
billon from within or without. 
Bf i^jci.'tion will be obtained, besides the aav- 
If tine and money, an uniform distribuFJon of 
yiwui litjye substance, while by maceration, 
iMIy if largv pieces be acted on, the portions 
Mift the outside, brcomc suprr-saturatrd with 
biAatjaooe. before the internal parta have re- 

II MrfBcient to prerent their decomposition.'* 
•M. defoting himself to the examination of the 
bMeefl wluch migbtbe used instead of common 
I M- tiann>l rtftrred to the soluble salts of 
k nkaUnort which have the power of prevcnt- 
jhe putrid feruieotation of animal matter, but 
f •T •Ki'-' ^ • T~ ■•:iriite to it an unpleasant 

•r IdJi) ties. According to him, 

- iicea exist in the chloride of 

said be, *' theorcLicttlly convinced that 

by this salt in a state of parity, 

DO tasXc^ because, in the first plact*, 




the qonntity used ta vrty smal), asd hejiideft, from 
the reaction which is operated, tberv resulla only s 
small quantity of clUoride of potaiaium, aodmm, or 
calctuu — salts which are dally employed in oor 
hoQfieholds. in the grey »alt consumed in our kit- 
chens. As for the portion of alumina iDtroduoed 
into and corabined with tlie animal matter, it is met 
with in such email qoantities that it need not ht 
stopped. 

" Alum is employed in medioioe, and acts as on 
ostringeut ; but. in this case, the argiUaceuus earth 
u combined with an arid, while in meat it is no- 
thing more than an earthy powder, without ictioa 
on the animal economy. On this subject, it may 
be affirmed that the inhabitants of the borders of 
the Seine, who drink the water of that nver at least 
half the year, daily drink ten timea more otuminoua 
earth than they would take by habitually eating 
meat prepared by my proctMS. 

" Rxperimeuts on the degree of concentration \ty 
be given to my liquid to eifect the preservation of 
meat, wtthoat uselessly adding too Urge a quantity 
of salt, have shown me that the suitable solabon 
ahould mark lO^'of Bsnroe'a Areometer. Now one 
kilogramme of this salt, aa prepared by M. Uuerin, 
is sufficient for six quarts of water : from nine to 
twelve quarts of tJiia liquid are required for the pre- 
servation of an ox, that is to eay, from one kilo- 
gramme and a half to two kilograniinei are em- 
ployed. 

*' The madua operamdi is very simple. Wben* 
the animal is felled by a blow on the forehead, the 
carotid and the jugular are opened on one side, by 
making an inciston ftoox the larynx to those two 
vessels ; then, by a brisk movement, the cattinf 
InstrumcDt is raised, which divides all the parts, 
and allows the whole of the blood to nw oat. 

*' Hlien the blood ceases to flow, a syphon in In- 
troduced into the carotid, a hgatnre is made at the 
superior part to prevent the liquid from moning 
out, both the apertnrefl of the jugular arc tied, and 
the injection is then introduced. 

" The most suitable instrument for this operation 
is a tube of waterproof Unen, of two metres iu 
length, three centimetres in diameter at the bottom, 
and five or aix centimetres at the top i tbis tube 
must be fixed to the syphon, which should be of 
wood or bom. 

*' As suoa as it is perceived that the animal i» 
well injected, that is to say, whea no more hquid 
gors in, and when the subcutaneous veins are vrell 
swelled, tbe tube must be squeesed between the 
finger and thumb, which must be mode to descend 
with pressure for the length of the column ; by this 
means the quantity of tbe liquid is increased in the 
interior of the animal. A ligature u made below 
the ayphun, which ia then withdrawn ; twenty mi- 
nutes afterwards the animal is skinned, then emptied* 
and, finally, cut up ia the ordinary way; there is 
no necessity for removing the boues and fat, as la 
the )iroccss of salting. 

" When the animal has been well bled, and the 
injection welt performed, it ia scarcely perceptible 
that the animal has ludergone any preparation at 
all. The only part where tbe injection leaves traces 
is in the lung», which arc dried up and discolored. 

" When the animal ia cut np and hung in the 
air. the tiesh is left in this state until tt is cold ; the 
only precaution to be taken is to prevent the flies 
from getting at it. 

" Meat which tt ia wished to pre&erve for a cer« 
tain time, requim uo other precaution ; it is suffi- 



G4 



MAGAZINE OF SCIENCE. 



dent to hang it in a dry tnd airy place. ^Vb«n it 
i* intcudcil tu preacnre it mure thim 6fteen iIstd, 
ibo flesh mtut be washed in a tolubon at ten dt^' 
gTtes of ctUoride of aodium, and an eqiuU quantity 
of chloride of alumiouui. W'beu this ia done, the 
meal ia a|iplied to the parpoura for which it ia in- 
tended. That which ia tu be dried, miut be hung 
in a chamber heated by meana of a currcDt of hot 
air, or air charged with wood smoke, or even in the 
open air ; but io thia caae, iliea muat be j^tarded 
againat. 

" Whan this meat is dried, it ii sufficient to pack 
it la barrels hermcticaUy sealed, and to keep the 
latter in a dry place. 

" To use tlus meat, all that is required is to 
macerate it for four-and -twenty iiours, and aa it ia 
not salted, the swelUog may easily be effected in sea 
water. 

" When it ia wished to preserve fresh meat, it is 
piled up in barrclB, aa is done in the common me- 
thod of salting ; when the cask is fuU it is closed 
up i then it is filled with either a saturated solution 
of chloride of iodiuni, with the wsshing mixture, 
or simply with dry chloride of sodium. The three 
means have given good results. 

" Thif bath contribates but little to the preierra- 
tion, but it prevents the vegetatiuo of byttua ; with- 
out this precoufcioD, the meat would become musty. 

" Among the e^iperimonts which 1 made, a barrel 
was opened after three montlu, and a leg of mutton 
was taken out which was roosted and eaten, and j 
pronounced very good by twrlve pursuuH ; but the 
twrrela having been badly closed the Utiuid of the 
bath was losf. and the mt'-at was covered with mould, 
but was not dccompoied.*' ' 

A committee, consisting of MM. Thenard, Ma> 
gendic, Dumas, and Seguier, has been appointed 
by the Academy to investigate the merits of this 
process, and to report thereon. 

MEMORANDA. 

Vt§etttti(m in Atmo»phere§ (^ differmt Dnuitien. 
— The following experiments have been made by 
Professor Dobercmer, of Jena : — Two glass vesaela 
were procured, each of the capacity of 320 cubic 
inches, two portions of barley were sown in portions 
of the same earth, and moistened in the same degree, 
and then placed one in each veasel. The air was 
now exhausted in one, till reduced to the pressure 
of fourteen inches of mercury, and condensed in the 
other, until the pressure equalled fifty-six inches. 
Germination took place in both, nearly at the same 
time, and the leafleta appeared of the aame green 
tint ; but at the end of fifteen days the following 
differences existed : — The shoots in the rarefied air 
were six inchea in length, and from nine to ten 
inchtes in the condensed air. The first were ex- 
panded and soft ; the last rolled round the stem and 
solid. The first were wet on their surface, and es- 
pecially towards the extremities ; the hut were 
neariy dry, 

Sound. — The French academicians made, in 1738, 
some experiments for measuring the velocity of 
aonnd : liie board of longitnde renewed them in the 
Bonth of June laflt, vrith all poetaible precision, 
when they found tlut the velocity of sound in the 
air, at the tem]>eratare of bh° Fahrenheit, differs 
very little from 1014 feet per second. 

The Chtck in Ooo, — Mr. David Ritchie says, he 
hai heard of a mode of discoveriitj; the sex of the 



chick in the egg, UlfToring from any whichj 
proposed by noturalifts. The foUicolua 
air-cell, which is to furnish oxygen to the 
chick, is situated at the larger end of the q|g. 
has not in bU eggs the sanu: poaittftn at the i^gm 
end ; and in varioui districts of Scotland, it ii hi* 
liev«l that eggs bearing the air-cell only 
top of the larger end prinlucc fcmalea. 1 
tain this Mr. R. instituted a series of ex| 
These experiments go \ery far to prove 
opiiuon which has been ilated is correct, 
determine what naturalists of Germaoy, France, 
£ngLand, have endeavoured in vain to disrova. 

Change* of the KaieidoKCfjpe.—Suppoti 
inRtrument lo contain twenty small pieces i 
ficc., and that you make ten changes ia 
minute, it will take the inconceivable space 
462,880,899.576 years and 360 day* to go 
the immense variety of changes it ia capable 
ducioti, aasounting (according to o«r firail 
the nature of things) to an eternity. Or, if 
take only twelve small pieces, and make ten cbai 
in each minute, it will then require 33,i{64 daj 
91 yeara and 49 days lo exhaust its variationa. 

Wei$hl ft/ thf National Debt of E 
BanJt NotM,~Ont hundred men 
the national debt of England in t' : Ik's, 

b\2 of which weigh a pound ; i*o ti :>ga 

of pounds sterling (which was iht i tti^ 

national debt in 1770, when ihi- 
made) would weigh 17»650 pouniI.> : <r A' 

hundred men. would be 437 pounds c-bcb. 

Cnrion* Erperimettt teith a Tulip. — ^tliebalbi 
a tulip, in every respect, resembles abnd. « 
its being produced under ground, and 
leaves and flower in miniatnre, which are to 
panded in the ensning spring, lly cautlaoalj 
ting in Uie early spring, through the ovnMPtilr 
coats of a tulip root, lougtiludinally fron tbft^ 
to the bose. and taking tliem off surxesatvcly, Ike 
whole flower of the next summer's tulip ia beautl. 
fully seen by the naked eye, with its petals, pi 
and stamina. 

The TroveUing of Liyht. — Light travels at 
rate of an hundred and fifty thousand milea 
single second ; and it ifi tfeven mJnutcs in pi 
from the sun to the earth, which is nearly a 
of seventy mUtions of miles ! Snch is the 
with which these rays dart themselves forward,'^ 
a journey tbey perform thus in less than eight' 
nutcs, a ball from the mouth of a cannon would 
complete in several weeks '. But the miuut 
the piLTticles of light arc stiU several degrees 
their velocity ; and they are, therefore, 
because so very small. A ray of light is 
more than a constant stream of minute parts, 
flowing from the luminary, so inconceivably " 
that a candle, in a single second of titue, hail 
said to diffuse several hundreds of milUona 
particles of light, than there could be gnimiBj 
whole earth, if it were entirely one heap of si 
The Btm fbrnishes them, aiA ilie stars also, 
out appearing in the least to consume, by 
us the aopply ; lis tight is diffoaed it) a wide 
and leems inexhaustible. 

To produce Fire from Vane. — The Chioeatt 
ton, which is used, when ipUt, for the maki* 
cane chairs, will, when dry, if struck against 
I other, give fire : and arc used accordiugly tji i 
placefi, in lien of flint and iteeL 



ucaiu ui K uiuoe oi uucuveru)j{ uie bu ui mc | piHccn, in ucu ui uuii. uhi iicct. 




THE 



AGAZINE OF SCIENCE, 

^n^ ^c&ool of ^xt9^ 




SATITHDAY. MAY S3, l&ll. 



riK 




BRIDGEMANS OXYGEN LAMP. 



6C 



MAGAZINE OF SCIENCE. 



s 



BRIDGEMAN'S OXYGEN LAMP. 

7*0 xAff ISiiiiir. 
SxB.— Being engai;ed in the curly part of tbc winter 
of 1839. with B flcicDtific genilcmBa oi this town, 
Mr. Edward Mugridge, iu experimenting with a 
mftgic lanthora, andend^rouKng to obtaia ii better 
light than was given by the common Inoips, utnally 
sold with them ; the idea was soKgestcd by the 
latter gentleman, of supplying the flame with oxy- 
gon gu : the attempt was mode, but dkl not answer 
in the way we tried it. 1 then turned my attention 
to it more minutely, and, after a long course of ex- 
periments, Mucceeded beyond my most sanguine ex- 
MctationB ; my idea was, that it might be obtained 
by filling the interior of the flam« of a common can- 
dle, ur small Limp, with oxygen gas, which has 
proved correct. The gas b passed through a inrt/e 
mperturtr with but littlw pretsurty and produces a 
lights both steady and perfectly under controul. 1 
have had one burning for three or four hours at a 
time (witli a light scarcely to be borne by the naked 
eye, without requiring to be evea touched), and am 
convinced, by my own experience, and the opinion 
of a first-rate London optician, who*c judgment 
may be relied on (und who, when he reads this, will 
see the original of a piracy), that the inrentiou will 
be of great benefit to the optical world, and particu. 
Urly OS its construction is so simple that any one, 
pOMBssing a mudenite share of uiecbanlcal talent, 
may eonstruct one for himself, and on that account 
I have been more partioular in giving Che miuutis 
of what I have found to answer best and most sim- 
ple ill coastrvction. and have given the drawing the 
exact sis*. 

A is of tin, with the brass tube B soldered to the 
hoitom, and projecting about ^ of an inch below it. 
C is a circular broia Ud, with the tubes D and E 
Nolderpd in it, and resting on a wire soldered ronnd 
the inside of A. F is a brai<s ferrule' with one of 
the (hr<^ pins actini; on the screw cut on the out* 
aide of U. G is n brass nut tapjied to fit the screw 
uu the tube H, and locking into the niche on the 
lower end of the tuhe U. }1 iu the brass tube 
through which the gas is passed to the flame, I is 
K tin cup Moldtrtd uu the tube H to catch the over- 
Jlawini; oil. K ts a nut to fasten thr. tube into Uie 
end of thu tube V, the lowereiid of which is soldered 
t« the smnll screw of a comaion uniun joint M, 
which allows it to he attached by a flexible tube 
cither to a gasutncter or gna bag. 

The wirk is made of the common (Vat cotton, the 
two aides l>cing sewn together and placed loosely on 
the tube 13 ; it is then cut ofl* le^'cl with it, and 
opened from the tube n little. Tlie inner tube H is 
about 1-lGthof an inch smaller than B, which hoId< 
it in the centre by three points, filed on its end and 
bent towards the centre ; Oius allowing the over- 
flowing oil to pass down between the tubes into the 
tin cup I ; the gas is thrown obliquely into the 
flame, by the small inverted plstina cone N, which 
is attached to a fine wire, bent so that it may be 
pushed gently into the tube, and remain where it is 
placed. The tube L tsrves to support the lamp by 
boiiig fixed in a spriog socket, and the Inmp rest- 
ing on the nut G, tlie end of the g&s tuhe may b« 
ndjuftvd to a great nicety in the flnme, by merely 
turning the Lamp round — a practiral point to be at- 
tended to. Another great advantage of this form 
of lamp is. that it may, in a moment, be taken off 
and used Zi a common lamp for carrying ^MUt, 
and, although the tube B is »pt:o, the air du«i uot 



pass up it so as to give il the form of 
Aame. When taken off, the ferrule 
turned up till it doet not smoke, and byl 
that it may be made a light of any p 
consuming a cubic foot of gas per hoor, 
it to one-fourth that quantity, regulotii 
the size of the flame. The three not 
feet to prevent the lower aid of the 
injured, and the oi*emng E is for alU 
filled with oil without reiooving the 
only required when a new wick is put 

Mitf fvh, I&4I, 

ENCAUSTIC PAINTINO. 

fUttiimrd /rampant C3, <j'ki cancUfitA,} 
3. C. Wernxk, of Newstadt, in Germae| 
the following process very efl'ectual in aNl 
soluble in water: — For each pound of wbtfel 
takes twenty-four ounces of potush, wUdh 
solves in two pints of water, warming it get 
this ley he boils the wax, cut into little 
half an hour ; at the end of this time hA 
from the lire and leu it root. The wax &i 
at the surface of the l^tfT in the §omk «( 
sairanaceoofl matter, wSHh bdng tiitanti 
water, produces a sort of tnm |i < p n wbldi h 
wax milk, or encaustic wax, and may ba a|ii 
pictures, f^uniturc, or leather, aftvr hmri 
cleaned them : in an hour after the Applies 
article should be rubbed with a piece af 
doth, which will cause the pictures to ha«* 
effect, and the furuiture to acquire a pccuHac 
ness. Another advontogc of thii pcosil 
wax is, that it can be mixed with aU kiodXli 
and consequently be applied in ■ ringiSB *p 
It is also oseliil to fix water colors. 

The following imporUnt obsenratkma tn 
lated from the Italian of the Cfir 
who has deeply investigated the mi 
but valuable tract, called •' ?': " 
Punica. ' ' The andcnts (ujs : 
to Pliny, used three species v- 
three they used Bre ; so that to pniti 
or with a burning application, (>' 
is derived from a Greek wurd. 

We have never thoroughly known the aatai 
Punic wax, which was anciently uoed, asd 
after all, was the essential ingredient of tb« 
painting in encaustic. The Chevalier prali 
genius and industry of M. Requeuo and M. 
lier, who have also Irenttrd of this iuSjfTl, b 
have not fuUy succeaded in finding out the tt 
of making Che said wax, then quotes the pM 
Pliny on the method of making it. Pmiiet 
modo. He, (see Pliny's Nat. History, 1. tX, 
and asserts, witli many other writers, ttiflt 
Hilit is not the nitre of the modema, pmp 
called, but it ia the natron of the ancieota, 1 
native salt which is found crystallised in Kg) 
other hot countries, in sands rairounding [ 
salt water ; it must not b«' mistaken for the 
of the new nomenclatuce of our College of F^i 
which is the new name of the minenl alkali. 
In the pUins of Lower Rgypt, which wa 
covered by the sea. in the environs of the ■] 
of that country, at Tripoli, at Tonis, u thu 
adjacent parts of ancient Carthage, the natr% 
same natron which, under the name of mi 
Carthaginiuns, according to Pliuy, used in pri 
their wua, is to this day extracted, and benc« 
CiiUcd Putuc wax. 



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MAGAZmE OF SCIENCE. 



C7 




now (mjrf Lorgna,} succctsitely to try 

enU. firtt with three parts of wax and 

UD, and then with four of waji, and so 

uwd twenty parts of white melted wmx 

one of nstron, with ai much w«t«r bi wu 

t to mcU the natron. 1 held the mU' 

Iron veatel OTcr a alow fire, ctirring it 

& wooden spatula, till the two substances 

by rrapormtion, and in clotelj uniting 

bj degrtea «»«umed the rontisteiice of 

tlie color of milk, i remOTed it then 

and put it in the shade to let it harden 

t itself in the op^^n air. ThU natron 

from tbe ley of kali of Malta, erapo- 

a dry ; it may alio be extracted from 

Spain, .Sictlr. Sardinia, and from thnt 

•nd of Tripoli, which may be procured 

difficulty. The wax t>eing cooled, it 

water, and n milkv emulsion rt'§alted 

tliHt which could be made with the beet 

P- 

another pUee« c. 7. 1. 23, girea further 
r the rannner of qbio; cauiitic on paint- 
illi; but nB it cof^cems the antiquary 
I have forborne from making 
:,'ins at these norda, Vt jiarie- 
ca, btc. 
vie of this wax in pointing in cn- 
rsaya, that magnificent and re- 
were made In the apartments of 
ni Battisia Gasula, by tlie Iialinn 
Jintnuio Varcheri. He diasnlvrd the 
when it woa not yet so much hardened 
I to be iKTii reaoluta, as expreswd by 
pan waier. lightly Infuiied with gum 
M of sarcncolla, male incenMf. men- 
liny. He afterward* melted nnd mi:?ed 
rith thii was aa liquefied as he would 
with oil, and proceeded to paint in the 
n*: nor were the color* aeen to run or 
leut ; and tbe mixture was ao flexible 
DcQ ran aaioother with it than it would 
|iriCh oiL The painting being dry, he 
kwttc over it, and rubbed it with linen 
irfaich tbe nolor* actjaired a peculiar vi- 
brifhtneat vrhich they bad not before the 
tthe rubbing had been effected. 

lOUNTAlNS, Ac. IN THE MOON, 
poon is viewed through a good trlc-KCope, 
■ppeon to be diversified Mth hills and 
It thia is roost diacernable nhcu vbe in 
fevnlgbu after the change or opposition. 
ia either hometi or siiHmu, the edge 
of the iUumiDBtcd part is jagged 

lebrated astronomers have delincAtcd 
i face of tiip moon ; hot the moct oele- 
those of llevelius, Grimoldi. Riccioli, 
{ in whi(!b the appearance of the moon 
M in .ts diffiircnt atatea, from new to 

iz ited pnrts which appear upon 

tUe ai'-^.-n nre clir\.itcd tracta, some of 
to very Uii:l ;: ■ «; / liri!. while the drirk 
to be pr rf ' and level. Tliii 

ithnes* parts, naturally 

fts to -ro, ' '117 were imtnenM 

nd tiip namca giren tn thorn, 
^ i^tronomcT*. are founded on 

fiiotx. For Hetvliua diftins^uiAiicd them 
the uamei of the scius on Like earth ; 



whtlc be di:FtJncniahcd the bright purts by tbe namra 
ftf the countriPi and islenda on the earth. But 
Riccioli and Langreni distinguished both the dark 
and Itght spntK, by gi\ing them the namea uf celf- 
bratcd aatronomen and mathematicians, which il 
DOw the general manner of diatinguiihing them. 

That ^e spots which are taken for mountalna 
and ralt<ys are really such, is evident from their 
whadow9. For in all sitoations in which the moon 
i» seen from the earth, the etfTnted parts are con- 
fltaatly found to cast a triftngular shadow in a di- 
rection from the sun ; and on the contrary, the 
caricfei are always dark on the aide next the sun, 
and iUuninated on the opposite ade, which if quits 
conformable to what we observe of hills and vnllrys 
on the earth. And as the tops of these mountaina 
nre considerably elevated above the other parts of 
the surface, they are often illnminated when they 
ore at a considerable distance from the line whirit 
Bf^aratea the enlightened from tbe anenllgbienrd 
part of the disc, and by this means afford us a me* 
thod of even determining their height. 

i'rtfvious to tbe time of Dr. Hencbel. some of 
the lunar monntnioR were considered to be double 
the height of ajiy on the earth : but by tlie ohser- 
vationa of thai celrbrated astronomer, their bright 
is considerably reduced. 

For after measuring many of the most coo- 
fipicuouK proniinenres, he says, " From these ob- 
aervQtiont I believe it is evident, that the height of 
the lunar mountains is, in general, overrated ; and 
thnt when wc. hive excepted o few, the generality 
do not exceed half a mile in their perpendicular 
elevation." 

As the moon*a aurfucft is dtveru6ed by mountains 
and valleys as well as the earth, some modem w- 
tronomers any they have discovered a still greater 
similarity ; namely, that some of these are really 
volcanoes emitting lire, as those on tiie eartlv do. 
An appearance of this kind was discovered by Don 
UUoa in an eclipse of the son, which happeoeil oa 
the 2]lh .Tune, 177H. ll was a smidl bright spot 
like n star, near the margin of the moon, which 
be supposed at the time to be a hole ur Tallcy, 
which permitted the sun's U;ht to shine through il. 
Succeeding observations have, however, led aatro- 
numcrs to believe, that appearances of this kind are 
occasioned by the eruption of volcanic fire. Dr. 
Hcrschel, in particular, haa observed severnl eruptions 
of this kind, llie last of which be has descritwd in 
the Philosophical Transactions for 1787. as follows: 
" On April the I9th, at lOh. Gm. I perceived tbr*c 
volcanoes in different places of the dark part of the 
new moon. Two of iktm are cither ah*eady nearly 
extinct, or otherwise in a state of going to brrak 
out, which pcrlmps may be decided next luiinlion. 
Tbe third i-hows an actual crnptioo of fire or 
luniiuous matter : its lii^hl ia much brightcrr tliau 
the nurleud of the comet which M. Mechain dis- 
covered at Paris, on the 10th of this month." Tbe 
following itlght the Doctor found it burned with 
greftter violence ; and by measnremeni be found 
that the shining or burning matter must be more 
than three miles in dinmeter, of an irregular round 
figure, nnd very sharply defined about the edgea. 
Ttie other two volcsnors resembled large fatnl 
ni-huLT, wliirh appeared to be gradually brighter 
towards the middle, but do well-defined luminoos 
spot could he discovered in them. Dr. Her»ciiet 
adds, *' The appcnmnce of what I ha^c called lbs 
acUial firfi, or cniplion of a volcano, exactly re- 
iwtubled 4 small piece of boxuiug charcoal, nheii it 



I 



«8 



MAGAZINE OF SCIENCE, 



is covrrcU by n very ihtn com of while nshct* 
which frequently adherr to it when it has hoen tciine 
time ignited ; and it had a degrtc of brightnns 
ftboat US 9tron|c as thnt with whicli a coul «uuhl be 
seen (o glow in fair clij light." 

The appearaoce which Dr. Ilrrscbel here de- 
oribfls to minutely, wai alio obserred at the Royal 
Obaerratory of Pah*, abont nix days before, by 
Dominic Nouet, like a star of the siitb roafoicude, 
the brigfatneu of which ocoaaonally increaacd by 
flaihea. Other aitronomcn alao saw the aame 
thing, for M. de Vilieoeuve obaerred it on the 22 nd 
of May, 1787. Tliis volcano ii situated in Llie 
nortb-eaat part of tlie muon. about 3' from her 
cdgCi towards the ifiot called Helicon. After cun- 
aideriog all Uir eircumstances respecting ihrsr ap- 
pearances which have just been mentioned, we rauet 
subscribe to Dr. Uenchd's opinion, that volcanoes 
exist in the noon as well as the earth. 

fTotm r*mliMU*^.J 

POLARIZATION OF LIGHT, 

f ltr§umtsi /mm pnf:e 38. J 
In the tninBTniBsion of ordinary liglit through trans- 
ptrent or refracting bodies, ptiTfectly bomogroeoua 
in their structure, and of a aniform temperiturG 
tiiroagboui. such as pure water, well annealed 
glasa, and many kinds of cryvtallized bodies, as 
almn, common salt, Fluor epar, ^cc, a single beam 
will be refracted singly ; and if we make a pin-hole 
in a card, and place it behind one of these bodies, 
and behind the card a candle, so that the Ught may 
first pass ttroogt the hole in the card, and then 
ftrongh the subject of experiment to the eye, the 
hole will be distinctly seen, and will be perfectly 
•ingle. But in roost crystalliac substances this 
is not the case, for surh usually posoesB the pro- 
ferty of double refractioD, a beam of light passing 
through any of thrm )>eing refmt'tfd into two beams 
of oqnal intensity. This beautiful and interesting 
phanomenon is seen, in an eminent d^ree, in Ice- 
land spar (calcareous spar), in which it was first 
discoTcred. 

f' The gczicral effect Is Men in the above cut. The 
Beit figure is a drawing of a model representing a 
rhomb, with a ray of ordinary light A.\ incidcut 
upon one of its natural faces, and which, in passing 
through the crystal, Is divided into two rays, one of 
^bicfa, CC. being refracted according to the ordi. 
nary wajr; the other. DD, not obeying the same 
law, bat being refraclrtl in an extraordiuary maa- 
aer, ia called the extraordinary ray. 









Now, on analysing these rayi, rillier wit)t a vmnl 
rhomb, or otlier«i>e, which will be better under* 
stood as we proceed, they are fotmd to be pfeckih 
alike in every respect, of the saoBk* cbaraqter, w 
posscaaiag the same properties, but that thaw fp^ 
pertica and character are at right ancica to 
other ; the donbly refracting action of Che 
upon light consisLiug in the aeparatjoo of tfaa 
sets of undulations, or tranarerMl vlbratbaib tf 
which a ray of ordinary light consists ; the rfbo- 
tions of the ethereal molecule, in the ardioary of, 
will be in one plane ; while the vibrations m tW 
ethereal moUxmles, in the extraordiEiary ray, will bt 
in another plane, it right angles to it, aa rrpf»> 
Rented by the last 6gure ; and, if we inpposc 4b 
to tv: a bird*<>eyr view, the vibmtions of C C 
in a borixontal plane, and the vibrations of D 
a per|>eodicuhir plane ; each of which is said 
polariecd light : hence, when tlie question ia 
what is the difference belwern common and 
ized light ^ the reply, accordini; to the imd 
theory, is, that a my of ordinary or common 
whether arti&cial or solnr, consists of two 
undulationfl or vibrations <^ the molecnlea 
ethereal or imponderable medium, which w« 
supposed to fill all space; and that these t 
of undnlations are performed in planer, at 
angles to each other ; but that pol <- 
sists of one set of nnditUrioDS, or 
fonned In one plane. The polan/. iiii<li ui ii^K" 
then, is simply the separation oftlie twu fets of ua 
dulations, or vibrstions, of which ordinary light U 
composed, and thus producing a beam of light ii 
which the vibrations of the ethereal motecoki m 
alt in one plane. 

Now, this separadon. or polarization (u It 
rather iinpro)>crIy been called), may be effect 
common crown glass, either by ordinary 
or refraction, each of which will exliibit 
effects. In order to undcrKtAnd this, let BB 
sent a bundle of pUtes of common glaaik 




that a ray of ordinary light A A may form an to|kl 
of incidence of bG"* 45' with a line p rpcndinU« r 
their surface ; then tlie light reneclc-d, and i 
■ented as passing off at D, will be. pnUrixed 
and if a proper number of pUtes, which, 
same angle of incidence. Is 27, be exnplc 
light transmitted at £ will be polarixod alio, « 
rays possessing the some projwrties, bat at 
angles to esch other. Thus, in the reflected 
D, the vibrations are supposed to take phe 
peipendicalar plane, this being a bird's^eya 
wliUst, in the refracted ray, £, the Tibraltai 
performed in a horizontal plane. ThiawUlbe 
understood oo analysing either of tha tays, 
may be done by the some means as tliat by 
the original beam is polarized. Thus, sapi 
we experiment with, or analyse the rtrflected i 
in whieli the vibrations are ia a per)>endicular 
when it is made to foil upon a second bai 
glass U U, at the ssme angle of incidence, 
glass be so placed that the reflection may 
in the same planer ll will again be wholly : 



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MAtJAZINE OF SCIENCE. 



C>9 



•C R B, Kfid xtanc mil be trinsmilttHl or refnictr<l 
frtiiwii the MCOiiJ bumllf v( glnw, for ihr very 
- UiaC prvtiurcd iu reUcflion from the 
■■■Mr; \\t. that thff nbmttons cootinao 
Co the rcficciiug »\XTitct». But if the wcoad 
of glui ii put in tDch a pocitioo that the 
o« ttliaU be performed In s pttoe perpendi- 
to ihe rrrtecliiip iorfjce (whioii may be done 
tamtog it round QU", in such a condition that 
ny of lit^t shall be the uiis npoo which H 
lUwBfs making Ihe sanie angle of ioH- 
) i thfM, MiMon am it begins to torn, the re- 
ft^t ^(11 begJD to deor^je in intensity, uid, 
1 portion will hcf(in to be transmit- 
1 through the glus, ivliich will in- 
rrisc ta lite *Aaie ratio as the reflected light de- 
■ *■» €> i and wht'n the baodht of ghui has turned 
W". in which po«ition we tee it rciprcsented at the 
irfnlVevr rit:w, and at the horiaontal view in the 
t rut, the ligltt D ia wholly transmitted or re- 
frmct««l. as nt CC, no portion being reflected, la 
a |>o«itioo, the vibrations will be in a fUno 
tliieulAT to the reflecting aurface ; and such 
■re always traiiBmtLl«d, and not reflected, 
Hpv has taken place in the polftriKation 
if Am original beam of cooamon light before rc- 
brrrd to. Now let the second bundle of glass II U 




ii> turn, it will be seen that, as soon lu it 

move, the transmitted light CC will be- 

: - ^. a portion beginning sgain to he re- 

:LS the glass turns, will increase in 

l'i[< iamo ratio as the transmitted light 

. until it hfls turned another OO'*, or reached 

<>> die first position, as seen at the next cut, 

wicrvtlte phcne of reflection is again parallel to the 

ftane in which the Tibratiuus take place; cunse- 

the whole light is again reflected at EE, 

£ truismitted. for the same reason as be- 

>J. On contiuoing the revolution, the 

I "^^ 

-1^ occurs at each quadrant of s circle. In 
Al^re, the bundle of gtms H H is roprt>. 
11^ turned 270", or } of a circle. Iii 
the same thing occurs as at 90^'. 
D is wholly refracted or transmitted 
ssa, ai at CC ; bo tliat it is evident, 
-- - , :uicnts, that there ore two positions 
m »tech the same ray of polarized light D is wholly 
i ifl w ^rd. and two other positions in which it is 
' rinamitted by the annlyung bundle of glass ; 
;<ieii af« easily understood, b)' bearing in 
ripiiou uf tlie original ray of ordinary 
z to the unduUtory theory, and the 
I ^t. or polari;tiDg bundle of glsKS. 
- been sUted that a beam of ordinary 
iif a rapid sncces^ion of systems of 
log an immense number of rays, the 
I ■ Ijich are performed in every possible 

^^^^^^miy be aaked, what becomes of those rays, 
^^^^^Hloaa of which are in pUoet iiicliDcd at 



diifer^nt angles between the pcrpcndtcuUr and 
horixoulnl ? Now it is of great importance to an- 
derstond this cU'arly, oa it will aUo nmble tis to uo- 
dcrstand how all the various and beautiful phe* 
nomena of colors are produced. Tlie esperimenta, 
however, which we have been noticing with the 
aualysiug bundle of gloss, will assist as in this ; for 
if we refer amin to Ag. 3, we find that the Tibrations 
of the potnrizetl light D are represented as being 
performed in a perpendicular plane, thot the second 
bundle of glass 11 \l is so placed that such vibra- 
tions are parallel to its ploMe of reflection, nnd that, 
eonse^uentty. in such a position the light is again 
rerlnt^ted, fur the reasons there stated. Now, if wo 
miurk well what follows, when the second bundle ol 
^loss is made to turn round, we shall understand 
what becomes of those vibrations which are inclined 
at different angles, between the perpendicular and 
horizgntol : fur when the second bundle of glass be- 
gins to turn, its plane of reflection will begin to 
form didorent angles with the perpendicular and 
horioontal, and as soon as it begins to move, a |>or- 
tion of the reflected light begins to be transmitted. 
which. OS it turns, increoses in intensity ; and when 
it has reached 4b'', the light D is divided into two 
equal portions, one of which is reflected, and the 
other refracted or transmitted through the second 
bundle of glass, in each of which the vibrations are 
inclined Ab" to the i>erpendiculaT, bnt at right an- 
gles to each other. Thus, in the reflected |K>rtion, 
the vibrations will be parallel to the plane of reflec- 
tion, which is MOW inclined -15^ to tbc perjwn- 
dicuLor ; but, in the transmitted portion, the vibra- 
Cions will be in a plane porpendicular Co the plane 
of reflection, and, of course, inclined 45'' on the 
opposite side of the perpendicular, and, conse- 
quently, at right angles to the reflection portion. — 
It will be understood, then, from these experiments 
that, in a beam oi ordinary light, those rays, the 
vibrations of which are inclined at diflTcrent angles 
between the perpendicuhu" and horizontal, are di- 
vided into two portions, one of which is reflected, 
and tiie utlicr refracted or transmitted, the vibra- 
tions in each of which are at right onglea to each 
other ; but in neither are they in the same plane ai 
in the original ray, tlie reflected portion bring 
parallel to the plone of reflection, and the refracted 
portion being at right angles or perjiendionlar to the 
reflected portion ; and, cooaeqaently, whatever an- 
gle the plane of reflection makes with the plane of 
Tibrations of the original ray, the vibrations of the 
reflected portion will make the same cnglr^ heing 
always parallel. But the intensity of the reflected 
portion will decrease as the angle increases, being 
at its maximum or gre^teAt intensity when pnrallel, 
and at its minimum ur nothing when perpendicular-, 
and vice vcraa with the transmitted portion, which 
increases as the an»le increases op to 90", being at 
its maximum of intensity when perpendicular, and 
at its minimum or nothing when paralleL 

(To be eontinntxLj 



ON PREDICTING THE WEATHER. 

From a very great number of meteorological ohser. 
vatioQs, made in Enghind between the years 1677 
and 1789, Mr. Kirman has deduced the following 
conjectures of the weather : — 

1. That when there has been no storm before or 
after the vernal equinox, the ensuing summer is 
generally diy. at least five times in siit. 2. That 
wbcQ a storm happens from an easterly point, either 



70 



MAGAZINE OF SCIENCK 



on the 19th, 20th, or 2Ut of Marrh, \he ^nccfcAins 
nromer U grnmilly dry four times in fire. 3. Tlut 
when B ttorm arise* on the 25th, 2Gth, or 27th of 
March, Hiid not before, in any point, the succeed- 
injt Buniinrr is generally dry. fuur times in five. — 
■i. If (here be a stonn at S.W., or W.8.W., on Hie 
19th. 2ath. 21st, or 22nd of March, th^ sacceedini 
summer is genemlly vtt fnur times in five. 

To the Ethove we shall adtl the foUntring observa- 
tions from the Eacydopedia Britannica : 

1. A moist autumn with a mild winter, is Rcne- 
r^lyfoUowedhy acold and dry spring, which greatly 
retaurda Tegetation. 2. If the summer bo remarka- 
bly rainy, it is probable that the ensuing winter will 
be serere; for the nnusual eraporotion will hare 
carrried off the heat of the earth. Wet summers 
are generally ntte-ndcd with an unusual (jnantity of 
Mcd on tba white thorn and dog-rose bushes. Hence 
the unusual fridtfidneas of these shrubs is a sign of 
a aerere winter. 3. The appearance of cranes, and 
binds of paasage, early in autumn, announces a rery 
severe winter ; fbr it is a sipi that it has already 
b^tm in the northern countries. 4. When it rains 
plcotiliilly in May, it will rain but Uttle in Septem- 
her, and rice ven£, 5. When the wind is S.W. 
during summer or autumn, and the temperature of 
tlic uir unusually cold for the season, both to the 
foeliiig and the thermometer, with a low harometer, 
much roiu is to be expected. 6. Violent tempera- 
turfS, as storms or great rains, produce a sort of 
rri^ in the atmosphere, which produces a constant 
temperature, good or bad for some months. 



POUNCING DESIGNS UPON CLOTH. 

Thk ordinary means employed in thta art are as fol- 
lotrs : — Uavuig pricked any deaign upon [taper with 
a needle, It is dusted over with a piece uf ninslin, 
contaiuing charcoal very finely pounded and aifted, 
the dujt gets through tlie hrfU-b pricked on llie design, 
and settles on the cloth which La to be embroidered ; 
then with a black or white pencil, according to the 
color of the cloth, the marks left by the charcoal- 
dust ore exactly to be followed. 

The person who docs this ought eitlier to possess 
a knowledge of drawing, or else to have much adroit- 
fieas, in order that the fonii of the deaign may be 
exactly preserved ; but often before the pattern can 
be finished, the dust tlica^off, and thus occasions 
much eaibarrafwoMmt to the workers. Messrs. 
Revol and Kigoudet perceiving all the ilifficulties 
which attend this method of proceeding, have sought 
for, and at length ingeniously contrived a remedy ; 
and the patent which they obtained for their inven- 
tion having expired, we shall proceed to describe the 
means they employ. 

Previously to this progress no means of fixing the 
dust upon the cloth had ever been ascertained, and 
every person wlio was employed in this work was 
obliged to trace n-ith a pen or pancil the design 
formed by the dust, which not only occupied a great 
part of their time, but often ocouionttd Diisttakc;^ in 
the figure to bo embroidered. The new mcthad 
poaaesses the advantages of being able tu cunvry tu 
the cloth the exact figure of the design, and ftu4U- 
tates the progress of the embroiderers, allowing them 
to attain the greatest exactitiide in their work, and 
sparing them the trouble and time they had em> 
ployed in retracing the design. 

The method of |irep&rin^ the composition of the 
powder for pouncing in black, is as follows ; — 
_ Place an earMrw j»ot_over the fire, and put into it 



n given quantity of gom mastic, adding thereto oar- 
thirtieth part of wax, oil. tar, or pitrh ; wlieu ihtt 
is melted, throw into the pot as much tamp-blark is 
may be deeded neoeasary for the color of dw 
pounce, stirring the mixture all the time with an 
iron fpoon. When all is well mixed, take It ftiM 
the fire and povr it into sheets of paper, with d« 
comers turned np to prevent Its ronning over, 1x4 
when well cooled, pound and sift it, and enrioM % 
in B piece of muslin. Pounce with thia wfaafiesv 
design it is intended to form nfKHi any kind of eta^ 
and then it is instantly to be fixed on the ctodt, 1)f 
pusnng it ower a pan of coals of a gentle heat, or Vf 
going over it with a hot iron. In thia latter cttt, 
it La necessary to put a sheet of pB]>er between tie 
design and the iron ; then the design will remain in 
the doth neatly and correctly. 

7>) mate a Wftite /^nerfer. — Take a kaomm 
quantity of gum mastic, and melt it in a glased 
earthen pot over a sk)w fire ; add to this 1 -30(h 
jiart of virgin wax, and when the whole Is meltMl, 
add as much fine white ntver as the gum and «a 
will imbibe, taking grett eare. all the while, 
it in proportion aa the white ia added. Tbe 
when well mixed, must andergo lbs sk 
as black powder. 

ELECTRICAL EELS. 

Thb rivers and lakes of the lowknda of Vcnesiote 

and Cnrnnca are taU of electrical eels, cdled by At 

Spaniards treniblador. (the tremblfr"^ — ' 

French colouibts of Guyanne, the 

These ecla hare Uie astonishing £b > 

their prey by a discharge of clccl^ical matter. 

arc found also in the small ponds or fioota intit* 

spersed in the vast plains lying between the Oronoott 

and the Apura. 

The electrical eel is commonly about six i 
The structure of its nervous system haa 
scribed with sufficient accuracy ; but what 
said of its cellulary rcserroirs, and the 
of its electrical batteries, is purely ima^nwy. 
sensation occasioned by the shock is extremriy) 
All ; and in the paits affected it leaves n ni 
it resembles u sudden blow on the bead, d 
the commotinn produced by the ordinary 
fiuid. The Indians have to great a terror 
animal, and such a repugnanoy to oosnoaBH 
living, tliat Mr. Humboldt had the greau^t i 
in procuring some of them for maki: 
For this purfKjse he atjiid seventi 
Apnra, in the smalt village of CalohofOr 
learned that there was a great number of 
eels near this river. His landlord uadi 
to procure a number for him in vaio. 
Mr. Humboldt resolved to go himaetf to^ 
whuA duMe eels inhabit. Mr. Hnmboldl 
companions witnessed amidst the abodei of 
a sight altogether new and extraordinary. 
thirty moles and horaes had been havtihr^ 
togeiher from the neighbouring an. 
they Live in a wild state in so gre-A' 
the proprietor, when he is known, ] v 

for about seven shillings each. Th" In-'n 
rounding the mnlca and horaes. drovr •:. 
water, and prevented them 5vm re: 
by means of harpoons, ailixrd to t 
bamboos, which they pushed forv 
animaU with loud vocift ration. T, 
or pymrio/i. roused liy the-noiatf anu ttL'r.uir. 
up tu the sarfooe of the wvtan i and swlnntl 



MAGA2INE OF SCIENCE. 



71 




livid teipenui, glide ander the bcUiea of 

aud bone, to whom they couitnuiiicfite 

JBiotions the most sudden and violent. Tbo 

Inipeds, in erreat Agony* their hair tCaj)diiig on 

and theit eye* rolUug wildly with p&in, moke 

lA for their t^ropc in Tiiin. In leas than fire 

of the hoFMi wen dnwa ander thewn- 

)vmed. Vtctory eoemad to be decJuwl on 

of the electriea) eeb ; but their activity 

, and Ungaiih : btigned by the repented 

thax acrvout^etgf, they lannched the 

^" ' m frequently, and with less effect. 

bad cacaped destruction gradually 

atreagth ; and in about n qujutfrr of 

retired from the combat^ in snch a 

tor and exbauction, ttiat they were 

bo land, by means of anaU hivpoona 

to oords.— JEfiMiAtMf'a 7Vae«<r. 

K7OTH OP VARIOUS SUBSTANCES. 

^pmwiE found the following wdgfata reqaiaite 
^Bf acabical inch of the undermentioneil snb- 

K Efan 12«llbs. 

■ WhiteDcal 1928 

■ BocliihOikk 3860 

^^ Portland Stone .... 620 

Crafleith Stone 8688 

of a quarter of an ineh, of diflierent metals^ 
" by the foUowing weights ; — 

Cast Iron 077^ lbs. 

Cast Copper 7320 

FfauYeUow Brass 10306 
Wrought Copper. . 6509 

Cast Tin 966 

CaslLesd 483 

iooa calculutions have been made by Mr. 
dTil engineer, on the comparAtive tens* 
metal*, in the pare nnd alloyed sLitc. 
"If I take copper, whose tenacity or 
the square inch is 12 tons, 1 5 cwt. I qr. 
and to six parts of it Slid one of tin, whose 
I ton, ISewt. 2qrs. and 16 lbs. finite 
ttild tell me 1 should weaken the copper 
If 10 cwt. 3 qrs. and 7 3-7 lbs., instead of 
Dl^ I add 11 tons, 15 cwt. 3 qni. and C lbs. to 
or strength, as eipcrimeut deiiiouslrates ; 
lake three parts of tin, and add to it one 
weakest of all metals, it^ tenadtj or 
the square inch, being only able to 
Sqra.ftud 2.11bB., mere humou reason, 
il calculation, would tell me the 
would carry only I ton, 11 cwt. 2 qrs. 
inataad of which they will carry 4 tons, 
B tb»*» which actual experiments de- 
Sow hami Hating this to the knowledge 
aQ Ida ehemioal researches I How lit- 
kaow or comprehend of the secret work- 
t" 

foree of metals is very much in- 
kwninering or rolling them. To draw 
rkadrieal bar of iron, of M inch dia< 
a force of 43 tons ; while a bar of 
LAmIi ifamrirr. and whose cubic admeasure- 
bi|||^i)l as mach as the li-inch,] requires a 
^^^^to <• draw it uander ; and if we take 
PIBlKaf an inch diameter, which boa been 
Vli 4rawn lo repeatedly, in reducing it to 
le shAlt find that it will require a force of 
it asunder. 




ON THE IMPORTANT USES OF SODA. 

Paw artidea are of greater importjuice to the arts, 
manufiictures, and domestic economy, than soda. 
It is essentially neceasary for making hard soap, 
and forms an excellent substitute for that article ; — 
as four ounces of the former, and six of the lattOTi 
arc fully equal to sixteen ounces, or one pound of 
soap, in washing, white it softens the hardest wnter, 
making a sahng of from one-third to onc-haU die 
expenac, according as the operation may be |>ef- 
formed by hand, or by a maebiae. In the oleansiiw 
of worsted or flannel, the effects are fully evinced, 
which, when managed with worm water, soap, and 
potash, acquire an unpleasant odour, and ore apt to 
Bhrink, in consequence of the rubbing, particuUirly 
if they bo immersed in eold water ; wherots, by 
using the fossil alkali, these ioconveoiencea are said 
to be completely avoided, and neither the quality of 
the goods will be impaired, nor the hands of the 
women be injured in the same manner as generally 
happens with the oommon ley. 

As frequent bathing or washing of the body greatly 
conduces to health, it has been recommended to 
dissolve, in the water so employed, a small portion 
of soda, or to wash with a towel wetted with a solu- 
tion of soap and soda, which opens the pores, and 
removes the unpleasant odour arising from profuse 
perspiration ; a sioiilar spplication will be pro- 
ducdve of equal advanCagcs to horses that are em. 
ployed for racing, post chaises, or other purposes 
where great exertions are required. 

If a weak solution of Bodn be poured into fool 
bottle or casks, in which wine has been kept a con- 
siderable time, it will completely dissolve the crust 
of tartar which adheres to the Inner surface. Root 
tops, saddles, or bridles, are efTcctuolly cleansed by 
a solution of soda, preserving, at the same time, 
the original color of the leather. This alkali may 
likewise be employed for sweetening kitchen uten- 
sils, and particularly for removing grease or adda 
from copper vessels; because these concretions, 
when suffered to remain, form a strong poison, la 
a umilar manner it is used for tin and iron vessels, 
to keep them from becoming rusty. Utensils of 
the dairy that acquire an unpleasant acid smell, 
during the summer, and particularly aiter a thunder- 
storm, though every attention be bestowed upoa 
them, such fetor may be completdy removed by a 
small portion of soda, which will render the milk 
vessels perfectly sweet; Awhile it neutralises and 
dispels the acid ferment imbibed by the wood, which 
would taint the milk. The crystals of soda are not 
less osefol in a medicinal point of view ; a solution 
of it forms an excdlent gargle for cleansing the 
throat, mouth, and gtims, both in a sound and in a 
deceased or ulcerated state; while it whitens the 
teeth, and dissolves all iocnstationB that may be 
formed on their surface without injuring the enamel . 
And, if a small quantity of this liquid be occasion. 
ally swallowed, after washing the fauces of the 
throat» it is said effectually to remove a fetid breath. 
Soda is, in many instances, preferable to magnesia, 
(or correcting acidity in the stomach ; nay, it is- 
even asserted, that it prevents the gout, gravel, 
stone, and similar disorders ; hutly, tf the alkali be 
mixed with cream of tartar, in the proportion of 
fourteen parts of the former to twelve oF the latter, 
it furniahes one of the mildest laxatives, oamelyp 
the ilucheUc salt. 



72 



MAGAZfNE OF SCIENCE. 



IFaUkerat 



Loaooa ... 
Ovm-iH . . . , 



Jperaget^tMfjtttmgeqfllu Quantity (ff 



Thtrmomeltr. 



an 

MIC 



NOTES ON TRB MONTH OP JUNE. 

— Bugloo— Borage^MoUda— Mallow^ HoasulV 
tongue, not forgening 



Btirvmrter. 



tt-VS 
MM 

B0«6 



Jbin. 



33S LaciL 
O-ACO 



Trb ^rigoar ftnd fmhncM of May is now more fully 
eouftriiied, and without jet yieldiug to the languid- 
iWMof th« sultry month* of Jtily &iid August ; the 
young of animdlfl sport in the glade, and luxuriate in 
Uw grusy snd Aower-enamelled fielda. VegetAtion 
no longer appears nipped with cold, and the gardener 
DO longer findi it neocsary to ahield his plants from 
dw aUgfat frosts vrfaicfa he had reason to apprehend 
in tbo bit month. May hna been called the Venus 
of the mBona — June tlie Apollo — 

•• Th« ratuly benuly vt the year. 
Like Ui« (inrd (jod of Il«l«-»liin!." 

AMIHATBD NATUBB. 

If there are lingering songsterv who bare not 
bdisre viiited ut, the first week of the month will 
bring them ; and thoae which pursue ttieir prey in 
the long evening cnn scarcely bo aaJd, before this 
time, to have completely thrown off their' toriiidity, 
and to rerel iu the blandnesa of the bright seaaon. 
Hie Sedge Sparrow and the Fly-catcher we may not 
before have seen. Tlie vnnous OwU and Bats ore 
now toore active and frequent. The smaller birds 
hare hatched thdr young, and are teaching tltem to 
provide for tliemi^clves ; tlic larger fowl are not 
generally so early, nor are the bird£ of snmmer poa- 
sage. It ia not till near the close of the month, 
that the Partridge, the Riil, the Pheaaant, the Lark, 
and the Gronae, have completed their neata and 
hatched their egga — ^having waited for the gross to 
grow and the earth to become somewhat dry, be* 
fore they ventured to by their egga. Nor are the 
Swallow tribe more early, althoagh their habitation 
b ao different. Towards the end of the month, the 
fingtng fairda gradually retire to the woods, and, ex- 
cept the Nightingale and a few others, leave olT their 
charming melody. 

The insect world b all alive ; Bees iwarm— Wasps 
and Hometa abound — and numerous ijieciesof But- 
terfly, Moths. Beetles, and Flies, make their ap. 
peacBooe. 

TBDBTABLE LIFE. 

The flowers of the wild and waste arc inftnttcty 
more absadont now than In any other month ; by 
the botanist the hut week of thu month and the 
first of the next are more to be regarded than, ])cr- 
hapa, any others throughout the year. To enumerate; 
what plttuts he may ordinarily find would occupy 
much space. It may suffice, perhaps, to draw his 
lUentkm particularly in the tnirly part of die month 
to tbe Sedge tribe, and to the Orchideona plants, and 
nther bter to the family of the Grasses, the Urn- 
belliferous plants, and the Rotes, and to collect the 
loaves of Ihoae Willows of which he may previously 
have obtained tho flowers. He will be aware that 
it u not till bte in June that he will find many of 
our alpine or northern plants ; the mountain regions 
are too cold to offer him most of their little beauties 
earlier than this. Tlic plants of the valley are, 
however, rich and varied — he will find the Goat's- 
bvard — the Pimp«iiel — Clover, in it6 various kinds, 
—Wild Thyme — the Pheasant's. eye — the Scabious 
—the Poppy — Larkspur — Corncockle — Greenwccd 



** Tba HoDtyncki« say. 
Waked by Ul« •«rU*r tirtath vl wiiy. 

and hundreds of other pUtiLs equally 
many of them more plcntihil thui thuae 
enumerated. Tlte Yellow Violet, and tho 
green Ladies' Mantle clothe the hilk of Dei 
The Fern or Brake fills the thickeU and 
commons. The meadows are yellow with 
tercup. The woods of Kent abound witli tlie 
tribe, and the hedgcf everywhere with the Ha 
the lloae and the Privet. 

The Water |JantB, the tribe of Labiatac, inclaAn{ 
the Mint, Thyme, ike. for the moat part bcion^ to 
a later seusou. Yet some of them towards thsetU 
of the month may be found in perfection, |iarilc»' 
lady the Y'ellow Iria, which bo much abounib k 
many of onr ditches, and on the river benka. 

CARDKNIXG OPKnATIONS. 

The tearan for lowing, for summer nee. is dm 
over, except, perhaps, a few bte annnab. Bat B | 
the early part of the month the gardener w 
avail himself of any showery wemier to 
various of his crope ^particulariy flowering 
and biennials. HU main attention, however, 
rected to preserve which lie baa before 
watering the smaller kinds, unmoving sucker* 
his fruit-bearing shrubs ; training and trim 
the summer shoots of hu espalier treest end 
ing and destroying insects. In the kitchen 
ment, hcwill still sow Beans, Peas, and 
a bte crop, also Carrota to be drawn youngs. 
will also sow Endive, Brocoli, Savoy, Cu 
for pickling, and other crops. Late m Che 
is the proper season to propogate nuuerxjoa 
ahruhn, trees, &c., by cutting*. Tlius. 
Camationa most be piptnl ; the rvuts of 
Thrift, Gentianella, \c. must be divided and 
out, and slijn taken from the Lavender, tfie 
mary, the Southernwood, and numenna of 
herbs. Those half hardy annnab wUdi 
raued by artificial best, may be removnd 
borders, as soon as tiie Mulberry conoes \attt 
which is ronaidercd hy thi* gardener as a sign 4 
oisual frosts and cold wincb having bft us fat 
season ; this, therefore, affords a crHrrien 
merely for him to remove his tender stnnnals to 
open grounds, but warrants him to bring hi» 
house planttt into the open garden, that their 
ties may add tu tliose of the genonl partecnk 
gardener will not foi^ct abo to take his 
roots from the ground, and to keep thcnt dry 
autumn, well knowing that be diert-hy m; 
increases the vigour of their growth in the 
season. He will be careful abo to take 
them all olTeetB, tliat the snp of the parent 
be too much absorbed by the offspring being 
tached to her. Ranuncalus and Anemony 
ahonld be taken up as soon as their leaves 
All these bolbs and tubers may be ki-pt woU as 
shelves, or buried m dry sand or sawdi 
roob, if large, not touching each other, 
anming of the fruit trees is now over, and 
dener is afaeady looking forward to Us «rUer 
of Strawberries, Raspberris*. Cherriec, 
Potatoes, which shotdd be in the market 
open ground during the third week of June. 



LoiiDOM :— rnnled >•> O KmaxcI", 6, While ilotM tAur. Mik ]£ud--^rublul)rd by W DaiiiAtN, 1 1, l*«Utiiv«Ui 



riH^llMi 



THE 



AGAZINE OF SCIENCE 



^nD Sc&ool of ^m. 




MAGAZINE OF SCIENCE. 



REFRACTING AND REFLECTING TELES- 
COPES. 

AttrAnomicni TeUwcopf. — Th«t this trie scope wm 
Enrentrd in the ihirteeoth century, and perfectly 
known to Roger Bacon, and tbit it wu used in 
En^Und by L^nard and Thomas Digge« before the 
time of J&nsen or Gtlileo, can soLrccIy admit of a 
doubt. R is rcpretented in fig. 1. It consists of 
two eonvcx lensfs A B, C D, the former of which is 
called the objnt glau, from its being next the eye 
E. The object glass is a lens with a long focal 
diiCAnre; and the eyeglass is one of a abort focal 
distance. An inverted image O of any dlttaot ob- 
ject MN is formed in the fwms of ibo object glass 
AB *, and this image is magnified by the eye glass 
CD, in whose anterior fooos it is placed. By trmc- 
ing the mya tbroogh the two lenses, it will be seen 
tlwt they enter the eye at E parallel. If the object 
M N ia near the observer, the image O will be 
ibund at a grwlter disUnce from A B ; and the eye 
glass CD must be drawn out from AB to obtain 
distinct vision of the image O. Hence it is usual 
to fix the objert glass A B at the end of a tnbe 
longer than its focal distoocc, and to place the eye 
glass CD in a small tube, called the eye tube, which 
will slide out of, and into the larger tube, for the 
purpose of adjusting it to objects at different dis- 
liuiees. The mngnifying power of this telescope ia 
e<)ual to the focal length of the object glass divided 
by the focal length of the eye glass. 

Telescopes of this construction were made by 
rampani Dirini, and Huygcns. of the enormona 
lengtli of 1*20 and 13G feot ; and it was with instru- 
menis 12 *ind 2i feet long that Huygens discovered 
the ring and the fourth satellite of Saturn. In order to 
use object glasses of such great focal lengths with- 
out the incpmbrance of tubes, Huygcns placed the 
object glass in a short tnbe at the top of a very long 
pole, so that the tube could be turned io every 
possible dirrL-tion upon a ball and socket by means 
of a string, and brought into the same line with 
another short tube containing the eye glaas, which 
he held in his hand. 

A« these telescopes were liable to all the iropcr- 
ftctions ariffing from the aberration of refrangibility 
and that of spherical figure, they could not show 
objects distinctly when the aperture of the object 
glass was great ; and, on this account, their mag- 
nifying power was limited. Huygcns found that 
the following were the proper proportions : — 



rocal Irogth 


Arwrttkre of 


Foral Icngtb 




«r the objsct 


the olivet 


of (ti« eya 


Magnlfytag 


,!!•.•». 


K «!*» 


tiJ: 


l>offvr. 


1 ft. 


Ohib in. 


0*605 


20 


3 


0-94 


104 


33i 


6 


1-21 


1-33 


44 


10 


l'7l 


l-gfl 


62 


90 


3B< 


420 


140 


MO 


5-40 


5-95 


197 


120 


5-30 


632 


216 



In the artronomical telescope, the object, O, ia 
llwnys seen inverted. 

Terreitrial Tf>i*$cope.—To accommodate this tele- 
•eope to land objects which rrqnire to be seen erect. 
the instrument is eoostructed as in fig. 2, which is 
the same aa the preceding one, with the addition of 
twobnsea EP. GH, which have the same focal 
length ns C D, and arc placed at distances equal to 
double their common focal length. If the focal 
lengths sre not «iual. the distance of any two of 
them must be equal to the sum of their focal lengths 



In this telcacope tlie pn^ren of the riyt is exacllf 
the same as in the aatronomioil one, aa ftv aa L, 
where the two pencils of parallel raya C L, L 
cross in their anterior focus L of lite aecood cyr 
glass E P. These rays, falling on E F, form, in ttt 
principal focus, an erect image 0» which is sea 
erect by the third eye glass G H. as the rayt. dJTa|- 
ing from O in the focus of G II, enter the eya fei 
parallel peociU at E. The magnifying power «f 
this telescope is the same oa that of tha foriMr 
when the eye glasses are equal. 

Galilean TV/mco;??.— This telescope, which is Iha 
one used by Galileo, differs iu notlung from the a^ 
tronomical telescope, excepting in a concave <yi 
glasa C D, fig. 3, being substituted for the coma 
one. The concave lens C D is placed between the 
Image O and the object glass, so that the image if 
in the principal focus of the lens. The penefl ot 
rays ABO, A fi P fall upon C D, converging to 
its principal focus, and will, therefore, be rrfractal' 
into parallel lines, which will eater the eye al & 
and give distinct vision of the object. The 
fying power of this telewope is found by the 
mle as that for the astronomical telescope ; it 
a smaller and leas agreeable field of view th< 
astronomical telescope, but it has the advaui 
showing the object erect, and of giving more 
vision of it. 

Grepon'ttw HrfUciim^ TkUscope, — Father 
ehins seema to have been the first peraoo who 
niied objecta by means of a lens and 
•pecnlum ; but there is no evidence that he 
itructed a rcHrcting telescope with a amaU specnlia. 

James Gregory was the first who described 
construction of ihit instrument, but be doe 
seem to have executed one ; and the honor of 
this with bis own hand* was reserved for Sir 
Newton. 

The Gregorian teleseope is shown in fig. 4, 
A B ia a concave metnllic speculum with a ! 
its centre. For very remote objecta the 
the specnlnm should be a parmbola. For 
ones it should be an ellipse, in whose farthv fccV 
is the object, and in whose nearer focos it At 
image; and, in both these eaees. the wptati 
would be free ftrom spherical aberration. Bnt* 
these cnrrea cannot be communicated with 
to specula, opticians are ntisfied with gi 
them a correct spherical figure. In front of< 
lai^e ipeeulum ia placed a small concave one 
whioh can be moved nearer to and farther froB tke 
lai^e apecnlnm by means of tlie screw W at tto 
side of the tube. This speculum should havt It 
curvature an ellipse, lliough it (a generally ■ 
spherical. An eye-pie^:e consisting of two 
lenses. E, P, placed at a difUnce equal to hall 
sum of their focal lengths, n scrvwi^ into the 
immediately behind the great speculum AB, 
perroaneotly fiaed in that position. If rays 
N B, issuing nearly parallel frum the estremt 
a dtitsnt object, fall upon the specolnm AB* 
will form an inverted image of it at O. 

If this image O is farther from the small 
lum C D than Its principal focas, an inrerted 
of it, P, or an erect image of the real 
since O is itself an inverted one, will be 
somewhere between E and F. the raya 
the opening in the speculum. This image 
have been viewed and magnified by a conraa 
glass at P, bm it ia preferable to receive the 
verging rays «pon a lens E, called the field 
which hiutcus their conTcrgeneOr aod fbnnj 



MAGAZINE OF SCIENCE. 



of to the (bcus of the leni F, by which 
thef are micjmfied ; or. wliac U the same tbtn;^, the 
pcBCilc tlivergitif; from (.he imiiii;*' P arc refracted by 
r, r» at it» enter ihe rye pnmllel, and ^ive dintinct 
of the imaiiT'. If the object M N ii brought 
Cbe «|>eeulain A B, the imof^e of it, O, wilt 
front A B and approach to C D ; and, ood- 
MMHitty^ Cbe oiher image P in the conjugate foca« 
ViC D will recede from iti place, and ceaie to be 
MHO diatinftly. In order to reatore Jc to iU place, 
we have only to turn the screw W, «o as to remove 
D D fiirther from A B, and, conaequentty, farther 
rmn C), which will cause the imn^e P to ap|»ear 
If 4iaCiDct as before. The niacnifytcg power 
tdeaoope may be funud by the followiog 




the focal distance of the great speculum 
of the small mirror from the image 
MrtChe ejt, •« formed to the anterior focuii of the 
lOVVTz eye ghms, aod multiply also Che local du- 
jance of Che small speculum by Che focal disUiure of 
he eye glaaa. The quotient aiuing from diviiUng 
h* fenoer product by the latter, will be the nug- 
|Mns power. 
■Bb nk auppoiei the eyc-picce to couaist of a 

pRt foUowiug Ubk, showing the focal lengths, 
fncrers, and prioe« of some of SluHt's 
•III exhibit the great superiority of le- 
to refrtcUDg ooea : — 

powcn. 



tibs 



Aprrfun* 
tfi inrlw*. 



I 



30 

-4-6 

6-3 

7-6 

12-2 

16-0 



35 to 

90 
100 
120 
200 



lOO 
900 
400 

500 

8D0 



300 1200 



Prtusbi 

u 

3r. 

7r> 

100 
3O0 
800 



CatMifraiiuOH TeitKope, -~ThB Cass^miuian 
■ksonpr, proposed by M. Ciissegniin, a French- 
|WB< didfcrs iTom the Gregoruin only in having its 
m»lk apeculum CD, &g. 5. convex insteul ofcoa- 
ttvcL Ttie spectiliim is, therefore, plaoed before 
h'* tmi(^ Pof the objeec M N, and ao erect image 
' ill be formrd at O between E aod F ex- 
i> the Gregorian instrument. The advsD- 
a^e 4t[ UL> form u, tiiMt the telescope is shorter 
Ian ih# Gregorian, by more Chan twice the focal 
■■gth of the louill speculum ; and it is generally 
(fasitted that it gives more light, and a dijilinoter 
!, in conivqaence of the convex specujom cor* 
tibe aberration of tbe ooDcave one. 

7>/#«co/*e.— TbeNewtouiao telescope, 
Bay be regarded aa an improvement upon 
IvOnsoiisa one, ,ii represented ia 6g. G, where 
iB b a ooncare speculum, and O the inverted 
Mfe which it forms of the object from which the 
kytMN proceed. As it is impossible to lotro- 
htpBthe «y« into the Cube to magnify thia image 
dikolU obsCmoting the light which comes from tbe 
IIiIhU a acoall |»Lsne speculum C D, inclined ii'^ to 
Mob of tho Lai^e speculum, and of an oval form, 
hMM boiag lo one anotlier as 7 to 5, pUced be- 
WB ttw apeculum snd tbe image O, in ord^r to 
|dHt It to a aide at P. so that we can magnify it 
lllh OA fff* glass E, wtiicU causes the rays to enter 
t#4]ia pttnlleJ. The small mirror i* lixed upon a 
(■der arm, connected with a slide, by lihich the 
ibror may be made to approach to, or recede from 
Itlwg* specnlom A B, according as the image O 
to, or recedes from it. Thia adjust. 




ment miglit also be elfectcd by moving the eye Imts 
E to or from the small spccitluui. The magnify- 
ing power of this tdejcoi>e U rt|ual to the focal 
Icagth of the great ipecuLum divided by thitt of th« 
eye glass. 

Aa about half of the light Is lost in metallic re- 
flexions, Sir Isaac Newton proposed to subsHtttle, 
in place of the metallu: speculnm, a rectangnhir 
prism, in which the light suffers total reHexion. — 
For thiti purpose, however, the glass is required Co be 
perfectly colorless and free from Tcins, and hence 
moh a prian boa almost never been used. Sir Isaac 
also proposed to make the two faces of tbe prism 
convex, and hjr placing it between the image O and 
the object, be not only erected the imsge, bat wu 
enabled to vary the niagnilying power of the teles- 
cope. The ohgiiul iclcscope, constructed by Sir 
l«aai:'s own bauds, is preserved tu the Ubrsry of the 
Royal Society. 

The following t«ble ahows tbe dimensiona of the 
Newtonian telrjH'opes, which has been computed by 
taking a line telcscojie made by Hawksbee, aa a 
standard : — 



FiK-al len|[th 
of BTvst 
■IMrruluoL 

1 ft. 

3 

4 

6 
12 

24 



Aperture itf 
ipcculuin. 

2-23 in. 
3-79 
5'U 
6 56 
8*64 

uao 

24*41 



Tocal length 
of ey« gt£n. 

0129 in. 

152 

0168 

0181 

0-200 

0-2.18 

0-283 



tfSgitirytng 
|w«»r. 

93 

214 
2fiA 
360 
601 

10171 



On account of the great loss of light in metAlltc 
reflexions, which, according to the accurate expert- 
ments of Mr. R. Potter, amounts to 45 rays in 
every 100, at an incidence of 45^. and the imper- 
fections of reflexion, which, even with perfect iiur- 
faces, makes tbe raya stray jfSre or rtx times more 
than the same imperfecHoik^ in refracting surfaces. 
Dr. Brewster proposed to construct tbe Newtonian 
telescope, as shown in fig. 7. O ia the imsgc of 
the object, C D an achromatic or double pri«ai, 
which refracts tbe image O into au oblique position, 
so that it can be 'jk'iewed by tbe eye at E through a 
magnifying lens. Nothing more is required by the 
prism than to turn tbe rays as much aside as will 
enable the observer to see the imnge without ob- 
structing tbe rays from the object "M N\ As the 
prisms of crown and flint gl'iss which compote tltr 
achromatic prism may be crmcnted by a substanrtT 
of intermediate refractive power, no mure light will 
be lost than what is rellected at the two surfaces. 

In place of setting the small speculum, C D, of 
tbe Newtonian telescope. Fig. 0, at 45", to the ind- 
denC rays. Dr. Brewster proposed to place it much 
more obliquely, so as to reflect the image out of 
Uie way of the observer, *nd no fartiier- Thia 
would of course require a plane speculum, C D, of 
much greater length ; but tbe greater obliquity of 
the reflection would more than compensate for this 
inconvenience. It might be adviAable, indeed, to 
use a small speculnm of dark glass, of a high re- 
fractive power, which at great ioddeocea reflects 
as much light as metals, and which is capable of 
being brought to a much finer surface. The fine 
surfnees of some crystals, such as ntbyatlver, oxyde 
of tin. or diamond, migbt be used. 

A Newtonian reflector, vjMoh/ an eyt gla»», may 
be made by using a reflecting gloss prism, with on* 
or both of its surfaces concave, when the prism ia 



MAGAZINE OF SCIENCE. 



place*] b«t*reeD tbe itnotge O atij th^grmtspccuhim, 
^M> Bk to reflect the rayi pKraltel to the ryr. The 
ijCnifyiiiK pwwer will he rijiuil to the Uw.n\ lenG;th 
the grent ftyirculum, diTidcd by the rndiua of the 
concftre iurfar« of the prism, if both the furfiices 
Are concave, anil of equal cooeavlty, or by twice 
the radiBS, if only one surface is concave. 

SPOTS. MOUNTAINS, 8lc., IN THE MOON. 

I Hfiunrit from futgf 66. ami cuncludni. ) 
It hitt Ion;; been a disputed point amonf; astrono- 
mers, whether or not the moon is surrounded by an 
nlmo9phere. Tlioie who deny that abe is, »ay thai 
the moon always appears with the some brightness 
when oor atmosphere is cleor, whieh could not be 
the csae if >he were sorrounded by an atmosphere 
like oars, so rarinble in density, and so often ob< 
wmred by clouds and vapours. 

A second ar^ment is, that when the moon ap- 
proaches a star, before she panACS between it and the 
earth, the star neither alters its cdor nor its situa- 
tion, whirh would be the cajie if the moon had an 
atmosphere, on account of the refraction which would 
both alter the color of the ktar^ and also make it 
appear to change its place. 

A third argument is, that as there are no seas or 
Lakes in the moon, there is, therefore, no atmoaphere, 
as there is no water to be raised up into rapoiir. 
Bat those who contend that the moon is surrounded 
by an atmosphere, deny that she always appears of 
the same brightness, even when our atmosphere ap- 
pears equally clear. Instances of the contrmpy are 
mentioned by Hevelius and sonic other sstronomers, 
but it is unneccsBnrr to take any further notice of 
Ihem here. In the case of total eclipses of the moon, 
it ia well knovm that ahe exhibits very ditferent sp- 
pearances, which it ia supposed are owing to cbaugea 
in the stattt of her atmosphere. It ia remarked hy 
Dr. Long, that Newton has shown that the weight 
of any body on the moon is but a third pnrt of the 
weight of what the same body would be on the 
earth, from which he concludes that the atmoaphere 
-of the moon is only one-third part as dense as that 
of the earth, and therrfore it ia impossible to pro- 
dure any aensibic refraction on tlie liu;ht of a fixtil 
star which may pais through it. Other astronomers 
assert that they have observed such m refraction ; 
and that Jupiter, Saturn, and the fixed stare, had 
their cirrntar figures changed into an elliplical 
one on these occasions. But allhaiigh the moon 
be surrounded by an atmosphere of the fcame nature 
as that which surrounds the earth, and to extend 
- as far from her Rurface, yet no atirli effect as a 
gradual diminution of the light of n fixed star rould 
be occasioned by it, at least none that could be 
obMrved by a spectator on the earth. For at the 
he%ht of 4^1 miles our atmosphere is so rnrc, thAt 
it i> incapable of refracting the mys of light ; now 
this height ia only the IHtli part of the earth^s dia- 
meter, but ai douda are never observed higher 
than 4 miles, H therefore followfi thnt the obscnrr 
part of our atmo^here is about the 2000th part cif 
the earth's diameter, and if the moon's apparent 
diameter be divided by this number, it will gire the 
angle under which the obscure part of her atnioa. 
phere will be seen from the CHrth, which w not 
c|Uitc one second, a space passed orer by the moon 
ill less than two seconds of time. It can. there- 
fore, scarcely be expected that any obscurMtion of a 
alar could be obserrcd in so short a time, allhoogb 
it do tilie plar<. 



\» to the orgTuiicnt ogtrlnst a lunnr iitmosplkn, 
drawn from the conclusion Ihnt ih--" 
ttr lakes in ihe mnuu, it proves nc: 
is not pfMitively known whether th- ■ 
in the moon or not. 

The i|Ufrtinn of n lunar •hn«»plM»re wrma t»tfc' 
at lost settled by the mn > acr* 

Tailoni of the relebr -oa 

and Pitni, who have pi-.v'M '<- '"utiTi^inKij «• tla 
nature of the subject seems to allow, that the mam 
has really an atmosphere, though much Lb«s 
than ours, and scarcely exceediiog in lieigbt 
of the lunar mountains. 

It ia remarked by Dr. Brewiter, " Tb« 
scenery of tiie moon bejwv a stronger cetci 
to the lowering sublimity and terrific 
the Alpine regicms, than to the tamer inc 
less elevated connlries. Hugh masses of 
at once from the plains, and raiae their pnltsAi 
summita to an immrnse height in the air. *«hiV 
projecting crags spring from their rogi-' 
and, threatening the valleys below, stMn '-■ 
fiance to the laws of gravitation. Arnnmi the 
of these frightful eminences are strewed nui 
loose and unconnected fragments, «hi<;h time 
to bare detached from their parent maet. and' 
we examine the rents ond ravinca which at 
the overhanging cltfis, we exf^ect every 
that they are to be torn from tbrir base, aM 
the procesH of destructive separation which 
only contemplated in its eficcta is about ta 
hibited before us in tremendous real : ' 
mountains called the Appennines, whid ' 
portion of the moon's disc from north-east i< 
west, Hm; with a pmupitoua and craggy front J 
the level of the Mare Imbmm. In some 
their perpendicular elevation la above foar 
and though they often descend tn a much loi 
th(^ present an inaccr«sible barrier to the 
east, while on tbe^ soatb-we»t they sink in 
derlivity to Ihe plains." 

The caverns whirh are observed on the 
surface are no less remarkable than the roi 
mountains, some of them being three or fen 
deep, and forty in diameter. A high angl 
of rocktt, marked with lofty peaks and tittle 
generally encircles them, on insnUted m* 
frequently rises in their centre, anrl 
contain smaller cavities of the i>::' 
themselve^t. Thrae hollows are mii->> i>»»>r 
the Ponth-wcBt part of the moon, and it 
this cause that this part af the moon ia 
liant than any other part of her disc. Ths 
tainouB rid;;es which encircle the mrT*tr^, 
the greatest quantity of light ; and. '■ 
in every possible direction, they h\ 
time of full moon, like a nQuber ut rmiiu 
diations issuing from the BmiUlest 
Tycho. 

It is difficult to explain, with an^ 
hability, the formatinn nf these inini 
it is highly probable that the cartii wi>uld 
the same figure, if nil the seas and lakes sh 
moved : and that the lunnr cavitie« are eiilu 
tended fur the reception i)f water, or that 
the beds of lakes and seas which have fori 
isted iu the moon, 

The cirruiwtauee of there being no vratvr' 
moon afforda tt strong proof of the tmlh 
theory. 



spot. 



MAGAZINE OF SCIENCE. 



77 



rock, the Mscntiil ingrcdicntji of 
'■nr Mcbpnr, qtivrtx, Hnil w'w.a, htrifiK tlif^ 
Htcmf of gnciiM. frnm whtrh ^anite dilTeni 
Sn the ttrrangrrarDt of thr three companmt 
tlhetr bein^ mingled wttlMtut order or rr^u> 
irodurei b (p^nuUr •cructure, while that of 
imllT slaty. Thi;t ate of granite fur 
■od rronomiral purposec. is p<<rhn|M 
)retDiply diaplajed ttian at I'cterBburgh. 
otily ike imperial and other paUcea, but 
Unary dweiltni^.houanf, have their lowrr 
Tith alalM of ^n^nite. The left bank of 
It Neva, from the Foundry to the Gulf uf 
lA, and both banks of tbe Fontanka and of 
te canal, are lined by high walls con- 
anch slabs of granitf ; a» are ninny 
the Neva, balustmdeti. He. The pillars. 
&c. ID the palocr of Cronnladt, 
an of thr 6nrflt kinda of granite. Thotwi 
for ornameiitol architecture are cut and 
lidariet ; but tbo4e mtenilml for leaa 
i. anch BA coinmoo alaba, ittepa, 
)Ofh<t, SiC. are worked by peaaanta, 
larly bythftfc of Olonesk. The government 
bowc\er, Moscow not excepted, arc too dis< 
the chitrf frranice mounlains. to be enabled 
frFcjoent use of that rock for the above 
Granite haa been more particularly ap- 
ther witli itenite, for the purpoaea of ar- 
and statuary, by the anciratg, eapertally 
'B^ptiana ; and many very interesting mono- 
ir »k)tl and patience arc still exlftttni; in 
of anliqiiiciefl. Mr. Brandc haa di. 
Ivrcnt panitea used in the arts after 
linaat colore ; thr following are the 
in which, however, the black- 
kind ia not included, one of ita in^re- 
ig hornblende, whidi aaaigiia it a place 
ite*. 
1^-Cketti, in the department of the 
ot white quartz and black mica, 
ratals of roae-colored feldspar. The 
tlic KgliM d'Enee (ancirnt tennptc of 
Bt Lyons, are of this kind of granite, 
IBT a1«n hem worked by tbe Romana. 

•fTham, conaiits of grey (juartr. 
\n ^liitc feldspar cryat&la, which are 

tr^ irutn two to three inches long. Tbe 
of (hri« granite are on the roait from Lyona 
loe. nn the rij^ht bank of the Rhone. It is 
11 a<da;iti^il for the eonsCniction of large mmia- 
The t^nmiCe of 6t. Peray, not lar from 
Ik exactly like ihta, except that ita fcldapar 
are M n ni**" color. 

Grr 'zzi, a. atnall island near Bo. 

«w' I, in the straita which sepn- 

isUiKi <i"iii .>>trdinta, ie composfd chicHy 
liar eryitala of feldspar, miierl with a 
«iiea, besides fihich it contains nisu ft>ld- 
ila« of a milk-white color. In the quarry 
B br?T unfinished colnmn is U) be aecn. 
-hed hy the Roman workmen. 
'. — Its Brain is pretty uoi- 
ii*;r«(.m( umeaapproachea to light violet. 
ir r<ilumna of thi« variety to ho *<-en in 
fapttleon ; ihcy were taken oat of the 
contained tite tomS of Charlemagne, 
iprHe. Tbe rrry granites ore mnch 
, ihe green or greenish, of which 
re to be mentioned. 



Antique Gretn Omnih, — Ita predominnnt ingre- 
dient in white quarts, with here and there aomr light 
green feldspar. Itiere is a column of it in the Villa 
Pamfili, near Rome. 

i^ae Grained Autiqut Gmnite. — (Bnaftlt«Terd 
oriental.) Tlie component parta of this aort are 90 
minute and intioiatcly hlendrd, that they can 
acarcely be diatinguiahed by the naked eye. lu 
color Bppronchea to deep ohve. It is very hard and 
takes n tinr polish. The Egyptians have much em< 
ployed it for the construction of monuments; and 
aeveral statues of it mny be si^en in the Capital and 
the Villa Albani. There is another variety with 
white spots, known nt Rome under the name of 
Iltualto OriMttnle pidoehtotQ .- but it is very rare, 
for there are hut two coliimoa of it in cxiatrnce, 
namely, in the rhnreh uf 8t. Pudentiitia at Rome. 
Some vurietin5 bearing that name ore selonite. 

Granite uf St. Chriatophe : composed of violet 
quartz, wliile fcldripar, and green mloa. This n»g- 
niticent rock is found at Oiaaos, in the department 
of the Iserc. 

Cortican Orticuhr Granite. — This beaulifol rock 
(which probably belongs to the sienite formation) 
was discovered by M. Barral, in the island from 
which it derives its name. Its coTn)iOHition m very 
extraordinary ; it has a baeis of ordinary grey gra- 
nite, which, however, in most (Mirts exhibits a con- 
sidirablc portion of hornblende. But what more 
particularly charactenxes it, is a number of baUa. of 
from one to two inches in <bnmeter, each composed 
of sevcjul nmcetttric and perfectly parallel tayera, the 
outermost of which, generally white, opaque, and 
two or three lines thick, is composed of quartz and 
feldspar, blendtMl in variotia proportions, and exhi- 
biting a radiated appearance, rather converginf 
towards the centre of the ball. The second layer, 
which is of a greenish black color, and about one line 
thick, is composed of fine laminar hornbleude ; and 
thia ia anccvedcd by a white and usually translucid 
quartz layer, of about four or five lines in thickness, 
ioduaive of two or three very thin layera of horn- 
blende, that are commonly seen within Uie ^ubsta&oe 
of this third principal Inyer. Kach of these layers 
is generally of equal thlckncM in the whole of its 
circumferenoe. Tht»e three pans may be considered 
as the coating: the interior of each ball is less de- 
fined than the surrounding layers, and consists of a 
blackish and a whitish substance, the former sur- 
rounded by, and posatug into the Utter, the centre 
of which is usoaily a dark grey spot. The quarry 
of this rock is unknown, a singl\? block only having 
been found in the gulf of Valirieo, in Conina : ita 
weight was about 80 lb. ; bat it was soon broke 
into small fragments, which are now distributed 
among collectors. There is a beautiful vn5e of it, 
one foot six inches high, in the cabinet of M. Dedrce. 
Tlie grioiitr uf Corbira is figured by M. Paujas de 
St. Fond, iu his Emai de Geologir, and in Mr. 
Sowerby's Erotic Mineralogy. Among tho red 
granites, we have what is called rtd oriental yranitet 
which usually coDUioe hornblende, often in largd 
separate patches. 

Rfd Granite of Ingria.—^* This granite, ** Myi 
M. Patrin, "is distingaishcd from otbera in this, 
that the fehUiiur, instead of betug in grains, or jwt- 
rallelopiprd crystals, aa in most other grmatea, 
consLantJy appears in the shape of round or oval 
pieces, of from half tin inch to two inches in diam- 
eter. This granite takes a very fine [>o)i»h. and in 
this state exhibits the feldspar in the shape uf white, 
roandr or oval fchaioyaaJj spots, in a reddish 



MAGAZINE OF SCIENCE. 



gToond. The rock, which ierre* m a pedestal of 
the equestmn it&coe uf PeCer the Great, at St. 
Petersburgfa, u of this punite i the block was qH- 
giiiaUjr 32 feet long, 21 feet thick, and 17 feet 
wide i bat, in order to give to ita preacnt sha}>c, 
imitative of a picttirei<iDe uatnral rock, it has been 
mach dintinished in lixe. Thii blotrk vas diien- 
giged from a swamp, about forty veniU from Petera- 
burgb : ilt weight wu calcnlated to be above three 
roillioni of ponndi." We baTo aeen icversl frn^- 
manta that were detached from the yery block form- 
ing the pedeatfll of the statue ; but in none of tliem 
M we obaerve the form ascribed hj Patrin to the 
feldspar. The public summer {irDiorciade-gardea at 
Petersbargh is decorated with a superb colonnade 
of this granite : the columns, which are sixty in 
aamber, arc of the Tuscan order ; their shafU, 
made of one piece, are about twenty feet hif^h, and 
three feet ia dismeter. The island called Kotlin- 
Ostrow, on which is the fortrc«s of Cronfttadt, it 
covered with blocks of this granite, the feldspar of 
which is sometimes uf the kind called Labradorstone. 

Hed Granite of tht VoMgeu MouniamM. — This 
granite ia composed of large laminee of ro«e-cotored 
feldspar, grer grsinit of quartz, nnd small acaira of 
mica. It has so strong a reseuiblaitce to the Egyp> 
tlan red granite, tliat it in difficult to distingoiih 
them. Jta quarriea are on the heii;hta of Moataajen, 
near the Papcan mountains, in the Vosgee. 

VioM (rrtxmie of Elba.— The fcldepar of this 
variety it in large violet (-4'yBtals. TIte pedestal of 
the equestrian statue, in the Piazza della Santisslma 
Aiiiiuttzidta at Florende, is made of it, as alto the 
9itde4 ia the chapel of $t. Laurence in the same town. 

Koge-eotorrd Grtmiie of Sarcno, — This beautiful 
gnuiite consists of fl<rsh>colored feldspor, white 
qDartx, and tome grains of black mica. Consider- 
able quarries of it are found on the borders of the 
Lago Msggiore, which are worked without inter, 
misaion. for aujtplying Milan, ond the whole of the 
iMUghbouriug country, with this granite. It takes a 
tery fine (Kiligli : here and there it rxhibils ribands 
or zoneH, of a grey trolor, which are composed of the 
same ingredients as the rest of the moas, but reduced 
into very minute particlea. Many columot, por< 
tioos, Jkc. are seen of it at Milan. The name of 
ffraphic granite is given to those kinds in which the 
feldspar forms large concretions, intermixed with 
grey quartz crystala, esiiibiling. when cut trans- 
versely, angular, mostly shaped like a 7 ; while 
others are lest regular.and bearadistant resemblaDce 
to rode alphabeticsl writing. They are not considered 
to be genuine granite by some muicrslO|tisti. 

Orcp/iic Granite of P<irt$oy. — ^The feldspar is of 
various tints of psle flesh-red ; the quurti dark, but 
trADiparent, with now ind then some small particles 
of mica. This rook is miiiutdy described by Dr. 
illutton. 

GrapAic Granite of Siberia. — Ita feldspar is of a 
^eUowtih white, or reddtih color ; the quartz, exhi- 
biting figure! sioiilar to those of the quartz in the 
Mvacding sort, is of the variaty called wmokf topaz. 
Mica occurs in it in aniall ncitt, and in acicutar 
crystals. 

Graphic Granite ff Autvn. — Of a pale rose color; 
quartz rryst«ls grey, very ntiinerous ; found in the 
neighbourhood of Autun, dt-piirtment of SJsdne and 
Loire, particularly at Marmagnc. This, in Mr. 
Brand'a opinion, is the most beautiful of all granites. 
Another vsriety of this stone is found at the same 
place : iU frldspar is white ; the quartj grey, in 
•ftiall orystils : it is suscrj>tible of a very fine polish. 



Graphic Granite ^ Cbm'ea.— Lik 
color ; bat generally paler than that ol 
which it is ako distinguisluibte by ita 
being larger, and at greater distanced 
It contains some tliinty disseminaud b 
mica, and lakea a 6ne polish. 

The above givea no •ccoont wImi 
granites which o«r owq islMuto prodal 
the Bore remarkable, as we can bn 
the flneat gmltc in the world, both ol 
the grey species. The fine red % 
from the qtiarriea of Uevonahire ia 
passed in color, clearness, and capabOl 
iiigli fiulish by any other in the worU 
two splendid riilumns of it, each ro 
block, in the King's Library, at the Brl 
which cost i^lOOO a piece. They we 
v&lry to sitnilar columni at Petersbar 
granite pf Ingria, as befiire alluded \ 
these columns arc two equally magni0 
of the grey granite of Aberdeen 
block. The value of thii species to 
be too highly appreciated ; it ia 
which our bridgei and greut boil 
and which broken into fragments of 
nacd to pave the public thorougbfara 
granite, some of which is greyi other J 
is also moch eateened. 



SOLUBLE GLASS 
A suiPi.a silicate of potaasa or soda, 
perfect sulnbtlity in boiling water I 
general properties of common gUsft. 
aute. it may be applied to cloUi or 
pnrpoee of reodcriiig tbetn incomboatih 
by the evaporation of tlic wster in whj 
solved, a hiyer of a subctooee capd 
when heated, is deposited on these bod 
tects them from the contact of air 
combustion. The ibllowing aooooa 
fncture and uses is derived from ■ 
Professor Rcnwick. of the Traxtf dtCk 
oirx j4r/s, per M. Awsuu. 

Preparation. — Soluble glaaa may b4 
dissolving pure silica, obtained by pnd 
boiling solution of caustic potaasa ; bol 
being both inconvenient and coatlf , ci 
tlaed upon a large ooele. When land 
of potaaaa are heated together, the OH 
never wholly driven off, eicept wheB 
excess ; but the whole of the carbooi 
expelled by adding powdered <A«roM 
ture, in lurh proportion that the 
that part of the carbonate whlnh is 
by the carbon, the carbonic oxide 
potaaaa thus freed, either sabUmos, or^ 
the ghua already formed. 

Tbe sand freed from lime and eload 
bonate of potasea (pearlaab) are 
portion of 2 of the latter to 3 of the ft 
10 parts of pearlaah and 15 of s&nd, 4 
coal must not be taken ; ou the oeatiBl 
of potash employed be not stt6&caeoU]r ] 
proportion of charcoal may be advi: 
ployed. Tliis lubatanoe aooderatea 
tbe gloss, find separates from it all thct 
of which there would otherwise renute^ 
tity that would have an injuriooa 
respects, the same precanttons that era 
the manufacture of common ^lasj ve 14 
The materials muat be hr»t wd'i nrt&ed 
and findily melted in a glaaa / lOt, auitll 



A 




MAGAZINE OF SCIENCE. 



M ud bomogtfDcoiu. The melml matter 
t of the pot witb sn iron UiMa, and the 
filed with fn»h frit. Thirty poniMls of 
\ of mod. iDfl I21ba. of poirdered cbar- 
la^eo for a. charge ; with thia quantity 
}mX. be coatinoed far 6ve or lix houra. 
tbiu obCtined U uaoally full of air 
%m ■• hard as commoa glasa of a blaclc- 
v*« and at othera ia jelJowiah or rvddiah : 
■<:atioDa that the quaotity of charcoal 
luffielent. If it be ezpoaed for tome 
Kir, it uiuleq;oea alight changet. which 
> improTe than injure its qualitiea. It 
E^ mouture from the air, which atowly 
^2UM, without changing ita aggregation 
a-zioe ; it merely oncka ; and a alight 
a Ppear* at its aur£u:e. If it be expoaed 
&C have undergoDfl thii change, it iwella 
Ibe ftcape of the aqucoua matter it 
In order to prepare it for solntioa 
it muat be reduced to powder by 
were Dot done, it wonld diiaoUe too 
part of gU»f reqairea from 4 to 5 of 
olution. The water ia firat beated to 
niast be oontinuod three or four hoa rs , 
a l^ass ia diiaolved t the Uqaor will then 
d. the proper degree of concentration. 
tion be citecked before tfata atate ia 
'1>oiitc Acid will be absorbed by the 
Is the air, which will produce an injuri- 
for the same reason, too great a quan- 
ts BRiat not be eaaployed, for during the 
n it will re-Adily combine with the 
\ tiuie a precipitaUon of the silica. 
Uqnor becomes too thick, before the 
|ba« is dissolved, boiling water must be 
ricn the solution h&a acquired the cod- 
p, and a density of 1.24 to 1.26, it 
tratedf and fit for use. It is 
t, in order that the insoluble 
ostted ; wbilc it is cooling, a pel- 
upon the surface, which after a time di«- 
itaelf ur may be rv-dissolved by depres- 
Iw liquor. Tbis pellicle begins to appear 
BbBUllion* and its concentration. When 
^aaa ia of a proper composition it contains 
Aaline imparities, and no snlphuret of 
it nay be created in the way we have 
bot if it contain any notable proportion 
they must be separUed before 
1 1 this separation may be effected in 
\ Bttaner :— The powdered glaas is ex- 
action of the air for three or four weeks, 
tb time in uoiU weather, it must be 
The glaaa, as we hare atated, attrarta 
the air. and the foreign substances 
or eOQoreaoe. It then becomes easy 
tJbvm from the glass. It is sprinkled 
{ud frequently stirred. At the end of 
I the liijuur is remoTed^ it will then con- 
Lhe saline impurities, and a little 
potaasa ; the powder Is again to 
h water, and the solution leaves 
To preserve it in the liquid 
eve is necessary, as even after a 
landerfoes no perceptible change, 
properly prepared. The 
t« allow loo free an access of air 
may be obtained by using a 
inatead of one of potassa. In this 
of the soda of the shops is required 
This gliM hoa ihe aame pro^r- 




lies as the other, but is more valuable in its uses. 
The soluliou of these two kinds of glass may be 
mixed in any proportion whatever, and this mixture 
li more serviceable in aoae caws, than either of 
them separately. 

Propertiet Soluble glasa forma A viscid aolatiaa. 

which when coDcentrated becomei turpld and opa- 
lescent : it has an alkaline taste and redaction, 
TliQ solution mixes In all proportions with water. 
When the density of the solution ul.25, it contain* 
nearly 2S per cent, of glass ; if the ronrentration be 
ouried beyond this point, it becomea to viacid that 
it may be drawn out in threada like molten glnaa. 
Finally, the liquor passes to the sUte of a vitreous 
msas, whose fracture is conchoidal ; it then reaem- 
bles common gloss, except in hardneaa. When the 
solution is applied to other bodies, it dries rapidly 
at common temperatures, and forma a coat like a 
varnish. Soluble glass when dried does not undergo 
any perceptible change when exposed to the air, 
nor does it attract from it either moisture or cor. 
bonio acid ; neither has the carbonic arid of the 
Btmogphere any well marked action on the concen- 
trotyl solution ; but when a current of carbonic 
acid is passed through the solution, the glnss is de. 
composed, and hydrate of silica deposited. But a 
weak aoltttion becomes turbid on exposure to the 
air, and ia after a time dei:ompoaed wholly. When 
the glass ia impure, on efflorescence is formed after 
a while, which may be produced either by the car- 
bonate and byposulphate of potaaaa, or by chloride 
of potoaaium. Soluble glass dissolves gradually 
without residuum in boiling water ; but in cold 
water the solution is so alow as to have led to a be- 
lief that it dues not diuolve at all. It however never 
become! entirely insoluble, except when it eontains 
a much larger proportion of silica, or when it ia 
mixed with other bodies, such as the earths, metalllo 
oxidea, &c., with which double or triple salts are 
formed, u ia the case in the common glasses. 
Soluble glaas which has been exposed to the air, and 
is afterwards snbmitted to the octioo of heat, swells 
and cracks at first, and melts with difficulty ; it then 
losea about 12 per cent, of its weight. It therefore 
contains, even when solid, a considerable quantity 
of water, which it does not lose when simply dried 
by exposure to the air. Alcohol precipitates it un- 
altered from its solution in water. When the solu- 
tion is concentrated, but little alcohol is required 
for precipitation, and it need not be highly rectified. 
Pure soluble glass may therefore be easily obtained 
from an impure solution by the use of alcohol. 
The alcohol being added, the gelatinous precipitate 
is permitted to settle ; tho supernatant liquor is 
decanted, the precipitate collected, rapidly stirred 
after the addition of a tittle cold waUr, and objected 
to pressure. In truth, however, this process is at- 
tended with some loss, for even cold water will ra. 
pidly diaaoWe the precipitated glaas in consequence 
of its minute division. The acids decompose ^e 
solution of glass. They also act upon it when solid, 
separating the ailica in the form of powder. 
( To be cuntintttd t 

Chinese Weiffkh.—Kn interesting experiment has 
recently been msde at the Royal Mint, in the pre- 
sence of its principal officfr*. A set of Chinese 
weighta was compared with the English sUndard, 
and the reeulta were found perfectly to correspond 
with similar comparisons made in China, nearly a 
rentury ago, by the miuiooary Duhalde, of scientific 
memory. 



80 



MAGAZINE OF SCIENCE, 



MEDICAL RECEIPTS. 

PoitOh Jot Bvgt. — Dmolvc I ouDce of biclilo- 
ride af mercarj (corrostve sublimate) id a pint uf 
rectiBed RpiiiU of wiue, antl odd 4 ounces each of 
caaUir oil and tarpentioe. 2d. receipt. — Reduce 
1 ounce of bichloride of roercurj, and 1 of white 
ancnic to a 6ne powder, mix %vith it 1 ounc? of «al 
ammoniac in powder, 2 ounccfi rAch of oil of CQr|)cn- 
dne and yellow n-ax, and 8 ounces of olire oil ; put 
all these in a pipkin placed in ft pan of boiling 
water ; and, «hen the wax ia melted, stir the whole 
tilt cold in a mortar. — Brandv'n Chemintry. 3rd. 
—A *oIntion of sulphate of copper. 

F/y Wfl/er. — Either of the above receipts mty 
t>e UKrd, but being poisonoiu, should not be placed 
where children hare^cci-u. l^Tuit is as good, and 
perft'i-tly hannless, exce])l to the Ales, Is the water 
in whieb quassia hai been boiled. It abould be 
fiomewbat nwcctcncd. 

littim qf Gilead. — f Solomon's.) An empirical 
me4lir.ioe, which it nothing but a disused prepara- 
tion of cincture of cardamoms. 

Balm vf Mrcca. — This ts rarely, if erer, to be 
produced genuine in Turkey, much less in Eoglnnd. 
It is a liquid resin, of a whiti.'th color, approaching 
to yellow, with a strong aromatic Sfuell resembling 
riiat of lemons, and a pungf-nt high>flavored taste. 
It is mut'h esteemed in the East as a cosmetic. — 
'U''hat in sold here for balm of Mecca, is some of 
the finer balsams scented with nil of lemons. 

Balvt of Rakatirt, fJordtm'M.J — Ad einpiriral 
nostniro, prepared by disguising common gin with 
oil of rosemary. 

Bctsam qf Jlonpy. fUUr».J — A nostrum pre- 
pared with n^ual weights af honey and balsam of 
Tola, and diluted with rectified spirit. \MUiout 
the spirit it would he a good expectorant. 

BaJnam of Honey. {Prrtorat.J — Tliis ia idmply 
the Alcuholic tincture of Benzoin, or Balsam of 
1'ohi, It cnnlains no honey. 

liaham ^f Harthmtnd. (Fard's.J — A nostrum, 
the uctivc (ngrediftit v( which is opium, being an 
infusion of Imrehonnd and liquorice-root with a 
large proportion of brandy and opium, with cam- 
phor, benzoin, squills, and hmey ; and flavored 
with oil uf anise. 

BaUmn qf Life. — This is merely the componad 
Je'"octioii of aloea. 

Balsam ^f Litjhorief. — A nostrum prepared with 
lic(Uorice, opium, and balsam of Tolu. 

ftftrriay'tf Antibilous Pills. — Take '£ drams of 
rxtrnct of <iolocynth, 1 dram of extract of jalap, 
1 \ dram of almond soap, 3 drama of guaiac, b 
gruius of potaiutio-tHrtrste of antimony, 4 drops 
each of the esselilial oil6 of juniper, caraway, and 
rosemary, make ioto a mau with syrup of buck- 
thorn, and divide into five dozen pills. 

Bateman^a Pectoral Drops, — A nostrum whose 
biitiis is tincture of castor. Take 2 ounces of castor, 
I utinne each of opium and oil of anise, 8 onncea of 
camphor, 2 ounces of sweet fennel-seeds, A ounces 
of tincture of antimony, and 1(1 pounds of proof 
spirit; color it with cochine&l- Other formulae arc 
given, varying in the proportions, and sometimes 
In the ingredients. 

Bates's Anodyne Balsam. — Thhs nostrum is the 
ooBipouml tincture of soap and opium, und is pre- 
pared with I ounce of tincture of opium, and 2 
ounces ol opudeldoc. 



RattUy'M Grfm Sstsna Pcneder.—h mI 
{nippoBcd to be Henna lesTrs hnttrd till thvyln 
yellow, and then miied with powdered efaaroOi 

Batttey's Liquor Opii Sedativ^ta, — A ferrr 
paration, which la s powerful nitft 
uniform and mild effect thin other , 
opium. It is chiefly eompoved <>r areu 
morphia, and may be imitated bymaoeratiai 
tartaric acid the drrgt lett aibr "■^i.""' »"■•-• 
opium. Mr. Uattley's prcpar 
well without the addition of sj t 

ita superiority as a mild narcotic. 

Bear*s Grtane. — There are two sorts nf 
one of the consistence of thick oli^ 
procured by boilinsr. from the fat - 
and the inteatines of the animal; tbt: ijlilcc, 
harder, and in appearance like frozen bone 
tained from about the kidneys. Both soiti] 
rank, rancid, and intolerable smelL Raadi 
is oden sold for bear's grease. 

Bittering, or corruptly Bitrem, a fraudoleii 
paration, sold to brewers and others for adn 
ingbeer. andcoroposedof coculuf in<1i ' 
tobacco, quaasia, and aulpliate uf ir' 
A similar prejtaratton is sold for the ruuui j.. 
under the name of bitter balls. 

Black Jyrop, or the Lancaster or Mnni 
hlaeh drop, or the Quaker's black drop. Tl 
lowing is the originol receipt, publi^^icd b 
Armstrong : take ^ pound of opium alioe^ 
3 pints of good Terjoice, 1 \ ounce of nittine| 
^ uuoce of oaflron. Boil to a proper thJo 
then add ^ pound and tiro spoonfuHa of ^ms 
the whole In a warm place ue"- '^■' »>•■'■ *'•* 
eight weeks, then iu the open 
syrup, when it is to decanted, 
up, with a little sugar added lo en> 
drop equals three of the Tincture ol 

Black Rtfiter. — Boil in 2 pint* ut 
to 1 , 2 uunceb each uf Aleppo galls, in 
of logwood, 1 ounce of gum itrabtC) 
sulphate of iron. Thb amy be cTaj 
powder. 

Black Wash.—Wnh together I 
water and 2 ounces of chloride of merm! 

Blaiue's Powder, far the ih^ 
disguised preparation of the si 

Bleaching Liqvid. — ^^^IM is ?'<!<j underl 
is solution of the chloride of lime, which 
kept in the market under the name of Blti 
Powder, Bleaching Salt, or Tcnnanl's Salt, 
a deliquescent salt, of a sharp, bitter taste, i 
in alcohol. It is a chloride of lime (not of cm. 
mixed with hydrate of lime. It is prepared 
posing thin layers of recently «laketi Lime I 
powder to an atmosphere of ehlonne. Chin 
potass, prepared in a similar way, is »Iao foU 
this name. The snlphuret of Itme b altfol 
the some way. but is not so eAcacit 

Boerhaave' s Astringent PoWUt 
prepared by mixing equal parta of' 
and Armenian bole. 

Brc^hfs Ball, is prepared by 
Bath brick, 2 pounds of pipe clay, 
pumice stone in powder, and 6 
and coloring the mixture to the si 
with uchre. umber, rose-pink, Stc. 

Bitter Principle of WeWer, is procured b] 
ing oilk with nitric «ctd. ll oonilsta of car 
acid. 




LoNiKiM .—Prutud by u. rftANOit. 6, Wblle Hune Lao*, Milt fioO.— rubUshnl by w, Uafnaiw. 11. Pat«ntasicrfl 




THE 



AZINE OF SCIENCE 



^nt Skctool of ^rt0. 



SATURDAY. JUfiE Ifi. IMI. 



[lU 




82 



MAGAZINE OF SCIENCE. 



DOMESTIC GAS APPARATUS. 

Tas Domestic Gat ApparAttm, «hown in the en. 
graving, is an Invention by Mr. Hinkiifl, for ttie 
tunnufacttire of gas on ku imall a imic aa to he 
adapted to pHvate houses. An apparatus of the 
h.U)d was exhibited in use for a confiderabic time in 
the Strund, and we believe the invention hiu been 
adopted in various estrnsive privnie establishments 
■nd ftiiia'l iii^uiufactorin. Ki^. 1 it a front cU-vii- 
tioit ; ti^. 2, a lateral section of the apparatus ; fi^. 
.t, n section uf the retort ; tig. 4, is a section of the 
rond/'OBer. In tigurea 1 and 2, the same letters 
refrr to the same parts. A shows its application to 
a kitchen mnKP, hut i* equally adapted to any other 
common fire-place ; B U, 6g. 2. U a recess or fur- 
nace built in brick at the bAi:k of the lire-place, 
covered in front by an iron yi\mit, and Us\in)^ a Que 
opening in the chimney ; E, fig. 2, and 1, 5^. 1, is 
a cylindrical retort, divtdrd hy two or more internal 
psrtitions, radiating from a conical pipe F, us 
shown in lig. 2. The retort is turned wiih a small 
rim or flange at the fore end. vrliich htfe into Ihe 
plate, and the hinder end is supported by a stout 
pin projc-cting from the bsck of the retort, and rest- 
ing in un iron aot:ket let into the brickwork. The 
hinder end of the pipe F terminates in a cup or 
csvity fi, pierced with several holcf, and serving as 
a chamber for the gan to collect irv ; the pipe F is 
also pierced with numerous «msll holes, tu allow 
t)ie tar, as it forms, to fall through them upon the 
burning fuel, where it, as wtll n* that portion which 
runs down the conical pipe F and the cup G, is de- 
rompoftcd snd converted into gKs. In the fore end 
of the pipH F is screwed a stuffing box. through 
which passes the pipe H, leading to the condenser. 
Each compartment of ttie retort has a door or 
mouth-piece MM. by wtiich the coal, or other 
msteniij for making gss, is introduoed, and the 
door IB seriirt-d by screws, the joints being cither 
ground trut- or luted ; N is an iron plate, eliding in 
grooves, and when lowered down, scrvittg to de- 
feud the face of the retort and the pipe H from the 
motion of tlir fire. Fig. 4 is a vessirl divided into 
two parts, the lower part O, which is air>tight, con- 
taining a quAUtiiy of tar, into which the pipe 11 
dtps a few inrhcs ; it is supplied with tar from 
another vessel V, by me^ns of a bent pipe Q ; R is 
■ pipe fur drawin;f utf the tsr uhvn required, atxl S 
an opening by which the tar ruiu down the pipe K 
into H, and Uierioe into the retort. The upper di- 
▼iiion of fig. 5 contains & range of bent pipes L L 
surrounded by water, one end of which, V, opens 
into (>, and the otlier end X leads to the gasometer; 
from tlkc lovrer bends of these pipes short pieces 
Y Y dcdcend into the tar in O, by which meaos 
the lur condensed im the pipes L L de.«cends into O, 
while the ga< rannot escape throogh the tthori pipes. 
The opffralion is as follows : — Tlie retort being 
charged, and the doors ttccorcd, the retort ia tamed 
tiU the chambers are in the position shown in figs. 
1 and 'Si the shutter N u then let down and the 
fire lighted, a portion of the heat nnd flame from 
which pasKes through an aperture in the bock of tlie 
range into the furnace B, causing, in a short tiine, 
the lower part of the rctart to brcome red hot, and 
the coiiU or other materialH in the interior to give 
out gas, which, colleciing in the chamber G, passes 
thritii^h the piprn P and 11 to thr condroscr ; at I 
Che same time the tur ^ivcn out by the couU in the 
uppi-r chmitlHTi of the retort, drsctinds thruugb F 
aud G on tu the buruuig lucl iu thu lower cUautM^, I 



and heeomrs ilcoomposed. When tt ta snpfiiMsiA 
that the mutcruls ill the lower r-.r-:-.-. 
given out all tiie gas cuntiinrd in 
is turned purlly round, so as to br; „ 
partment immediately ovpr the flame, wlim tlnr 
gas is again given out as before. The gas, tliai 
formed, contains tar and other imptuitira, froai 
some of which it can br freed hv a rrdoelion c4 
temperature; Che pipe li is, thoi --.'.» to 

dip a few inches into tlie tar veasr <ugk 

thin tar the gus hoa to rt»e to enter ...naef, 

by which means it is divested of a portion nf U* 

impurities, and upon entermg the r.-nd 

passes through a great length of ( 

by cold water, when all the condt i 

are aeparated, snd dntecnd Into the c.tr 

tlie pipes Y Y. The tar, aa we have before 

retnms to the retort by the pipes K and H, 

decomposed by fulling on the burning coke 

retort. From the condenacr the gia pn^'c* 

purlfter, and thence to the gas-holder; i' 

thod of purifying the gas, either upon r. 

small 8c»le, forms the subject of a srpjr.iic ^LuaL, 

to Mr. Pinkos, wbit^ we shall now prucevd ta (1^ 

scribe. 

The purifying substaDOea employed by 
Pinkus, are the chlorides of soda or of lime, 
engraving, No. 5, represents an arrangeount 
purifying vessel, adapted for the tue of 
houses, to purify the gas aa it pasaes frooi 
public main to the bomerB. The method j 
follows: — The ga», upon leaving the "■ ' 
passes through a solution of tljc chtori>i 
or of lime, which may be conlaiurd In 
sembling that shown in aectton at fig 
which the gu may be made to pass, n. : 
a pressure of from tea to twenty iiK'hc« "f » 
by which means it will be pnntie«l. and its 
noxious odour and bad sniL-II 
ture of thia tcsscJ t» easils 
foUowiug short dcscriptiuQ. i .^. .. .. ,.i,=>...j 
or iron cirruUr vevsei, ctosrd at both ends. 
andCC are two shrives which abpe_ down 
and pass round the vcs»cl. A is a pipe whick 
trnds very nearly to tike bottom. D D are 
circular shelves, put up and flxed to (he 
pipe A. £ is a pipe to fill Ihc ve^el with 
F the pipe to convey awoy the purified ^a*. 
H CLHika to empty the vea»el wbeti rr<]uisile 
preparing the solution, the patentee directs 
ploy one part of chloride tu about thirty-fi< 
of water, and when the chloride is in ib> 
ceutratcd slate a diluted acid, sulphuric ori 
may be added to thr solutiou toNA»i»t the 
of the chli>rine gas from the lime; and cbe 
of water may then be inurcused to /ortj 
parts, with one of the chloride. 



SOLUBLE GLASB 

f liftumt^/nfrnfMigt 70* atad 
Vk«4. — Tlie properties of - 
numerous and varied appii 
used io the theatre of Muni^i. ■,• 
from Are. All aorta of vrgetat 
cotton, bemp, linen, paper, Aci. . 
known .combustible ; but, in order that Uii 
bum, two conditions are re{|uUile, an ele 
perature, and free routact of air, to 
oxygen necessary for their transfonnalion i 
and carbonic acid. When otirv »^t an 
own combustion develojiea Ibe he«t oe 



fui 



flr«^1 



^^■fa 



MAGvVZJNE OF SCIKNCE. 



sa 



the cliemical action, provided their be in 
trilh u\r. \( dcjiriied uf sucU couUct, and 
hnii Ibc7 wUl, it it true, yield inflamnui- 
le products, but the carbon which is left 
barn, as it u deprived of air. and thui the 
>ii iiUl atop it»ir. Such is the part which 
ed fufeibli: ialts are capable of performing, 
. in Addition, cotD|>o5cd of aubi>tances iii- 
tit jricldiiig thfir oijrgeo at a low red heat, 
csrboo or hydrogen. These stUta melt an 
table matter bfcomes heated ; they futia 
■ coal impeDCtruble to the atr, and cither 
i^ltiigethcr, or limit its combnation. Tbo 
and borate of ammonii hare such a cha- 
they are so reatlily soluble in coid water, 
liable to objections which faiinoi be ur^ed 
lulde glass. AUhuugh Auluble glou is of 
pod preservative from lire, il fulliU the ob- 
r when it is mixed with another combus- 
' in puwder. In this esse tlie solution of 
in C^ same manner as the oil of piiuters. 
eoAto have more body, become more 
re durable ; and if the substance which 
be of proper i|unlity, coagulate by the ac- 
R into a strongly adhesite crust. Clay, 
calcined boue?, powdered glass, ^(C. may 
Bployed for tJiis purpoae i but we cannot 
rilh cirtuinty which of them is to be pre- 
pA nii\ti)rt* of cUy and whiting appears to 
than cither used separately. Calcined 
B, with soluble glass, a very solid and 
auku. l^ittiargr, which, with the glou, 
easily fusible mixture, does not give a 
t«d for coating wood, as the mixture con- 
trying ; it therefore cracks, and is easily 
ft Flint glass and crude soluble glaM are 
additions. The latter ought to be exposed 
r aflci It is pulverized, in order to attract 
if ic be mixed witli the solution, and be 
fiea to any body whatever, it. la a short 
a eoatiog as hard as stone, which, if 
bff of qo.xl quality, is unalterable by ex- 
knd re«iat£ fire admirably. The soorisc of 
lead, fct>p)r, floor, may all be employed 
iblt gU«* : but experience alone can decide 
thes« substances is the best, and in what 
B Ihoy are to be employed. We should 
It Uw ftni cuat should always be a simple 
if tbe glaaa; and that a similar solution be 
WW eoats composed of its mixture with 
i> irticularly when such a coat is 
Tbe last named Bubatancea 
•tiable coating, which safiers no 
to the air, diKS not involve nay 
is readily applied ; hot, in order 
not fail, particul.tr care is to be taken 
4riDg and employing it. In order to 
•lid t>(her bodies with it, the solution 
« of pure glass, for otherwise it would 
Hualiy fall ofT. However, a small 
ty is not injurious, although, after 
jght eOlorescencc Hill appear ; this 
will) water, and will not show 
time. When a durable covering is 
fen wood, tuu strung a solution rouftt 
ycd at fint ; for in this citae, it will 
will not displace the air from the 
ec)uenre, will not adhere itrotigly. 
to rub the bru»h several tintes 
ace. and not to spread the coating 
Pur the last coats a more concentrated 
J be employed ; atiU it muat not be too 



off 



pi- 



thittk, and must he ApreJid as evenly ns posaible.^ 
Esch coat must be Iborougbty dry before aoollier If 
applied; and this will take, in warm, dry weather, 
at least twenty-four hours, .\fter two hours the 
coat Appears to be dry, but is still Jn a itate to be 
softened by laying on another. The S!ime incon- 
venience Mill then nriiic, which occurt when a thick 
cont [if a concentrstt'd solution is ajiplied ; the coat 
will crack, and does nut adhere. This, however, 
is only tbe cuse when potassa is the base- of tlie 
gla^s, for that formed from soda does not appear 
to crack. In applying soluble glass to tbe wood- 
work of the theatre at Munich, 10 jwf cent, of 
yellow cluy (oc^trcf) was added. After six months, 
the coat had sulTered but little change ; it was 
damaged only in a few places where it had need of 
some repair. This aroK from a short time only 
baring been allowed for the preparation and appli- 
cation of the glass, and they were, therefore, dons 
without proper attention. When this mode is em* 
ployed for preserving a theatre from fire, it is not 
enough to rover the woodwork, it is also necessary 
to preserve the scenery, which is still more exposed 
to danger. None of the methods yet proposed for 
this purpose appears as sdvantngeous as soluble 
glass, for it does not act upon vegetable matter, 
and completely fills up the spaces between tbe 
thread ; it fixes itscif in the web in such a way that 
it cannot be separated, and locrea&es the durability 
of the fabric. The tirmncss which it gives to stutfs 
don not injure them for use as curtains, because 
It does not prevent them from bring easily rolled. 
So far as the pointing of scenes Is concerned, the 
glass forms a good ground for the colors. To pre- 
vent the changes which some colors, Prussian blue 
and lake for instance, might undergo from the alka- 
line mutter, it will be*^e4.-e£sary, before painting, to 
apply a cuat uf alum, and then one of whiting. — 
There is no great dilliculty in applying soluble 
glass to cloths ; still this n|)erstion is not so easy 
as might at first be imagiucd. It is not suffidcnC 
to cout or dip them in the solution ; they still re- 
quire, after this operation, to be subjected to pres- 
sure. This object might, perhaps, be best attained 
by pawing them between rollers plunged in the 
solution. W^hen a cloth is only coated with soluble 
glass, and put into the tire, it will rvmoin incan- 
descent after it is token out. This is not the case 
when it has been properly impregnated with tliis 
solution. A still better purpose is answered in this 
case, when litlurge has been added to the solution. 
The stuff in drying yields to the shrinking of the 
mixture, and bt-comes inseparable from it, nhich is 
the reverse of what happens when it U applied to 
wood. A single |>art of litharge in fine powder ia 
sulfiuicnt for fourtcoo parts of concentrated liquor. 
Soluble glass is capable uf many otlier applications, 
and partittuturly as a cement ; for this use it is 
superior Vi sll those which have hitherto been em- 
ployed for uniting broken glass, porcelain, &c. It 
may be used in place of glue or isingUtiS, in apply- 
ing colors, altliough, wheu employed by Itselif, it 
docs not moke a vamisb which will preserve Its 
transpareiwy wheu iu contact with air. 



CHANGES WHICH THE STOMACHS OF 

CRABS UNDERGO. 
A THKY accnrate account of these changes is given 
by Dr. K. £. V. Boer, in the lUth number of 
" Miiller's Archiv." Crabs, it is well knovm, 
change their shells at a certain seasoD of the year ; 



«• 



MAGAZns'E OF SCIEKCE. 



ftod U is a very oM opinion that the; chan^ their 
Biotnachs at the lame time, a new stomach being 
formed round tbe uld, which is digested hy the re- 
cently devcloijed organ. Baer haa proved that the 
crab's stofnnch consista of two coats ; one inner, 
which, ill every respect, may be compared to a cal- 
lutu. horny cpidrrmis, and which is destitute of 
vitality ; and an outer or containing coat, tronspa- 
rrnt, hut aufficicntly strong and vascular. The in- 
ner cuat coitsiftts uf varioaa and very curious parts, 
aoine ri'TiembHng bony plate«, others compared to 
Reth : now, at the period when the crab changtis 
tU skin, it likewise casts the inner coat of the 
stomach, and, on thja sceount, this process, analo- 
gous Co the moulting of birds, and to the renewing 
of hair in qnadrupeds, is, in the crab, attended with 
very great confitiiution«l distarbance, and a toul 
interruption of the digestive function. Bner relates 
rery accnratdy the changes which the stomach un- 
dergoes preparntory to the casting of ita inner coat. 
It would be beside our present purpose to follow 
him in this description, however interesting. Some 
tilings he mentions are, however, specially worthy 
of remurk ; in the first pitice the softer ports of the 
old epidermis or inner coat uf the stomach arc very 
nkpiJIy digested in the stomach, as soon as it has 
recovered its functions, and has, which it does 
quickly, fbrmed a new lining on its inner surface. 
But there are other harder parts that cannot be so 
readily digested and dissulveil, and which are other- 
wise disposed of. The hard and hollow bones, 
popularly termed the treth, arc got rid of by being 
discharged through the external oriflee correspond- 
lug to the mouth. There are other solid plates of 
the epidermic |>ortion of the stomach, which are 
not of a shape oidculutcd to^irritate the new and 
tendrr rpidcnnis, and, consequently, they con be 
retained nilh impunity, and ure destined to p<'rfurm 
a tu'w and curious function, fur, according to Dser, 
these plutcs, for some time preparatory to the oct 
of casting the shells, rapidly increase in weight and 
in solidity, so av, nt the period we arc speaking, 
they may he conridered as forming conaiderohle 
reservoirs of earthy matter, to be gradually dissolved 
and digLHtcd in the newly-lined stomach, nl the 
very time earthy matter is required by the animat 
for the formation uf it^i new shell. These plAtra arc 
popuhirly called eroi-alonen, and, when submitted 
to the digestive prorr«s, soon lose their maghness, 
■nd become smooth and polished befoie lhf>y are 
entirely dissolved. These crob-stnnes are chiefly 
composed of carbonate of lime, and Baer has proved, 
by repezited analyses, that the fluid contents of a 
crnb's HtumoL'li cont/iin, ot the time these .atones 
are in them, a considerable pornon of lime, carbonic 
acid, and muriatic acid, It is interesting to ob. 
serve, that the chemical inveatigatiuns of Dulk, 
render it highly probable that the chief solvent in 
the crnb's stomach is the same acid which plays so 
important apart in human digestion and in dyspep- 
sia, xxz.Jiet muriatic acid. 

BOTANICAL NOTICES. 

A 9TBM is that part of a plant which supports the 
Howers and leaves. It usually grows upwards, and 
towards the tight, hut occasionally it trails along 
tlie ground, producing young pUnts at intervals, as 
Jw the ruNner of the strawberry, and not unfrequently 
within the ground, as in tho couob grass, the mint, 



Sec, already described as roots* hy m 
such stems are generally known. 

Stems are most scientifically distin| 
their structure, whether belonging to die 
or monocotyletlonoos plants; thoae of 
class are called rxoffynous stems, incr< 
by a layer of fresh matter to their outer 
time to time, and being hardest towarda 
Those of monocotyledonous plants, 
yffJtov»i increaae by a deposit to their 
therefore force* the former part onti 
are hardest on the outside. These diad 
however, too difficult for the yonng bol 
following more usual and obvious 
therrforc continued : — 

lyuneut or 7VttJi*. — This is seen i 
shmbfl, and is the only kind of item 
most complete stnictnrc is plainly diM 
consists of bark, wood, and pith. V 
sacb a stem as this across, we find out 
very tliin sitn, called the eitfielf or 
When this is stripped off we find fixed 
^rwe back or corte-r. The next coal 
f^ark or iiber. All tbeae three diatitM 
called hy the genera! term, the bakk ; 
tended to preserre the inner portion froc 
of droaght and exposure to the weaibcn 
in Che inner bark that the principal aap 
contained, by which the moisture tha 
previously absorbed by the rmits ia carri 
Wit!an the bark is, first, the new wood 
— this is the lost portion uf the solid 
haa been formed, for tree* increase by a 
of wood being depoatted yearly and« 
llins, by conntiDg correctly the numl 
seen upon a transrerae section of a 
of the tree of which it formed a part 
tained. The alburnum, which is I 
workmen by the name of $mp, is more 
uitunlly of a lighter color than the ol 
This difference of color is ^crj often 
rulers which are made of lignum nl 
alburnum is white, and the rest of 
bUck. Under the albuntum ts (be rrof 
wood, or ligmvm, and within this, in 
the whole, is the pith or ruedntia, i por« 
body, occupying frequently the greater j 
shoots, as in the twigs of the elder treo^ 
grees becoming smnllcr, until in prooa 
is nearly or entirely lost. Joining Ihs 
burk, and running through the whole 
the wood from tha centre outwards, are 
or flakes — these are tlie medvilMty 
stitute what is called the Mttfr 
plninly in the oak when cut into boarda 
and adds much to the beautifully mot 
ancr of mahogany, satin vpood, ^. 
always divided more or less— in 
ground, in trees not till some oonaic 
above it — the larger and thicker divisioi 
hranche$ or Oftvtjhx. and the smallrr 
thoolSf or Mprayi. The whole of whic 
getber ia cadled the head of a tree. I| 
off, the tree ia suid to be a pollard, •»« 
a pollard willow, &c. If the side bnwi 
separated it is said to be lopppd. 

CauliM or ntem, — This inolade* tl 
most herbs, and is an imperfect state oi 
kind ; for on account of its shorter di 
bacooua stems lasting hut one year,) an 
greater rapidity of its growth, there ia : 
between new and old wood — the onl] 



MAGAZINE OF SCIENCE. 



85 



y, ftnd the pith Is either very much In 
or »lta^ther wanting; io whjcb latter cue 
bfcomei hollow. 

if fl nimr given to the stem of the 
!e» tbe COCOA nut, and other spedrs of tbe 
it inrtreftsn in length jear hj year, but not 
Aer: it is knotted on the nurracc bjr the 
oU leives ; and \b not formed of layers of 
t of an irrr-gular fibroua maif. the outside 
is exceedingly bard. The stipe is scTer 
It and bean leaves only at the top. 

or ttratr, ia a hollow jointed stem, 
ily in the tribe of gntssea. Although these 
deed no hard woody substance to support 
ibey are not feeble — for the materials of 
Rnr are formed, being disposed in a ring. 
ben stem twice the thickness it would be if 
hides which they are further strengtbeued 
' of flint upon their sorfaco, bj their solid 
d aheaibing lesves. 

ia a stalk which supports the flower 
B tbe primrose or cowslip : if Che flower 
I not come from the root, it is not a scape 
Hiafi/e, so if it supports a leaf only, it is 
stalk or yetiole. 

last-described stems admit of little 
but the trunk and cauUs are almost end- 
tr diflerenees of form, manner of growth, 
xonsistence, a stem msy be either woody, 
succulent, pithy, solid, or hollow. In 
md, Ttrioualy angled, winged, channelled, 
vm^, &c. He. In manner of growth, op- 
red, procambmt, or lying on the gronnd, 
or twining around the bodies. It maybe 
H twi»teil, amootb, or covered with hairs, 
thorns, Ac, while its Tarioas branches 
rom it in difTcrent directions, and more or 
erouitly, according to the speciea of the 
HadtfAh they funn so considerable a part. 
^^■ftms are thin as hairs-— at others, strong 
^Pinilte the most majestic columns. In 
Sne iT|;ionSf almost absent, or reaching 
nn inch in height ; hut in the tropical 
, growing often to the altitude of two 
fe«t, wbile othf r stems, still longer, twine 
kem. These, clinging to each other, form 
from tree to tree, nnd again extending 
lis from the sommits tilt they reach the 
make the whole forest appear Uke a fleet at 
bat decorated from mast to msst with the 
Inves and splendid flowers. 
en already observed, as the first stem of 
cd from a bud, which is situated at 
embryo, called tbe plumule ; so also 
branch added to it by Its after- 
. arifcs, in most invtancrs, from a similar 
hud. If we eiamine tbe oak, ash, willow, 
ber tree, in the summer time, we shall And 
MBS or ajciU of all the leaves small ^caly 
I. ^Slien the leaves fall olT in the autumn 
be still more apparent : in spniig they 
w off* their scales, and burst into leaves, 
tirir snmmer's growth, tbe leaves, which 
fa a buuch, become removed from each 
nn e^xteusion of their axis of growth: that 
e formntion of a twig or stem between 
hUe in the bosom of every leaf is seen a 
ar to thst of the preceding season, and 
lioe time will grow In the same manner. 
t therefore, appear tlitt no fresh brauches 
uniesM buds be first formed ; yet in the 
ijrtlw, tad shmbe, bo buds are to be seen, 



and in tbe plane tree, though eridont enough in the 
winter season, yet in summer the buds are com- 
pletely buried in the stalk of the leaf itself. The 
axils uf the Iritves, and termination of the last year's 
shoots, arc the only parts in which buds are naturally 
formed ; but it sometimes bspi>ens, that buda 
appear in other purta of the tree; as for example, 
if a tree be lopped, buds will appear upon tbe old 
stem, and produce new and vigorous branches — all 
such as these are called adrentitious buds. Goose- 
berry trees, too, often spontaneously throw up 
xuckert ( these arise from such accident^} bods 
being formed below tbe ground. 

Buds, as above described, are to be considered as 
arising from the wood itself, and not from the bark 
or its vessels : thus, the branch or twig which it 
produces is firmly connected with the last year's 
wood, and the bud in general only grows so long as 
the connection between it and its parent twig is 
kept op ; but this is not the case with all, for in 
certain plants imoU buds or bulbs.called by botaniata 
petHntOf, are found in the axils of the leaves or on 
the stems, which are readily separated, and if im- 
mediately put in a situation favorable to growth 
their vitality continues, so that they maintain a dis* 
tinct and separate existence. 

Well-known instances are the bulbous toothwort 
and the tiger lily, along the atcni of which very 
many gemmae are borne. Another example of 
gemmee is seen in the tree onion, where, instead of 
a head of flowers, and afterwards seed, is a number 
uf small bulbs of a simitar character. An exami- 
nation of the bulb spoken of nnder tbe description 
of roots, show that these, Uke buds, consist of a 
number of scales or coats folding over each otlier, 
and shielding from injury the growing point in the 
centre, and which alone produites tbe future stem, 
flower, and leaves — the scales themselves decaying 
away when no longer wanted. It will be observed, 
that the solid bulb of the crocus ia not of tliis for- 
mation — the growing point is at the top uf it, and 
not withtDsidc. It, however, wastes away year by 
year as they do, a new bulb being formed below it. 
As was before stated, this is colled a cortHtu or 
swelled -out under.gronnd «tem. 

In some uf the species of a particular tribe of 
plants, (the orchis tribe,) the stem forms a bulb 
above the ground, also solid ; this Is called a 
pxeudO'bulb, J 



SMALL AIR BALLOONS. 

Fon experiments in courses of natural philosophy, 
mechanics, and chemistry ; as alao for determining 
the currents existing in tbe upper regions of the 
air, there are required little ballooas of hydrogen 
gas, whose small weight and ascensiooul power may 
enable them to rise to a sufficient height. The 
baudruche or blind gut of tbe ox, prepared for tlie 
use of the gold heater, is the best aubstance that 
has hitherto been used for this purpose. 

For the purpose of making the ^mall air billoonr, 
a mould is necessary, made either of wood, or 
which is at once cheaper and better, of plaster of 
Paris. This mould is generally a hemiapheri! of 
2-1, 30, or 36 inches in diameter, and is pUced upon 
a stand or table, so tbst a peraon may walk round 
I it. When used, it is to be carefully greased alt over. 

The baudruche, or prepared akin, when bought 
of tbe bladder-dealers, is in the form of very dry 
and very hard slips, la order to cover the moold, 
(he skin ia soaked io warm water for 12 or 15 faoan; 



86 



MAGAZINE OF SCI 



it u iheo tprrad ont witb grnt care. 0Bd spplird to 
the mould, beginning At the top. The rmg^ca ed^es, 
or any accidental inctjualitiei, are to be remored 
with a deal of caation hy m pair of cntting pin- 
cen. A second baodrache is then applied* so ai 
to cover ooe-half o( that applird to tlic mould ; 
and then ■ third, alao eoTeriag ooe-half of the 
■ecood. and to on, in snch manner that every part 
oi the moald may be coTcrtd with two thickneaMA 
of skio. Care maat alao be taken that the ikio 
already on the inoutd be kept moiat until the neit 
layer is ajtplied, as otherwise the baodnichra would 
not adhere together; for this reason, a wet clulh 
mutt be kept on the skins until the whole Is finished. 

IK'hen the whole of the hemispbericaJ mould is 
finished, a tape, well greased, is tied round the base 
of the hcini^her* ; and those pieces of skin which 
Are left at the lower edge are rolled ap and kept 
moist, while the hemispherical part U left to dry 
for A few hours: when dry, the part already made 
is greased, to precrat the adhesion of the skin, and 
is used Ai a mould, beginning at the bottom with 
UiA loose fi-ipa remaining from the farmer hemia- 
pbere, and adding frcih «kios up to the top of the 
Mmlsphere, where a short cylinder, aboat an inch 
in diameter, ts placed, and the skins brought round 
It. To etrengtbeii this intended ojwolng into the 
balloon, the skin is berc trebled, or even fourfold. 

A few hours ire sufficient to dry this second 
homispbcrr, when it is to be taken off the mould, 
from which it parts with eaae, in consequence of 
the grease ; and in like mnnnrr the ts^ie is nitb- 
clrswn from the iutcmal part. I'be nozzle of a pair 
of hand bellows being then applied to the cylindri- 
cal mouth, it is blown np, and hcing tied, a very 
thin cost of varnish is rubbed over the surface by 
niAAas of a sponge. This being done, the balloon 
la tumod ioiide out, and a^ain blown up and 
vtraUhed ; after which it will hold hydrogen gas 
perfectly well. 

A balloon of this kind, 3 feet in diameter, when 
weJI made, ought not to wnj;h more than 2 ounces 
■nd A half: so that, when filled with pure hydrogen 
gas, it ought to rise in the Air, willk the torce of 
between 6 and 7 ounces. 



PYROLIGNEOLS ACID. OR WOOD 
VINEGAR. 

Ira piece of green wood be introduced into an iron 
retort or other close vessel, the retort bedded in a 
common coal fire, and a receiver applied, it will be 
found that in proportion as the wood heats, the 
water which constitutes its natural juices will distil 
over, and drop into the receiver. This water almost 
imtDediatcly changes its niture, and becomes first 
uerb, and then sour to the taste : it conies over 
impregnnted with a dork oil, whtrh soon puts on 
the appeardnct: of thin tar, nnd in fact, is such ; part 
of the tar tloatt, part dituolves in the liquor ; but 
the greater part sinks to the bottom of the liquor, 
jhleanwhilc gna, consisting of carbonic oxide, car- 
bonic acid, carburetted hydrogen, and bicarburrttvd 
hydrogen, is generated abundmiily. At length the 
liquor which conies over is very acid ; but its acidity 
^ in some measure disguised by the strong taste of 
the tar, which is dissolved in the liquor, and gives 
^ K reddish color. 

|C is easy to trace the theory of these changes. 
4lw wood chiefly consists of oxygen, hydrogen, and 
proportions, and in a certain 
The elements separate during 



the heating of the wood, and tliry rcconil 
diately after in dtfTerent proportionn, and^ _ 
to new substances. Psrt of the OJiygen and ' 
gen combine and form water. Another part 
nxyiren and hydrogen combine each nithaiKii 
carbon, and fonn two fif.ta of compuutuls, a 
oxide and carbonic acid, with carburrtted and 
boretted hydrogen. .Another portion of the 
and oxygen, with a very small quantity of hyt 
then combine, and produce acetic acid. 1 
maindrr of the carbon and hydrogen, with 
amall portion of oxygen, also unite and prod 
peculiar tar. The water, acetic add, and the 
distil over together, &n the form of what is o 
ooturnvTCK pffroHfuous acid. The acid whiol 
over towards the end of the distillation is tbri 
est portion ; no doubt because the water « bi 
timber contained has been at this time all voUtJ 

The name gi%eo to this liquor by the Frew 
mists was pyroHgneoua acid ; but it was ann 
by Foarcroy and Vauqoelin that it is not « 
wui femeru, or of a ]>ecuUur nature, as bad fa 
yean before been supposed. They deten 
be merely acetic acid disguised by tar. 
was by no meana a new discovery. Gl 
ascertained the same thing two centuriea 
in describing the carbouization of wood, 
this acid liquor, and calls it vinegar. The 
not to have been generally known ; for 
stated something similar to the French A 
1701 ; and Boyle details some experim^ 
spirit drawn from box-wood, in which 
detected an acid which '* was in iceiit 
vinegar, so that had I not known how 
tained I should have suspected it to 
radicatvm." 

Vinegar, whether obtained by ftrm*'"' 
the di:}tiUslion of wood, ia s dilute a. 
is, a mixture of a very coacenlmted. j 
inflttmmahle acid called the acetic, 
in variable proportion. The water muf] 
rated by a variety of means. Thus, if comi 
gar be strongly frozen, and the vessel in^'cr 
unfroien portion, in smalt quantity, vriUj 
which is acetic acid deprived of much wat 
be mixed with cbarcuul powder and 
liquor will come over (the first portions oT 
should be rejected), which at a moderate dej 
cold wilt shoot into beautiful crystals. Th< 
occtic acid, otherwise called radical rintfior. 

Acetic acid, wlirn as free froui Mater mm it 
made, is a colorlcM liquid at ordinary teiapei 
but crystallisrs in the cold: it has xn ci.-i-i 
pungent smell, and a powerfully acid 
ing (o actual caustiutty, When apyli ■ 
it is capable of forming a blister, and e\cii a t 
some eschar: it also destroys warta and otl 
crescencrfl. When heated so as to emit lap 
vapor will readily catch flame from any I 
body. The liquid sold under the name of a\ 
vituffttr is acetic acid, holding camphor ant 
essenlinJ oils dissolved. This compound w 
merly known under the name of riufgar <ffi 
ihifvei, or thievct* rineffar, on account of tlui 
ing circumstance: — "When the pljigua n 
Marscillefl, four rogues broke into the houod 
sick, and carried ofTwhatevirr they pteaaed, 
to a sernet place with their bfM>ty ; nnd ( 
turned to the same business at different tic 
they auisMed great nches : but tbri 
apprchtuded and hnuged. Being 
durst venture into the pcstilcalial fa( 



muo 

in\-cr 
riUji 

4 




MAGAZIXE OF SCIENCE. 



87 



Moautl 



tfurt tbMj pretervtfd tbemfielves by driokin^ s Ii;lai8 
of their vinr^r t*io or tlire^ tiaiei m day, fpriukUng 
their hAndkctchiefii and clothrs with the same, and 
Ihcj were not Nfniid.** The viiipf^r thua jierfumed 
■■d lurd by the tUieves wan, of rour«r, rommnn 
i lmA T , not acetic acid ; and all thai they contributed 
to tne invention was the idea of combining the 
AiiBcs of riueipir with the perfume of nromatica, 
ftzid using the compound as an ftlexipharmic, the 
powers of which arc Tcry questionable. 

Id pyrolijDcoiu acid manufactories it is usunl to 

prrparr what arc railed r^rf Uqvor uiid iron liquor 

for the use of calicopriatprs. The formRr is an 

fceeUite of alumioa formed by mixing; the aceUte of 

Gmr. herrnfTer to be described, with common alum. 

By <-i?mpoHition. icetatc of alumina is 

for' remains in solution ; and sulphate 

ol iiuir. Kiiu-h, bein^ insoluble, sobeidea to tlie 

bottom. I'his sulphnte of Hme is not allowed 

to r''< to waste: it ii employed BS the lute with 

■ end piecea of the retorts are cemented 

- it answers the purpose extremely well. 

Tba Uun liquor'iB made by dissolving old iron hoops, 

he. in tbe pyroligneous acid which has been recti- 

fted by di^nlUtion, but no further purified. In 

pyroliiineouti arid manufsctoriea llie at^id dues 

-> Oironch all tbe processes for puriHcation that 

^rrsently deecribed. After being distilled 

' iron retorts, the acid is rectified by a 

disttlUtion through a common still and 

br tticke means a purer acid is procured ; 

'-far from being as pure as ft is possible to 

The steps by which it may bo rendered 

»»...nv |*erfectly pure are next to be described. 

TIh appnratos and process employed for difitilliug 

PTroTicDeooii acid are ai follow : — The wood made 

: difttillstioD is introduced into a cast-iron 

i.aped like along drum, but of a very large 

i ilia vessel consi«ta of n cylindrical body, 

feet and a half long, and four feet in dia. 

Dinrr. imvini^ two circnlnr end-piects, which Ht la at 

ndi end of the cylinder, and arc secured there both 

M mi^^MpAble bolts and luting. The cylinder is loid 

-Jly in a fire-plare, the fire surrounding it 

■«-hnIe length. The eude of the cylinder 

■ beyond the fire-place, bo that they, 

■ two circular end-pieces, are always 
!>cn cool. From the centre of ttie end-piece 

linder springs a very wide tube intended to 

i ibe ignited wood, D3me1y, tbe vapors of tbe 

I , tlu- tar, the water, fee. This tube at length 

a large cistern of water kept constantly 

; ends in a copper worm surrounded by a 

' (try : the water, acetic add, and tar, are con- 

: it; they are discharged in a state of mii- 

« large ritttrm : here the liquor is allowed 

lie: the great balk of Oie tar subsides to 

Mfil. Above this lies the acetic arid and 

<ixed« and holding in solution as much tar 

iparta a considerable deftrre of taste and smell. 

tng r%n fhr aurface of all lies a little more tar 

> nee and trjts specific gravity than that 

It to the bottom. In order to nepa- 

iiqQor, which constitutes the middle 

up ii made use of. the lower end of 

_ ' *D fsr down into the acid liquor as to 

t a tew inches from the lower deposit of tar. 

Use pump i« pnt in action it draws the acid 

otit. and nt length tbe upper tarry surface is 

untU it joins tbe lower drpoiit uf tar, 

puiuping IS discontinued. Tbia is the first 

towM^s removing the t«r ; and by it the chief 



quantity ia removed. The add liquor removed by the 
pump is received into tbe body of a largo still, where 
It undergoea the procesn of diintilUtion. This distil- 
lation IS conducted slowly: the object of it i» tii re- 
move anothrr portion of the tar nhich is held in so- 
lutioti hy the liquid; and if the distillation were urged 
by A strong lieal, the separntion would be much lesa 
effectual. The first product that ditcila over is uf a pe- 
culiar nature : il is culled wowltjiirit, and is kept sepa- 
rated, for a purpose that will be presently mentioned. 
The product which follown this is still a tarry vine- 
gar ; for it now holds in solution not tar but the es- 
sential oil of tar : it has still the strong taste, but by 
no means so strong as when first obtained from 
the wood. When nearly the whole of the acid haa 
been drawn off the process is stopped ; and the tar 
now collrrted in the bottom of the stttl is allowed 
to run off by a oock. 

(Toht oomtinued-J 

SPIRIT FROM THE M.VNGO. 
Tea discovery that a very wholesome spirit, some- 
thing stutilar to gin, could be manufactured from 
the mango, was made some two year* ago in Gre- 
nnda,— and there was some talk at the time in 
Jamaica about establishing a distillery there. Tbe 
mode of proceeding is very simple : — A Tat is as 
nesrty filled as poAsible nith tbe ripe fmlt, and as 
much water added as will cover them. They are 
then allowed to remain from thirty-sU to forty, 
eight houra, until frrmentation commences, when 
the seeds are divested of whatever palp may still 
adhere to them, and care Is taken to retain the 
whole of the rind and pulp in the rat. Thirty-tive 
per cent, of water Is next added, and five per cent, 
of sugar or molasses. Tbe whole is then allowed 
to ferment for five or six days, when it ia transferred 
to tbe still, and ibe process conducted in the usual 
manner. The spirit thus extracted is mild, and haa 
nothing of the pungency of new rum. It is de- 
scribed as strongly resembling In taste Britiith gin : 
and this flavor ia derived, without doubt, from the 
essential oil, contained in the rind of the fruit. It 
is free from empyrcuma, and is pleasant and slightly 
saccharine. In Grenada, fifty gsllons proof 
were obtainctl from " a very inconsiderable quan- 
tity" of the fruit ; but it ia to be regretted, ** the 
quantity" had not been specified. Considering the 
deficiency in the staples of mm and sugor from the 
West Indies, for the last two or three years, this 
discovery may be considered of great importance 
in a financial point of view, since, should it become 
an article uf export, it may in some measure com- 
pensate for the falling off of the revenue. It rests, 
however, with the West Indisnsi whether or not to 
avail themselves of this very valuable discorery.^ 
The capital required for a mango distillery would 
be very vniall, while it appears to us, that if the 
spirit were used in Tamisbes alone It would bo a 
very profitable speculation. — Belhe GBxeit*. 

MEMORANDA. 
THrpin on the caute qf the Color qf Affates. — 
The red color of Agnte is owing to a number, 
greater or amalter. of Protococaa KentuirinM (one 
of the lower .AlgK), sccumutated together, or more 
frequently reduced to their small red globules, 
(seminulcs) agglomerated or coaguUted, and dis- 
tributed, according to certain circumstances, in the 
colorlesa structure uf these silicious compounds. — 
By microscopic and comparative inveatigatioa. Tur- 



: 



■ 



88 



MAGAZINE OF SCIENCE. 



piQ was led to conclude thftt the vMrioas colore, 
oninfe. roM, blood-red, nnd reddish-brown fvirie- 
tici Offing to more advanced grovrth) which are in- 
e1o«cd in, or which lurroand the tranalurid and 
colorless strticlure ofdifTerent kinds of AgsCes, will 
be found to be owing to the presence cither of red 
globules, Qiiironnlj mixed u in the Camelian 
Agate, or agglomerutrd into small irregular clots, 
■od diftributed into clrcuUr waves, according to 
certAia forms or conditions which existed st the 
time of the tilicious coDglomeration ; or finally. 
thougli more rarely, tn these small, red vrgctsbtes 
tbeniselTcs, f|Qite entire, snd most diatinrtly Tisible 
with the microscope. It is impossible to fiud a re- 
semblsuce In color and polish more striking thsn 
that which is seen in a wliitf" glsss phial filled with 
Protoeoccuw Kermfimif, when compsred with s cnr- 
netian, u may he fully established by the trial. — 
TUrpiH in Jameson'* Jonmai. 

TMMperiny on Slfft. — In the year 1739, Mr. 
Hartley obtatoed a pstetiC for a mode of temper- 
ing cutting instruments of steel, by immersion in 
oil, heated to a regolatcd temperature, meaAured by 
a thermometer. This v.-aa certjiinly a grcjit im- 
proTement, both in point of prerisJnn and di<tpatrh, 
on the common method of heating the instnirocnt 
over a dnnie, till a certain color, produi*ed by a film 
of Clyde, appears on its snrfncc. • These colors arc, 

At 430° F. a *ery faint yellow for lancets. 

14bU . . a pale straw color for razors and sur- 
geons' inBtmmtntfi. 
470 .. a foil yellow for penknives. 
490 . . a brown for scissors and chisels for 
catting cold iron. 
510 .. « brown with purple spots for axea 
and plane irons. 
530 . . a purple for table Icntves snd large 
ehcars. 
550 . . a bright blue for swords, watch springs, 
truss EpringN. and bell springs. 
560 t. a full blue for small, fine aaws.dag- 
gers, Stc. 
000 . . a dark blue, rerging on black, if the 
softest of all the gradations, when 
^ the metal becomes fit only for pit 

' and band sawp, wUirb rau»^t be sof^, 

' that their teeth may hear sharpen- 

ing by the file, and setting by the 
hammer or pliers. 
On /A« Infiufnct of a Low Temperature on the 
Jt\/kuoria. — The researches of Elirenherg agree 
with those of SpalUnzani. and proTp that cold is 
generally l^tsl to Infusoria, especially to the Rofa- 
loria. It ia even more destructive to the living 
animals than to the eggs ; but water, when recently 
thawed, may be found inhabited by individuals 
which have escaped death, and inclose the germs 
of future generntions. Hie animals generally die 
after they have been encased in the ice from one 
hour and a quarter to two hours ; but it appears 
thst at the moment when congelation of the water 
takes place, each animalcule is surrounded by heat. 
A sudden thaw always produces a fatnt effect on the 
Inftuoris. Tfasy are found in winter at the lower 
surface of ice, oovoring ponds, &c,— J/irrosco|nc 
Jtmtrmal, 

Mr. Owen calcolmtea that 200 ]>ersons, with 
machines, now manufacture as mui-h cotton as 
20,000,000 of DWD were able to manufacture with- 
out machinei forty years ago, and tliat the cotton 



now manufactured in the course of one ) 
Great Bntain would require, without nia« 
I I5,000,OOU of workmen with simple whock 
calculates farther, that the quantity of au 
turea of all sorts, at present produced by 
workmen, with the aid of machines, la to 
that it would require, without the asatstnnce 
chinery, the labor of -100 millions of workmc 

Vibration qf Wiret in the Air. — A gentle- 
Burkil, near Basle, in Switxerland. is said I 
observed, some years since, that a long wire sti 
in the air gave musical tones tn certain stotei 
weather. In consequence of this tad. other 
vations, a kind of musical barometer ia deseri 
having been ron.<^tructrd by Captain Hani, of 
in 1787. Thirteen pieces of iron wire, esc 
feet long, were eitended from bis $nranicr-hi 
the outer court, crossing a garden ; they were 
about 2 inches apart ; the largest were two I 
dia.meter, tlie smallest only one. and the othei 
one and a half. They were on the side of the 
and made an angle of 20 or 30" with the hi 
They were stretched and preserved tight by 
for the purpose. During ccitain changes 
wentJier, these wires make a considerable ooi 
scmhling that of a simmering tea-orti. ai 
monicon, a distant brll, or an organ. It an 
be snpposod that wires placed east and wei 
no sound, snd that to produce the rfffct thei 
be in the direction of the meridian. In the o 
of M. Diiberiener, as stated in the BnllctiaTi 
Ingiqnc, this is an clrctro-magnetical|ibenameT 
JVnr Monthly Magazine* 

yatuml Ice Caret, — In a memoir on aorat n 
ice-caves, read by Professor Pictet to the tli 
Society, in 1822, thst author advanced the sii 
fact which was attested by the nei^hbourii^ 
bitants, that Ice is formed therein more in M 
than in winter, and he accounted for diiseSee 
two roticoraitant causes, vis. : descending m 
of air, snd the cold produced by cvaporatioB. 
of the ice caves visited by Professor Pictet. is si' 
near the summit of Mont Vergy, in Faucignj 
is called Montarquis. To determine the fact 
absence of ice during the winter. tv«o counli 
of the village of Sionsler, near the road to tl 
cave, hud the perseverance and courage to 
three visits to the place during the autVRM 
winter, and having drawn up the foUowiog 
acoount of their visits, it was read before the 8 
of Geneva : — 

" On the 22nd of October we ascended 
ice cave of Montarquis with some difficulty, bi 
of the first snow, and we found very little 
colamni ; it had begun to meit. 

" On the 26th of November we re-ttsccDdsd 
cave ; we found very little ice at the boUooi ( 
cave, out of which there proceeded ft ki 
warmth. 

" On the 2rith of December we re-aseendcO 
above-mentioned ice cave witli great diificull 
trouble, and were almost carried away by an wall 
This circumstance discouraged us. but rceo 
from our fear we ascended to the spot. We 
a moderate warmth in the cave and no ice ; li 
of which where there was ire in snmmer. dim 
octually water : in winter therefore it is m\ 
this cavern, and in summer it is cold, T% 
appears cavemoua; it appears as if tbeft 
chimoies.** 



LmiWMr^l>rlnlvd bjr 0. rsAvoii, «. Wblis Horta Lsae. MUa Ead.— PablUhvd toy W. OairMw. tl, Pai#Tw>«tM t(- 




THE 



GAZINE OF SCIENCE 



^n& ^cDooI of Itrts. 



SATITRDAY, JDNE It. 1641. 



IHd. 



iiiiuiiiiitiiiiituiiitiiiiiiiitnuyiiw 



SAXTOK'S MAGNETO-ELECTRIC APPARATUS. 







THE WATER RAM. OR BEILIEU HYDRAUUQUE. 



'JO 



MAGAZINE OF SCIENCE, 



SAXTON'S MAGNETO-ELECTRIC 
APPARATUS. 

Ohb of the most elrfcunl. (H>nvcnient, ahd powerful 
magneto-electrical machines, it that o( Mr. Saston, 
the pritici)jle and node of actian of which hai been 
aJready deschtxd. tn tmling of an aiulogoua ma- 
chiDi), invented by Mr. Clarke; thia, hoMrc^er, baa 
tlie adrantoge that the amatore worka on the pnds 
of (he poles of the magtiet, instead of at the side of 
Iheni, by which meana the arrangeoient ia much 
aimptth«il. The machine will be immediately nn- 
df rstood by the foUuwing short deicriptioa, aud the 
figure to which it refer*. 

The magnet in this apparatai is 7 inches long. — 
The space between the potea. from centre to centre, 
2 incbea. A, a steel horse-shoe njojjnet, cnnaisting 
of three plates screwed together. B, the tirniatufe, 
or keeper, of soft iron. C C C, insalated heUcea 
of copper wire. D, a wooden cup for containing 
mercury* moyeable by its stem H. E, a copi>er disc 
dipping into mercury, and communicating, by a 
bruBs socket. I, with one pole of the helices. £', 
a pointed slip, or croas-bar, of cupper, in contact, 
by a central screw, J, with the other pole of the 
helices, and so adjusted, that when the armature is 
at right aiiglas with the polea of the magnet, the 
ascending point of the cross-bar shall be about 
]-20th of an inch above the iorfaceof the mercury. 
F, a grooved wheel filed upon the oxis of the arma- 
ture, B, to which mpiil motion is imparted by the 
larger grooved wheel and leathern band F. Q, a 
thuntb-acrew for adjusting the axis of the wheel, F, 
,•0 as to tighten or tUckea cbo btnd. 

THE WATER RAM. OR BEIUER 
HYDRAULIQUE, 

Aa it was called by its inventor, M. Montgolfier, of 
Paris, is a highly useful and simple machine, for 
tfafs. purpose of raising wotcr without the expenditure 
of any other force than that which ia produced by 
tbe momentum or moving force of a part of the 
water that is to be raised. The eiTect of this machine 
depends entirely upon momentum, or the new 
quantity of force that is generated whenever a body 
is put into motion ; '»nd the effect of this is »o 
great as to give the apparatus the Appearance of 
acting in defiance of the established laws of hydros- 
tatic equilibrium ; fur a muTtng column of Email 
height is made lo overcome and move another 
coUunn mach higher than itself. The form and 
construction of the hydraulic ram is »howii in the 
figure on the next page. Suppose O to rrprrsFnt 
a. reoervoir. or the source of o spring, which is con- 
tinnolly overflowing and running to waste by means 
of a channel a few feet lower than itself, oj at the 
level line P P, (we have shown a cask, the principle 
is the same, and the description as easily understood.) 
IitalBad of permitting the water to flow over the 
fidea of O, let it be conducted to the level of P P. 
by meana of pipes Q Q, connected with the side of 
the reservoir, and terminnting by an orifice R, in 
which a conical or other valve S is placed, so as to 
be capable of effectually closing the pipe when such 
valve is drawn upwards. T is an adjustable weight 
fixed on the S)iinillc of the valve S, by means of 
which the valve is kept down and open : any water, 
therefore, that is in tho cistern O will flow down 
tbe pipe Q Q, and escape at the orifice R. so long 
as the valve remains down ; bat the instant it is 
xjused and shot, all motion of tiie water is sua- I 



pended. Thus situated, tbe adjustme-nt 
T must take place, and by adding to, oi 
from it, It must he made just so bei 
capable of sinking or forcing its wa 
against the upward pressure of the wa 
of which will depend upon the 
distance from the surface of the wate 
point of discharge at R, (represented 
line O V;) conirqueDtly, if the valve S 
the hand or otherwise, all motion of 
the pipe Q Q will ceoae, but the ins 
is released, it will fall down and permit 
escape. The water, by its motion, 
mentum and new force, and cooaeq 
longer equal to the column () V, to whi 
has been adjusted, but ia aaperior to 
it is enabled to overpower the reais' 
weight T, and it carries the v«lri 
closes the orifice R. This is no 
the water ia constrained to become 
by which the momentum is lost, and t] 
weight sgsln become superior, and fi 
opening the orifice, and permitting t 
flow again ; and as the presaure of tbi 
the weight of tbe valve esdi alternately pr 
the valve is kept in a constant state 
or of opening and shutting, without ■ 
aid whatever. Such ia the principle I 
the motion of the water in the pipe 
daced; but the motion generated cannot! 
annihilnte«l ; and it is not only of su 
to raise the valve S, but likewise to but 
lower end of the pipe Q Q, unless a 
be provided, by which this arcumolai 
tscape. Accordingly a second valve 
near the lower end uf these pipes, and 
open upwards into an air vessel W. 
charging pipe X, and consctjuently, i 
valve S is closed, tbe water which wou 
have flowed from the orifice R now o 
U and eaters the air vessel, antil the 
coutoined oir overcomes the gradually 
force of the momeutam, when the valv 
and that at S opens to permit the w 
set-find blow or pulsation, and in this m 
of the machine continues unceasingly, 
external aid, so long as it is supplied 
and remains in repair. A small mnni 
necessary for this machine, as the 
should be kept at one constant eleratioi^ 
the perfeclinn of its action. A much greal 
tity of water likewise escapes at the o 
between the pulsKtions, than can be raised 
livery pipe X, particularly if it extend to 
siderable height, for the comparative q« 
water discharged through X, and permitt 
to waste at R. must always depend u 
spective perpendicular heights of 
column O V, and the delivered or 
W X, and the rapidity of the pa 
wioe depend upon the same ci 
Millington, from whose Epitome of X01 
sophy the above description is taken 
erroterl several of these machines in diffd 
of England, which gave great sstiofoctioR 
to show their efficacy gives the following p 
of one, which, at the time when he wr^tr, 
in constant use for abont two years : — The 
O is a basin of iboot 10 feet square and 3 < 
formed partly in limestone rock, and partly 
work, the supply of water being from 1 
spring. Tbe pipe Q is of cas; iron, II 71 



gmg 




MAGA/fNE OF SCIENCE. 



91 



ichea in diameter. The piece at the end, 
tug the air veuel and the vulves, ii about 
loof : the viWes 1) inches each in dia- 
aod made of brau; conteota oC the air 
iboat one gallon. The height from the surface 
vater mt O to ita puiul of diacbarge at R, ia 

inchra. oaeaa ured perpendicularly. The de- 
Ipe X ia of lead, I inch in diameter, and 
kboriKOotJilly under the ground 104 feet, and 
n prrpendicularly to the height of 54 feet 
I ftbove the diubarge valve at R, where it 

the water into a Urge cistern. The water 
nised 651 inches above the surface of the 
■hich vappliea it, and this bj a fall of only 
inches. So* circumstanced, the valve S 
iboQt fifty Tibrations, or opena l^y times in 
^ when it toees about two f^uurts of water, 
fctJt n<parly a qaarter of a pint into the 

cistern at each puUatioa; the water lost 
\ that wbieb ia raised nearly as 17 to 1 . Tbia 

ar a liniall quantity of water, but when it 

;ted that the machine is at work night nad 

lieu purposely stopped.) and furnishes six 

wftter every minate, this will be foQnd to 

ipply adequate to a very large hou<9eh(ild 

intent. The construction above dtscnhcd 

rcr, incomplete, as, owing to the mutual 
%tioa which lakes place between' air asd 

le successive quantities of water that are 

Into the ur vessel would soon absorb the 
F the air contiuned in it, and it would cease to 
tmt rUittirity which is indiMi>ensable to the 

of the machine. Tlits was discovered in 
by M. Mootgolfier, who added an improve- 
^Kbe machine by introducing a very small 
waive, opening inwards Into the lower part 
ir vessel, but kept shut by a small apring. 
bown to the separate shaded figure above 
l«scribed, ond represents an improved form 
ir vessel. This valve is srlf-acling, and 
ly prevents the escape of any air or water 
the Hir vessel [ bat when the wnter ii thrown 
the ahucting of the vntve S, it produces an 
leoos vacuum at the end of the pifie Q. 
ieh the shifting valve opens, and admits a 

quantity of the extrrnal air into the air 

keep it constuntly replenished, and by this 

diciun the water mm is rendered continu- 

action. 

pUGNEOUS ACID, OR WOOD 
VINEGAR. 

fnmptigeSil, and ctmciuded.) 

V viue(C"r produced by this disCilUtion is 
red ; it is now quite pale, and is even a 
Ity. [t Can never be rendered much purer 
Umw of ibe process ; for such in the affinity 
oil to tiie vin^ar, that they will Iwih rise 
U aiul come over together. The method 
ion adopted is engaging the vinefnr. which 
sent of the tar-oil, by meAos of ita aUrmty 
line substance. The liquor is accordingly 
ritber with lime or carbonate of limr. — 
auecrefls better, as it exerts no action on 
I. which, therefore, to a certjiin extent, 
, floats, and may be readily removed by 
The objection to carbooato of lime is 
r. When lime is used, it not only sntu- 
Acid, but it *»mbmes, in some degree, 
If -oil, ami forms a sapumiceous com pound : 
Vtt of tw-oil separates, and fioats, as 




in the former case. The solution of acetate of lime 
by saturation still further (lurified, and decanted off 
clear from any esrets of lime and a little tar-oil 
which falls, is evaporated to dryness in an iroo 
boiler. During the evaporation to dryness, etpe- 
uially towards the latter end, when the boiling pro- 
cess is somewhat elevated above 212", some tarry 
mstter is volatilised. The acetate of lime which 
results from this process is almost white ; it is iu 
small dry ma«M*s. 7*bis salt is intrfldured into a 
cast iron still with an earthen bead. The beak of 
the bend enters a large cask containing pure water : 
sulphuric acid is poured into ifae iron body, over 
the acetate of lime, and heat is applied. Vapors 
now arise, which are concentrated acetio acid, and 
which contain almost no impregnation of tar. These 
vapors pass over throegh the beak into the cask of 
water where they are absorbed ; the water betomes 
more and more acid ; nnd at length, when suffi- 
ciently iinprt^nnted, which is known by its incrcas« 
of specitic gravity, the wood vinegar is 6ni8bed. 

When well prepared, it has scarcely any peculiar 
smell or taste ; it ccmtsins no foreign vegetable 
matter, and is, tlierefore, purer than that from 
nmit, sugnr, fruit or wine. It succeeds better as a 
pirkhng vinegar, because it may be concentrated to 
any strength. It is perfectly transparent and 
colorless. 

The beat timber for making pyrollgneons vinegar 
is oak : but beeeh, ash, sycamore, and birch, an- 
swer exccedinRly well; in short, every kind readily 
procurable is found to succeed, except elm, and the 
diiTereut kinds of fir. A singular circumstuncc is 
asserted by the mannfacturem, namely, that elm 
timber, on distillation, does not afford acetic acid, 
but a watery liquor. Probably it atfordv a litilo 
acid, but so hide as to be inappreciable. Dry 
timber atTords a less abundant, but more valuable 
product. It should never be used in log, but cleft, 
as otherwise there would be much waste of fuel in 
permeating the large masses of wood by the heat. 
Taking the average of the different kinds of tim- 
ber, it may be stated, that the quantity by mciisure 
of tar obuiined, is about onc-twclfih of tlie product 
of the whole distilled liquor. The ratio of pyrolig- 
nenus acid can scarcely be determined, it dependa 
so much on the mode of applying the heal, the age 
of tlie timber, and various other circumstances. 

Generally speaking, a gallon of the liquor, as 
di<«tilled fruru the average charge of the retorts, 
afror>l:<, when saturated with lime and evaporated 
to dryness, about one pound of acetate of lime. — 
And a pound of acetate of lime, when put through 
the prticesa of decomposition, by sulphuric acid, ns 
already described, is capable of affording five pints 
of good house vinegar. 

Instead of the apparatus just described, namely, 
the cylmdrical retort, some manufacturers make 
use of tlic ordinary still, head, and worm ; the two 
former parts of the apparatus being made of cast 
metal, and the latter of copper. Various nxidih- 
calions of the apparatas have been also inlroriuced. 
Formerly, the inHammable gases generated duriug 
the distillation of the wood were allowed Co escape 
into the air; at present, they aro conveyed, by 
meAus of a tube springing from Ibe retort, tiitn the 
furnace where the fire is bunting, and thus contri. 
bute to heal the rcLurt, and cause a cortsiderable 
saving of fuel. In burning, the gas product* ■ 
flame possessed ot sufficient illumioating power to 
render ic an object of some consequeniT in this 
respect. The iufUoiuuble gaa comes over chirtfy 



MAGAZINE OF SCIENCE. 



during the last Itirre or four hours o( the diitilU- 
tinn. IL8 illiiminahnf power is at I'lrst very feeble; 
H then iocreaws; ia at iu tn&xitnum towards the 
■imI ; it then tudUfinly diminisbea ; in a abort time 
It docA not exrf rd that of the hydrogen; immodi- 
ttrly afifp, tbc flame goes out, 

TtiLTf 13 another prucem for purlfyiug pyrolig- 
neoits vinegar, nlitch hu been employed, and pre- 
sents a very pure aceltc nrid ; it ia thus described 
by Thfojird : — Ai much chalk ia added to the im- 
pure luid as can be decompo«ed by it at the ordt- 
nnry temperature ; a bUckUh-browu froth is formed, 
which is carefully rrmored. The liquor is then 
mndo to boil, aod the saturation is finished with 
lime. A proper quantity uf sulphate of soda is then 
added, which produces acetate of soda, and «ul- 
phitta of lime, the latter of which hnng iusoluNe 
preoi^tAte), and drawi down aJong with it oiure or 
less tar. 

^\ hen the atUph&te of Utne hae subsided, the so- 
lution of acetate of soda is dec-anted 09*, and is eva- 
porated to a pellicle ; on cooling, it concretes into 
a oryilolltnc mass. This is very impure : it ia 
bUck ; and ta fpreatly impregnated witli tar. It ia 
purifu'd by causing it to undergo the igneous fusion, 
re>dissu1ving it inwntrr, utid crystallising it at least 
ouL*c ; during the fusion, the tar is either volatilised 
or CMfbontsed, and the cry^uU formed are peroepii- 
hly purified. The crystals thua obtained are dis- 
frolvett in water, and sulphuric acid ia added : sul- 
phate of soda is producf^d, which crystallbes almost 
nnliivly ; and the mother liqnor, being diatiiled. 
alforiJ^ puro acetic arid. Tl^e specific gravity of 
the acid prepared at Choisy is 1057 : it is capable 
uf saturating about tliree-tentha of its weight of 
subcarbonate of soda. 

Hie following method of purifying pyroligneous 
acid hits been given by Berzelios : he saya that it 
may bo deprived of even the last traces of empy- 
reuointic oil by means of nninial charcoal. He 
found that the carbonaceous reaijnam left in the 
mahiMg of Prussian blue, wWn the prusaiate of 
pntash has been extracted, pnsftcsses this property 
to such a degree, and so cn*ectually removes Che 
etnpyrciiraotic taste, that the smallest qnantities 
ar<; suSirimt ; nml that it in only necessary to mix 
the acid with the rbsrcoal, and filter forthwith. He 
proved, itlsu, thut the arid (hua deprived does not 
lerovcr ita t^mpyrruma^ far some that had been 
loosely corked in a bottle was, after flvo monthi, as 
good as ever. 

Lowiut li>ne oira showed tlie porifying power of 
rommon chArcnal on pyroligneous acid. He says, 
**'rhi^ mi called acid of wood, which I obtained by 
distilhtliun from lignum vitic or guaiacum, was like 
vinegar very readily purified by distillaiion with 
rharrn^l, from the great quantity of empyreumatic 
oil which adheres to it. It thereby acquires the 
tjole and smell of distilled vinegar ; and after con- 
centratini^ it ta a very high degree by one of my 
new methods (freezing), 1 hare brought this acid of 
wood, as it is termed, to crystaUisc in the same 
manner as Tii)<>gar, and have thus obtained a true 
glatnal vinegar." 

It !(«» bren atccrtaiiicd that pyroligneous acid in 
its unpurified stnt.: possesses the remarkable and 
usrful pmperty of prtvcniiiiQ the piitrefsctiDu of 
anitnat Auhttsures, and etcn uf clitrckmg putrefac- 
tion when livt;iin. It has been always known that 
srookud provisiuus keep better than those which 
have been dried, an efl'cct which seema to depend 
on the imprr^nation of pyrolif^itoue acid, which 



they receive from the rmokt ; for it t» turf emoki 
that IS rmployed, and tnrf b; dttflillalion in dose 
vesseis affords pyroligneous acid. The fullimtac 
account is given by Mr. Hamsay of npcnmwiu 
made by him : — A number of herrings were rle«Deil 
Ofl the lOUi of July. 1819. and. without bcini^ saltrd, 
were immersed for three linurs in ■' * '- ' — 
ncooa acid (sp. gr. 1012). '\Vheik 
were softened, and not ao firm a* ^ i 
out of the common pickle. They were bun* up u 
the shade. July and August wf re very hot mnndis 
— but the herrings had no sign of putrefaction 
aboat them, but had a very wbulesome smell roo- 
hined with that of tlie acid. One of them hciii| 
broiled, the empyreumatic aaell was very atniBig. 
The rest, in six months, were in complete pnHiw. 
vation. 

U was afterwards found that the period cf li^ 
mersion had been too long. If the fish be sbnpl| 
dipped in acid of specific gravity 1012. and dned 
in the shade, it ia sufficient fur their preserMAtt) 
and Hurh herrings when broiled are very a, 
and have not the disagreeable empyreomatic of 
former. 

A number of haddocks were cleaned, split, 
slightly sprinkled with salt for six hours ; tlinn ba> 
ing drained, they were dipped, for about 
seconds, in pyrollgneont acid, and hung in the 
for eight days. On being broiled they wera of 
uncommonly fine flavor, delicately white, andeusd 
to the highly esteemed Fintun haddock, no- 
rings wer« t:ure<l in the same way as the 
After beini- dried iu the shade for two moathl, tkm 
were equal in quality and flavor to the best ni 
berringa. The fiah retained the shining and fi 
appearance which they had when taken from rhe 

A piece of be«f waa dipped for mie 
pyroligneous acid (sp. gr. IU12) in Jti' 
On March 4th. 1H20, it was as firce from t 
when first immerted. No salt was oaed in 
periment. A piece of beef was dij*;"*' '* '^ 
time in pure vinegar of specific ;-! 
was perfectly free from taint on tin; 
her. This experiment indicates sntiiwpHc: 
in pure vinegar ; some haddocks wcrv cured with 
which remaioed free from taint, and. nheaooo' 
had an insipid taste. 

Dr. Jorg, of Leipxig, repeated acme of cfaese 
perimenta, and with success. He even 
perfectly in making BDatoinical prBpmratMHW 
pUcation of pyrolig;neotts acid. 

It has been already stated, tbst ia the 
distillation of the pyroligneous acid, Ifae 
duct that comes over is of a peculiar miture* 
rjilled wood.ftjnrii. This is purified by 
ttllations from some alkaline subatancr, 
from oxyde of lead ; and when aufficiciOly 
it assumea the appearmnca of a tnmapsfial 
nearly colorlesa fluid, poaaessiog msoy of 
pcrtiea of alcohol. At first it waa 
tical with aleobot ; bat there an pointt of 
ence. It ia highly inflammable) aod bamo 
pate flame, emitting very little light. It 
culiar penetrating smell, and a *trutig 
ethereal taste. It disaolves Indian rubber, 
forma a varnish applicable to a variety o< "'■'*■ 
This solution of Indian rubber is alao > 
manufacture of a useful and beautiful v- 
wooUen cloth. Wood-spirit dissolves reaiasc 
hence is used, by some makers of watcr-proflf 
as a leas expensive 
their nroccu than ali 




MAGAZINE OF SCIENCE. 



9f 



•spirit tft aiUled by cbeniuts pyrortlic 

-...I :.:^^ fronj nitiriate of Um«, JL is 
gi . It boil* at l.'iO"'. It burns 



l'- 



Dy reaiiiuum. 



ATALANCHER. 

of the great and rarioas phcnomnit 
V irogbt not to omit tho»r tremcndoufl 
drstmction, the nvalanchri, prculiJir to 
countries, tlutt frttqucntlr clo6c up 
lUeji ; nllKT the courvea of rivers, and 
fcheir oTerwfaelming maitscB, entire dia- 
their towns. viUfifes, and inhnbitinta, 
hurry into eternity without a moment's 
ice. 

I which ure subject to tlie particular 

fraUnche, sometimes termed ■ I^and-Mlip, 

itghi-bcrg and Ross-bcrg, are usually 

M Breccia (which seeniB to be u conglu- 

■ Band and stooes, more or less firmly 

Ikgetber), that is peculiarly liable to be 

y rains and rrost, siid even by droughts, 

r«d to open in large fissures, that soon 

by the melting: of the snows, or by 

in tan\ being acted upon by frost, bursts 

I detaches hagcniiuses that^come rolling 

noise like thunder, bearing ererything 

into the vnlleyn beneath. Thi$ pro. 

ler expanding by freezing, is so well un. 

Roaaia, that in some parts they avail 

of it* aa we dn of gnnpowdcr, for the 

. rodca — alt that Ja necessary being to 

^a. aa in the other case, in the direction 

it to split, and thus Ichtc it to nature l<i 

rrst. The apertures ore soon filled by 

rhich fall in Uh: early part of winter, Htiil 

sdTaoces, the work is completed by 

IVeca ond roots, which are often of a 

there* arc frequently i^plit by the same 

^ro lo the subject, another powerful 

operates conjointly with the others in 

[great renta in theae mountains, is found 

txamaUtioa of vast niiuues of cungenled 

adhere to the peaks and overhanging 

neight of which is often sufficiently great 

mountain to separate. This whs sup- 

T been tlie case with one at the RaaB> 

took place at p. ra., on the 2nd of 

1806, as it was particularly remarked of 

e had been almost a continued full of 

the months of July and August pre- 

aeded by hciivy rains, and snbseqoently 

en load reports like the cracking of the 

been heard at different times. The 

however, which had, no doubt, 

taoaped obMrvntion at the time, from 

Vtance of tlie rauuntAin being thickly 

Kb wotHl. On the day on which tlie 

occtnred, not more than thret or /our 

1 any intimation of what was going to 

loae people were at work on the lower 

Boonlain, but being alarmed by the in- 

« they heard, and hnnlly by a vibra- 

ri itself, they had only time to 

-, wilLuut being able to afford 

v.. u.. Ttllugea and^ inhabitants that 

At last the mountain was 5ccn to 

the whole 4>f thitt pure wbn-h e:ttendei) 

^pitzbugiU and The Steinbergrrrtonc. 

ood came down, bnaging with it a 




whole fbrcal of trees, with a horrible crash, cover- 
ing nearly two-thirils of the beautiful, smiling, and 
hitherto peaceful valley of Goldau, ond a Bmrtll part 
of Bonsingheo. to a depth of perhaps '201) fret, and 
burying ander the niins the Tiltaf^es of Goldau, 
Rousinghen, Ober-Roethcn, Unter-Roelhen, ami 
Lowerts, together wiih their inhabitants, formerly 
so celebrateil in thcAo [wrta for their fine appear- 
ance, their bravery, and frugal and iadustrioua habits. 
Fovr Aimdre'l and Ihirhf-thtrc personit are known 
to have periihed on this unfortunate occasion, in- 
cluding tixfeen tonrists or strangers from vuriona 
parts, and eigM individuals that were known to bo 
there from Berne and ArEovi(^— whilst about Jhe 
hundred and thirty more were ruined by the entire 
destruction of their property; and what added to 
the loss of the latter, was the circamstance of some 
part of the debris having fallen into the western 
part of the lake of Lowertx, and forcing out the 
waters upon the land, swept with tUem, on iheir 
return back into the lake, many hoaaes with their 
inhabitants, that were placed m iu vicinity. The 
hltle valley of Goldan, which, before this, was con- 
sidered one of the most beautiful and fertile in all 
!<!witserland, is very narrow, having on oppofite 
fl1de«, the Rigbi. and Ross-berg, and is about two 
leagues in length, terminated at one end, by the 
lake of Zoar — and at the other, by the lake of 
Lowerti. Of this extent, about one leagne was 
covered over by the avalanche, and so completely 
did it reach across the valley, that the base of the 
Righi on the opposite side waa covered up to some 
height. 

Of this dreadful event, a traveller writes «a fol- 
lows : — " Whilst walking on the ruins of the moun- 
tain, which are heaped in horrible confoaioD on this 
spot, and. over which, a road has been cat to Art. 
it prevents to our view masnea of nibbtsh and rock 
(some aa large as a house), indiscriminately piled 
on each other, and intermingled with fragments of 
trees, of which some were seen with their stems and 
branches fixed in the earth, and the roots in the air; 
and bemmnl in us this valley la by monntains ot> 
each side, one seems to contemplate here the wreck 
of all the visible and material world around. The 
force, too, with which some of these tmmenae block* 
descended, muat have been very great, when we 
consider that the height of the Rosa-berg was about 
3,500 feci; and it was a melancholy thing to redect, 
that under the apot on which we were now tread- 
ing, were conceded for ever from our view thoae 
peaceful villages, with their inhabitants, who were 
surprised amid their peaceful and domestic occupa- 
tions, and hurried in a moment from the light of 
the world/* 

A gentleman of the town of St^hwitz, in thia vici- 
nity, who collected many affecting detatta of thia 
event, aaya — that in that town sncb was the 
uproar and noise it made, rrverbemted by the 
nnrrounding mountains, that the people actually 
thought the end of all things was arrived ; and tlita 
isi not tu be wondered at, when we are informed 
that BO great were the clouds of dast, of snow, and 
of water, which it sent up, that the air waa com- 
idetely darkened, and the sun hid from their sight 
for the remainder of that day. Amongst others 
which he mentions, the case of a [loor girl and a 
rhild are particularly remarkable. Tliey were walk- 
ing together in the garden of their cottage at the 
time the catastrophe happened, and the only oc- 
(ount of it the x;irl could ^ive, wmh, that she founil 
herself in an instant in the aituatiou innhiclisUe 



94 



MAGAZIKE OF SCTEI^CF. 



wtfl discoTrred, with hrr body j«romed in the earth, 
her heHd duwowardi, uid her feet ia (be air In 
this frightful pokition, her eyM forced frnrn their 
tooketji, and stretroing with blood, did thi& poor 
girl rcrniin for teTeral houn, during wfairh shecnn- 
versed with, and endeavoured to pacifv the child, 
which cried piteoasly for food, and which she found 
wan covered over by a «toue near lo her, and un- 
hurt — at tirst she tried to peniuade it to go lo »leep, 
and that some of the family werr coming to its re- 
lief — but despairing at last of thit, she encouraged 
it to say its pravcrr, and they were thus engaged 
together, when tbey were ditcovered by the subbing 
and crying of the child, which fortunately directed 
some people to the spot, who had gone out from 
Schwitz to »fe if there were any left to whom thry 
could afford succour. It is interesting to humanity 
to learn, that this poor girl actually survived, 
though with a total deprivaiion of sight, and a 
dreadful horror of the event ever afterwards. She 
haa of often said since then, that the greatest pain 
ahe felt during the time she was covered over, wan 
ftrom the excessive cold in her feet, which it appeara 
was the only part of her that was found uncovered 
and exposed to the air. 

Id varioaa parts of Switzerland, accidents of the 
kind here described, are perpetually ocrurring, and 
it waa only five years before, viz. in I HO I, that a 
considerable one took place in this neighbourhood, 
from the Right, near to the hnmlet of Sigiker, at 
which time a large portion of the mountain was 
precipitated into the Lake of Lucerne, which re- 
pelled the waters to such a degree, that by their re- 
Mux upon the land, they swept away several houses, 
atabling, and saw.millR, pUred at some considera- 
ble diatance from its banks; by which eleven per- 
sons are said to have perished. The agitation of 
the waters of the Lake on this occasion, are re- 
ported to have reached even lo Lucerne, a distance 
of, perfasps, six or seven miles, and did some 
damage to the shorea on the opposite side of the 
Lake. 

In point of extent and consequences, one which 
occurred lately in the valley of Bngnes, deserves 
to be mentioned, as it was attended with circum- 
stances very peculiar. This valley being very 
DBrrow, and almost entirely occupied with the river 
Drance, was stopped up near its source, by an 
avalanche, and the river being in consetiuenre dam- 
med up, a vast accumulation of water had taken 
place, so as to form a lake of considerable size be- 
fore it waa discovered, owing to tltc retired situa- 
tion of the place, ud being but little frequented 

As soon, however, aa it became known, it created 
a great sensation for the safety of the conn try, and 
the inhabitants along the whole course of that river, 
to where it joins the Rhone, above Martigny ; and 
afterwards to the Lake of Geneva, where the Rhone 
enters the latter near to Villeneuve ; a total extent 
of 14 or ir> leagues, and this was not without rea- 
son, considering so vast a body of water, and the 
force with which it would descend, if let loose sud- 
denly from so great an elevation amongst the moun- 
tains. Public meetings of the inhabitants were in- 
atantly convened, and as the danger was pressing 
and hourly increasing, experienced engineers were 
employed to effect the making of a tunnel, by which 
to draw off the waters graitually ; when it was 
supposed the impediment might be removed, and 
the progrean of the work, as it took place, was 
regularly Muti6fd to the people, and signals esta- 
blished along the whole line, to warn the inhabi- 



tants when the danger should seem re 
so as to enable them to rnnore tbei 
their storks, to places of safrtv. Not 
the excellence of these regulationt, 
danger could not be averted entirely, 
work waa considerably advanced, the 
throngh the tunnel, blew it up, and mpta 
hy which the nhole body of the water 
pcctedly set free, carrying away bridge 
habitants, with their cattle and gooib, M 
everything that was opposed to it 
lengthened course towards the lake. Al 
and Idm of lives it occsaioiied were vei^ 
the particulars were pubhshed in all ihfl 
at the time, we need not occupy our 
recapitulritiou; but the loss of livrs wt 
still greater, had it not fortunately 
very early hour, before the workmen 
to commence their work. Two of oor 
and their guide, who had gone up 
works early that morning, are aaid 1 
the unfy persons who witnessed tba 
escaped, by proceeding rapidly up a pr 
in such haste, tliat the horse, belongia| 
them, was lost. Certain it is, they 
terror to Geneva, and were the firvt 
accident known there. 

Another kind of avalanche is that 
posed almost entirely of congealed i 
and which ia so frequent riiout 
Chamouny. and other places, wbers 
glaciers ; that these valleys an* coustani 
ing with the noise of the falling bodies, 
re-echoed hy the mountains around, 
hke thunder ; and in some confined pli 
bration which is occasioned in the a 
firing off a musket, will sometimes 
siderable portions of it. When any of tl 
of snow arc sufficiently large to block 
or road, whirh ia of frequent occui 
come so condensed and (irm, owing 
weight, and fulling from such trcmeodi 
that a traveller on horse-back may pi 
in aafety, without fear of ainking. 71 
Valoraine and Tete-noir, was once clot4 
avulnuche of this nature, under wbid 
Trieni had worked itself a pissage, fiaf 
gutar arch through its whole extent, 
bridge travellers had occasion lo cross 
back more than once ; and in one or 
where the arch had fallen in. they 
near enough to look through the openii 
the torrent spending its rage underneath 
in the month of May, when the sua 
to be powerful, and a week after its fall 
few days more, they said it would be 
for about three weeks or a montb, after 
Ihc whole would disappear, and be 
the riwr. 



OF GASEOUS ANALYSI! 

This deportment of -chemtatrv, wh 
portance was l^rst shown by Cavendiril 
and BerthoUet, baa lately acquired ni 
consequencT of M. G. Lusaac's doctrine) 
his determination of the specific graritiel 
and sagacious application of both prnic 
derelopement of many combinations hit 
cate and inexplicable. 

Let us first take a general view nf thv 
of the different gaaea. Some of Ihea 



IIAGAZINE OF SCIENCE. 



95 



itf white vapori in the air; sotnff relume 
rilled k paint of its wick remnins i^nileil ; 
Did and redden tincture of litoiu» ; one 
imell. or bat ■ fnint one; a ai^rond set 
Ittble in water ; b third Nre suluble in 
ationBt and a fourCb are tbemaelves 
Somtt guei posaeaa aeveml of these 
t onoc. 

ttored goMtM ore nitrouii acid, chlorioe. 
le and deutnxide of chlorine. Tbe firat 
eat yellowish-green, or yellowish. 

produeing trAi/e vapora in the air. 
d. duoborie, lIuoHilicic. and hydriodjc. 

mfiammtUtle in air by contact of the 
r. Hydrogen r labcarbaretted and car- 
IroKeo. I ubphospbu retted and photphu- 
%cn, sulphuretted hydro^n, anMmuretLed 
lUuretted hydrogen, potauuretted hydro- 
}ua oiide. pmnine or cyaDogen. 

which re-kindle the expiriag taper. 
Dtoxidc of asote, oitroiu add, and the 
loriae. 

{[aaes, which redden litmua. Nitroua, 
nufiatic. fluoboric. hydriodic. lluosUicic. 
lOua, and carbonic acid ; the oxides of 
phuretteii hydro^^n, telluretted hydro- 
isaine. 
dmMtUute of nmelit or possesKing hat a 

Oxygen, azote, hydrogen, lubcarbu- 
carburetted hydrogen, carbonic acid, 

axote. 

lall of aU the others is iniap portable, 
Ij frharocteristic. 

Krry Bolubit in water, namely, of which 
es more than thirty times its volumn, 
reaanre and temperature. Fluoric acid, 
Mtlicic, oitrous, sulpharous, and am- 

§oMiU in atiatine soluttoni. Acids, 
huroufl, roariatic, fluoboric, hydriodic, 
llorine, carbonic, chlorocarbonoaf ; and 
e« of chlorine, lulphurettcd hydrogen, 
rdrogen, and ammonia. 
m9 gaaes. Ammonia and potaasuretted 

general outline of the chnracteristics of 
The great problem which now yrtttentt 
Ulermine bt/ eTperimenU the nature qf 
IS, or goneiiiu miiiuret which may come 

U a little glasa tube with it. and expose 
on of a lighted taper. If it iaflam», 
iie eleven above enumerated, and must 
ited by tbe following methods : — 
dees fire spontaneously on contact with 
g a Tery acid matter, it '\* phogphuretted 
Sabpbospharctted hydrogen, or the 
; of phosphorus, does not spontaneously 

!r b« capable of decomposing it, and 
it aaddeiily into hydrogen gas and 
I we can eaiily ascertain by transferring 
5Uod with it, from the mercurial trough, 
containing water, it is potaaturetted 
Dr Ure found in experiments on the 
f poiaasiuni, by passtn)^ pure ))Otash over 
turnings, of which nomc account was 
t 1B09, that potassuretted hydrogen 
y inflamed. M. Sementioi has made 
terra tt on. 

•aa a nauseous odour, ts insolable in 
i Oft the aides of the t^st tube in which 



wa hnm it, a ehcRnut brown deposit, like hydmret 
of arsenic, and if, after a^ptation with tbe quarter 
of ita Totamn of aqaeons chlorine, a liquid is formed. 
frt)m which sulphuretted hydrogen precipitatea 
yellow flocculi, it is artenurelled hydrogen got. 

\, If it baa a strong atuell uf garlic or pbosphonaa, 
if it does not inflame sputitaneously, if tlie prodnct 
of its combustion strongly reddens litmus, and If, 
on agitation with an cxcesa of aqueous cblurinr, a 
Liquor result!!, which, after evaporation, leaTca n 
very sour syrupy residuum, it ia ntbphosphuretted 
hydrogen. 

b. If it hss no smell, or but a faint one, and if it 
be capable of condensing one-half its volamn of 
oxygen in the explosive eudiometer, it is hydrogen. 

6. If it has a faint smell, be capable of con- 
densing in the explosive eudiometer oue-half of its 
volumn of oxygen, and of producing a volamn of 
carbonic acid equal to its own, which is ascertained 
by absorbing it with aqueous potash, it is carbanou* 
oride. 

7. If H has a faint imell, if one of the products 
of combuation is carbonic acid, and if the quantity 
of oxygen which it condenaea by the explosive 
eudiometer, corresponds to twice or thrice ita 
volumn, then it is either tubcarburetted or carbu- 
retted hydrogen. 

B. If it diffuses the odour of rotten eggs, if it 
blackens solutions of lead, if it leaves a deposit of 
aalpbnr when we bum ii in the test tube, and if it 
be absorbable by potash, it ia sulphuretted hydrogen. 

9, If it hns a fetid odour, approaching to tliat of 
sulphuretted hydrogeD, if it ia absorbable by potash, 
if it is soluble in #iiter, if it forms with it a liquid 
which, on exposure to air, lets fall a brown pulverulent 
hydruret of tellurium ; and lastly, if on agitation 
with an excess of aqueous chlorine, there results a 
muriate of tellurium, yielding a white precipitate 
with alkalis, and a black with the hydrosulphureta, 
it is telluretted hydrogen. 

10. Pnutine is known by its offensive and very 
peculiar smrll, and itn burning with a par]de Hame. 

If the gas be non-inflammable, but absorbable 
by an alkaline solution, it will be one of the Ihirteao 
following : muriatic acid, fluoborio, fluoailtcioi 
hydriodic, sulpharous, nitrous, ohlorocarbonooa, 
carbonic ; or chlorine, the oxides of chlorine, 
prussine, or ammonia. The firat four, being tbe 
only gaaes which produce white vapors with atmos- 
pheric air, from their strong affinity for water, are 
thus easily distinguishable from aU others. The 
Jtuoritieic ga* is recognised by the separation of 
silica, in white flocculi, by means of water ; and 
hydriodic go*, because chlorine renders it violet» 
with the precipitation of iodine. 

Murintic acid gan, from its forming with solntion 
of silver a white precipitate insolable in acids, but 
very soluble in ammonia, and from its yirlJing with 
oxide of manganese a portion of chlorine. Fluoborie 
gas, by the very dense vapors which it exhales, and 
by its instantly blackening paper plunged into it. 
Nitrout acid gat is distinguished by its red color. 
Prutojide of cJi/ortne, because it is of a lively 
grernisb-yellow hue, because it exercises no action 
on mercury at ordioory temperatures, and because, 
on bringing ignited iron or glois in contact with it, 
it is decomposed with explosion into oxygen and 
chlorine. 

Dtutojride qf chlorine is of a still brighter 
yellowish -green than the preceding, and baa ■ pe- 
culiitr aromatic smell. It does not redden, but 
blaochea vegetahle blues. At 212^ it cxplodea, 




9$ 



MAGAZINE OF 8C1KNCE. 



evolving oxygen and cliloriae. (^Uurine U ilit- 
tinRiiifihfd by its fainter 7«llanrish •green mlar, by 
iti lutlcring no change on beini^ bested, by iti dc- 
•Cruytiiie: C(»)(iri, and by its rapid combtnaCion witli 
niereiiry at common tern perntu res. SH^hnrott* 
and, by ita smell of burning aujphur. Ammtmiaj 
by itA odour, alkaline propertiea, and the denae 
while vapors it formfi vriih gaseoiu acids. Cftlon^ 
caHnmoug gn» ii cunvertcd by a very »mail qiiaittity 
of water into a<)acou.i( muriatic acid, and (urbnnir 
ftdd, whicli Tf^Xti above. Zinc or antimony, aided 
by beat, resolvea it into carboooiit oxide giu, whUe 
ftSoUd metallic chloride ia formed. With tlie oxides 
of the fame motaU, it forms chlorides, aod carbonic 
add, while in each caac tUe qanntity of gaseous 
oiidc of carbon, and carbonic mad disengaged, is 
equal to the vuluwn of clilorocarbonousgss operated 
on. Carbonic arid ffot is colorlesi, aitd void of 
siDcU, while oil the other gam-s absorbable by tlie 
alkalis bave n ttrong odour. It hardly reddenf cvtn 
very dilute tmcttirr of litmus ; it gives a white clood 
with lime water, from which a precipitate falls, 
•oluble with (iflerTpscfnce in vinegar. 

[f. linnlly. the gas be fneiiher iDflsmroable nor 
capable of being absorbed by a solutioii of potash, 
it will be oxygra, asote, protoxide of azote, or 
deutoxide of nsole, Ojypen can be mistaken only 
for the protoxide of azote. Thu property it posaesaea 
of re-kiodling the expiring wick of a taper, dk- 
tiDgaishef it from the two other gases. They arc 
moreover charanteristid. First, btcaosc oxygrn is 
void of tasrc, and capable of condensing In the ex- 
|dosive eudiotnelt^r twice its Iploiiin of hydro^^en 
gaa ; the protoj:id*^ qf' azote, taVauBe it has a sweet 
taste, is soluble in a little less than half its voluma 
of cold water, and because when dctonHted with ita 
nwD vnjamn of hydrogon, we obtain a residuum, 
c^mtaining much ajsote. The two other gases are 
distingui<ibcd thus: — Deuloride q/'oso/e iacolorlesa, 
and when placed in contact with atmospherical air 
or oxygen, it becomes red, puniug tu the atate of 
nitrouH iicid Tnpor Arotr ie void of color, smell, 
aad taste, extinguishes combustibles, experiences no 
change on contaiet with air^ aod produces oo cloud 
with lime water. 



ON BEN NUTS. 
BsN Ki'iv are the fruit of a tree which f^rowa Id the 
Indies, Ceylon, and Egypt. Linnieus calls it guU 
Umdia moringa; but Lamarck has changed it to 
mormga Znlinica, or M. oiei/va. Its fruit is a 
three-volved pod, full of a white Hesfa. and a number 
of three-cornered seeds, the sixe of Urge peas, co- 
vered with a thin, tott, whitish-grey shell ; these 
seeds coDtoin a white oily kernel, of a very sweet 
taste. 

The oil of ben ii obtained by pressing these nuts : 
this oil is swoet, loentlees, and scarcely ever be- 
comes muk ; by cold it separates into twu parts, the 
one solid, the othtr li(|uid. 

The property pouesied by this oil, of not becom- 
ing rank, has made the watchmakers use the lujuid 
portion of it for oiling the wheels and other wurks 
in watches and clucks. Nevertheless, partly on 
acconut of the difficulty of procuring good oil of ben, 
and partly from other motives, many watchmakers 
use at present the best salad oil. 

The oil of ben is used by the perfumers of the 
countries where the tree grows, not only because of 
its keeping so well, but also because, having no smell 



uf its owD, it th>es not alter that uf t}ie*roinati<! s«A- 
stsDoewilh which they tmprrsrn''' ■' "n.r^ i,* *k. 
flowers of tuberoses. jcfMun 
aceiiled flowers, wbi^h yield u 
in beds, in a clove pewter vessel, along muk 
cotton soaked in this oil ; the reasel is Chen 
for some time in boiling water. When th« 
judged to have Itub^bed tlie scent, it is 
from the cnttnn by llie press. OiJs thus prepsMrf 
nre L-ulled AuUrs antiqum, as being the oldest mednd 
of prrpinng scented oils. But the perfumenu 
the uortli of Europe mostly imitate these oils, ky 
udding easeutiaJ oils lo the best salad oil, or tu AS 
oil : and, in tome cases, by ahaking up eithwr of 
these oils with spirit of wine distilled off the flo«er«i 
Kheii the oil abaorhs the aroma of the flowcn Mot 
befwmas scented. Thase svhetitutioos render the 
nil of ben R-arce in the cooatries where the liM 
does not grow, by diminishing the demand fur it 



MISCELLANEOUS EXPERIM 

DfLAVr n landscape with Indian ink, and 
foliage of Tegetables with muriate of cobalt,,^ 
some of the flowers with acetate of cobalt, 
others with muriate of copper. \\Tille this 
is cold it will appear to be merely an ootUaei 
landscape, or winter sceoe, bat when gently 
tlie trers and flowers will be dupfagtd m 
natural rolorK, which they will preserve Oftly 
they continoc warm. This may be often 

Write upon paper with a diluted solution of mV' 
riste of copper ; when dry, tt wUl not be visible 
but on being warmed before the fire the writiag viH 
become a bcnntiful ye//mr. 

Into a large glass jar, inverted upon a flot bnci 
tile, and containing, near its tup, a limiuli 
rosemary, or any other such bhrub, moislcntJ «J 
water, introduce n flat (hick pieoe of heated 
which place some gum benzoin in groas poi 
The benzoic acid, in consequence of the hta^i 
be separitcd, and ascend in while fumes, which' 
at length condense, and form a most beantitf 1 
pearaoce upon the leaves of the vegetable. 
will serve as on example of mblimation. 

Mix a little acetate uf le^d with an njunl 
of sulphate of zinc, both in flnc powder ; stir 
together with a piece of glu^is or woo^l. and 
chemical change will be perceptible ; but if ttap 
be rubbed together in a mortar, the two sr>bd« m 
opcnitc upon each other, an intimate union td 
take place, and a Jtvid will be froducett. If i 
or Glauber ault be used instead of sulphate of iltali] 
the experiment will be equally surcessful. 

Curious Motion produced in Liquids by Hntm§ 
and Cooling them. — Fill a large phial with wi 
and put into it a smalt quantity' of powdered 
having previously added to the water a 
quantity of potosh, to make a solution of the 
suecific gravity ss amber. Immerse the pMll 
giBBS of hot water ; upon which a vvry 
internal rnotioo will he immedistelr perccii 
current of the fluid will rise up the aides 
phial, and another descend in the centre of it Kl 
take the phial out of the hot water, and obtcrrf tW 
cffectsof its cooling. The currents will tf 
the external one will descend, and the in 
ascend. The use of the powdered amber i« 
the opposite currents into which the water is 
visible. 



LsMOOM :— Printed bj I> FajLMCii, 6. Wbilf Uona Laos. UU« £Bd.-4*ttbliiheil by \V. SairzAiM, II. I'alai 



Bv*. 






THE 



AGAZINE OF SCIENCE, 

Stnii School of ^rt0. 



•ATlTKt)AT. JUKE M. 1841. 



[IK 




9S 



MAGAZINE OF SCIENCE. 



ATTWOODS MACHINE. 

FOR ASCKIITAJNINO TUE LAWS mCLATIVX TO 
rAXLtlCO BODICS. 

A RSrKKSXNTATiON^ of thii buutifal and nsrful 
suatriTance is given ia the engraving. A B C U 
ibe rim of the wheel over whtrh. the ihrrad sua- 
taintng the weighta paast-a. Tlic enda uf thr aile 
of this wheel rest upon the rims of two pairs of 
wherif, at h rcprrsentcd in the ftgun-. The itnnd 
oarrjtng the apparattia ia EiippnrrrJ by a strong 
pUlnft and imiuediately under tliia tittiiid ia placed an 
upri)[ht ahaft. divided into inches, Iialf-inchcs, and 
tenth*, for the purpose ofmeaKiiring the rate of de> 
scent. E and F are two eqaal cylindrical weights 
fttupended from the ends of the thread, which rests 
in a groove on the edge of tlie wheel A B. H ia a 
imall stage which can be screwed upon the gra- 
dnnted ihaft. at any particalar division at which it 
Is designed to stop tlie dc&cent of the weight. G ii 
ft clock, attached to the principal pillar, which beats 
Moonds, in order to mark the rate of descent. 

The wcigliU K P are, commonly, ao adjusted, 
that, by placing on the top of the cylindrical weight 
F a weight O uf a quarter of an ounce, the weight 
F will descend Ibroagh three inches in one aecund. 
Thus we hare obtaloed an ac<:elurating force, which 
b sixty-foor times less than that of gravity, and yet 
which retains all the characteristic pecnliaritiefl of 
that force. In fad It u the force of gravity oor* 
icctly rcpreaented in miniature. 

We shall now show how this machine Is applied 
lo estabUih by experiment the laws which regulate 
Ihe descent of heavy bodiei. 

Ex. 1. — To establish these lawi by experiment, a 
ring I is provided, Bttache<l to a bloclc 1), which rnn 
be Axed by a screw to any division of the grudaated 
shaft. A bar of metal J ii also provided, weighing 
a quarter of an onncf?, and longer than the diameter 
of the ring I. I-/ct the ring I be (Ued by the vcrew 
to any division of the icdle, and let the ytnge H be 
■o fixed, that when the weight P rests upon it, the 
top of the weight will be six inches exactly below 
the ring I. This done, let the weight F be elevated 
by drawing down the weight E, until the top of the 
weight K is exactly three inches above the ring I. — 
Holding the weight F tn this position, let the bar J 
be placed upon it, and observing the heats of the 
docli, let the weight F commenre its descent with 
tnybeat. It wlU be found that the stroke of the 
bar J on the ring I will exactly coincide with the 
Dext beat, and that the stroke of the weight F on 
the stage H will coincide precisely with the succeed- 
ing beat. It will be observed, that the accelerated 
motion of the weight F for the first second,, and 
before the bar strikes the ring, is entirely owing to 
the action of tht force of gravity on the bar. When 
the bar is taken off the weight P by the rin? at the 
and of the first second* this cauee of acctleratioa 
ceases, iha aetion of gravity is ituspeodedf and the 
weight F moves oo to the stuge If with the velocity 
which it bad acquired at I. Now we hitve seen 
that this velocity was such that it moved through 
six inches in one second. 

Kr.2. — Again, let the stage be placed so that whan 
the weight F re«a upon it, the top of the weight will 
be twelve inches from the ring I, and let the wei|;ht 
K be depressed until the top of the weight F is 
twelve indies above the ring I. This done, let the 
bar J be plaoed on the weight F, and let that wright 
he disengaged at the moment of any beat of the 
eluck ; it wtll be observed that tbestroka of the bar 



a is£ 

-I 

atV 

"J 



J upon the ring I. will coincide exact 
third beat, tlie desrent through twelve ' 
made in two seconds, and that the 
weight F upon the ataje II will roinct* 
with the fourth heat, the weight moving i 
twelTc inches below the ring with the vt 
acquired in two seconds. 

Rx. 3. — Now let the stage H be 
moved, and pliced so that, when thi 
standi upon it, the top of the 
eighteen inches below the ring I. 
E be depressed until the top of the 
twenty-seven inches above the stage ~ 
bar J be Then plac«d upon the weight 
and permittini; the wctgiit to cooiiueni 
with the firec beat of the pendulum, 
strike the ring I mitli the fourth beat, mni 
V will Ktrilie the stAge U with the fifth 
weight, therefore, descends thnmgli 
inrbcH vritli an accelerated motion in Ihf 
and, at the end of that time, has acqiiirfi 
veiocity, aa to move through eighteen is£ 
second. 

Now let us review the results of thi 
penmentf. By the first it appears, that' 
acquirnl in one second b surb as to maki 
F move at the rate of six inches per 
the second experiment it appears, that th4 
acquired in two seconds is twelve inches |i^ 
md, by the third experiment, it ap| 
velocity acquired in three seconds is ei| 
per second. Thus the velocitaes aoqt 
two. and three seconds, are as six, 
eighteen, which numbers are as «nei 
Hence the law that " the velocities sec 
the time of acquiring them," is verifii 

In the first experiment the weight 
three inches in one »econd ; in the 
mrnt it fell through twelve inches in ti 
and in the third it fell through twenty-scve 
in three seconds. Now the oumben three 
and twenty-feven, are as one, four, and niii 
are the squart-a of one, two, and three, 
law that " the q)aces fallen through are 
to the squares of the tiroes," is verific 

la the first experimcot it was sbol 
velocity acquired in falling through 
was such aa would carry the weight 
time through m inches when eontioi 
and without further increase. In the 
periment it was shown, that with the 
quired in falling through twelve 
seconds, the weight F would move thi 
inches in one second, and it would, th( 
through twenty-four inches in two 
like manner, iu the third experiment* 
that wirii the V4>locity anquired in 
twenty-seven inches in three seconds, 
moved through eighteen inches in one 
therefore, would move through fifty-fa 
three seconds. Each of these rxperir 
fore, verifies the law, that, " with the 
body acquires in any time, it woafd, if U 
city were continued uniform, move tt 
that spare in the Funie time.'* 

Also by the first experiment it sp[ 
space fallen through in the first raeoiuf < 
was three inches. By the second ex| 
peared, that the space fallen 
two seconds was twelve inches. It 
foUowi, that the apaoe fallen through- i 
second must bsvs been nine inche*. 



MAGAZINE OF SCIENCE. 



99 



tfaetptee fallen throuich in three leconds 

ity-Acvsn iiichra. TAing from this the 

tm throagh \a the tint two seconds, which 

re inciu^*, the remainder, lifteeu inchei. Is 

faUen throogh in the third second. Thus 

described iu the first, second, and third 

of the fsll &re three, nine, and fifteen inches 

tnlf, which are as tlie numbers cue, three, 

!. This verifies the law that " the spaces 

by a fallen body Eu the succesiiTe equal 

ftre as the odd inte^en." 

Um beifhti from which bodies fall are pro- 

to the aqnares of the timrs of the fall, and 

Ivea are proportional to the velo- 

rs that tbe heights are propurtional 

of the Telodties. That a body may 

iblfl Telocity, ic is requisite that it 

a fonr-fold height, and so on. 

MANUFACTURE OF ALUM. 

• compoand §abstanoe, consisting of the 

anited with tbe sulphnric odd, n 

of an alkali, togetlter with tbe water 

lUsatinn. M. Thenard's onalyais of au 

with potash, giTca the following pro- 

in 1 00 portt : — 

Dry acid »«.... 54.23 

Potash 7.14 

AJomina 12.54 

Water 46.09 

1100. 
all portion of alnm is found in a nsUre 
; ud that mixed with heterogeneous maltera. 
yhoripally obt^ned by various processes from 
minerals called alum ores. The pnrrst of 
'US ores is the sulphuretted cbty of La 
ir Civita Vccchia, from which the article 
A!um tA made. The ore is wtiite, 
bard, whence it is called petra almni. 
1 1 It is found in veins, and is separated from 
«fpclt by bbftbig. Tbe stones are taken to the 
kiAf oven, which is simply a hole dog on a 
j;iioDB of gronnd about five or six feet deep, 
diameter, having a lateral gallery 
with tbe open air, and the bottom 
On tbe bottom are laid faggota, 
th* aluminoua stones are skilfully 
to form a hoUow rault ; between the 
of which the flame and amoke find a 
The ore is considered lo be suihciently 
it has acquired the peculiar swcot as- 
of alum. 

process is that of piling the calcined 
loaf beds npon a sloping floor, upon the 
of whioh is a ditch of water, which ex- 
whole length. From this ditch the beds 
itly sprinkled with water, which, aa it 
them, nmi bark into the reserroir. The 
iJanith begin to crack and full down, and 
days the whole is converted into a 
tread with a reddish efftoroaoeooe. 
next tilled with water and made 
tW prrpared ore is stirred into it by de- 
■ solatioo la obtained of the re<iuiGite 
it is then drawn off in a turbid state into 
whpreiii it is subjected to a very 
by which the superabundant water 
tbe earthy matter is deposited, and the 
eUtar. Being reduced to the point 
in. It is drawn otf into a SMuarc 



wooden Tessel. eight feet high by five feet wide, and 
constructed so as to be taken to pieces readily. In 
this vessel the solntion becomes crystalHxcd in a 
few days. The mother water is then ponred ovt, 
and used in the solution of fresh alum ore. The 
crystals being dried are ready for sole. 

At Soltofsra* a few miles from Naples, is a plain, 
Qt the top of a hill covered with a white soil, which 
exhales sulphureoos vapors, and exhibits, daring 
the night, tlie emission of a pale blue lambent light, 
in which state it boa continued from the age of 
Pliny to the present time. Tbe white, clayey soil 
being constantly penetrated with solphnreons vapors, 
which together with the constant wetting by tbe 
rain and due. the alum is thus produced by nature 
in large quantitiea, but In an impure state. It it 
therefore collected daily, and lixiviated in large 
CBuldroos, and afterwards crystallized in the usual 
manner as Ust described. The Abbe Mazeos pro- 
cured from sIt pounds of the earth of the Soltafara, 
two and a half poandx of cryatala of alnms. 

The most considerable manufactory in Greit 
Britain, is at Uurfleet, near Paisley, on the estate 
of the Earl of Glasgow. The next in magnitude ii 
that of Whitby, an interesting account of which, 
and the processes, was published by Mr. winter, in 
the 2^th volume of Nicholson's JoamaL The 
stratum uf aluminous schistos is of grcst extcnti 
and about twenty-nine miles in width. It is covered 
by s stratum of alluvial soil, sandstone, ironstone, 
shell and clay. If a quantity of the schistus be 
laid in a hesp, and moistened with sea-water, it 
will take fire opootaneously, and continue to bnm 
till tlie whole iatlammable matter is consumed. The 
ore is broken into small pieces and brought to tbe 
furnace or kiln to be calcined. A bed of fuel com- 
posed of brush-wood, upon which the ore is laid 
and piled up in tbe first place to the height of four 
feet, when the fuel is lighted. Fresh portions of 
rock are afterwards added, pouring it on tbe pile 
continually until it reaches the height of from 90 to 
100 feet, with its base nearly 200 feet square, and 
containing, in solid measurement, about 100.000 
yards of ore. One buudred and thirty tons of this 
calcined schist produces, npon an average, one ton 
of alum. Tlie calcined mineral is digested in water 
in large pits, from whence the liquid is drawn into 
cisteroB, and afterwards pumped npon fresh quanti- 
ties of calcined mine. Tbe strong liquor is drawn 
off into settling cisterna, where the sulphate of lime, 
iron, and earth are deposited. In some works tbe 
liquid is boiled to Hid the purification. The liquid 
is next poured into leaden pans, 10 feet long, 4 feet 
9 wide. 2 feet 2 inches deep at one end, and 2 feet 
B at tlie other, for the greater convenience of 
emptying. In these pans the liquor is concentrated 
at a boiling heat, then emptied Again into settling 
cistems, where a quantity of the muriate of potash 
is added, and then allowed to settle again for the 
spare of two hoars, when it is run into coolers to bo 
cryatAllircd. After atuuding four days the mother 
waters are drained off, to be pumped into the pans 
oa the Buccecding day. The crystals of alum are 
then washed in a tub and drained. They are next 
put into a leaden pan with as much water as will 
make a satnratt'd aolution at the boiling point ; — 
when tbia 15 eiTected it is run oH* into caKkt. In ten 
or tifteca days the caska are unhooped, and taken 
asunder; round the sides the alum u foond in Mlid 
cakes, but, in the inner cavity, in large pyramidical 
crystals. This Ust process la called roching. 



^QAU 




100 



MAGAZmE OF SCIENCE. 



POLARIZATION OF UGHT. 

{HctUTtitetJrx/m page S9.} 

AuoNorr cryiUUixed miDerals, there are manypcu- 
Kssing the property of polanxiog the light tnu- 
mittcd through them ; tbu most retutrkablr of which, 
bowerer, ii the toormaline, nhich, from the mis- 
taken importance and vala? that has beco ftttacbed 
to it, we must briefly notice. 

Thlj> loiueral crystallues id long priimt, whoie 
prinittivc form is the uhluBe rhomboid, having the 
mis par&U«l to the axis of thfi priim. It muct be 
rewemberrd, altv, that the nx\% of rrystala ii nut 
like the axil of the earth, a single line within 
the crystal, but a single direcUun tbroagh the 
•filial : for ■upjKuliig this ligurc 4a] rpprctcnt a 

A 




crystal of any kind, the axb of which is in the di- 
rection 'A X. if we divide such o crystal into four, 
along tJicUuesBB and C C, each beparately will 
hiivejiu axis AG, OX. C"B, ond B C, which, 
when united in oneoryBtal.arealLparallel: every line, 
thrn. within the qry^ parAUel to A X, is an axis. 

Now if we cat a crystal of tourmaline of a proper 
kind, parallel to the axis, into thin plates uf u uni- 
form thickness (about one-twentieth of an ioch]. 
and polish each side, it possesses the property of 
polarizing the light transmitted through it in a re- 
markable maimer. This figure reprMcota one of 



theae plates, the lines across which we maynip- 
posc to be parallel to the axis. Now, if wc hold 
such a plate before the eyr, and look at the light of 
the sun or Hame of a candle, or any artiticial light, 
a great portioo will be transmitted tfarotigfa the 
plate which will appear quite transparent, haTing 
only the accidental color of the crystal, which, in 
apecimens nitcd for these experiments. \% generally 
brown or green ; bat the 'light so transmitted will 
be polarized light, and on being analysed by a 
second plate, which may be done by looking through 
both at the same time, we-shnll find that when the 
axes of both pistes coincide, i. e. are parallel to each 
other, the light which has pnised through the first 
will also freely pasa through the second, and they 
will together appear perfectly tranaparcnt ; but 
whan one is turned round, so that the axea of each 
pUt« are at right angles (scrota each other) as rr- 
preaentvd in the neat figure, not a ray of light will 
pass flirough.— they will appear perfecly opsque, 
although we may be looking at the meridian sun. 

Now if we suppose the structure of the erystal to 
be Tcpreiented by a grating, the bars of which ore 
the axis, we may conceive thnt ita action ujwnordi- 
nary light will hr to traniiDiit turh vibrMtUJii* only 
OS are perfurmed in a plane piiallel with the mu, 



and to itop all others. Henre the ligKt t 
through a single plate will be polariaed. l 
exactly the same properties as the light 
by any other meaoa ; aa may be proved 



i» 



sinr it by any ol the neuw wUeb we 
scribing. But let ua anppaae a aeoood 
to be used ; and as it is understood I 
light which makes ita way tiirough the fit 
line, the vibrations are parnllttl to the axia,~iS 
vlbratioiis being stopped when the axia of tba 
or analysing plate Is perpendicular to tbc t 
represented io the above figure, the vili 
which have passed through the first brings 
pendicolar to the aecond, will also now 
by the se-cond plate in such a positioa, 
is turned round, there will be found to 
tions in whioh the polarizrd light 
the anslysing plate, and two posit 
will not pass through, being whoU] 
posUJons being at right angles to 
will be understood by the last figure, 
the first or polaniing jThite, and B'B 
analysing plate, overflapping the ArsC. 

Having thuB briefly coit»idered the phf 
polariKation according to the undulatory 
must now, iu the aame way, notice tbc ex)di 
whlrh this theory also afl'urda of the sph 
tiomena of interference, which, it will 
seen, must necessarily result froiO'l 
law* of vibratory or uodulatory mc 
have consequently been a principd 
lishing the lluygcnian theory, and 
Dated and most ably propounded 
Dr. T. Young. 

Suppose there-are two aets of wi 
on the aorfece of a still pond of water 
points, at certain parts the waves 
half way between each other, ao that km] 
directions there will be a amooth surfa 
each set of waves is produced by pri 
degree of disturbing force, so aa to 
equal and alike in every raapect, aad 
of one set rjiartly half a wave io advance 
wave of the other ; while, at the 
otiier directions tin waves coincide an^ 
elevations or vibrations of double extent T 
intermediate spsces, intermediate effecla i 
coarse, be produced. 

The sane laws of interference exiat 
which, it is well known, consists in th 
or vibrations of the particlca of air actii 
aensonum of the ear, and producing i 
culled sound ; but the consideratiOQ i 
nomena would here occupy too aauch 
not necfasary to our subject. Tbe 
acoustics fumisbea experimentaldemoi 
two sets of andulatioDs ot air pmdi 
may be made to interfere and destroy 
(or, m other words, two sooiiris may be 
tcrfcro aad produce tilcnoe) j nod ■ 



MAGAZINE OF SCIENCE. 



101 



^er produce the nme effecU, we m«y, 
[7. expect, if light consUu in tlie uadu- 
n tlastic medtuta, that two U)(liU may 
)« to interfere and ^roUoce dapknesa. — 
I ta-anck a thing may appear to be, the 
Viiatcace of aach a phenomenon in light 
I by Grimaldi, aa long liacc aa 1G65. — 
Dr. Young that Hcience is indebted for 
i prored — and thti Freanat and Arago 
roiUirmrd beyond all question or dlapute 
|ia d&rk baadi and colored IriQges afe 
f the interference of light. 




It ii quite irapoauble, Id a paper like thif, to do 
juitioe to thia great and important branch of the 
theory ; and aa we arc now conaldering only the 
phenomena of colora in polarized light, the ex|dana- 
tion already given of the interference of the undn- 
lationa in water, will enable ua to anderstand how 
the splendid colora are produced, according to the 
lawfi of interference, by the action of doubly re- 
fracting bodies upon polarized light. 

For thia purpoae let D, in the annexed figure, by 
the polarized ray incident perpendicularly upon any 
double -reTracling cryatal ; the beat for this parpOM 



K 



bin film of aelenite E, vhiob U rrpn- 
nrayi, and should be about the fortieth 
f an in£h in thii^nesa, and may easily be 
kiufe from a large piece of the mineral ; 
lite tntnsparent, aud brr^k most readily 

B sired form. If such a film is placed in 
liolder of the polarizmg apparatus at- 
9be hydro-oxygcD microscope in certain 
rhich will hereafter be eiplained,) an 
fl film will be projected by refraction 
analysing bundle FI of glass, upon a 
IB duvction L \ but instead of being 
dorleaa, as the cTyital appeara in ordi. 
its wbote figure wilt be covered with the 
t colors, and, if of a perfectly unifi}rm 
iuroaghout, it will be of a |>erfcctly uni. 
throughout ; but if of different thick- 
rill he of dtSerent colors, varying and 
ith erery degree of thickness, no matter 
or imperceptible by any other means of 
, or the most powerful microscopic ex- 
Polarised light exhibits a different tint 
kriatioo, bat all of the most bnlliant de- 
At the aame time a second imsge will 
! fhim the aoalysing bundle Fl, and can 
ftpon a second screen in the direction 
• of which will be equally brilliaat, but 
Ury to the other reflected rays, 
pposing we hare a film of a uniform 
^Ttng in the refracted image L a red 
the reflected image S will be green.^ 
hing will take place if the film is of dif- 
oesaes giving different colora, aa every 
complimentary color, and those of one 
ftlwayi be complementary to the other ; 
blended together or superposed, will 
Ught. 




film b made to torn round in such a 
the jiotots or angles may follow ench 
alternately uppermost, the polarizing 

parts of die apparatus rcmaioiDg ala- 



'<^J=^ 



tionary, tbere will be found certain positions ia 
which the film will have no action upon the poU- 
rized light D passing through It : these positions 
are when either of the cross lines, A B or C D, ia 
parallel to the plane in which the vibrations of the 
polarized ray are supposed to take place. 

In such positiona the tight passes through the 
crystal without anffering any change. This ia 
proved by causing tlie analyaiog bundle of glaaa 
H H to revolve, the aelenite remaining stationary ;~> 
when it will be seen that at each quarter ot a cirdtt 
the tight will be alternately reflected, and trans- 
mitted or refracted in just the same way that it ia 
when the aelenite ia removed; as we have previously 
noticed in explaining the action of the analysing 
bundle of glass. 

As the Sim is turned round, it will be alternately 
in four different positions. Hence these lines in the 
sclenite A B and C D are called neutral axis i be- 
raase, in the pDattinnsdeacribed, it exerts no acdon 
upon the light passing through it ; white, ia the in- 
termediate positions, it does alter the character of 
the light, and in which all the splendid phenomena of 
colors are aeeo. 

Let OB now sqppoae the film to be turned from 
its first position : aa soon as it begins to move, the 
two images seen at Land S will b^n to exhibit the 
moat brilliant colors, which will increase in bright- 
ness until the film reaches one quarter round, where 
they will t>eat their maximum or greatest brilliancy; 
and when L ts red, S will be green ; or if L is blue, 
S will be orange, &c. &c. Bat, as the film tnrna, 
the colors wilt fade ; till, having reached the next 
quarter, where they will be at their miDimnm or 
nothing, there being no actiou exerted by the film 
in anch a position ; but, as soon as it has paaaed by. 
the colora begin again to return, till it haa reached 
the fourth position, where they are again at their 
nuxiinum. The same thing will occur at every 
qaarter of a circle ; and, in continuing the rrvolB* 
tion of the film, we ahali find four positions in 
which the film eierts a peculiar action upon the 
polarized light passing through it. 

Now, to understand how these colon are pro- 
duced by the interference of the undulatioos of the 
tight, let the film I^ be placet! in the polarizing ap- 
paratus, in such a position that the two neutral 
axes A B and C D are inclined 4^" on each side uf 



loa 



MAGAZINE OF SCIENCE. 



the plane of iribntions or the polariced light, or 
perpendicular, aod of such a thlckuekS u to gift a 
red itna([e at L, and a green one at S. If the 
unaJyslng bundle H H ta now removed, the image 
wiU atiU tw leen at L, but pmfcctly clear, Mrt bflTing 
the least appearuice of color. It ii erideut, then, 
that the analysinp part of the apparatoa la equally 
necessary fur the pruducCiun uf colors. Let oa, 
however, first notice wh«t the action of the selcnite 
E is in such a position upon the polarized light 
puaing through it. Nov, being a doubly refract- 
ing crptal, whrtn its neutral axes are thus inclined, 
the light passing through it will be doubly refracted) 
and, olthoagb not perceptible to the rye by ordi- 
nary observation from the tatreme mioulencsa of 
the sepsrstion in so tbio s film, yet, from this pro- 
pvrtT which tre kuuw it possesses, it is nevBrihelesa 
divided into two equal portions or sets of waves, 
the vibrations of one being parallel to the neutral 
uia A B, and the vibmtiona of the other parallel 
to the axis CD, and, consequently, both inclined 4b'^ 
to the perpeodicuUr, as shown at O X : O we may 
call the ordinary ray, and X tbe extraordinary ray. 

ilut iu the pisaage of the two ruys through the 
crystal, they have traversed it in different directions, 
with different velocities ; one of these sets of waves 
will, therefore, on emergency, be retarded and lie 
behind the other; but, being polarixed in different 
places, cannot interfere. To cause them to inter- 
fere and exhibit the phenomena of colors, their 
planes of polarisation or vibration must be made to 
coincide. For this purpose, let the analysing bun- 
dle of glass bt! placed as at H H, in which position 
tbe vibrations of both the ordinary and extraordi- 
nary rsys O and X are each inclined 45° to a plane 
perpendicular to the pUne of reflection, and, con- 
aequentty, that vibrations in a beam of ordinary 
light, inclined at angles between the perpendicular 
■nd borttontal planes, are divided into two portions, 
one of which is reflected, and the other transmitted 
or reft«cted ; so now again, the same effect will, of 
coarse, take place, and the vibrations or waves of 
the reflected half S of the ordinary ray O, will be in 
a plane parallel to the plaoe of reflection of H H, 
and the waves of the reflected half L of the extra- 
ordinary ray X, will also be in tbe same plane- 
Here, tnen, we have two sets of waves onglnatiDg 
f^om the same vibrations in the polarised rsy D 
brought into the same plane, and, consequently, 
DOW pOBScising all tbe conditions necessary for in- 
terfering with each other ; and tbe same aUo in the 
two transmitted portions. 

Tbe colors of the images at L and S produced by 
this interference will depend upon the interval of 
retardation of one of the rays within the medium E, 
which, of course, will vary with its thickncM. When 
this thickness is such as to cause the interval of re- 
tardation to amount to half a wave in the reflected 
rays K and L, they will interfere half way between 
each other, and ao far destroy each other as co pro- 
duce in the image at L the black uf the first order, 
•een by reflection, in Newton's " Table of Colors ;" 
while, in the transmitted rays, the waves being In 
opposite phases of vibration, will coincide and ex- 
hibit in the iaiage S, the white of the same order 
aeen by transmission. When the thickness is snch 
as to cause an interference in iotcrmediAte degroes, 
Intermediate effects or colors wilt be produced ; — 
consequently, when there is exhibited at L any one 
of tbe coh>ri ia Newton's Table seen by reflectiott, 
tbe image at S will always exhibit the comply- 
nrntxry color been by transuiiBaioo, tbe waves of one 



being always in opposite phases of ribratian to tha 
wQvea of the other. 

And we iboll find, as the film of selemte is made 
to revolve, tbe bundle H li remaining itatiooaryt 
that it will produce one color only at L, appearing 
and difiappearing alternately as it passes Uirougk 
them, and the same with the complcmcotsry rolor 
at S, But if tlie flhn is fixed in any o( tius posi- 
tions in which it gives the brightest color, and thfi 
buudle of glasi H H, made to revolve, two colora 
will be seen both at L and S, which change altor* 
nately at each quarter of a circle ; thos, wbok H H 
is in one position, and the image at L is red, aad 8 
green ; when 11 H has turned round 90°, L vriU be 
green, and S red; at 180° L will be again rtd^ 
and S green, and at 2^ff L will be again green, and 
8 red. 

These, and aU the splendid phenomena of colon 
in polarised light, will readily be seen to be simple 
conaeqnenoea resulting from transversal vibratiooa ; 
for, when a single wave or vibration in any one 
plane, as at D, is divided or resolved into two at 
right angles to each other, one will, of oeceaslty, be 
half a wave behind the other, the two being tbe op* 
posite halves of the same in D ; and as each of these, 
O and X, is again divided or resolved into two 
otiiers, there will be four waves or vibrations pro- 
duced from tbe original one. Two of them in one 
plane must, of necessity, coincide or consplrei 
while tbe two in the otJier plane are opposed. 

Tbe colors produced by the interference in one 
plane have been shown by Fresnel to correapond to 
the amoant of retardation within the cryatal, and 
tbat in tbe other plane to be due to the same amoanC 
of retardation augmented or diminl.sh^d hy b&lf a 
wave, and, couscqucntly, complementary to the 
former. 

In this brief notice of polarixed Jight, tke expla- 
nation is confined to the phenomena exhibited by 
a. single plate or film of srlenito ; tbe colon of 
which wc have seen, vary with its thickoess. M'ilh 
this single crystal, then, numerous splendid and 
beautiful effects mny be produced, simply by pro- 
curing different thici^nesses for giving difl't'reDC 
colors, and so arranging them upon a plale of glass 
as to represent different subjects ; such as painted 
windows, bunches of flowers, fmitSy and other 
figures. These, in ordinary light, will be pet/ArUy 
transparent; but, when viewed in polarized light* 
will exhibit the most gorgeous coloring, and 
made to undergo the most extraordinary c 
by simply causing the analysing part uf the 
ratUB to revolve. If single plates of selcnite, 
any doubly refracting crystal of considerable thick- 
Dees, be ground away on one edge so u to give then 
a wedge shape, thc-y will preaent bnuds or fringes 
conipused of all the colors of Newton's Table, aris- 
ing from tbe various thicknesses whii-h such a shape 
possesses, or by grinding a concavity in a similar 
plate, a number of conctntric rings are produced* 
Thus it will be seen a variety of forms may 
given, prodacing a variety of effects; these, 
thousand more, such as tbe small cryetdb 
duced by evaporating sin^ drops of aol 
acetate of tine, chlorate of potUi, eolphato 
oxalic acid, oxalate of ammonia, ami natty 
may be exhibited by means of the polarixiag app**" 
ratus adapted to the hydro-oxygen microeeope.^ 
This apparatus will be described in tbe next paper 
on tbe sabject. 

fToheeonlinueiSJ 






MAGAZINE OP SCIENCE. 



103 




ESSENTIAL OR VOLATILE OILS. 

IK t-oUcUe oili ocoar In every part of odoriferous 
Ats, w1iu«e MromA they diffuse hj their exhaU- 
R ; but ia differeut organs ot different ip«cie«. 
rrtala plint«, such as ttijme and the icented 
ttel«. in geoer*! contain ToUtila oil in ill their 
rti I but others oontaln it on\j in the blossoois, 
l i wdt, tha leaveit the root, or tlie bark. It 
atJuiM bappena that different parti of the same 
Bit dootoio different oiU ; the oran^, forfiampte, 
thm different oilt, one of which residrs 
another in the leaver, and a third in 
lidvmis of the fmit. Tlie quantity of 
only with the apecies, but alao in the 
tm ffaflt, irilfa the toil, and cspeciaUjr the climate ; 
m in bol countries it t> generated moat profusely. 
Mnrml pbatSi the roUtile oil is contained in pe- 
)hK Ofdara of veasda, which confine it so closely 
kl It doe* not escape in the drying, nor i* disjii- 
loll by keeping tbe plants for many years. In 
and particularly in flowers, it is 
mally npon their surface, and flies off 
of its formation. 

ore usiiiilly obtained by distillation, 
the plant is introduced into a still, 
upon it. and heat bein^f applied, the 
lilisfid by the aid of the watery vapor, at 
toreof 212^, though when alone it would 
obably not distil over unless the heat were 100^ 
M9b Most of the essential oils employed in medi- 
M«ad perfumery ore cxtractod by distillation from 
M pUftts ; only a few, such as those of the rose 
4 «nage flower, are obtained from fresh or anc- 
llest Mited plontj. When the mingled f apors of 
oil and water are condensed into the liquid state, 
jf iW refrigerator of the still, the oil separates, and 
Ikir AoaU un the surface or sinka to the bottom 
fibs water. Some oils of a less volatile nature re- 
lira* hifber beat than 212^ to raise them in vapor, 
■d moat be dislodged by adding common s^lt to 
te wUtTt whereby the beat being augmented by 
y, tbey re*dily come over. If in such distilln- 
ioos tiw marb water be added no oil will be ob- 
riaed, because it is partially soluble in water ; and 
bw mrrely an aromatic water is produced. If on 
Uolber hand loo lUtlc water be used, the plant 
taybappen to adhere to the bottom of the itill, 
lift partially charred, and thus impart sncmpyreu. 
MOe odour to the product. But as the qaulity of 
Mv dtstiiled depends leas upon the i|uaiitity em- 
lloywi. than upon that of the surface rxpui^ed to tttc 
■^ it is obvious that by giviog a suitable form to 
butfUt, wc may get rid of every incouTenicuci'. 
^Hl the narrower and taller the alembic ia, vrtthin 
Hb liniita, tbe greater will be tlie proportion of 
BSUitiT« to thnt of the aromatic water, from like 
|i«peniODS of oqaeous and Tegccable matter em- 
flayed. iioBtc place tbe plants in baskets, and 
ffRld Iheae immediately over the bottom of tbe 
■ader tbe water, or above its surface in the 
taaai. Hot the best mode is to stuff an upright 
nttndcr fall of the planl«. and to drive down through 
Maa, atcmm of any desired force; its tension and 
hbpaiatsrr being further regulntcd by tbe size of 
hi onllflt ortAce leading to tbe condenser. The 
■HoJtr abooUl be mnde uf strong <!opper, tinned 
■Me, Oftd moased in the worst conducting species 
If wood, anch .is soft deal or sycamore. 

Tbe dtattllation is to be continued as long as the 
Vtl#r eomes orer of a milky appearance. Certain 
||mU yvsld so little oil by tbe ordinary procesaes. 



DOtwithfltandiDg every care, that nothing bnt a dis- 
tilled water is obtained, la this case, the same 
water most be pnorcd upon a fresh quantity of the 
pUuta in the still ; which being drawn over, is 
again to be poured upon fresh plants ; snd thus 
repeatedly, till a certain dose of oil be separated. 
This beioi; taken off, the saturated water i* reaerved 
fur a like diBtilladon. 

Tbe refrigeratory veasel is ustwlly a worm or aer- 
peotine plunged in a tub of water, whose tempera- 
ture should be generally cold ; bnt for distilling tbe 
oils of aniie-serd, fennel, &c., which become con- 
crete at low temperaturea, the water ahoold not b« 
cooler than 45'' Fahr. 

The liquid product la commonly made to ma at 
the worm end into a Teasel called an Italiaa or Flo- 
rentine receiver, which is ■ conical matnus, standing 
on its base, with a pipe riung out of tbe side close 
to tbe bottom, and recurved a Uttle above the mid- 
dle of the flaak, like tbe spout of a coffee-pot. The 
water and the oil collected in this vessel soon aapa- 
rate f^m each other, according to their mpective 
apeciflc gravities ; the one floating above the other. 
I f the water be the denser, it occupies tbe under por- 
tion of tbe vessel, and continually overflows by llic 
spout in communicatioo with the bottom, while the 
hghter oil is left. When tbe oil is the heavier of 
the two, the receiver should be a large inverted cone, 
with a stopcock at ita apex to run off the oil from 
the water when the separation baa been completed 
by repoae. A funnel, having a glaai stopcock at- 
tacbed to its narrow stem, ia tbe moat convenient 
apparatus for freeiog tbe oil finally from any ad- 
hering particles of water. A cotton wick dipped in 
the oil may also serve tbe same purpose by its capil- 
lary action. The less the oil is trsnuvased the bet- 
ter, as a portion of it is lost at every traiihfer. It 
may occasionally be useful to cool ttu; distilled 
water by surrounding it with Ice, be<tause it tbua 
parte with more of the oil with which it is impreg- 
nated. 

There are a few easeotial oils which may b« ob- 
tained by expression, from the substances which 
eotitnin tbrm ; such aa the oila of lemons and ber- 
gamut, found in the pellicle of tbe ripe fruits of the 
eitruM anrantium and medico .- or the orange and 
the citron. The oil comes out in this cose with the 
juice of the peel, and coUecta upon its surface. 

For collecting the oila of odoriferous flowera 
which have no peculiar organs for imprisoaiogtbemf 
and therefore speedily let them exhale, auch a* 
violets, jnfmine, tuberoie, and hyacinth, another 
process must be ivsorted to. Altemste layera are 
formed of tbe fmli flowera, and thin cotton fleece 
or woollen cloth -wadding, previously soaked in a 
pare and inodorous fat oil. Whenever the flowera 
Imve given out all their volatile oil to the flxetl 
oil npon tbe fibrous matter, they are re-placed 
by fresh flowera in succession, till the fiit oil 
has become saturated with the odorous purticleH. 
The cotton or wool wadding being next submitted 
to distilUtion along with water, givea up the vola- 
tile oil. Perfumers aloue ote these oils ; tbey cm- 
ploy them either miied as above, or dissolve tliem 
out by means of alcohol. In order to extract tbe 
oils of certain flowers, as for instance of white lUiet , 
iiiTuaion in a fat oil b sufficient. 

Essential oils differ much from each other ia 
their physical properties. Most of them are yellow, 
others colorless, red, or brown ; some again are 
green, and a few are blue. They have a powerful 
amell, more or leaa agreeable, which immediately 



104 



MAGAZINE OF SCIENCE. 



after tfadr diftiUation ii occuionaUy a little rank, 
but beeotnci lesa ao hj kiteping. The odour ia aeldom 
«a pleaaant aa that of the rccrat plank. Tbeir taste 
if aerid, irritating, and beating, or merely aromatic, 
when tbey are largely diluted with water or other 
oubstancea, Tliey are not gmMj to the toncb, bite 
the Ht oila, bat, on the contrary, make the skin feci 
rotii^h. They are almost aU lighter than water, 
only a very few faUinK to the bottom of thia liquid ; 
tbeir ipeeific gravity Wes between 0'H47 and 1*096; 
the firat aamber denoting the denaity of oil of citron, 
and the aecond thst of oil of nnafraa. Although 
styled ToUtilo oiIji. the teodoo of their vapor, aa 
well ai ita speciiic heat, ia much lean than that of 
water. The boiling point differa in different kindH^ 
but H ii uiually about 316" or 320'^ Fabr. Tbeir 
Tapon aoRietimei render reddened litmus paprr 
blue, althoDgb they contain no ammonia. When 
distilled by tbemaelves, ttie volatile oils are par. 
tially decomposed ; and the gaacooa prodacta of the 
portion decoaipo*ed always carry off a little of the 
oil. When they are mixed with clay or Mod, and 
caposed Co a distilling beat, they are, in a great 
neasare, decomposed ; or when they are passed in 
vapor through a red-bot tabe, combustible gases 
■re obtsioed. and a brilliant porous charcoal ia de- 
posited in the tube. On the other hand, they distil 
nadiXj with water, becaoae the aqneoua vapor, 
formed at the sorfaoe of the boiling Raid, carriea 
along with it the rapor of the oil prodnred in virtne 
of the tention which it poMCsses at the 212ih deg. 
Fahr. In tlie open air, the volatile oils born with 
a shining flame, which deposits a great deal of soot. 
The congealing point of the essential oila varies 
greatly ; some do not solidify till cooled below 32", 
others at this point, and some arc concrete at the 
ordinary temperature of the atmosphere. Tbey 
comport themselves in this respect like the fat oils ; 
and they probably consist, like them, of two differ- 
ent oili, « solid and a fluid ; to which the nsmea 
Hearopt^ and ckoptme, or stearessence and oLei- 
easeoce, may be given. These may be aeparated 
from each other by compreuing the cooled concrete 
oil between the folds of porous paper ; the atcar- 
essence remains as a aofid upon the paper ; the 
cleieaaence penetratea the paper, and may be re- 
covered by distilling it along with watrr. 

When exposed to the air, the volatile oils change 
tbeir color, become darker, and gradaally absorb 
oxygen. Tbia absorption commences whenever tbey 
are extracted from the plant containing them ; it is 
at first considerable, and diminisbea in rapidity ns 
It goes on. Light contributes powerfully to thia 
action, during which the oil disengages a little car- 
bonic acid, but mudi leas than the oxygen absorbed ; 
no water is formed, 'ilie oil turns gradually thicker, 
looe»itsnneIlt«nd is transformed into a resin, which 
beoomas ffventually hard. De Smssure found that 
oil of lavender, recently distilled, had absorbed In 
foor winter months, and at a temperatare below Si4'* 
F., 52 bmes its volume of oxygen, and had disen- 
gaged twica its volume of carbonic add gases ; nor 
was it yet completely saturated with oxygen. The 
atearesaence of anise-seed oil ahaorbedat its liquefy- 
ing temperatare, in the space of two years, 1&6 
times ita volume of oxygen gas, and disengaged 26 
times ita volume of cnrbonic acid gas. Ao oil which 
has begun to eji{ierieuce such an oxidizemeut )« 
eompoeed of a resin dissolved in the unaltered oil ; 
■nd the oil may be separated by distilling the solu- 



tion alor^ with water. To preserve oils In an ii» 
changed state, they must be put in phials, filled U 
the top, closed with groond glass stopples, an^ 
placed in the dark. 

Volatile oils are little soluble In water, yet 
so as to impart to it by agitation their c 
istic smell and taste. 'Die water which distila witll 
any oil is in general a satorated solution of it, to 
as such is used In medicine under the name of di« 
atilled water. It often contains other volatile sub- 
stanoea oontaiued in the plants, and hence ia apt lo 
putrefy and acquire a nauseous smell when kepi fai 
perfeoUy oorked bottles \ but In reasela purtiallf 
open, these parta exhale, and the water 
sweet. The waters, however, which are made hf 
agitating volatile oil with simple distilled wster, ar« 
not apt to spoil by keeping in welUcorked bottles. 

l^e volatile oils are soluble in alcohol, and tbfl 
more so the stronger the spirit is. Some 
oils, devoid of oxygen, such as the oils of tarpentiM 
and citron, are very sparingly soluble in dilate 
aloobof; while the oils of lavender, pepper, &c. 
considerably so. De Saaaanre has inferred fro« 
bis experimeuts that the volatile oils are the enora 
soluble in alcohol, the more oxygen they coBtain.— 
Such oembinations form the odorifmnis apiritl 
which the ))erfumers incorrectly call watera, 
lavender xgater, eau de Coiopte, eav de jantun. 4-f. 
They become turbid by admixture of watrr, whtcb 
seizM the alcohol, and separates the vobtilB (rila 
Ether also dissolves all the easential oila. 

These oils combine with several vegetable acids* 
such as the acetic, the oxalic, die succinic, the fat 
acids (stearic, margaric, oleic,) the camphoric, and 
suberic. 

With the exception of the oil of cloves, the vola- 
tile oils do not combine with the salifiiblc buses -* 
Tbey have been partially combined with ranstifi 
alkali, as in the case of Starkey's soap. This li 
prepared by triturating reoenlly. fused caustic mm1« 
in a mortar, with a little oil of turpentine, addrd 
drop by drop, till the mixture has acquired the nm* 
sistrnrc of soap. The compound is to be dissolved 
in sptrita of wine, filtered, and distilled. Wbit 
mains after the spirit is drawn off, consists of 
combined with a resin formed in the oil during thi 
act of tritnration. 

The volatile oils In grneral abaorb six or rigfcC 
times their bulk of ammooiiical gas ; but that «i 
lavender absorbs 47 times. 

The esAentiol nils dissolve all the fat oila, tiM 
resins, and the animal hU. 

In commerce these oils are of^en adultrrated wtKb 
fat oils, resins, or balsam of captri diasolred i 
volatile oil. This fraud may be delecled by pattio 
a drop of the oil on paper, and exposing it to heat* 
A pure essential oU evaporates without leaving snf 
re«daam, whilst au oil mixed with any of the abor^ 
subslannrs leaves a translucent stain upon the psprr. 
If fat oil be pre«ont, it will remain undisFolved, om 
mixing the adutlcrated essential oil with tbrice iti 
volume of spirit of wine of specific gravity 0*840.— 
Resinous matter mixed with volatile oil ia easily 
detected, being left in the alembic after dittillation. 
Oil diluted with spirit of wine, forms ■ milky emnl 
sion on the addition of water ; the alcoholic part t 
absorbed by the water, and the oil aftcrwaril!i found 
on the surface, in a graduated glosa tube will show 
by its qaantity the amount of the adultervtioa. 

f To be continued. J 



L/onDOM ■— Pruttd by U. faAMCts, 6. WtiUt Hone L^ajis, Mtla EwL— I'ubluii«u ity W. fiatttAix. tl, Psisruoaifr Mo*. 



THE 



AGAZINE OF SCIENCE, 



^nif StDooI of ^m* 



SATimDAY. JULY 3. IMI. 



[IK 




Fig, 1. 




HYDRAULIC ENGINES. 



5^* a. 




UYDIUUUC ENGINES. 
(Betuawi fn» potg* % I 

Archimedra't Screw. — It rrprc«mtr<l and tlc- 
■crilied us IoHowp: — A I* ii Uiillow [liitc, coU«l 
arotuid a ryliiidriciil mi* ; wbi<!U hxU U incline*! itt 
ao iui£lt' with the Kroviml, nnd suppnrteU at enrh md 
upon pi\oU(, the upper pivot bcini; furnished wirli 
handle. WliPTi thin in turned i-ound. the lower 
end of the pipe dips into thr wnicr in the well biilow, 
aiid turniiipr upwards directly scooj'* up some of tlie 
wolcr. M hen Uk* end point? up, the jujrt B will 
buu(;uic Inwfr thnn it, therefore the wuter will full to 
B. Another hiJf turn of lii'- hiuidlc brings C to 
Ihe loweal point, »nd thi* lirst wnter will oerupy 
tbftt pfirt of tie !ul>c ; id the wme time more wjiter 
wiU be scooped up at the end. Ill n numbpr of 
turns uf Uip liandlr, cqu.il tn that of (he roils of the 
tube, the lii>t water >« ill rtac)i, ;md finw out at the 
top ; Bhd from that time a. flow will lake plai-c »t 
every revolutioa of llic rocctii:ic. 



itlut np^ninff nptmrd". 




Barkrr'n Ctmtr^wyaJ Miti. — TbU raiiinblo inrtru- 
tneiit di^rivCB its pow.M" from the force ac<jnired from 
■ stream of writer ni^iinic fn>in two hoK->, *o plnced 
uciu- the i-adi Litilu ..rn.rt of « moTeat>l- f-pindbai 
to throw Ihr water on em-li i-idp, and thereby to oc- 
coftioii a couolrr j«ctiou iigninsL the anus, propelling 
tbem, nnd svhnu'vcr may he ntfnched to them in a 
contrary direction. Suppose A in the cut to repre- 
8<<nt D fiiniit'l conurctid wiUi ttie hollow kpindle (■, 
thiA repts ut th.- Injttnm on a pi\ol C, and hear* a 
shaft above, wbiih i» eoiuiected with one of the mill- 
utone* E. n>e hollow piirt (1 is terminiitrd by the 
two hollow arms H B, whirji orniR hflTO ludes. ft* re- 
prccenled. A tt.'wuu of wuter tlowing into A will 
fidl down into G, and fill the arms B 13. at length 
ru*<hin? out of the holes. The nir will offer such a 
reai-^liiiioc to the iaimUtg of the wnter, that the armst 
toi^eihcr with thf* oibcr moveable ports, wiUrevolre 
rBpidly. — at f Jig. \. 

Ducket KHffin*. — A aubfltitnte for an over-«hot 
water wheel, and fur superior where ihe fall of water 
is enntiderable, and the bupply limited. An endlesf 
chftiii, carrying a series of burk(-t.s, is made to re- 
volve ou two wheels, A B, called ray-xohecU. The 
water flowa into the highest bucket, and when it de- 
it/^ct\iU the nett bucket takes Itt^ place and it, Uke«'l^ 
filled, And thuf every bucket on one side is filled, 
wliile those on the oppt^^itc side, being inverted, are 
empty. The chnin of biii^keLs i? tbert£fore conalnnlly 
carrital round by the wcipbt of the water. — Setfg. 2. 

LVntt'ifti^at Vumjf. — A machine dependent upon 
cctiirifugul force. «^'iabincd with the pressure of the 
atmosphere. It coni-itts of one, two, or more amia, 
erect i'i*Iow, and branching opt above, joined to a 
vrrtical axle. Near the upper citreraity of cnch 
ami 1* a fla»^k volve openiug upwrirds, while near 
the lK>itoui of the vertical tube, or the bottom of 
«acb , {\f tbca« are more than one,) 12 a siniibir valve, 



Wftt^r hrin? poured tula 
r >1 moiion beiity 

'.rr in the ajtUn 
'.- tbr 

t" . ■. .. .... ..!...../ . ' ■:_ . ..' . ..live 

u a wrlUniade pump. — ^ee_Tl(;. i, 

C^ain FJtmp, — An instrument which act* upon « 
principle contrary to that of tlic bucket cni^nc : h 
may be either fomted of bti<rketAintlte!wmr nmnner. 
or what i» more simple nnd com 'j 1 of 

budtets, there ore set at certain m ' >rr- 

vali on on endlcsf ctialn a (<en-" ■■* -nd 

plates of metitl, which nertrly lite 

tabes in which they work. I la 

motion, pupposinj; the bottom ot' n fhr 

uater of R well, eueh pi:iton will ioi it 

certain (jnanlilT of water, and bear thii Wdii 10 tli* 
top, where it overflows into a ciatern preparrd i* 
receive it. — Serjig. \. 

Ecvmlrie Pump. — Conisifita of a hollow dram 
cylinder of met;tl, JJ D ; iu the interior of wbirh, a 
solid eylindrr, D, of (he frtmv Irnieitb, bat of ItA A* 
ameter, it made to revolve in water-tight axw. 
The inner cylinder being plai-ed «o nuicb out of iJic 
centre of D D, that in it? revolution, one side of if 
toihbrs the side of B. T!ie aurfni-c of the inorf 
c>hnder!s also faniiAhL-d with four clrculor Ha^ 
C C C C. Two rodR of metnl slide tlmiiigb U. fo 
to o]Hrn the Tulves on our fide, nbfn the oppovOa 
valves close by pressini; ajainrt the case of D D. 
The water is .'Upplied from the well, through A; it 
i^ then scnopeil up by the opeitiug valve, and con 
veyed by that vatfVe to the top, where, oi the v«lw 
dopes, the water is sfjuet-r.cd up into llie [npe E. 




THE LAW OF PATENTS.' 
Wc have been so often urged to pivea pBper (*r twQ 
on the pst<*nt laws, and brlieve It to be a iubjcel to 
fraught with interest to .-lUbelonpng to an inTtnllte 
and manufiicturiug country like thi», that it ii with 
the very greatcat plesfure we iDtrodnca a iubjcd ao 
generally interesting. 

Tatent, in l»w, jk the exclusiTe rij;ht of usineand 
vending a certain composition or combioatioD of 
matter, rb a medicine or a mnehinc. Thi- 
not drrixed from the Ian- of nature, a« ' 
field of inventions and improvements is uj . 
men, and one cannot monopolixe a part of it hy 
prior discoveries. By the common l.iw of Engbind, 
monopolieB were dc<*lared to be grnrni!ly void, and 
patents fur new inventions, being a ^pri'ire of mo* 
nopolirs, would, according to Ibis <'. 
by thit law. But they teem to for 
to thin rule; for it waJt brl'.) ' 
confer on the inventor of any 
art the power of uting it for l i _.. 



rito 



MAGAZINE OF SCIENCE. 



Cho law of ptttroUi, n H no<v tCnmU in England, 







■■ ?1 Jan. 1, c. lii, nml in tl»c 
K-'it cin <riitni« I-V>. 21, 
>. In IVuni;*, mail WOO, 
(ibligt'fi to keep tli'jjr tlU- 
10 <i*ruro t»» tiiem»<!lvM a 
'>t'tti«m. In Ha CMtiy itc* 
■ iiioii, ft Uw WM5 p«sfted in 
rortnrJ ou the UiaU a( the 
••nob kwof Jan. 7. 18t0. 
' i^r new iuveuiiaii, in 
<• , it tUe pru|irrt]r uf 
, .ittj ftro now» [48 Ibcy 
•I Juines I, gronted by tbe 
<rc wiilv uitl Ity lUo »ecre- 
•1 or tUe L'nilvd i»LaUta uf 
I lie president. 
' '' . ^In jseiicrtil, uny inTcntiun 
I a.rt, uifti^hiue, uunuiucture, or 
:cr nol knowu or lucd befure, ur 
il tinpriivemcnt in any art| nin- 
(ure. or cumpoiiltioTi of luatlur. 
must be new. lii Knglnnd, « munu* 
'►rottsht (ri«u tlie kiugiUmii friiin be- 
rf, v^ nllowed by the 
: suture nllows a pa> 
witiuii ibis ruiini. 
1 Slatir<) of Ainericu, 
. ..riginally diEniTercU 
• bad Uiru in utit?, or bud been 
I'ublic work niitrrior to (be Bup> 
iy by tbe piiteiitee, or if he baa ftur- 
lilnined » pnlr-nt for tbe diKovery of 
<n, H>c pntcnt is voM. In France, by 
n. 7t 1810, whucTcr introduces into 

, . I... , Jj.^ovcry sball enjoy tbe 

■J were the inventor. In 

f sn in7entio)i is entitled 

r be be tbe inventor or not. The 

nutut be vendible, in L-ontradi&- 

ing that ifl Itarued by pntctice. 

■I hf maferiai attd us^iil : thus 

I'lrcrtol fnrt^iiotber is iiuuf- 

il ; at of bmsfi hoops tu n 

.1 onta. So there ciiiinct be 

: iu one piece nhat before was 

if one trlemeotary thing be sub- 

iut anollicr, sk if Ihnt be done by a tube 

4ft hrfore done by a ring, a pileut for the 

■ would hej^uud. It must not be burt- 

ii'jr getiL-rally inconvrnient, nor mis- 

: ioimurol, bj uii invention to poison 

'i> promote dt-bauchtrry. Patents for 

- Mtc Tslid, ai for an improved steam- 

^f the improTcmeoti cannot be used 

nginc whirh is protected by a patent, 

t the expiration uf the patent. But a 

iv be taken unt fur the improvement 

It of old QiateiiikU, by which 

i-d, may be tbe subject 

. .. i.M^ it ni«y cuustKt either in 

11 of a new iiriiilf, or in mnlnn^ an 

I hriUix uianu'ir, iu a ttbortcr tin.c. 

■•r rate. A I'litriit may be ubl'iiitcd 

•r pn>ce«a by which wiDelhing ucw ur 

when it ii connected with cor- 

Tiid i* carried into effect by tuii- 

Mic (MAt- of W*tt*a atciun-cngine. 

■'I to be a mt'lliotl of Usaening 

I fuel th a "'• iii.-.ri,.i,>,.. Sn u 

. whfn It Ki' Minmnity 

If, uitd bvti JBce, or 



m 



roupoaiid artiele. ia u subject uf a patent, as m«dU 
ciriea, Kr, tint a pntent fur n mere turio«ity ia 
void. If the niJi'infarturn in il* ntw slute merrly 
answers M ni-ll iH bcfoii'. the dltrrotion is not ihe 
subject of a |ijiLvut ; nor is a rncre phUtHoj>bicAl 
abbtrsec princijite, nur the Bpi>licatinu or {iractice 
of tt printMplr. tlic titjbjt'ct of a patriit. No pntfut 
can be ubtuined for ihr t-xpatu^ive opcruttou \f( stcmn ; 
bnt only fur a new uiode ur apjilicutiun of maublncry 
in eiiiploj'in;; it. 
AV/'f Aof/' iani. — The inventor mny lose hia right 

to a patt'iit by u>in^, ur nllonuii; oTJicrs to Ufe, hi* 
invention puuliely, It was L'uM^ule^cd tbal Dr. 
Hall bad net lost the right to u )ulcnt fnr his dis- 
covrry of certain objcct-gtaAAes, bceituse be bud nut 
made it known 10 utbcra, tjiougb it wu not imme- 
diatt^ly patented. If the aecrel uf an inveniiou ia 
kiiown only to a few pensonN, nnd nnr* of them pulv 
ic in ptAcLu-c, thru a patent afterwards obtained by 
Kny unn uf thcra is toIiI. Thi« luippeiicd to Mr. 
Tvunattt, btH*auiii: a bleacher, who had nut divulged 
the secret lo ituy other person but bifi twf> servant*, 
had ufcd the same kind of bicachine-liquor for 
aevrral years onterinr to tlie ilule uf Teuoulit'a pa. 
Cent. M'hrre a )M-rtM>n who xnught a patent for tn^ 
king ffpertikJcs intautinu*ly tuld an ari^uaintani^ uf 
the piiiiiuple of the invi-tititm, by which meaufl a 
ptrtton iif the snaie trNdv made ;i Himilnr fvur, nrid 
(hi-'invrntor, •rrin^ thrm in » shop wintlow, «aw 
ploj'ed a fnend tu purchase thcui (or hini, and the 
pdteiit WHB ofierwards grnnled, it was said to ha 
secure, llie queaCinn does not, however. ap|>ear 
to have bfcn brought before u court, and Mr. (iod- 
soti thiiiks thiit (be pNtrnt waa vonl, A pntmt for 
British iniperial vrrdi|.*rt» wj$ dcrUmt to be vuld, 

becauae the: ■■ • ■ f ' H, four mouths prior to tliu 

aeuling of il 1 tlir diticle undL*r udifTcreut 

iia&ia. \VhL , iautti^ made with a view lo 

try the efficacy ol an invention, ur the extent of a 
diacovcry, are a •v/nnfft and drdicnttng the invention 
to tlie public, wiikin the at'ituto of Jumes, haa not 
bnn dt-ridfd ; but it Wduld be dilfii'uU to say lu>w 
Dincb II dubolann' or inikrbine might be Used without 
rnniiing ttrriit rii^k of invididating the right to a 
patciit. ill riiini'r, It t^te inventor do nut, within 
two years, put hiji diseovrrji into activity, or do not 
justify hi« inartiuij, the putLut ia annulled. 

/Juration qf the Patent. — In England and the 
United ijtulrfc uf America, peteLta arc granted for ■ 
turtn nut exreeding fumtcrn yearft. The time in 
Knfclnnd maybe prolonu;e<t by a private act, and, in 
the United States uf Aoierita, by act of congrcai. 
Iu Frnnc-e, by the Ibw alicidy mcntionlcd, jMitenta 
are given for live, t«:n. or fifteen yeara, at the option 
of the invrnlur; but (bis Inst ti-rm il never to be 
prolonged without a parltouliir di-crro of Ihe Irgia. 
iature. The duration fur imported dUcoverica ia 
Dot to extetul beyond llie term fixed fur tbe privi- 
lege of the original inventor in bin own country.— 
[n France, if the iuvciitur ublaiu:* J |>atent in « 
foreign cuutitry. alter biivttig obtuincd one in I'rancf*, 
thi- pnlent is aiiowUrd- — Carfttl. In England, a 
car*rat it an inatiuiueut bj which notice is rL'quested 
tu be yivi-n lu the pervon who enters it, whenever 
any appUcalion ta made for a pateut for a certain 
invention, which ia therein dr*i:ribcd in grnciol 
tciins. It must be renewed (ntnualiy. It ia Mmply 
n ret|ueat that, if any other p<r«ou should apply tur 
II patent fnr the hoine ibiii^. Ibe prrfiTrnce may be 
givi-n lo Iiim nhu eutcrtd it. In llii* United Matta 
o( Amrncii, in case of interfrring B]iplinitionn I'tir n 
pMciit, ihcy arc auhmitud lo tbe arbitraliuu of 




MAGAZINE OF SCIENCE. 



i 



thre«p«rfonB) uppotntrd onr by each applicant, uid 
one by the secreUrr of state. 

Speci/lcot iun.— The inrention for which a p«tent 
ia (franlcd roust be accuralelj ascerUined and par- 
tioularly deuribed. The discloffore of the aecrac 
la the price of the monopoly, l^e fpeciAcmtion 
must be such that mechanics may be able to make 
the micbine by foUowiag the directions of the ipe- 
ciflcation, without any new invrotioiiB of thrir own. 
The patent and specificauon are linked together by 
the title givt*n to the invention in the patent, and 
the description of it in the ipecification. 'nie spe- 
cification muit support the title of the patent ; thtu 
a patent taken out for tapering. bnuih ia not sup. 
ported by tlie specification of a brush in which the 
briatlei are oi unequal lengtbi. h tnoat point oat 
what parts are nrw and what old. k must not 
oover too ranch ; if it does so» it 19 not effectual, 
even to the e:ttent to which the patentee wotrid be 
otherwise entitled ; as, if there be a patent for a 
machine and for an improTcment upon it, which 
«uiiioC be sustained for the machine, althoni^b the 
hnprorement is new and nacful, yet the grant alto- 
gether ia invalid, on account of its attempting to 
eover too much. A potent fnr a new method of 
drying and preparing malt is not suitaiDed by a 
apeci^catian in whioh is described a method for 
heating, he, ready-made malt : so a patent for an 
invention founded on a principle already known, for 
lifting fhel into the fire grate from below the grate, 
in the apecificatioa whereof was described » new 
spparatua, was held to be bad for not claiming the 
new instrument as the thing invented : so when a 
patent was " for a new method of completely light- 
ing cities, towns, and riUnget," and the apecifica- 
tion described improvementsupon lamps, the patent 
wu held to be void. The subject most be given to 
the public in the most improved itate hnuwn to the 
hiventor. A patent, in Bngland, for stef> trusses 
was held to be void, becaoae the inventor omitted 
to mention that, in tempering the steel, he rubbed 
H with tallow, which was of aome use in the opera- 
tion. The specitication must not contain a de- 
•rription of more than the improvrmrnt or addition. 
If thero be several lhini;8 specified that may be pro- 
dnoed and one of them is not new, the whole patent 
ia void. In England, if any consider able part of a 
manufacture be unnecessary to produce the desired 
effect, it will be presumed that it was inserted with 
a view to perplex and embarass the inquirer : thna, 
in I Term Reports, 602, in Turner's patent for pro- 
ducing n yellow color, among other things, ntinium 
la ilirectrd to be used, which, it appealed, would 
not pr<idace the desired effect, nnd, lor this reason, 
the validity f>f the patent might be itnpeac^hed. In 
the specification of Winter's patent, 1 Term Re- 
ports, 602^, a great number of aalts were mentioned, 
by which it ajtfteared that either might be used to 
make the subject of the patent, but only one would, 
iu fact, produce the etfect ; and, for tln» ri-nson, the 
patent wu held to be void. If tlic patentee maUeis 
Ibe article of cheaper materials than those which be 
has enumerated in his specification, although the 
fetttcr answer equally as well, the patent ia void. — 
In Engtand, if the improved manner of using the 
ioveotion be unintentionally Uft undex^ribcd, still 
«bo patent la void. (1 Moion'i Repttrta^ 1K9.) In 
Prance, the general rules, in these respects, are 
similar. 

CTohe eotUimueii.j 




OF ECLIPSES. 

I AfiMTJMrf/mia pi*if<f TCv) 

Or aU the various phenomena of the heavnifl, titer* 
are none which have created m murh curiosity, CL' 
cited so much interest, or caused so much surpria* 
throughout the world, as eclipse* of the nun amk 
moim ; and to those who are u^aoqumiitcd with tb« 
principle of astronomy, there is nothing, pertu^Cr 
which appear more catraordinary than tha moauwof 
with which they can be predicted. 

In the cjirlirr nges of the world, before wrigaot 
had enlightened the minds of men, appearanoei of 
this kbd were generally regarded as alarming devia- 
tions firom the established laws of nature ; and bur 
few, even among pliilosopbera tbenuelves, were abkr 
to account for these rxtmordinary appearanca.— 
At length, when men began to apply theoMelrea ta 
observattons, and wlien the motions of the odestiAl 
bodies were better understood, these phenomena 
were not only found to depend upon a regmLaroauni 
but to* admit of o natural and easy aolutiom l^Mnr 
ore, hflwpver, nations that still entertain Che 
superstitiuus itotiona respecting ecUpacs, p4 
Hx Mejricons and Chinese. 

Tbtu, wbea the inUnt mcKin bar drcUog ivtMra 
Wbeel* o>r tlw «un » tirosi) 4\ak. b«T tbadow (kits 
On vsrib's fair bt^aoin ; HukitMs chllU th« ft»Us, 
AoA drrary night kuvMU tiw fkc* of hosvcn. 
Henert«d from th« l«ko full oixpy ■ alat 
6llmin«n «(lh fe«bl« Inncour. India'* •ons 
AITrlgblvil In wild lumult rrnd lb» Ur. 
Itcfore hU idol god wilh buti'rou* >hn*k 
The Brsfhnian* (bUs i wlicn moti itir cy« of dUy 
t>aru hia uU'Checrtni ridtoiicr. Uum thr glainn 
K"i'n{*"(I ■'"y iBVMdM the wi)ud'ni%ti crawd. 
And acclmnsUuu ruihv* frwm tht b-flitiM 
or tbootinds. Uiai araood ibclr bluing p^^ 
Illol m antic rianc« noddUionaDt ■ong.— Zovea 

Many instances are to be found, not onlr in aa- 
(rient. but even hi comparatively modem ustoryi 
where the superstition of the times haa continiLed to 
connect the records of eclipses with the deUib of 
some remarkable event, which either happeoi aooa 
after or during tlieir rontiouance. But theae dctaik 
being foreign to the nature of the present jnper, if« 
shall procet^ to gjve an account of the causea, muf 
various kinds of ediptts of the sun and moon. 

As every planet, belonging to the sulor system, 
both primary and secomlary, derives its light from 
the sun, it muat cost a shadow towards that j]art of 
die heavens which Is opposite to the sun. This 
shadow is, of course, notlung but a privation of light 
in the space hid from the sun by the opaque body, 
and will always be proportionate Co the relative mag- 
nittid^s of thi* stin and plnnct. If the sun and planet 
were both of the same size, the form of the si 
cast by the pUnet would be that uf a cylinder, 
diameter of which would be the same ai thAt of 
sun or phuiot, and it woald nerer converge to A 
point. If tlie planet were Uirger than the sun, tlu 
shadow would continue to spread or diverge ; but 
as the sun ia much larger than the gn-atest of tb« 
planets, the shadows cast by any one of thc« bodia 
must CDnTrrs;e to a point, the distance of which from 
the planet will be iiruportionatc to Uic »i»e and dia- 
Unce nf the planet from the sun. The magnitiwhl 
of the Eun is such that the shadow I'ust by ench of 
tlie primary planets always converges lo a [>o\nt be- 
fore it reaches any other planet ; so that nut oimi aT 
the primary planets can eclipse another, yet the «hado* 

* Altlii>U){h th# Chiiv^v iirrfunn lh» tnml lidlculntia a»4 
iut<vrititi><M> err* moil tffi ddriri^ lite Itiit* al au ccii)M«, jaa 
they CAU lalL'oliit* Ibem nilh Tbr grrslctl prffeJ<i4n,, 



let which is Hcompuiied by iatellites, 
rertmn occasions, ecKpse these sateUites -, 
[not long enott^ to eclipte any other body. 
iw of a fitt«Uit« or moon may also, on cer- 
I, fall on the primary aud ecltpiie it 
ttpmi of Uie «nn and moon hnppen when the 
i m near her nodes, that is, when ihe is either 
i pUne of the ecliptic or very near it. Those 
B son happen only at new moon, or whci» the 
t U in conjuDction with the Kun ; whilst thoae 
ic moon happen at the time of /nli moon, or 
Qim moon is in opposition to the sun. The 



sun. earth, and moon, mast, therefore, always be 
nearly ia the tame stnight line at the time of an 
eclipM ; and coorersely, when tbeae three bodies ar« 
nearly in a ttroight line, on oclipse must take place. 
Hence it is evident, thnt an eclipse happens in con- 
seqoence of one of the two opaque bodies, tJie earth 
and the moon, being 90 placed as to prevent the 
sun's li^ht from hilling on thv other. See Che fbl- 
lowifig figure, which represents the moon paxsing 
through ttie dark shadow uf the earth, as she moves 
in her orbit N Z, while the earth moves in the ecUp<- 
ticRQ. 




ition of the moon between the sun 
prodncea an ecti{>se of tlie sun ; and 
ition of the earth between the moon and 
that its shadow foils on tJie moon, pro- 
edtpse of the moon. On these principles 
hole pbenomena uf edipscs depend, ojid admit 
n|ilete explanation. 

M moon s orbit we|T coincident with the plane 
Iptic, the moon's shadow would fall upon 
•nd occasioo a central eclijue of the sun 
ooiynnction, or new moon ; whilst the 
would fall on the moon, and occasion 
of that body at every opposition or 
ir as the moon would tlien always 
iptir, the centres of tlic nun, r^rth, 
Id all be in the fiame straight line at 
times. But the moon's orbit is In- 
Ftiie ecliptic, and funns with it on angle of 
flO' ; and. therefore, the moon is never in 
|e excqit when fihe in in one of her uodet : 
may be a considerable number of con- 
tand oppunitious of Uie son and moon with- 
taken place. 
u always at aomc distance from the 
when ihr is in one of her nodn:— 
is called her iafihtdf, which is 
according as the moon is on the 
ideof the echptic. Now if the moon 
there cannot be a eenirat ecHpie, 
hspjtt-n when thir moon is in one 
at tht rnomrnt of conjunction, winch 
the case ; and, of course, very few 
ises of the stm have taken place since ttic 
world. But the section of the 
(through whii'h the moon passM 
ipBcd) bring inach larger than ths 
the moon may be totalty eclipsed, 
^ sbv be at some distance from her node at 
nc of opposition ; but its duration will be the 
r tSie UBBLrer she is to the node. An eclipM of 
IS may also happen, although the moon oe at 
Sistance from hex node at the lime of cunjunc 
ihwt its form, as wcU as its duration, depends 
upon that dirtance. This circumstance 
the dif-ijiion of eclipsci into central, 
and portml. 
u-4iiing uf these terms most be obtiousto 





the reader, it is almost onneceaatry to gire an ex* 
planation of them. 

A central eclipse, is that in which the centre of 
the shadow folia on the centre of the body which is 
eclipsed. 

A total erjipse is the obwuration of the whtrfe 
body eclipsed. 

An annular eclipse is Chat in which ttie whole of 
the body eclipfird is hid, except a ring round its 
edge, which remains luniiuous. 

A partial ecli|>se is that in wludi ptft of the 
body is hid from view. 

iTobt tMntinued.) 



ESSENTIAL OR VOLATILE OILS. 

( Itentmfd /mm iMge llH.) 

Oil qf Bitter Almondt, is prepared by exposing 
the bitcer almond cake, from which the bland oil 
has been expressed, in a sieve to the vapor of water 
rifling within the still. The steam, as it passes ap 
through the bruised almond parenchyma, carries oET 
its Tolatile oil, and condenses along with it in the 
worm. Tlie oil which first comes over, and which 
falls to the bottom uf the wnter, has so pungent 
and penetrating a smell, that it is more like cyanogen 
gas tlian hydrocyanic or prussic acid. This oil baa 
a golden-yellow color, it is heavier than water ; 
when much diluted, it has an agreeable smell, and 
a bitter burning taste. When cjii>ased to the air, 
it absorbs oxygen, and lets fall a heap of crystals 
of benzoic acid. Tliis oil consists of a mixture of 
two oils i one of which is volatile, contains hydro- 
cyanic acid, and is poisonous; the other is less 
volatile, ia not poisonous, absorbs oxygen, and be- 
comes benzoic ucid. If we dissolve 100 parta of 
the oU of bitter almonds in spirit of wine, mix with 
the solution an alcoholic solution of potash, and 
then precipitate the oil with water, we shall obtain 
a quantity of cyonide of potash, ca|>able of pro- 
ducing 22 J parts of Prussian blu(^. Oil of bitter 
almondn cnmbines with the alkalis. rerfomers 
employ a great quantity of this oil in scenUug tb<dr 
suaps. One manufacturer in Pnris is said to (ireiiare 
annually 3 cwt. of this oil. A similar jMtsoiioua 
oil is obtained by distilling the following substsncei 
with water: — The leaves of the peach, {antyjftlaiHg 



HO 



MAGAZINE OF SCIENCE. 



/f^rtiCA,) the leavet of the bny-laurel, {frrnntu lauro- I 

^'-.--itnv 1 i1>f:- bark of thf f'M'c 'r- ^^'rrugpaHuM,) 

;rod kemelr^ i n-stonec* 

.'■ < 1- i»ntam liyl ' li rnitlArs 

ibrtn puisunaus, ftiid ihcy <tUo g^ni-rdir: benzoic acid, 
b; atiHorhiu; oxyi^cn on txpnsurr to oir. 

(hi qf Anist-tePiif is rAtrartrd bjr disitiUation 
fkmn the Kcdi of the pirn/jiitflla anUum. It ts 
either colorless, or has mei^ly a faiitC Tclbjw rolur, 
vtth thf> smeU and Caila of the leed. It fu>nrrctes 
in lamellar crystals at the temperatore of ^0 '. and 
does not melt again till heated to 64'^ nearly. Ita 
BpecifiL- KrHvity at 61^ is O'lMJoH.and at 77^, 0'9S57. 
It is sptubte ia all proporlions in alcohol of 0'S06 ; 
but ODif to the extent uf 42 per cent, in alcohol of 
0'84. When it becomes resiiioas by long cspoaure 
to the air, it loses tit coogvaling projwrtr. It con- 
iriita of two oili ; a solid atearesitence, and a liquid 
oleteswnce, which may be separated by compression 
of the cnld concrete oil. 

Oii t^ Berffamot, u extracted by preiifliire from 
the rind of the ripe fruit of tbe citru* terffamium 
and avrantium. It is a lioipid. yellowish lluid, 
harin; a amell resembling that of oran;;es. Its 
speriSc grurity Tariea from 08H8 to 0*B{<5. It be- 
camc« concrtte when cooled a little below 32". 

Oii of Cajejjut, is prepnred in the Moluccas, by 
^tilUoK the dry leaves of the melaieuca Ipvcnden. 
dton, Cnjeput ts a native word, signifyin^r merely 
n white tree. Tliis oil is green ; it has a banting 
taste, a strung snicll of camphor, tiirpetitine, und 
SaTine. It ia very fluid, and at 48^^ has a specific 
gravity of 0'918. Tlie calnr areros to be derired 
from the copper Teasels in which it is imported, so 
that it is runiavcd by distillation with Kstcr. which 
also separates the oil into two sorts; the l^rst which 
comes over haring a density of 0'897i the last of 
0-920. This has a green color. 

The Oil of Caritway, is estractcd from the srcJs 
of the carwn carui. It has a pate yellow color, 
and the smell and taste of the plnut. Iti sprcitic 
gravity is O'i'tiO, The seeds of the cvmittum 
Cj/mintmi, (cumin.) alTord an oil similar to the pre- 
ftt-diatc, btit not $o agreeable. Its specitic gravity 
is 0975. 

The Oil of Cassia, from the laurug catitia, is 
yellow passing into brown, has a specific gravity of 
l'071t and affords a crystalline stenrcuencc by 
keeping in a aomewbat open vefsel. 

The Oil of CAfinwtiiile, is extracted by di»t;llHlion 
from the Aowers of the mitrtrtinti rhamomiUn, It 
has a deep b]ae color, is almost op't(jue, iind thick ; 
and possesses the peculiar smell of the plant. In 
tba atmosphere it becomes broa-n and unctaous. 
If an ounce of oil of lemons be added tu 3 lbs. of 
this oil, they make it sepiirnte more readily from 
tbe adhering water. 

Other blue oils, liaving much analogy with oil of 
chnmomite, are obtained by dtstilEinz the following 
plants : — Roman chatcomilr, (antfiemii not/itht) 
the flowers of arnica itvoutana, and tUo»e of milfuil. 
{aeAtiiitn miHifoiia.) The last baa a specific gravity 
of 0-852. 

Oil f]f Cinnamon, i« extrartrd by distillation from 
tbo buk of the taurtis etnnamumum. It is pro- 
duced chiefly ill Ceyluo, from the pieces of bark 
unfit fur exportation. It is diiitiUcd ovtr nith 
dilliculty. and Uic proceig is promottd by the 
addition of salt water, and the u:^e of a low tlUI. 
It has at first a pale yellow color, but it bccomf*a 
brown with age. It possrases in a high d'-grrc hotti | 
the street boxning taste, and the sgiecabk amrll of 



cionamon. It ia hearier than water; its spooti 
gravity being 1'035. It concretes below 32* F- 
aod does not fuse again till heutetl tu 41^. It 
very sparingly soluble in water, and when agi 
with it readily separates by repose. U dt 
abundantly in alcohol, aod combines with ai 
into a viscid mass, not decumpoeed on ei\ 
tu air. 

When oil of cinnamon is kept for i '■ 
it dcpogtits a stcarcsscnce in Urge regul.i 
or yellow crystals, which mar be puUr- 
which melt at a very gentle beat into n coltirii 
liquid, which crysullises on cooling. It has 
odour intermediate between that of cifinninoa an^ 
vanilla; and a taste at first greasy, but afterward^ 
burning and aromatic. It crackles betweovj 
t«eth. It rv({uiresahigh temperature for distil 
and become!^ then brown and cmpyreamatic. 
very soluble in alcohol. 

The on of Cloveft is extrnoted from the 
flower buds of tbe caryophyllta arottiaticita. 
colorless, or yellowish, has a sfron^ smcU of 
cloves, and a burning taste ; its yptritic gravity 
1*061. It is one of th-,- least volatile oiU. and 
most difficult to distil. At thtr ev.-i of i < 
time it deposits a cryslnllinc roticrct^' i»il. A 
gtearextence ts obtained by boiling the bmisttli 
in aloohol, and letline the solurion cool. The i 
thus formed arc brilliant, while, grouped in 
vrichout tjisle and smell. Oil of dovrs hM 
markabic chemical properties. It distntvr* in slcnl 
ether, and ijcelic arid. It docs :: 
temperature of 4'' under 0" F., t\ 
to that CT)M for wvenil hours. It 
gns, becomes grtreu, then broftn.tn 
Nitric acid makr» it red, and it i' 

convei-ts it into oxalic acid. U mixed by 
degrees with onc>tlurd of its weight of s«lph 
acid, an acid litiuor is formed, at whose 
resin of n fine purple color Is fnniid. AfVcr] 
washed, this re«in hccouics htrd and brittle, 
dissolves it, nnJ i»Vr« a red color; and wa( 
cipitatrs it of a h^tod-^ed hue. It disao) 
in ether. When we asitate a mitturr of st 
caustic soda lye and oil of rlovt-s in rtiual 
the mass tliickens very soon, and forms 
lomelUr oryi^tsls. If we then pour water 
and drttil, there pluses along with Ihc water, 
qtianlity of an oil which dilTprs from oil of" 
both in taste and rhemicnl pri)[»crtif». Uoi" 
cooling, the li(|nor left in the retort kc»/ 
quantity of cryfltuUme needles, which being ai 
by expression from the altcaltnr liquid, are 
inudorons, but po-sess an alkaline taste, }< 
the burning taste of tlie oil. These crystala 
for solution from 10 to 12 purls of cold 
Potash lye produces similar ctrcctf. Ami 
gas transmitted through the oil is absort 
makes it thick. The courrrlc comhii 
formed remnins solid as long as the phial cot 
it is corked, but when opened, the c< 
becomes liquid : and these phenomena m»j} 
produced as tnany times ns we ptcasr. SnCibr 
nations arc dircomjioiied bv aculs, and iUr 
liberty has the luime faatc and *nicll as ftt Hi 
it hns A dsep red color. The aK. ' 
detect ihe prf*''nce of other oil«, a» ■ 
or SHSsafras, in that nf cli)vt:», biv .. 
latter, while ttie former may be tolaiiltu 
water by dij>ttllin^ the mixlun*. Tlie oil of 
fonnd in iHtmmcrt^ is not pore, but 
mtAtun; of the tincture ot pink» w di 



MAGAZINE OF SCIENCE. 



r 




Kcrid renn in thereby introdoccd. 
<hi»tiriitt-d wish other ntU. 
r, \a exiracled by di^tillatinn 
il}e Momhucwi nigra. Ic hu the 



- extraetcd by ilUtUIation from 

or tne niirthum famicitlum. It is efther 

r*T nf n yrllow lint, hns tlic Rmrll of the 

irtc (TTavity of 0-99:. Whrn 

Bcirl. it affordi* benzoin. It 

.u i;r- (■.mperatare of 11" F., ond then 

ltrr>>ure b lolid and a liquid oil ; the 

...<.. ring in rryntalline plaCea. It i« med 

7 for fcmtin* sonp. 

, rrmfuied l.iquQm. — The mbjitancef 

tit»l ront^iu a small quantity of 

. ^rhicb bcrome volatile along vriih Ibc 

-■T% in distillation, and progressively 

■' spirits become weaker towards the 

•c.ts3. The Tapors then condeoae Into 

Tbe«e oiU iidliere itronply to the 

L-ire it n peculiar acrid tntite. They 

lit to the vinoni wa«h from which they 

nnd combine with grc'itcr or leiia 



' •. — At tlw ordinary tempe- 

pir'ttiiy II nitite iuKd ; whi-n c<ir»1ed 

uowa the aspect nf tuct, and therefore 

'fly of ateareMcnct'. Its taste and smell 

iiJiTc ; it swims upon the surfat^c of 

■ -n of spirit contaitiing 30 per cent, of 

li tonieiimcs derives a green color from 

iV" worm of the ilill. When heated it 

onia yellow. ^V^e1l it baa become 

\\e agency of the atmosphere, it girea 

ttaiii to papL-r. It dissolves in G parts of 

us alcuhol. Olid in 2 of ether; and is said 

' illirc irhrn the Kpirit solution has been 

:< ic hot, and is allowed to cool. By 

frecxing D-.ixtare, the whiskey which 

£•> '- it fall. Caustic potash dissolves it 

y* 'id forms a soup «^oluble in 60 pnrtA of 

• fc-.i r It i< «b«orbed by wood charcoal, and still 

bttur by hui»e black; whereby it may be com- 

»leleJy abtlrsrted from bad ivbiskey. AL-cording to 

Bnobtkcr^ another nil mny aino be obtained from the 

fuidiiuin of the second distillation of whiskey, if 

salur«ted with sea salt, and a»>iin distilled. Thus 

re e>)t.iin n pale yellow fluid oil, which does not 

r^^ 't cold, possessed of a disngreenhle 

»' :-) taste. Its sjKcific graTity is 0-83.'t. 

t: a alrohol and ether. 

from Pofatv Sfjiritx, has properties 
: from the prei'rding. It is obtained 
:• quantity by continoj ag tbe distillation 
'T the alcohol has come over* and it 
ID the form of a jellowlsh oil, mixed with 
dispirits. After being agitated first with 
tuth a stronf; lolutiou of muriate of 
I tiled afresh, it possesses the following 
— It if colorlcM, limpid, has a peculiar 
a bitter hot taste of considerable per- 
il leaver no greasy stain upon piper, 
at D*' F., but cooled below that point 
like nil of anise-fieed. When pure it 
F. ; bat at a lower degree, if it contains 
Its spcrific grarity is OHlil, or 0*823, 
.'^ins a little water. It burns with a 
'hout smoke, but it eti<>ily goes out* 

•<'''• R wick. It diisnlvcil ill -'^ttl! 

It which it impnrts its taste 
jrming a lather by agitaliun. .^ 



diisolves in all proportioos in alooboL ChloriDO 
render* it ^reen. Concentrated tulphurle acid con< 
rerts it into a crim<H)n soltttiun, from which it is 
precipit4ted yellow by wbLit. It diseoNes in all 
proportions in noetic arid. Concentrated caustio 
lyes dissolve it, but give it up to water. It does 
not appear to be poisonous, like the oil nf com 
spirits; because, when given by spoonsful to dogs, 
ic produced no other etfect but vomiting. 

3. Tfif Oil of Br/jntii/, Of Grape Spinft, Is 
obiuincd during the distillntion of the fermented 
residuum of eipresscd gnipcs ; being produced im- 
mediately after the spirituous liquor has pajtMfd over. 
Jt is very fluid, limpid/of a peoctrattog odunr, and 
an acrid disagreeable taste. It grows soon yellow 
in the air. When this oil is distilled, the first 
portions of ic pass unchanged, but nfterwards it is 
decomposed and becomes empyreunialic. It dis- 
solves in 1000 partR of water, and communicates 
to it its pecoliiLr Listc and jimell. One drop of it 
in capable of giving a disagreeable flavor to ten old 
English gallons of rpiriti. It combines n-ith the 
caustic alkalis, and dissolves sulphur. 

Oti of Juniper, is obtained by distilling Janiper 
berries along with water. These should be bmised, 
because their oil is contained in small sacs or reser- 
voirs, whicli nni«t bi* laid open before the oil con 
escape. It is limped and colorless, or Fometimes 
of a faint greeniali vrllnw color. Its speeiHc gravity 
is 0-91 1 . It has the smell and taste of the juniper. 
Water, or even alcohol, dissolves very little of it. — 
Clin contains a very minute quantity of this oil.— 
Like oil of turpentine, it imparts to the unne of 
persons who swallow it, the smell of violets. Oil 
of juniper is frequently sophisticated with oil of 
tnrjtentine introduced into the still with the berries 
— a fraud easily detected by tlie diminished density 
of tlie mixture. 

TMe Oit of tawnder,\i txtncledUom tbe flower- 
ing spike of the larnndula Mpica. It is yellow, 
very fluid, has a strong odoor of the lavender, nnd 
a burning taste. Tbe specific gravity of the oil 
found in commerce is O'HDH at the temperature of 
72" F., and of 0877 when it bos been rectified. It 
is soluble in all proportions in alcohol of 0'B30, but 
alcohol of 0-B87 diisnlvcs only 4'J. per cent, of its 
weight. The fresh oil detonatea slightly when mixed 
wit]i iodine, with the production of a yellow cloud. 
There occars in commerce a kind of oil of lavender 
known uuder the name of oil of upic or oil of tpikft 
extracted by distillation from a wild variety of the 
lavatidflanpiC'h which has Urge leavca, and is there- 
fore called iatijhfia. This oil is manufactured in 
the south of Kurape. Ita odour is less character, 
istic than that of the lavender, reaembting somewhat 
that of oil of turpentine, with which it is indeed 
often adulterated. It is also so cheap as to bo 
sometimes used instead of the Utter oil. Oil of 
lavender depntits, when partially exposed to tbe air, 
a coQCrete oil, which resembles camphor, to (be 
amount of one-fourth of its weight. 

The Oil (if Xutmefff, ia extracted chiefly from 
mace, which is in the inner epidermis of these nuts. 
It is colorless, or yellowish, a little viscid with a 
strong aromatic odour of nulmegii, an acrid taste, 
and a spedfio gravity of 0048. It consists of two 
oils, which moy be easily separated from each other 
by agitation with water ; for one of them, which is 
more volatile and aromatic comes to the surface, 
while the other, which is denser, white, and of a 
lottery consistence, falls to the bottom. 
iTo 6tf (xriitimted) 



a 



112 



MAGA21NK UF SCIENCE. 



MEDICAL RECEIPTS. 

Bwrion Wairr. — Imitated by dissolTing ta a 
bottle of filtered water, 15 grains of carboaate of 
soJa, half a dram of taxtrate of »oda, «ith 80 minimit 
of wine of imn : before corking add 8 miuimB of 
fitilphuric acid. 

Campbell' M Green Liniment. — Made with 1 otmce 
eaeh of camphor and of extract of hemlock, 2 otinces 
of compound spirit of ammoiua, 6 ounces each of 
liquor ammoDte and of olive oil. For aweUings 
and enlarged joints. 

Camphor BaiU, auch aa Sdway'i , in perfiunerr, 
are made by grinding in a (ttarch-mill 6 pounds of 
very dry fftarch, 8 pounds of very dry white lead, 
cifting i>t through a lawn siere, and then mixing it 
with 14 pounds of very fine rice powder, l^en 
flbave down and dry 4H pounds of the best oil soap, 
and mix with the former. Next grind 1| pound of 
camphor in on iron mortar, with half a pint of 
Hungary water, and add Kradually half an ounce 
each of oil of ro<*rmary and of lavender. When 
reduced to powder, add a few pounds of tlie 
prepared soap, and after beating it well mix the 
vhole together, and make it in the same way as 
ambergris wash-balls. Used as a cosmetic, bat not 
aafiely. 

Camp Vineffar, is made by steeping in the best 
vinegar for & month 1 dram of cayenne pepper, 2 
table-Bpo4]m«ful of soy, amd -1 of walnut-ketchup, 
6 anchovies, chopped, and a small clove of garlic, 
minctid fine. Shake it frequently, Ktruin through a 
tammbt. itnd kvnp it well corked in small bottles. 

Catholicon Uvplicatum Rheo. P. — The doable 
catholicon of nicolai, or compound electnory of 
rhubarb, is prepared by simmering over a slow fire 
half a pound of polypody root, 2 ounces of succory 
root, 1 onncc of hi^uohce root, 3 ounces of the 
IflBTeB of agrimony and spleenwort, 6 pounds of 
water, till reduced two-thirds ; add 6 drams of fenncl- 
•eeds, strain and add 4 pounds of sugar, boil to the 
consistence of ^rup, and add 4 ounces each of 
extract of cassia and jiulp of tamarinds. Then add 
by decrees 4 ounces each of powdered rhubarb and 
aenna leaves, 1 ounce of liquorice root, 2 ounces of 
aeeda of violet, 1 ounce of the four cold seeds, half 
an ounce of fennel-seeds, and mix and form an 
electuary. It is too troublesome in the preparation 
to be much U!ied. ^Vitbout tlie rhubarb, and with 
hooey instead of sugar, it forms a good enema. 
It was formerly es&emed a nnivcnal remedy, bat is 
now disused. 

Chamberlain' a Hestorativt Pilli.— Dr. Paris dis- 
covered by RiuilyHiit that these pills consist of dnnabar, 
sulphur, HulphJste of lime, and a little v^etable 
matter, llie inventor, who resides at Ipswich, says 
the pills are the most eertain cure for scrofula, 
fistula, scurvy, and all impurities of the blood, but 
often take two years to effect » cure. 

CAamomile Dropt. — This nostrum is nothing more 
than spirits to which a little of the oil of chamomile 
has been added, for the sake of the odour and taste; 
but posaetsea none of the medicinal qualities of the 
flower*. 

ChtiMm Pemiionsr, — A well-known gout nostrum, 
•aid to have been invented by a Chelsea i^nsioner, 
and is prepared by making an electuary of 1 dmm 
of guoiac, 2 drams of rhubarb, in powder, ] ounce 
of nitrate of potass, and 1 ounce of flowerv of 
•ulphur, with 1 nutme]^, in powder. Dose, two 



table-apoonsJtil, night and morning, as a purgalivA] 
ami diaphoretic. 

CAimff's Worm Coseuj/et. — A po|)ular noctnuB, 
for worms, consisting of two preparation&, the 
of both of which is chloride of mercury. 

The yellate Jjizengei, are prepared by nixuig] 
1 pound of chloride of mercury, washed in aloohflj, 
with 4 drams of saifron that has been boiled in I 
I pint of water, and strained, and 29 pom 
white sugar, making the whole into a masa withj 
tragacanth mucilage, and rolling it out to an 
thickneas. Each loaenge should conuin 1 gnhi 
the chloride. The dose is one lozengr at bcd-tiiM«' 
and on the succeeding morning a brown loseuge ii 1 
to be taken. 

The Brown Losenyet. — ^Talce 7 ounce* of the 
chloride of mercury, washed as before, 3^ pounds 
of jalsp, 9 pounds of white sugar, and enoogb of 
gum tragacanth mucilage to make a mass. Eodir 
loaenge should contain half a grain of the ddoride. 

Tliese nostrums are by no means safe, as tha 
chloride Is wldom diffused equally, and may in : 
loxenges be in dangerous qoandty. When 
kept, also, or cxpoaed to damp, they may 
poiKonons properties. 

Cochrane'* Cough Medicine. — A nostrozn 
bears the name of Major Cochrane, is pi 
making a decocdon of the beads of white popplai* 
previously freed from the seeds ; rtraio this, Iml It , 
again with vinegar and brown sugar to the coo- 
sistenoe of syrup; then add sulphuric acid till it is 
pretty sour. 

Com Ptfuter. — The common green corn plaster ia 
prepared by melting 4 parts of Burgundy pitch, 
with 3 parts of wax, 2 parts of turpentine, and 
1 part of diarrtate of copper or vCrugo, and spr^ding 
the whole on cloth to a proper tlucknesa ; or mix . 
and spread 3 ports of mercurial oromnntacal pUster«| 
and 1 part of resin opiate plaster. Com 5o/M/Je«aj 
is solution of potass. 

Court PloMier, or Black Stickintj Plaster. — 1 
half an ounce of benzoin, and G ounces of 
spirit, dissolve and strain ; then take 1 ot 
isinglass, and half a pint of hot water, dissoJve iiS' 
strun separately from the former. Mix the !««#] 
and set them aside to cool, wht-n a jelly will be 
formed ; and this la warmed and brushed ten orj 
twelve timet over n piece of black silk, stretcbed:] 
smooth. "Ulien tliis Is done enough, and dry, 
it with a solution of 4 ounces of Chian turpentintpj 
in 6 ouoces of tincture of benioin. 

Dqffy^M Elixir, (/>ic«y'*.)— Take 4 ouncea_ 
senna leaves, 2 ounces each of rasped gnaiac < ' 
dried elecampane root, coriander-seedo, 
caraway 'Beeds, and liquorice root, 8 ounoesof i 
rusins, 6 pints of proof spirit. Digest for a ' 
strain through bihnloua paper, and add half a 
of treacle. Sometimes given to horses. 

Strinton'e Dcffy^e Elixir-'^-Take 3 pounds of' 
jalap root. 12 ounces of senna leavei,. 4 ounces caek^ 
of coriander-seed, anise-seed, liquorice root, and 
elecampane root, 1 gallon each of wine and water.' 
Digest for three weeks, strain, and add a gallon of] 
treacle. Do»c, 2 drams to G drams as a cannimttifCL j 

Dojmak Poicder, in prrfomery, is pneparW by, 
beating well in a mortar 3 pounds of cyprtta ; 
and dry damask roses. Sift the powder 
a fine cypress sieve, beating it and retumini 
it is sufficiently fine. The rosea make it ~ 
soft. 



XDiiDOM.-*Prtiit«d by.O. FajLMcu. A, While Uom Lant, MUa fad,— PubUahod bfW. Bajnaia, I i, ^lamostu lt««a 



THE 



MAGAZINE OF SCIENCE, 

find ^cj^ool of ^m* 



119.] 



SATUBDAY, JULY 10. 1841. 



[IK 



Fig. 2. 



iP - r^ 

Fig. 1. 





,D 




GODDARD'S OXY-HYDROGEN POLARISCOPE. 



HC 




Fig. 3. 



I. 111,'^KO. XT. 



MAGAZINE OF SCIENCE. 



THE OXY-HYDROGEN POLARISCOPE. 

( Met unusi from page 108, atuJ txttKludeii.J 

It haa been siready sUted that the object of the 
prMcding papers on the poUrixation of light hu 
beea to introduce and illustrate ihc polariicope of 
Mr. Goddord, of MrUicb the ftilluwiiig u a plain di*. 
tchplioa; merely prrmi»mg tbac the nuazle of the 
iiutniineDt, or that which is thus described, is to 
be fitted on the front ot a magic lanthoru, oiy-hj- 
drogcD microscope, Stc. 

Pig. 1. A, the cumpouud jet of the h^dro-oxjgen 
blawpiiie ; I), a pallet of lime ti;nited by the flame of 
1 jet of hydrogen tnd oxygen gasea impiuging upon 
it ; D, divergiug rays uf light refracted by the con- 
deniiug lenaes C C C, and falling upon a mirror 
FF. compoaed of ten pUles of thin flatted crown 
glaji*. placed in the elbow of a tube bent tu the 
polarizing angle of crown glass, C, conveying ruys 
of polarized light reflected from the mirror ; HH, 
a bundle of sixteen plntea of mica for anaiyiing the 
ligbt previously polarized by reflection ; E, a double 
reidecting uryslal (film of aelenite) pluced in the 
founi of the object>glaai I, which furma an image 
of the cr)-stal upou a di»c or screen at R. As the 
analyting bundle of mica H H, ia luaJe to revolve 
(or torn round), the image of the aelenite upon 
the disc undergoes all the changes, aud exhibita 
kltemntely the primary and roniplcmentary colors. 
This appaniiua buthe adTnatage of exhibitiag both 
the primary and ooroplementary colora at the tame 
time, one being reflected in the direction S, and the 
other transmitted and seen at R. 

The great advantage ut" polnrixing the light by re- 
ilectioD from a Dumber of plates, is the obtaining a 



beam of any required dimensions, of much greater 
intensity than by any other means ; for, whaterer 
single surface may be employed tiiat )>olarizes the 
light at the same an^le an the glass used (which, 
fur crown ghiss, is 56'' 45'), we obtain an additional 
quantity by laying on it a single plate of sacb glass, 
and a further quantity by the addition of a second, 
third, or any further number ; the quantity of Ugbt 
added by each Bueceeding plate being, however* 1cm 
in proportion lo the number of plates tlirougli which 
it has previously to pass. 

In this respect, the single image (^icol's) prism 
of Iceland spar ia decidedly the best for aualysiug. aa 
by this a great variety of objecu may be exbibitcdL 
Its application ia sbown in f)i(. 2, where E i* the 
srleiiite placed in the rays I) D D of polariied ligbt» 
an image of which is projected by the leuseft t. K 
is the aualysinc prism tltrougb which the ru|a of 
light RR are relracted. 

But there is one class of phenomena, nx. the 
rings seen to encircle the optic axes of crystals, 
the number of which iucrcasc in some crystals (tba 
topu, for example), witb the divergtfnre of the ray« 
of polarized light paaaing through them. It trill 
be evident, then, that the toumiahnes enable ua lo 
exhibit more of these nnga, and upon a Urger snle 
than the priifm, which will he belter understood by 
the arrangement shewn in fig. 3. D D U. con- 
verging rays of Iiij;bt polarizing by reflection ; I. a 
lens of short focus irsntiroitting a cone of light srith 
an angle uf divergence for it« rays R R, of 46'. E« 
a crysUl, say topax ; H, the tourmaline for aaalya- 
ing; 80 that, even for these purposts, the cost of 
the tourmahnes ia reduced one half by the polari- 
icope, as only one need b« used. 




OF ECLIPSES. 

{Hfaumed Jrmn ^f^e 109.) 

Tbk above figure represents n partial eclipse of 
the sun, which will be vieible to that tract of the 
earth marked NQ,0, the Une MN marks the 
greatest obscuration. 

If the distance b« very small, the eclipse vrlU be 
the greater, and continue the longer ; but no eclipse 
of the son can be either central or total, except the 
moon be in the very node at the time of conjunc- 
tion. But should she he in this situation when she 
ii at her least distance from the earth, and the earth, 
at the same time, st its least distance from the sun, 
then the eclipse vrill not only he central but total, 
and continue so for a few minutes. But if the moon 
happens to be at her greatest distance from the 
earth, and the earth at its greatest distance from the 
auu, the eclipse will be annular, or a small space 
round the sun's centre only vrill be hid from view, 
and a bright lucid ring round his edge will remain 
visible. 

If the moon be less than 17^ degrees from either 
node at the time of conjunction, her shadow will 
fall more or teas upon the earth, according as she 
H more ur lets within this limit ; and, of oootm, 



the sun will suffer a partial eclipse. And if ahe be 
less than Vl\ degrees from cither node at the time 
of opposition, she will pass through more or leu of 
the earth's shadow, according ma ahe is more or Im* 
within these lines, and, of course, ahe will cuffer an 
eclipse. 

As these Umita form but a small part of tba 
moon's orbit, which is HfiQ degrees, eclipaee boppcB 
but seldom ; however, in no year can there be feinv 
than two, and there may be seven of the sun and 
moon together — but taking one year with another, 
there are about four each year. But as the sua 
and moon spend aa much time below the horisoa 
of any place as above it. half the number of the 
eclipses will beinriaii/e at anyparticuUr place, and 
consequently, there will be only ttco eclipses visible 
in a year at that place, the one of the aun and the 
other of tlie moon.* 

Every eclipse, whether of the sun or moon, is 
risible at some place of the earth's surface, And in- 
visible at others ; for the rational horizon of every 
place divides both the eartli and heavena into two 
equal portions or hemispheres ; and as no celeatiel 

* ir iticra IM wvtn rcUpMi 1q any year, five of tlMMi ■■■t 
be of ih« sun and two of ibe moon. 



AIAGA2INE OF SCIENCE. 



lis 



I 



body can bf «rea ncept it b<t above the spectator's 
bw^a, it follows that nay eclipse which is visible 
IntlMOiie hemisphere cannot be visible in the other. 
fca W MB Ibe bodf which is eclipsed is belnw the 
Imrison of that other. If a lunar eclipse, for cz> 
— plii't hnppons at any hour of ni^ht, beiweea the 
IImi ofsun-strttiog aad san-risiuj^, at any particular 
ylBOK, it will be visible there, and invisible to the 
■dktbttaDls of the opposite hemisphere, who have 
ft* COB above their horizon at that time; fur i he 
nn afni tnoon are in upfwsite parts of the he;ivens 
«t tha iime of a lunar eclipse. And with respect to 
volar eoUpR*. it is evident that they can only be 
•oen at any place when the sun is above the horizon 
«C that plaet!. There is, however, a ditTerenee witlj 
t^anl to the visibility of solar and lunar eclipsca ; — 
for an ecl^se of the moon has the »ame appearance 
to ^^ tha iohabitiints of that heroiiiphere to which 
tlie moon is visible at the time, owing, in part, to 
tiM amaU distance of the moon from thf earth. — 
But an eclipse of the sun may be visible to »omti 
places and invisible to others in the same hemi- 
fphcr* of the earth, because the moon's ahadow is 
•akail is comparison of the earth ; for Its breadth, 
csclnding the prnooibra, is only about IKO miles 
wna ia Ct'Xitrul eclipfles.* Hence those places 
vhach are considersbly distant from the pnth of the 
ikailow vriU either bjivt no crlip<ic at all, or a very 
■oiaU one: while places near the middle of the 
•hadosr will have the ^eatest possible. There is 
■lao a difTcrrnce in the absolute (imentwhii-h a 
Mlar eclipse bappetu at the Tarioos pUcu it is visi- 
Ue ; for it appears more early to the western parti, 
«ad later to the eastern, on arconnt of the motion 
of the moon (aad, uf course, her shadow) from west 
10 cut. 

lo noct solar eclipses the moon's disc may be 
obserred by a televcupe lo be covered by a faint 
Ugbt, which is attributed to the leflcxioMfif light 
from the illuminated part of the earth. When the 
eclipses are total, the muon'a limb is surrounded by 
« pale eirctc uf light, which some uatronomrrs con. 
Mder as an indication of a lanar atmoe)ihere, but 
•tker^ ma ocr^-fionifd by the atmosphere of the sun, 
twcause it has hern observed to move equally with 
like lufi and not with the moon. 

f)r. Ilnlley, iu describing a central eclipse of the 
ich happened at London, in April, 1715. 
'^ althouigh the tlisc uf the sun wn« wholly 
by the moon, a luminous ring of a faint 
--bt surrounded the body of the moon the 
■ the time; and its breadth was nearly a 
'he moon's diameter. 

Mar rulipses, the moon seldom disipptars 

: and, on some occasions, even the spots 

■>tin?itisbed through the shade ; but this cjin 

'he case when the moon is at her greatest 

from the earth at thetimeof tbecclip!>p, 

p-ji . I arcr the moon is to the earth the dsik- 

•es» i-i 1 -.■■ '-iter. In some instances, the moon 

k*e duaip^aitd entirely; and the celebrated astro. 

•ottier. Ileraclius, has taken notice of one where 

tbe moon could not be seen even with a telescope, 

r nif^ht was remarkably clear. 

'•^h echpses of the sun and moon were long 

c^fiilered. by the i|:norant and supemtitiuits, as 

fRMfts of rtiV. yet they are ot the greatest use in 

*"^'""'''"*' "'H may be employed to improve some 

portnnt and useful of the iicirncrs..^ 

: Mju moon the eariM is prored to be of 

" * IwsombiA 11 tJi# Ul<i( thStloM t»n>duc«d by an ope<]u* 



a ff lobular form, the son lo beyrra/er than the eortht 
and the earth ^eatcr than the moon. M'faen thejr 
are similar in all their circumitaQcea, and lioppea 
■t considerable intcrviLl« of lime, they also servo to 
ucsrtain the real period of the moon's motion. In 
geogrnphy, eclip^rs are or considerable use, in de- 
termining the longitude of places, and pnrtirulirly 
eclipses of the moon, becaaso they are oftener viai- 
bie than those of the sun, and the same eclipse is 
of equal magnitude and duration at all places where 
it ia seen. In chronologr, both solar and lunar 
eclipses serve to determine exactly the time of any 
past event. 

For the purpose of finding the longitude of plaees 
on the earth, ecUpses of Jupiter's satellites are 
found much more UMeful thin eclipses of the moos ; 
not only on account of their htip|tening more fre- 
quently, but nn account of their instantaneous com- 
mencement and tennination. 

When Jupiter and any of his satellites are in a 
line with the sun, and Japiter between the 88teUit» 
and the aun, it disappears, being then eclipsed, or 
involved in lus shadow. When the satellite goes 
behind the body of Jupiter, with respect to a spec- 
tator on the earth, it is said to be occ*ttted, being 
hid from our sight by his body, whether in his 
shadow or not. And when the satellite comes into 
a position between Jupiter ami the sun, it cAAta a 
shadow on the face of that pUnet, whteh ia seen by 
a spectator uu the earth as an obscure round spot,— 
Lastly, when the satellite is in a line with JnpiCer 
and the earth, it appears on his disc as a roond 
black M|x>t, which is termed a transit of the satellite. 
As those phenomena appear at the same moment 
of aftjroluir lime at uU places on the earth to which 
Jupiter is then viiiible, but at different hours of re> 
/ff//re time, ai;cordiiig to tlie distance between the 
meridian of the places at which obsenrations are 
made, ic fallows that thia difference of time con- 
verted into degrees will be the difference of lonfltndo 
between those places.^ Suppose, for example, that 
a person at London observed on eclipse to be^n at 
11 o'clock iu the evening, and that a person at Bar- 
bndoes observed the same at 7 o clock in the eve- 
ning, tt is certain tlie eclipf.e was seen by both per- 
sons at the same moment of absolute time, although 
there is four hours difference in their manner in 
reckoning that time ; and this converted into de- 
grees (at the rate of 16 degrees to nn hour) ia the 
dilTen'nre of longitude between these two plucea — 
therefore, Uarbadoes is GO degrees vex/ fram Lon- 
don, the time not being so far advanced there as at 
London. 

Another phenomena, somewhat similar to an 
eclipse, sometimes takes place, by which the longi- 
tude uf places may be determined, nlthou^h not 
quite so easily, nor, perhaps, so occurutt-ly, as by 
the eclipses of Jupiter's satellites. This is the 
hiding ur obscuring of a fixed star or planet by the 
moon ur other planet, which t^krs phice when the 
moon or planet is in conjunction with the star. — 
AppcaruDces of this kind are termed oecultations. 
They are very Utile attended to except by practical 
astronomers, who employ them for the correction 
of the lunar tables, and settling the longitude of 
places, ai already stated. 

r To bo eontimtd.j 

* .llut^ute titnt ii that which >■ campnled fmm Iho nmm 
mnniftit: rtiaitre ia ibot wUcb la cninpttUil flum djfforcnt 
niAfnrntt. ; 



MAGAZINE OF SCIENCE. 



BOTANICAL NOTICES. 

1.EAVK8. 

Lkaves are among the most importaat vegetatiTe 
orguu. They may be said to perform the same 
office to pUnta which luoga do to animals, aa it ia 
through them thai vegetable breathing ia carried 
on. Bjr means of their pores and fine Teaaels, they 
absorb and tranamit the air and moisture which 
aurroond them ; and after thua aiding in the nour- 
iihment of the very excremitiea of tbu plant, they 
throw off from other pores not merely the super- 
abnndsnt juices, bat the air which they had pre- 
▼ioualy taken np, and that in a itate infinitely purer, 
aiid better adapted to the support of animal ciist- 
tence, than at first ; in fact, the very gas, (carbonic 
acid,) which planta absorb, la injuriouB to oa ; and 
that we want to breathe, which is oiygen, they sup. 
ply us with in return. 

The fdnctiona of leaves, therefore, are highly im- 
portant, and like the finer extremities of the roots 
require to be renewed from time to time : thoa, 
daring the greater part of the summer, fresh leaves 
are ariaing^when aatnmn comes, the whole fall off 
or decay away, leaving, aa is well known, herbaccoua 
planta dead, all but the root; and deciduotu treea 
Dare and leafless. 

Leaves have other uses, scarcely of less conse- 
quence. Those of the grass tribe by sheathing 
around it add much to the strength of the young 
and tender stem. Id trees they are so admirably 
placed as to shield the bud. and often the young 
flower, not only from ezteraal injur}', but from the 
too great tieat of summer, and where it is necessary 
from the chilling wiiida of winter. This latter pro* 
perty is seun in our evergreens ; and in some spe- 
cies of the oak ; where the leaves, ulthough AmA, 
still keep thtir place, till the swelling bud in the 
spring is ready to supply tlie tree with a new and 
living foliage. 

Ordinary leaves arc composed, first, of a skin or 
cuticle, which covera them on both sides ; within 
this is a green pulpy mass, called cellular ttMHue or 
farmchyma. and inside of all is a woody substance, 
branching out into delicate veins, intended not 



merely to convey the vegetable jnicea and secretioas* 
but to strengthen the more pi^py parta of the leaC 

Leavea vary ao much in shape end sixe, that 
scarody any twn plants (except in particular tribes) 
have them exactly alike ; thus in leavea are veiy 
often found sure marks to tell plants from each 
other. After dividing them into radical or root 
leaves, and caulme or stem leavea, they are cim' 
sidered with rrspecl to their pfMitiou, insertion, 
shape, surface, and texture. 

In thdr situation on the stem they may be wdisr 
aiiemate. (Pig. I,) that is, growing singly, first oo« 
on one side of the stem and iben one on the other 
— sppotite, or growing (2,) in pairs — trhirled, 1,3,) 
three, four, or more, growing out of the aame part 
oftheatcm — and imbrieated, (i,) when they fold 
over each other : sometimea they are scattered ap- 
puentJy without order. 

%.^-^ lb 



In their manner of growth leaves are ritber 9* 
presufd, (Fig. 1,) or growing rinse to the ateo>^ 
erect, (2,) or upright — j/atent, (3.) or spreading oat 
— hurizontal, (4,) — reclined, (^,)--aod SeyettdaU^ 
(6,) or banging downwarda. 




In their insertion or manner of attachment a leaf 
ia called etatked, (Fig. l.) if with a distinct atalk — 
jieggile, (2,) if joined at once to the stem — poymtffr, 
(3,) if abeatliing round the stem — clatjiing, {\,) tf 
the base dosed around it — deeurrent, (.'»,) if mn- 
ning down — perfoliate, (6.) if the stem run throng 
it — and connate^ (7,) whenever the base of tw» 
leavea are joined together. • 







The shapea of leavei are almost endle&s; they 
are either simple, compound, or doubly compound, 

I Simple leaves may be, I round — 2 oval~'S ovate, 
or ^g shaped — 4 oblong — h lanceolate — 6 linear — 



7 cordate, or heart abaped — 8 wpetfndate — 9 o l iww! 
date, that is, corfhite with the wider ptirt sway from 
the stalk — 10 reniformor kidney-bhaped— 11 ta^* 
tate or arrow sbajicd — 12 hajitate or like the haad 



t^ i% i¥ iT^ tfH ^ ^ a* 

e * 10 'it iir 3f 1^^ jsv 2^ 




MAGAZINE OF SCIENCE. 



117 



or • halbert~13 peitatt, tlut ii, with the ttalk 
growlof irom the middle of it — 1 4 tUltnid, or «oin«- 
tUoff like the Grerk letter Dclu— 15 runcinmU — 
1< iymfe, or gyitar stuiped — 17 lohHi—\S fiddU 
aUpi^ — 19 dictate, or fingered— 20 petlal§~~2\ 
Mhmafe, or like a band — 'i2 pinnatifid, that u, with 
lobe* cut down nearly to the inidhh~2:i;^er/jrtd/^, 
cut Uke the teetb of a comb. The loit eicht are 
WMatnTca. 

Compound teavet arc formed of many BicnplQ onea 
joined together. They arc called Otttate, temalf, 
tfig. I,) quctrmcte, qutnatr, (a.) A.r., as there may 
bt two, three, four, five, or more, eejiarate portions 



on the Keneral leaf atalk— vm^etf. (3.) when then 
are two distioct projevtiuoi below the blade of the 
leaf, u in the orange — ptnnaff. (■!,) whru many ire 
joined to aa to make two row> — and doubly pinnate, 
(A.) where several pinnate lenvcs are united; lo 
alM A leaf may be dnubly teniatf, or even ihrier 
temate. All iuttancca of this kiod form dtrnkl^f 
compound leaTeg, thongh the last term ia mostly 
applied to such as are loo much divided to hare 
Ihrir parta readily counted (aa in Fig. 6). When 
these parta are fine, like hairs, the leaf is called 
capiltactvim (Fig. 7). 






The fd^ea of leaves nrr another mark of distine- 
tion, whether they be cutn-f, (Fig. 1.) that is. with. 
«•! ootehea — cmate^ {2.) or scalloped— /ooMfJ, 
(li) — «rT * ale, (4,) or cut Uke a »aw — douhty «r- 
'**•' ' '<■ ) where a large and • small cut follow each 
sv*d, (6,)—indtnted, (7.)— erorfed. (8.) 
ii; as if it were kuawed — crisped^ (9,) or 
caricd — ciliated, (10,) Uut it, with baira around it, 




« to an eyo-Uah. 




i T 8 y lU 

Uke poinCi of learea are of no 1cm consequence. 
Tbry ue koown aa friMca/e, (Fig. 1.) if cot off 
'fii«, (2.) or blunt pointed — emarginaif^ 
ig « notch at the end — tridmi pointed^ 
\i^ — fnjipidate, (5.) or tapering into a bard point 
, —ta p tr m ff (6.) — uid hair poiultd, (7.) where the 
!■! tcnaiaatea in » long, weak, and fine point. 



0«r daily obserratioa informs us of many psr- 

(kalna hr«itlc!i these relative to this important 

VTe are accustomed to witness leaves 

with Ihoma, strings, baira and wrinkles.— 

W« kanw that the furxe bu«h ts scarcely furnished 

ftjih lama at all— numerous tboms supplying their 

piMVi Many plants can boast only of • few scales, 

inJ acme not CTcn these imperfect substitutes ; — 

V-aflesB dodder twines around the flax and 

>. choking them by Its embracot and stanr* 

tag thsfm by the absorption of the juices they hsd 

•tored up for their own use. On the other hand, 

bi tropical reginna the leavrs of many Tegetables are 

•f woriBans size — that of tlie talipot tree of Ceylon 

h oAcD 30 or 40 feet in eircumfrrence, snd sup- 

fsnedby % ttatk 12 feet long— s sini^li: leaf heint; 

ttlpkhle of shielding many prrsous fmm ihe Bttn and 

TUa. Thr Iravea of thr H«te tree, of Ihe banann. 

**4 of the cocoa out^ are ftlmoftt equally magoifi- 



f T 

cent. In our own country we witness nothing equal 
in magnitude to these ; hot we have instead of it 
richness of tint, and aa endless variety of apj^ear- 
ance. In the hotter regions trees are evergreen, 
always putting forth fresh leaves, and losing their 
olderooes. The forests, therefore, of countries like 
these are of a more uniform appearance than in the 
temperate regions. With us, aithough in the win- 
ter our woods are bare, yet during the remaining 
•easona we have an ever- varying succession of beauty, 
from the lively green, which the tender leaves as- 
sume in the spring, through the luxuriant uni) dark 
foliage of the summer, to (be rich and roellnw au- 
tumnal tints which prerede ** the/ait of the lee/,** 
casting ao bright a charm around the dying land- 
•cape, and contrasting with each other, no leaa in 
their decay, than tliey did in the previous times, 
when bnds were opening, and flowers shining in 
their freah and fragrant beauty. 



THE 



AND 



SUN NOT A GLOBE OF FIRE, 
PROBABLY INHABITED. 
TuK sun appears to be nothing elae than a very 
eminent, largf, and lucid planet, evidently the first, 
or in strictness of speaking, the only primary one 
of our system ; all others being truly secondary to 
it. Its similarity to other globes of the solar 
system with regard to its solidity, its atmosphere, 
and its diversified surfore. the rotation on it* axis, 
and the fall of heavy bodies, lesda us on to suppose 
that it is most probably also inhabited, Uke the 
rest of the planets, by beings whose organs are 
adapted to the pccuUor circnmstaaces of that vut 
globe. 

It may not, however, be amiss to remove a 
certain difficulty which arises from the effect of the 
sun's rays on our globe. The heat which is here, 
at the distance of ninety-five millions of miles, 
profluced by these rays, is so considerable, that it 
may be objected that the surface of the globe of the 
sun itself must be scorched up beyond all cod. 
ception. This may be very subatantiiUly answered 
by many proofs drawn from natural philosophy, 
which show that beat is produced by the sun's rays 
only when they act on a cslorifir medium ; titcy are 
the cause of the production of heal, by uniting 
with the matter of fire which is contained in the 
subetances that are heated ; as the coHiaion of flint 
aod sttel will inflame a magazine of gunpowder by 



U 



118 



MAGAZINE OF SCIENCE, 



putting tU the Ulcnt fire it containi into nation. 
But au iniitHncfl or two of the muiDer in which the 
folar rays produce tbeir effect will bring this home 
to our most common eiperience. 

Oa the tops of mountaini of a anffictent height, 
at an altitude whcrn clouds can very neldom r<iach, 
to shelter tbem from the dir«ot rays of the iud, 
we always find regions of ice and snow. Now if 
tht! solar rays themselves conveyed all the heat we 
find on this globe, it ought to be the hotteat where 
their cour8« is least interrupted. Again, oar arro- 
oauts all confirm the coldness of the appi?r regions 
of the atmofphcre ; and since therefore even on 
onr earth, the heat of any situation iir|M>nds on the 
aptness of the medium to yield to tlie impression 
of the isolar rays, we hare only to admit, that od the 
sun itself, the eloatic fluids composing it£ atmos- 
phere, and the matter on its aurface, are of sach a 
nature as not to be capable of any excessive nfffctton 
fWim its own rays, and this seems to be proved by 
the copious eniissiort of them ; for if the clastic 
fluids of the atmosphere, or the matter cnntaincd 
CD the surface of the sun were of such a nature as 
to admit of an easy chemical combination with ita 
rays, their emi5sion will be much impeded. 

Another well-kaown fad is, tbnt the solar focus 
of the largest lens thrown into the air will occasion 
no sensible heat in the place where it has been 
kept for a considerable time, though its power of 
exciting combustion, when proper bodies arc exposed, 
should be safficicnt to fuse the most refractory 
sttbstances. — Ucruchel. 



ESSENTIAL OR VOLATILE OILS. 

fRetumtd j'rum fage 111, and concIuthU^J 

Oil of Lemorw, Is extracted by prcsaare from the 
yellow peel of the fruit of the lemon, or citrus 
medica. In this state it is a ycUowiiih fluid, baring 
m specific gravity of 0'Hol7; but whea diittiUed 
along with water till three-fifths of thr oil have 
eome OTer. It is obtained in a colorless state, ond of 
ft specific gravity of 0-84 7 at 72' K. This oil does 
not become couerete till cooled to 4** below 0" P. 

The oil of lemons has a very agreeable amell of 
the fruit, which is injured by distillation. It is so- 
luble in all proportions in anhydrous alcohol, hut 
only 14 parts dissolve in 100 of spirits of wine of 
specific gravity 0'8.t7. This oil, e«j>eriatly when 
distilled, forms with moriBtic acid similar campho. 
rated compounds with oil of turpentiuet absorbing 
no less than 2i^0 volumes of add gas. 

Oil of lemons kept long, in ill-corked bottles, 
generates a quantity of sttfaressence, which when 
dissolved in alcohol, precipitated hy water, and 
onpomted, aifords brilliant, colorless, transparent 
needles. Some acetic ncid is also generated in the 
old oil. According to Brando, the specific gravity 
of oil of lemons is 0*878G. 

TAe Oii qf Mace, lets fall, after a certain time, a 
concrete oil under the form of a crystalline oruit, 
called by John mynWirtrie. 

TAe Oil qf Oranpe Flowen, called nero/i, is ex- 
tracted from the frob flowera of tlie ciinut auran- 
itiim. When recently prepared it is yellow; but 
when exposed for two hours to the rays of the sun, 
or for a longer time to did'use daylight, it becomei 
of ■ yellowish-red. It is very fluid, lighter than 
water, and bos a most agreeable smell. The aqueoas 
solution knovm under the name of orange-fiower 
nster, is used as s perfume. It is obtained ettber 
by dissolving the oil in WBter, or by distilling with 



th^ 
Th3| 



water the leaves either fresh or salted s ' 
being the strouicrr, but the last being tA 
fragrant preparation. Orange-flower water < 
by distillation, contains besides the oil, a (; 
which comes over with it, of a nature hith< 
known : it posiiessea the property of imptj 
water the faculty of becoming red with 
of sulphuric arid. The water formed 
olooc is destitute of this property. 
of the rose-color is a test in some measnn 
richness of the water tn oil. 

TTie Oil qf Parttey, is extracted from th< 
petroMelinum. It is of a pale yellow color, 
the smell of the plant, and consista of I 
separable by agitation in water. Its llqi 
floats upon the snrface in a very fluiil In 
stetreisence. which falls to the bottom, is but] 
and crystallises at a low temperature. Tl 
Crete oil melts at Hti*" F. 

Tfie Oil qf Pepper, Is extracted from ti 
niffrum. In the recent state it is liiD] 
colorlcsa, hut by keeping it becomes yet! 
swims upon the surface of water, la ^ 
resembles pepper, but is devoid of its hot 1^ 
7%e Oil qf Pcppermini , is extracted fi 
mentha piptfrita. It is yellowish, and t-ndu 
a very acrid burning taste. Its sprnfic gi 
0-920. At 6^ or 7* below O'' F., it deposii 
capillary crystals. After long keeping it ■ 
fltearesBcnre resembling camphor, provided 
bad been obtained from the dry plant gatl 
flower, but not from distiUation of the fres' 
Wlicn artificially cooled, it yields G per' 
steoressence, which crystallises in prisms wii 
sides, has an acrid somewhat rank taste, is 
in ether and alcohol, and is thrown down f 
latter solution by water in the form of 
powder. Peppermint water is choracl 
the sensatioD of coolnets which it diffa 
mouth. 

The Oil qf Pimento, is extracted from' 
lopes of the fruits of the myrius pimenta 
afford H per cent, of it. It is yellowish, 
colorless, of a ^mell analogous to that of ek 
acrid burning Uste, and a specific graritf 
than water. Nitric acid makes it fir^t n 
after (he effervescence, of a rusty brown h 
combine* with the salifiable bases, like oil of 
TAe OH of RhhdiiitH, is extracted from tl 
of the conroieoiiu scopariwt. It is very flu 
has a yellow color, which \u time becomes r 
has somewhat of the rose odour, and is \ 
adulterate the genuiuc otto. Its taste is bit 
aromatici which it imparts to the otto as vv 
fluidity. 

The Oil ofRosrt, colled also the 
is extrnctcd by distilUtiaD from the 
roM rentlfoHa and sempwTJrs m . Our nattv 
furnish such small quantities of the oil, th 
are not worth distiUing for the purpofe. '7 
wsy of operating is to return the distiUnf 
repeatedly npon fresh petals, and eventually 
the saturated water with ice; whereby a hltl 
raceons oil is deposited. But the oil Oius oi 
has not a very agreeable odour, being iiiji; 
the action of the air in the repeated distil] 
In the East Indies, the atur is pbtamed by 
fying ro«e leaves in earthen pans in alternate 
with the oleiferous seeds of a species of dj 
culled gengeli, for several days, in a cool sit 
The fat oil of the seed sbsorbs thft *— ***■' 
the rose. By repcstiug tbis praasva wfll 



of 
Bcteri 



petil 



J 




MAG.VZINE OF SCIKNCE. 



19 



v>d the Mine seed, thii becomrs eventawUy 

ti, anfj being then exprosscd furnijhes Utc oil. 

Tke turbid liquid tbtu obtainett is Ic/t at rest, in 
«cU-cJu»od vcskU. wben; it gets cUrifted. The 
tiffer of uil Hut floats on the top i« theu drawn off 
b| • capillary cotton wick, and subjected to dis- 
taUtioQ aloog with water, whereby the Tolatile utto 
l» Mp«ral«d Aram the fat seed^U. 

T^ oil of roses ia colorless, and posiesses the 

lell of ro«««. which ia not however agreeable, 

tifllst wtnTi ililfuscd, for in iU conneiitraLed state it 

I -^AOt to the nottrils. aud is apt to 

los. U» taste i* bland and sweetish. 

II water, and at tlie temperature of 

I cravity cumpored to that of water 

L^wif » •' -i^. At lower temperatures it becomes 

^^kpvte and butymceoiu ; and afLerwurdK fuaes at 

Ik It is but slightly soluble in alcohol; lOaU 

yirts of tbis litjuid at OHOGduiaolringonly 7^ parta 

tf 5ir* f'. Tliis oil coosidls of two parts, the stear- 

— eo oc and olciesseoce ; the latter being the more 

VOlfttUii odoriferooi portion. 

TAm on uf Rotmarjf, is extracle<l from the r09- 

■ ■ r ^w w t oJirialiM. It is as limpid as water, has the 

tB«ll of the plant, and in utlicr rc«]>ertfi resembles 

oil of lurpenliiie. The oil found in commerce has 

1 ijr. ih, gravity of 0-91 1, which becomes 08886 

ttion. It boils at 321) P. (occasionally at 

1 1 IS soluble in all portions io alcohol of 

U Mju. \\'hcn kept in imperfectly closed vessels, it 

depocita a a tear rue nee to the amount of one-tenth 

ito wvigbt, resembling camphor. It is someCimea 

led with oil of turpentine, a fraud easily 

dfteeird by Sliding aubydroiu alcohol, which dis- 

'v Ute oil of roeemary, 

' ^ Si^rofht is extracted from the ttigmata 

ol (be crocMt tatiru*. It is yellow, very fluid, falls 

to the bottom of water, diifuseii the penetrating 

' 1 be plant, and has an acrid and hitter taste. 

uc. 

* ..' t -- <{f Sajuafrai, is extracted from the woody 

MOt of th« launu Mcxiafraa, It is colorless, bat at 

Att cod uf a certain time it becoaiea yellow or red. 

U has ■ peculiar, sweetish, pretty agreeable, but 

hnt burning taste. lu specific grsfity is 

tng to Bonostre, this oil aeparatts 

• water into an oil lighter aud an oil 

IU mis fluid. When long kept, it deposits 

in transparent and colurlesi crystals, 

i.^»*- th^«mell and taste of the licjuid oil. 

irine, is extracted from the leaves 

^ itahina. It ia iimptd, and baa the 

Mid Us(« of tbe plant, whidi is one more 

v« of volatile oil than any other. 

'HI ^ ToBMjf has a specifir gravity of 0*946, 

pmctratiog odour of the ianacftum vnigarc, 

aa acrid and bitter taste. 

<M (^ Turjieuiinc, commonly called essence of 

It ia extracted from sererat species of 

A semi.tjtjuid rcsiaous substance which 

certain trees of the ^iiie tribe, and is 

by distilling the resin along with water. 

This Oil is the cheapest of all the volatile species, 

' '1. contains a UctJe reain, from 

by rc-distilUtion with water. 

■ ^1,, tM.ipuJ. very fluid, and has a very 

nrll. lu specific gravity st CO' is 0-872; 

hi', spirit on sale in the shops is 0-8/6. 

j>U always reildrns Utmus paper, because it 

httle suLviaiv acid. 

parts of spiri(s of wine, of apccific gravity 

H4| dtalve only 13^ of oil of turpentine at 72"!'. 



M'hen agitntcd with alcohol at 0*830 the oil retains 
afterwards one-Afth of its bulk of the spirit; hence 
ttiis proposed method for purifying oil of turpentine 
ia defective. Tbe oil if left during four months in 
contact with sir is capable of absorbing 20 times its 
bulk of oxygen gas. One volume of rectified oil 
of turpentine absorbs at tbe temperature of z?**, 
and ,under the common atmospheric pressure. 163 
times Its volume of muriatic acid gas,, provided the 
vessel be kept cool with ice. This mixture being 
allowed to repose for 2-1 hours, produces out of the 
oil from 2G to 47 per cent, of a whtto crystalliuQ 
substance, which subsides to the bottom of a brown, 
smoking, translucent liquor. Others ssy that lUO 
parts of oil of turpentine yield 110 of this crystal. 
Uoe matter, which was called by Kind, its diS' 
icoverer, artificial camphor, from its resemblance in 
Amdl and appearance to this snbstance. Uoth the 
solid and the liquid are combituktions of muriatic 
acid and oil of turpentine ; indicating tiie existence 
of a Btearioc and an olcinu in the latter substance. 
The liquid compound is lighter than water, and is 
not decompoR'd by it, nor does it furnish any more 
solid matter when more muriatic gaa is passed 
through it. Ttie solid compound, after being washed 
first with water containing a litile carbonate of soda, 
then with pore water, and fiaally purified by subli- 
mation with some chalk, lime, ashes, or charcoal, 
appears as a white, tran&luccnt, crysulUne body, 
in tbe form of flexible, tenacious needles. It swiou 
upon the surfsce of water, diH'uses a faint smell uf 
camphor, commonly mixed with that of oil of tur- 
pcntine, and has rather an aromatic ibun a cam- 
phorated taste. It does not redden litmus paper. 
Water dissolves a very minute quantity ; but rold 
alcohol of 0*806 dissolves fully one-tiiird of its 
weight, and hot much oiore, depositing, as it cools, 
this excess In tbe form of crystals. The solution 
ia not precipitated by nitrate of silver, which shows 
that the nature of the muriatic acid is perfectly 
masked by the combination. It is composed, In lOO 
parts, of 7C'4 carbon, 9*6 hyilrogen, and 14 muri- 
atic acid. The muriatic acid, or chlorine may be 
separated by distilling an alcoholic solution of the 
artificial camphor 12 or 14 times in succesaioa with 
slaked lime. 

(Jil of turpentine is best preserved in casks In* 
closed within others, vrith water between the two. 
lt» principal use is for making varnishes, and as a 
remedy for the tape-worm. 

The Oil (/ TAyute, is extracted from the thffmut 
Htyyllum. It is reddish yellow, has an agreeable 
smell, and, after being long kept, it lets fall a crys- 
talline stejfresseuce. It is used merely as a perfume. 

The Oif r^^VorfHtcwd. is extracted from the 
ariemisia ahttiiihiutn. It is yellow, or sometimes 
green, ond possesses the odour of the plnat. Its 
taste resembles that of wormwood, but without its 
bitterness. Its speriHc gravity is 0-urU3, accord- 
ing Co Briseoo, and 0*9725, according to Brando. 
It detonates with iodine when it is fresh. Treated 
with nitric acid of 1*25 specific grarity, it becomea 
6nit blue, and, after some time, brown. 



MEMORANDA. 

Iron, — Every person knows tbe manifold uses of 
this truly precious metal ; it is capable of being cast 
in moulds of any form ; of being drawn out into 
wires of any detired strength or fineness ; of being 
extended into pUtiis or sheets $ of being beat ia 



MAGAZINE OP SCIENCE. 



every dirertion ; of being shBrpened, hardened, uitl 
nof^ened at pleajiurr. Iron aerommodatrs itself to 
all oar wants, our desires, and even oar caprice ; 
it U equally «-*rviL-eubIe to the arts, the sciences, to 
agricultnre, and nar ; the same ore furnishes the 
vword» the plougb&hare , the scythe, the pruning- hook . 
the needle, the graver, the spriog of a watch or of a 
carriage, the ctUael, the chain, the anchor, the com- 
pjui, tlie canaon, and the bomb. It ti a medicine 
of much rirtae, and the only metal friendly to the 
humuu frame. The ores of iron are scattered over 
the crust of the globe with a beueficcot profusion, 
proportioned to the utility of the metal ; they are 
found under every latitude and every tone ; in every 
mineral formation, and are disseminated in every 
soil. — Dr. Un'i Dictionary qf Manufactures. 

Seo Wormi. — Tliese animals, which are so per- 
nicious to our shipping, appear to hare the same 
office allotted to them in the waters, which the 
termites or white ants have on the land. Were it 
not for their rapacity, many rivers, and parts of the 
ocean itRelf would be choked with the bodies of 
trees which arc annually carried down by the rapid 
torrents, and many of them would last for ages, 
and probably be productive of evils, of which we 
cannot in the present harmonious state of thin^ 
form any idea ; whereas now, being consumed by 
these animals, they are easily broken to pieces by 
the waves, and their entire dissolution is oherwords 
rapidly effected by a variety of canses. 

Human 7Vme Pi>rc. — The following singular 
account appears In a recent number of a valuable 
French work, the '* Bibliott'que Universelle," 

J. D. Chevalley, a notive of Switserland, aged 
sixty-seven, has arrived at an astonishing degree of 
perfection in reckoning time by an xnlemaf move' 
went. In liis youth he was accustome^l to pay 
great attention to the ringing of bells, and vibrations 
of pendulums, and by decrees he acquired the 
power of continuing a sacceasion of intervals exactly 
equal to those which the vibrations or sounds 
prodnced. Being on board the steam-boat on the 
Lake of Geneva, on July 14. 1B23, he engaged to 
indicate to the crowd about him the lapse of a 
quarter of an hoar, or as many minntes and seconds 
OS any one chose to name, and this during a conver- 
satinn the most divrr«ilicd with those stauding by ; 
and farther, to indicate by the voice the moment 
when the hand pn9i>c-d over the qanrier minutes, or 
half minutes, or nny other sub>divt»ion prCTioaiily 
stipulated, during the whole course of the experiment. 
ThtB he did without mistake, notwithstanding the 
exertions of those about him to distract hiiatleDtian. 
and clapped his hand at the conclusion gf the time 
fixed. His own account of it is thus given : — 
" I have acquired by imitation, labor, and patience, 
a movement which neither thoughts nor labor, nur 
any thing can stop. It is similar to that of a 
pendulum which at each motion of going and re- 
turning gives me the space of three seconds, so 
that twenty of them make a minute, and these I 
add to others continually.*' 

Humming of Gtiait, — It appears very probable 
that the humming noise emitted by the gnat when 
fljring about in a dark room is useful to the insect 
itaelf, for, as it would be differently modulated ac- 
cording to its distance from, or nearness to, sur- 
rounding objects, it may have the effect of prevent- 
ing its injuring Itself by knocking against obstruc- 
tions to its flight. As a proof of the great difference 



in »oandi orising from even but trifling cmaea* we 
have only to take a card in hand and whistle agaiasl 
its edge at a little distance, and then a greater dis- 
tance, and then against its flat surface at a greater 
or less distance, and we shall obserre that the tone 
widely differs under each of tboe drcumttanoM. 
Now, if ire suppose that the gnat knows, from either 
instinct or experience, that aoands thus differ ac- 
cording to such circumstances as the abore. it ms| 
learn its situation in a dark room by the rariatftsB 
produced upon iu piping noise (which may thus be 
as serviceable to it in the dark as its sight in the 
day time), and avoid breaking its vrings, or other- 
wise hurting itself by flying agunst anything tn its 
way. In the same manner, probably, one may erplahi 
the utility of the humming of the cockchafer (IfMns* 
tha f>uitjari»), the dung-beetle {Geotmpta «tferv9- 
rrirtttij, and many othej insects. 

Tht Veiocitiet ^ Wind.—yix. John Smeaton, 
the late celebrated engineer, has given in the 
" Philosophical Transactions/' vol. 51, the ve- 
locities of wind, corresponding to the usual denomi- 
nations in our language, Theee ore founded Ln 
u great number of observations made in the cuurac 
of bis practice in erecting wind-mills, and are oa 
follow :^ 

Light airs. .from.. I to 3 miles per hoar. 

Broen 4 to 5 miles do. 

Briakgale 10 to 15 miles do. 

Fresh gale 20 to 25 miles do. 

Strong gale 30 to 35 miles do. 

Hard gale 40 to 45 miles do. 

Storm &0 to 60 miles do. 

Hurricane 80 to 100 miles do. 

Tht Light of the Moon and Planeta is considered 
by Professor Leslie to be caused by phoflphoreaccat 
matter, and not by mere reflection from the sun. 
The light falling from the sun upon the moon's anr* 
face appears to him to be almost entirely abaorhed, 
and exerts there a power to cause the projection of 
a still greater quantity of luminous particles, whidl 
bad previously Isin combined vrith the substoDcc. 
which be supposes bears a resemblance to the vaX" 
phatc of barytcs. 

Bleaching Ivwy. — Antique works in ivory that 
have become discolored may be brought to a part 
whiteness by exposing them to the sun under gl 
It is the pariicutor property of ivory to retl 
action of the sun's rays, when it is under 
but when deprived of this protection, to become 
covered with a multitude of minute cracks. Many 
antique pieces of sculpture in ivory may be aeea, 
which, although tolerably white, are. at the 
time, defaced by numerous cracks ; this defect can- 
not he remedied; but, in order to conceal it* the 
dust may be removed which has insinuated itself 
into the hssures, by brushing the work with warm 
water and soap, and afterwards placing it under 
glass. Antique works in ivory that have beoow * 
discolored, may be broKbed with pumice sttaie, 
calcined and dilated, and while yet wet placed nn- 
der glasses. They ahould be daily exposed to the 
action of the sun, and be tamed from time to time, 
that they may become equally bleached ; if the 
brown color be deeper on one side than the other, 
that side vriU, of course, be for the longest time ex- 
posed to the sun. The bleaching may be ocoele* 
rated by frequently repeating the operation jost da- 
scribed. — Repertory qf Art*, 



a piuE 

3 



Umodm — I'rlnteJ by O. Fhakcii, 6. While Itarni! L»nc. Mile Eii4 — PublliliiMl Dy W, B>m*tM. II. PalemMitM Row. 
CommuaicaUinu, v*vhii:h are aaswrrpd Monthly.) (o be adOmsed to Ibo Editor, at 37, Col1*][C Orovf. MU« Ead Rsad 



anH ScDool of 5lvti5. 




m. 



111. NO. XVf. 



ELECTRO-MAGNETISM. 

tOnUmwfi frma pagr 978, ruf. M.i 

The last jiaper upon thii sabjecc gave an iccoant 
of Tsrioui electro* niBgnrlic rotatiimH, protlnoed 
upon wirtra i-onvcying the electric lluid aloii^ tbcm, 
aided by ibe eflVcts uf the propinqaity of v mmgnet. 
Tbt' present article continues llie subject by «how- 
jng that ntagnetj theaiMlves, if made free to rrvoWr. 
and subjected, in particalar wayi, to electrical car* 
rmtf , will olao trToKe upon their aici. 

Ampt-re was the first who tucceeded In accom- 
ptifihinK the reroluUou of a mu^net on its own axis, 
ilia apparatuB for thin pur{H)ae was a magnet, sua* 
pended vertirally on a i>oint. and with n mercury 
cup at the upper end, it beini; free to moTe around 
its centre. The lower half of the magnet wai im- 
mersed ID qaickaiWer — connected wiili which quick- 
silver, W88 8 serond mercury cup. Aa soon as con- 
nection was made between the poles of the electro* 
ma^etic battery and the mercury cups, the fluids 
pasaed through the upper half of the magnet, and 
occasioned it to rotate. The principal defect of the 
above arrangement was the weight of thp'Inrgc quan- 
tity of mercury employed, and the friction It ocoa* 
sioncd against the sides of the magnet, so retarded 
the mrition, that a very powerful battery was indis- 
penaaSlc. 

The same phenomenon has been exhibited in 
various ways ; the principle on which it depends \», 
That the electric current should pass through one 
half of the magnet only, so as to act exclusively on 
the pole which is situated in that half, and after- 
wards be diverted from the magnet, and made to 
pass Bway in such a direction as that it shall not 
affect the other half of the magnet. In the experi- 
ment of M. Ampere above relnted, tl»c elertrir car- 
rent, after traversing the upper half of the magnet, 
passes into the mercury, and being diffused through 
it, acta in no sensihle degree on the lower pole of 
the magnet, and dnes not interfere with the rotation 
produced by its influence on the upper pole. 

The same object is attained in the following man- 
ner, by an apparatus represented in fig. 3, and in 
section in fig. '1 ; a magnet, pointed at both ends, is 
supported below by an agate cup, fixed on a item 
rising firom the bottom of the stand ; whilst its 
upper point t» lightly pressed npon by a screw with 
a milled head, pRAfing through a screwed hole at 
the top of an arched bead, winch forms part of the 
sustaining frame-work of the apparatus, near the 
middle of the magnet. This frame supports a stige 
in the form of a ring, tltrough the centre of which 
the magnet passes freely, and carrying a circular 
cistern of mercury, which also surrounds the mog- 
net, without touching it. A similar cistern of mer- 
cury snrrounds the lower stem, which supports the 
«gule cup. A copper wire projecting into the in- 
tenor of each of these dstems, pa»>ses out through 
its sides, and being bent upwards, terniinatec in a 
anmll cup holding a little mercury, for efTecting the 
oommunication with the electro-magnetic battery 
by wires in the usual manner. A small wire 
pointed and amalgamated at its end, is affixed to the 
middle of the magnet, immediately nhovc the cis- 
tern, and IB bent so aa just to dip into the mercury 
contained in the cistern. A simibir n-irc, proceed- 
ing from the lower end of the magnet, is made to 
dip into the mercury contained in the lower cistern. 
The lower half only of the magnet being thus made 
to form part of the gaU-anic circuit — which is con- 
Ciauous from one cup through the cisteru of mer- 

■ 



cury. the wire belonging to the magnet, the mapact 
iUelf, the other wire, the other ciftem of roerciiry, 
and the wire terminatiaE »» the other cup, rec/'ites 
the exclusive influence of the electric current which 
passas throngh it, and begins to rotate with eon* 
aiderable velocity round the axis which is oofwU- 
tuted by its upper and lower points of support. — 
The degree of rotatory effect will depend very mueh 
on the delicacy of the suspension of the magnet, M 
that the friction at the points may bo as small aa 
possible. 

Different forms have been given to the magnet in 
the above apparatus, all, however, having the same 
obvious intention of diminishing friction and ba- 
lancing the magnet equally upon a centre. One of 
the more successfnl as well as the more effective of 
these pieces of apparatus, is that shown in fig. 2, 
and which will be readily understood by the preced- 
ing descriptions, and by that which foUoa-s, ei|iliin- 
ing the action of a double apparatus, by which ro- 
tations in opposite directions maybe exhibited a« 
the same time, and, by the same current, by phiring 
the poles of the one in a contrary direotioa to thoM 
of the other magnet. 

Fig. 1, represents this double appsratns. Two 
bar magnets k II and C D, are bent, so as to form 
a shoulder in the middle, io which arc anioll boles 
drilled, by which they are suspended on pivots, and 
made free to revolve. On the upper side of t^e 
shoulder small cups K snd F are attached to con- 
tain mercury. From each of these cups a soull 
wire is bent downwards, to dtp into the mercury 
contained between the concentric cylinders on the 
stand ; proceeding from the upright ^tem is a bnsi 
wire, I K, of a staple fonn, whose ends dip into tl»e 
small cups on the bendings of the magnets; the 
circuit is fortned by dipping the connecting wiraa 
into the cup U at the top, and the cups L M on 
each side of the apparatus. The nia|:neta then 
commence a very rapid revolution in the same or 
contrary directions, according as dissimilar or aiiai- 
lar poles of the battery are employed. H is a siercv 
for adjusting the brass wire I K, so that its ntre- 
mities may communicate properly with the atnall 
cups. 

By this mode of making the experiment, tfM 
whole length of both the magnets is ezpOfcd tft 
view, and by having the north pole of the one, and 
BOutJipoleof the other subjected to aimilariy eter- 
trifled wires, the different directions of rotation of 
dissimilar poles can be observed at one and the 
time. 

{To tm eottHnutd.) 



LAW OF PATENTS, 

f^ It^tumeJ from pit gi lOg, arul foneludtd. j 

Enrolment. — In England, a patent is void nal 
It is enrollcil. The time allowed for the enrotoMiC 
Is now generally confined to one month- Enrol- 
ment cannot be dispensed with, though it be to k«ni 
the specification secret. After a patent has paaMO* 
the time for enrolment cuauot be enlarged vrithanC 
an act of parliament. In the United Ststes 
America, the patent, after the seal of the United 
States of America is affixed, is recorded in a boolc 
kept for the purpose. 

InfringemvHi. — Whether any act is really an in- 

fringement of the patent, is a question for the jorr* 

The using the least jiart of the manufacture u a: 

infringement. In Manton r. Msnton, the infringe' 

i meat consisted ia making a pcrforatioa in the bam' 



im 



3 



MAGAZINE OF SCIENCE. 



12.3 



Oer of n i^n in a direction a little diffrrent froni 
llui ID Uwpatrnt article. If the article manufac- 
tored be of ■ ditfereut form, or made with alight 
mkI Immaterial alicrdtions or additions, if the maau. 
faBtum are really and gubitantiilly the same, the 
7»Btrn'rr is entitled to n rrmrdy, a* where the |K«ii- 
thc diHerent ^arta of b steam eoginn were 
i. Where reveral independent improve- 
1- i-^df^ in the same mac)ttiie, and ti patent 

i- r them in the aggregate, the patentee 

is (.....: > recover si^aintt any iierson who fthali 

UM any one cf the im prove men ts so psUrnted, not- 
Wttlislancling there shall bare been no vioUtian of 
Ifce other itn prove men ts. — Hemedy for InfrtHgt' 
w u mt* The rcmediei for infringemeal. in England, 
ATR by mn artion at law for tbo damages, or by pro- 
cveiinga in equity for an injunction and account.-^ 
The remedy sought in erjuity ia for instant relief, 
•nd it is i)ftcn preferable to proceed in equity be- 
lore a »uil ia commenced at law. In the United 
Slate* of America, the circuit coart has original 
OOgnuaticr, a» well in equity as at law, in regard to 
^Ceat*. and may ^rant injanctions. The dmnagea 
for a breach uf the patent rigbt, in the United 
SiaCn of America, are three times the actual dama^rc 
■■feiiiMd by the patentee : the jury are to And 
-i •»-^- rfAQiRges, tlic court are to treble them. In 
Lhe patentee, in case of infringement, ahall 
' the damage he may austain, and a penalty 
for tiie benefit of the poor, not to exceed 3000 
Craac*. eod double in cue of second offence. — 
S*yral. If a patent be roid, ia England, tbe king 
mvf bare a acire facias to repeal his own grant. 
AU pcreooi are injured by the eiiatence of an ille- 
)ri iMlcitt fur aa inveutiuu. aud every one is 
Ikenrfbrc entiUed to petition far a Metre facias to 
haw it canoeUed. Paients are repealed, in the 
United 8tatea of America, by a process in tbe 
of a fctre faeiat.—~ WAo may obtain a Patent. 
who have resided two years in the United 
of America are allowed to obuiin patents tin< 
darllia tot of IttOO, on their making oath that tbe 
iatentioti bos nut, to the beat of their knowledge or 
bvlief, Uma used in any country before. The Cng> 
liih law has no restrictions on this bead, and it is 
every diiy's practice to grant patents fur new inveo- 
ii4i*n fn Amr-ricaa* and other foreigners. 

tig [wrtion of this article is modified 
TcelLent article m the " Popular En- 
(jdoptrUii i and wbst followH from the " Com- 
IKioo to the .UmaoRC," fur 183G. 

Am Act has been passed in a Ute Session of Par- 

Baiflit to do tway with some of the defects with 

Vttdk o«r aaciquated Patent Laws are encumbered ; 

iail*altbough it does not pretend to an entire re- 

mnvsJ of tbe causei of complaint, yet, considering 

Mittrd diAiculties of tbe cose, and the very 

•liable iiAture of some of the former propDsi- 

- -^- i.ndmcnt, we are not sorry that the 

vemrnt has been begun with caution; 

--...- umc wc wish to consider what has been 

>'y aa a begiiming, and hope it will lead the 

> grneral amelioration. 

; reet Krirvance of the system, was the de- 

:i of all right to a patent which reiulted from 

:C claim pat in to any part of an in> 

' might nut actually be new, although ^ 

uioaiiioce should be unknown to the in. 

iod ereo althongh the part claimed should 

.11 :ittd unessential portion uf tbe whole in- 

this matter clear, it must be 

luing tUc nature vf oo ioveauoa, 




such as a inschlne for instance, the patentee is 
compelled to describe the construction of his inven- 
tion in the fullest detail, so as to enable an ordinary 
workman to con&truct a similar machine. As, in 
every such new invention, certain parts mutit also 
necessarily be well known, certain whccltf and levers 
will be like wheels and levers in other machines; — 
and as to these wheels and levers the patentee can 
have no rictusive riglit, he is eipected to declare 
in his specification what parts of the machine he 
claims an his own invention. To these alone be 
baa rjEclusivc right ; all other parts are pubUc pro- 
perty, and may be used by any one. Tbua far all 
IS rigbt ; if it were otherwise, a patentee mij;ht be 
allowed a right to what is not his own. Tbe grier* 
ance complsined of is, that if a patentee should in- 
advertently lay claim to any port of bis new inven- 
tion, which part might afterwords be found not 
original, tie lust not only his right to an exclusive 
use of that one part, but to tlie entire invention, 
however new it might be. He was thus cooped up 
in a dilcjuma ; if he did not cUlm the whole of hU 
invention, from a fear of overdaiming, he of course 
lost his right to that which he did not claim ; if, on 
tbe contrary, he claimed all which was his own, and 
it should be found that some part was not original, 
then he lust his whole patent. Tlie Bi:>tive to thu 
severity seems to have been the wish to prevent, by 
■ penalty, an unprincipled schemer from endea- 
vouring to appropriate to himself more than bis 
own. But while tbe schemer was punished, the 
honest inventor was often a sufferer. A new ma- 
chine might have great merit, It might in principle 
and action be perfectly new ; but some of its details 
might huve bei^n used in souie other machine now 
in disuse, quite unknown to the inventor. This is 
discovered by some rival manufacturer, and the 
patentee loses his right. Oy the act now passed, 
this grievance is done away with ; if a patentee 
should be in the situation supposed, if be shoold 
find that seme portion of hi.t invention has beea 
aniiripnted, he may now, on a proper representa- 
tion, uljtHin Irjve to enter and enrol a disclaitner of 
such portion, and remain in the situation he would 
have been in, had no such claim ever been put for- 
ward. 

It has been objected to dua olteraUon, that ad- 
rantage may be taken of it by a dishonest schemer, 
who may take out a patent for an invention not hie 
own, and then, as he tiad< himself discovered, enter 
a diiK-'laimer, finit to one part and then to another, 
aa such parts are objected to, and in the mean time 
reap all the advantage of his patent, aa though tbe 
invention were Ins own. This, we imagine, is an 
impossible occurrence : it must be remembered that 
tbe enrolment of the disclaimer is not a matter of 
right, that it may be refused by the Attorney. 
General, unless a sutficlcnt cause is alleged for the 
alteration, aud that, in cause of fraud, it would un- 
doubtedly be refttsed. There is also aoother check, 
and a strong oue, against such a practice ; tlio dia- 
claimer cannot be rei'cived in evidence, in cose of 
an action brought before such diaclsimer was eo 
rolled. A patentee, therefore, who should make 
an overclaim, and against whom an action ahonld 
be brought in conAcqucuce of that OTcrcUim, wilt, 
as far aa that acliuu goes, stand precisely in the 
situation he would have stood in before the new act 
was passed. He will be liable to the same penal- 
ties, and be put to the same expense in the suit. — 
The only diffLrence ia. that he will be enabled to 
protect hiuuoU' from the loss of his wlwle pateul iu 



124 



MAGAZINE OF SCIENCE. 




•ucb a catif, anJ will stand U}K)n his own rigbl in 
future. Now, un honest pateiitrc will, it iji Inir, 
Fiiffrr in the imnivdiiite action the pennlty of hta 
iriudvertcnrt, but no more. The dishonoit one will 
render himeelf linble to the tnme [icuuhy, as often 
u he ahtill attrmpt to make mo of uny right giren 
him hy a frtiiidulrnt cUiim. 

Tlie Kcond clause enacts, that If a patentee ah&U 
hhvc re-produced some old invention, believing 
himEelfto be the in»entor, it %hit\\ be in the power 
of the crown, upon a rccommendnllon of Ibe 
Jndicinl Committee of the Pnvy Council, to con- 
tinue the pQ^ent to the patentee, wherever it shall 
uppear Uiat tfae tOTeution has not hem publicly aod 
Erttierallj used. It is feared by aoue persona that 
all kinds of old inrentions will be brought up again 
and prDmul8;atrd as oen-, under favor of this clanse, 
and that every body will be taking out patents for 
old and abandoned projects. Tbts appears very 
absurd. To my notliiiig of tlie cTprnee of taking 
out patents, and the olmoet certainty of their brin^ 
useleia to the pafenlec (fur we may be well assured 
that in ninrty-nino cases out of a hundred the in> 
ventions would not hare been abandoned if they bad 
not br<fn useltas), there are au many checks againat 
the coutiniiant^o of soeb patent by the crown to any 
but a itonS fide re-inventor, that few persons wiU 
feci inclined to rake out old books for the purpose 
of picking up lost Inrentions. If any person should 
be lucky enough to re- produce an invention of value 
abandoned from any cause, and generally forgotten, 
we see no harm in his having the monopoly of its 
me for a few years aa a recompense for his briuging 
to light a valuable idea, though we would rather he 
should be eolitled to it without any mlsrepreKenta- 
tion. 

The third clanse contains a provision against the 
rrpentrd vexatious actions by which a patentee 
might be put to enormous law expenses under the 
former act. Before the pfl.isiug of the new law, 
llthough an nction respecting the validity of u patent 
light be decided in favor of the holder of Che pa- 
tent, this verdict was no bar to a future action, nor 
to any niimber of fiitnre actions. Although nothing 
new could be alleged, although it was but going 
over the same ground nguin and again, the patentee 
might be compelled year after year to defend him- 
self against fresh actions to hii great injury, perhaps 
to bis ruin. Tlie cJause enacts, that in any action 
respecting the validity of a patent, if a verdict pa»f 
in ravor of a patentee, the certiticnte of the judge 
who tried the action may be adduced in evidence on 
any future action ; and if the verdict in sueh snb- 
aequciit actiuii be given in favor of the patentee, he 
shall receive treble costa. 

By the fourth clause, an extension of the tenn of 
a paletit, not exceeding etten years, may be granted 
by hii Majeety, on a recommendation of tfae Judicial 
Committee of the Privy Council, who muy call and 
examine witnr«srs in the cjise of n petitinu fur ex- 
tension. This i5 decidedly an improvrnient ; the 
term of fourteen years granted indiscriminately by 
every patent, is too short in Rome cases to render 
any profit to an inventor, and this chiefly in thoM 
invculiuns of great value whieh require lime to ia- 
iroduor. We mity instance Witt's improvements 
oti the steam engine, which, from prtjudic'? aud 
other caoftt^, nne hardly in general use wli'ju the 
term granted by ttis patent had trajiirtd. By the old 
act, nu cileiiicinn could be obtained irithout nn uf- 
plication to I'drliament, which was attended with so 
many difficulties ibat it has been rarely resorted to. 



The fifth and sixth clsuses refer to the manner of 

rniiduetiiig trials for Infringetutsnt of ; -^bt*» 

an<i regulate the coiita in hucU a' : Ut4 

elauir triHiots a penalty upon any \.^^....:. , numg 
the name or mark of a putcutee apoa any artkiv 
vrithout his permission. 

Here follows a more detailed abr, : 'J»b 

act. An Act to mnend the Lmi> ' ''err 

pQtfni for InvmtiOHM. [5 and 6 \* lil. i^ . c <**, 
—10th September, 1835.] 

1. UcCTting that it is espedieni to make certain 
additions to, nnil altcrnlions in, the present law 
touching letters patent for invenaions, as well far 
the better protecting of patentees in their ngbta. aa 
for the more ample benefit of the public : eoaeoa 
that any perfon having obtained letters patnjt (or 
miy invention, may enter frith the clerk of the pa- 
tents of England, Scotland, ur Ireland, reapectivcly. 
as the case may be, having first obtained the laa«» 
of bis Majesty's attorney-gcnerDl or solicilor^Mio* 
rat in cose of an Engltoh fratent, of the lord adm- 
cate or solicilor-gencml uf Scotland in the caae 6t 
a Scotch pntL-nt, or of hia Majesty's attomey-g^w> 
ral or eolici tor-general for Ireland in the caae ol an 
Irish patent, certified by his fiat and signature, a 
disclaimer of any part of his apecifboation. or a me- 
morandum of any alteration therein, out being sunb 
as iihiill rxtrnd the exclusive n^ht granted by tkfl 
said letters patent ; and which, when filed, ahali \m 
deemed part of such tpecUication -, but a caveaK 
may be entered as heretofore ; and such disclainar 
shall not affect aetions peoding at tha timo ; ad 
the a ttoniey -general may require the party to ad- 
vertiae his disclaimer. 

2. Where a patentee is proved not to be the real 
inventor, though he believed himaelf to be so, hfl 
may petition his Msjesty in couocil to confinn Id* 
letters patent or grant new ones ; and the aaiU peti- 
tion aIiqII be heard before the jtidicial oommi(t<« of 
the privy cuuncil, who, on being satisfied that tuck 
patentee believed himself to be the firaC aod original 
inventor, and that such invention had not bvcn 
generally used before the date of such first le:trn 
patent, may report their ojijnion that ihc prsyrr uf 
mch )>etitinn ought to be complied with, when-upoa 
hii Majesty may, if he think fit, grant such praysri 
but any person opposing such petition shall be en* 
titled to be heard before the said jodidatcommiiier s 
and any person, party to any former miC touclu^g 
such 6rxt ktlers patent, shall have notice of s«ib 
petition. 

3. If, in any action or soil, a verdict or 
shall pass for the patentee, the jadge may 
ceriificate, which being given in cvidano* in ^of 
other suit, shtiil entitle the patentee, opoa ■ variirt 
in his fnvor. to receive tieble costa. 

4. AUuwi H patentee, on advertising aa Ifaenftt 
mentioned, to opply to the privy council for a pn»« 
longed term. If the judicial coramittca report in 
his finor, bis term laity be prolonged fur sewO 
years ; but such application must be made be&ir« 
the expiration of the original term, 

A. In ease of nction, &:c.. ootice of objections to 
be given with the pleadings. 

G. Costs in actions for infringing letters patent; 
to be given as either party has succeeded or fail*:*! 
in any part of his case, without regard to the (*• 
ucrj remit of llie trial. 

7. Penalty for utting, unauthorised, the name or 
device of a pitentee, Aco., j£:AO. one half Co tot 
Mnjesty, ami the other to any in/urnier. 

Mr. Porcy, who hits hiul much experieftoe io fl^ 



MAGAZINE OF SCIENCE. 



123 



takinx of patenti. •tatn, that the 

of a patent for KiigUnd, iuh; bs 

'12U; for Scotland, at i.100; «iid 

n 2b. 

COINS AND MED.VLS. 

tarit l«(cly drlitercd before the Society of 

Wj^oTi described our prc&cnt mode uf en- 

kd muluplyiug the dies. 

■cliou uf tlie best iteel for tlie parpoNe* 

Tory imporuiuc, nnd not tiitfu'ifiitly 

[at Ml Will Tba MTT 6nL*etrcl tlint fijrina 

■ gnv«n and other rtiltittf; instruDiuatA, ta 

lUc purjiuse. fur unlc«s Uurdeiicd wtth great 

i* iciy Imble to trtck. Tlie vety euiir»u 

objectionable, as it ttc<|uirra fisjiurea 

difl presi. The object therefore n, to 

il of ■ medium qualttr — but the bc»t steel 

I* by want of ekill in the amUU who 

[b die ia brx^ught to a table in the 

lAfter being soflened, the engraver com- 

)Sm labora, by working out the dc?ice with 

tools in intsglio (sunk in), and when be 

fled bis work, the die id ready for harden- 

is, iu itself, a very ainiple process— but 

is often Btttfuded witlt aerioiia di^appolnc- 

Cttgravor, for it not unfrequcDtly bap- 

the labor uf many montJiB u cither in- 

Qltcrly destroyed, from the steel itself 

cy or heated to exceai. But Buppoiinff 

tl die, ur, as it is technically called, a 

be uninjured by tlie process of hardening, 

lur the purpose of furniihing a pun- 

s Steel impression in relief). For thif 

tk of soft Steel is turned Hat at the 

ly conical at the top. In this 

kl Hurface is cunipreaed into the ms- 

Uuw from the mulciptyiug die press : this 

Uic commencement of en impression, 

i«s so hard by compression, as to 

It annealing and rc>strikitig before it 

An impression taken iu this way la 

sutfiheoQ. vrhicb, when tJie oniirarer has 

■It tbfi deUcauy of finish existing in the 

ift then hardened, and serves for the pur- 

dics for coininK. by a eimilar process, 

tg Ike hardened steel into that whioh 

tinclioiii said Mr. Wyon, between striking 
)d coins, IB very esaential, so much to, ttittC 
aayiBg a few words on the subject. 
ly engraved in high relief, like those 
rias, and it requires a succession of 
forty or fifty, with repeated an- 
Lc ■ perfect ionpression. A modem 
contrary, is usuiilly brought up with 
kongh with the disudTsntage of the 
irder. Slandnrd gtild, for iuttancCf 
StwcJI^h of alloy : medals are usuelly 
ifold ; thi? rngriving u^ton the coin is 
tnade with a RUitablc degree of relief, 
a coin or mtdal, the lateral spread of 
;h would otherwise ooze out, as ii 
ircn the dies, is prevented by the ap- 
KsirclcoUar. acouiatcly turned to tli? 
!tbedics. The number of pieces wbiob 
by ooe pair of dies, not unfrrijuently 
three and four hundrt^d tbou- 
««cnige amount is much lf»s. Mr. 
, Ifaat be remembered instances of 
datroy«d in one d^y, owing tu 



tbfl diSertsnt tioalitiea of steel, and to the casualtifs 
to which dies are liable. There are. It appears, 
eight presses in the coining-room of the Mint, and 
he considers that the destructiun of one puir ol dits 
for each press per day, is a very fsir proportion! 
though it IS generally rather mors. 

It must be remembered, that each press prddaiva 
sixty pieces per minute, without reckoning stop* 
puei oooaaioDed by cbaogiug of dies and other con* 
tingences ; und Mr. Wyon remarked, that in 1817. 
the dally produce of coins, in half-cruwits, shilhogs, 
and sikpeoces, amounted to the enormous quantity of 
343,«>U0 per day fur tliree months : at that time all 
the clj;ht preucs were employed; but, on the lat of 
April. 18;j2, there wrrc 126, UUU pitces coined with 
tivc prcasti only. Prom the 4th of June. 1817, tu 
the 3Ut of December, 1333, tbete nere coined in 
Bovereignsand half sovereigns, 52, lB7(2ti5/. stcrliug* 



CAUTION TO EXPERIMENTERS WITH 
THE ELECTRIC KITE. 
Tn8 following excellent rcmarics on the msnagement 
of the electric kite are by the well-known and excrU 
lent rlcctricisn, Mr. Sturgeon, who, perhaps, has 
bad more practical experience in electrical monipu- 
lution than any person living. The remurks also uu 
the electric kite by the Editor in the early part of 
Vol. 1. of this Magulne will be read by the tyro 
with interest. Mr. Sturgeon says : — 

*' I repaired to the Artillery Barrack grounds with 
an electric kite, and in a ven* short time got it afloat, 
letting out string through the hands bum a coil or 
clue which was thrown on thegruund. Wbon aboni 
a hundred yards of the striug had been let out, s Ire- 
mcudoua discharge took ploce, which gave mc sticb 
a blow in the chest and lejcs that I became completely 
Btunued, let go the Btring, and coa8e<iuentiy tho 
kite •oon fell. 

The accident was owing entirely to my own neg- 
lect, and could not powtlbly have happened had I 
taken the following precaution : — 

Let all the string intended to be employed be first 
taken 00'the reel or coil, and stretched on the ground. 
Let now tbe iusnlating cord, ribbon, glass, or what- 
ever is used for this purpose, be attached to the kite- 
string and fastened to a peg, tree, or anything in- 
tended to bold the kite during the time it is up. 
Nfjct fasten the kite to the other end of the string, 
and let it ascend from the huod. 

Thia is the manner in which 1 nsoally proceed 
when heavy clouds ere hovering about, and ought 
always to be attei>dcd to, altliuugh 1 tiegli-cted it ou 
on this occasion. The exjK:rimenter by this means 
is completely out of dang-^r ; and he may easily 
ascertain if tho atring be highly charged by going to 
the other end, because of the brushes of light, and 
noiae attending them. 

1 liud it conveuient to have a eliding copper wire 
on the ulken cord, which can be moved, by means 
of a long glass rod, to any retjuired distaDce firom 
the wired string, the other end being stuck fast in tba 
groand. If the electric Are strikes two inches over 
the dry silken cord, (and it will sometimes strike a 
yard,) it would not be ssfe to ipproach it ; and no 
man could hold the string when it alnkes over one 
inch uf the nlk, or, which is the same thieg. tbroDgh 
Iht? nir. 

After tbe electrical state of the atring has been 

ascertained, tlie wire may be sliJed away from it ai 

fnras pouibte (tbe sUk ought never to be less than two 

yardK long). 'J'be other end is then to be taken uut 

' uf the gronud oud ettaobed to the appantua for ex- 



tS6 



MAGAZINE OF SCIENCE. 



periment. Tlie wire is a^^ain slided up to Che wired 
string^, and left there during the time the experi- 
mmts ure carryini^ on. 

The only method of gflttng the kite down during 
an intrrtse electrization of the string, with safety to 
the experimenter, is to unfuten ttie BUken eord from 
it« hold and let all gn : the kite fsila. 1 have fre. 
quently been annoyed, whilHt holding (he kite-string 
during hot bazy days when no ctuud was visible, by 
ft rapid succession of dbcharges, from which 1 had 
DO other means of escape than by quitting the string 
utd letting the kite fall. The same thing sometiniea 
happens in cold dense fogs in the winter. I have 
eiperienced these rattling or Lrricalous shocks when 
the kite has not been more than 30 yards from the 
ground, and the wired string at the same time 
touching it. Hence great quaoticies of the fluid 
must necessarily pass into the ground directly 
through the wire, in addition to that which pro- 
duced the shocks. 

The publication of these particulars may possibly 
previ^nt some ioexpcriuuced electrician from receiv- 
ing a death-blow from his kite-string. 

Young persons who sire fond of kite-flying should 
nliio be cautious not to have tlurir kites up during 
thander storms, as it is poraihle that a wet string 
may transmit a violent discharge, from which ft 
serious accident might occur.*' 

MAKING ARTIFICIAL EYES FOR 
ANIMALS. 
Mticii of the character and expression of animals 
depends upon their eyes: it will, therefore, be evi- 
dent that great attention is necessary in the arti- 
ficial imitation of these. 

The instruments necessary for making these are 
enameller's table, bellows, lamp, round pincers 
about six inches in length, which are closed by 
means of a ring, and witb which is held the iron- 
wire forming the support, and the base of these eyes, 
which it is impossible to blow. Procure anuthor 
flat pair of pincers of the same length, which air 
used for hendjing the enamel, as also for stirring up 
the lamp. These instruments can be had ready 
made in every hardware shofi. 

The materials from which the eyes themseltes 
are formed is an osrartment of cyliodera of enamel 
of all colors, which can be purchased ; besides some 
fragments or clippings of mirror-glass, which are 
melted in the lamp into a kind of cylinder like the 
enamel, so that they may be ready for use when 
required. During tlic process of melting these 
pieces of glass, considerable attention is necessary to 
free them from spots and globules of air. These 
cylinders can be procured ready made in the shops ; 
and at various gloss-manufactories. 

The table is placed in a situation where the light 
of day cannot reach it, as the double light would 
distract the vision during tlio operation. 

After the lamp has been lighted, the pipe of the 
bellows is directed towards the middle of the wick, 
which is slightly scattered in that part so as to pro- 
care ■ clear light-bluish flame, which is necessary 
Co secure success in the operation, because if it is 
not clear, the colors of the enamel arc liable to 
oliange during the operation of making the eyes. 
The vnomel which wo wish to melt shoutd be ap- 
plied to the extremity of the jet of the tlaroe, which 
St will not bum, and often melts more easily than in 
the centre. 

As small eyes are less difficult than large ones, 
it will be adviftable to coumeuce with them until we 



lidcsaft 

onB 



shall have acquired practice. VoT smatt 
small iron-wire ir uied about an inch and 
long, one end of which is bcld iit tlieroiuid | 
and the ntht:r is approached lo tbc fire, tow. 
cxiKJsed at the same time the rnamel of the 
we wish the eye, whilst the other is turned 
the lingers until it begins to melt. The q 
necessary for the sise of the eye is then faai 
the end of the irun-wirr. This by being to 
the tlnmc forms a small globe, and when it is 
ciently rounded, a little spe^rk of block ens: 
placed in the centre, for the purpose of iiailotnig 
the pupil. It is again exposed to the flsme that tba 
pupU may be blended into the mass. When it im 
properly incnisted. some glass is put upon It, 
which shoald extend three quarters across thu hv> 
misphere of the eye. This glass is intended to rr- 
present thr vitreous humour of the eye, and from 
which all its brilliancy proceeds. The eye is sUU 
expu^ed to the flame until the gla$s bos c^itcndsd 
over ttiat part of the eye which is intended for the 
iris; when we etfect this, it is allowed to oeot 
slowly. This kind of eye is made hf joining artc- 
ral pieces of iron -wire together, which rendem it 
easier to make them all uniform in point of sik*' 
because the first bring close to onr eyes guides ■• 
in the formation of the others. 

Secamd Method q/* Makinrj Epe*. — .Another 
thod of making eyes is the following : — Some 
of iron-wire, from three to four inches Ion, 
prepared, which have been well burned, 
strength must be prnportinned to the size 
eye which is intended to be made. These are 
curved in the midtlle over a tube of gUua 
or any other cylindrical and polished body: the 
trvmitief of each wire are united by twisCin^ 
over the other, so that they perfectly fit the sub- 
stance which they embrace. It is this drde fomcd 
by the wire which mokes the diomeler of the eyo, 
and the wire thus prepared is in the form of a 
rocket. The handle of this meket is fixed into tha 
round jiineers, and the head of it cunred by miking 
it parallel to that of the pinrcrs. This cin:U to 
filled with common enamel, of the color which m 
wish, extending it from the circumference to th« 
centre, and when it is nearly the thickness of Um 
wire, it is prevsed while yet in a state of fusion 
with the finl pincers, so that it may extend equally 
over the entire circumference. It is then put into 
the fire to couaulidate it. This hiding been done, 
the iris is formed by a drop of enamel of the pro- 
per color. This is heated and pressed oa befofv 
with the flnt pincers, and when it is inoorporalsd 
with the first enamel, the pupil is represented vMi 
small speck uf black enamel, as before mcntioneii. 
When this is melted and incnisted in the iris, botti 
are covered with gla»s, and heated again until sUths 
parts arc smoulb, and the glafs boa diffused itoslf 
over the whole iris. The eye is now placed nn 
some warm cinders, and left to ooot slowly, without 
which precaution it is liable to break ; or it may be 
put into worm water, and allowed to coot gradualty. 
It is then removed from the wire by loosening thv 
latter. This method is only adapted for eyes of s 
middling size. 

Third Method vf Mak'my ^ye*.— Tlierc is sltU 
another method of making eyef<, which is ]>rrhaf« 
better than those we have otready descrit>ed ; and 
that is, to blow them if we possibly con ; «hlrfa, 
however, connotbe done when they are stnall. Is 
this operation, a pipe of baked earth is used, or s 
tube uf ghus six or seven inches in Icogih, at the 



MAGAZINE OF SCIKNCE. 



127 



■bI of which t llttir white en«mel ii placed. Thit 
tl pUced ta the Aimv, so that tt may be blown. 
TbU {ormi a globe, whose dimensionR depend upon 
ibfl qnintitjr of air introduced. ^Iien thU globe Ji 
of the fixe wiihed. we place In the middle, and per- 
paodicuUrW to the point of lUe pipe, the quantit; 
of «Bstoe1 necessary to form the enunel. 7*he vecond 
MttDtl ia then incorporated with the 6nit, by pre- 
•enHo^ It to the flame, while attention is pnid in 
isra the pipe gradually round, »o that the I'nnmcl 
may difTuae itself cqunlly. and the irii be eiactly 
eirnalar. If it it rrquirrd that this iris should he 
of vmrioiu colors, like that of man for cxamplp, 
amall filaments of enamel are distributed in diverg- 
ing ray<t of Ihr luttable eolor ; the eye is then plticed 
in the tinme. until these have incorporated with the 
IT)*, afler which the pupil is placed as before 
tfifrirtrH. 

Dnnng (his operation, the globe is almost certain 
.Jo, , 111... down, partly from the air escitpini^, pnrtly 
heat, and from the pressure which is used 
;jn; the diflerent substancfi : air must iigain 
-■d from time to time to prevent it from 
!•* form. This becomes particnlarly necea- 
nry '^Ijlmi rIsss is applied, and when it is extended 
over the whole surface of the iria. 
The eyp hsTing got Its form and tHe. the pipe is 
n away. To effprt this, nf\er the air fans btn-n 
dii(!ed, the entrance of the pipe is stopped with 
r, and the back part of the eye exposed to 
: <- ; when the air contained in the globe and 
rucAeJ hy the pipe, comes through at the place 
«4kere the flame has moat action. This opeaing ia 
f^r* ' turning the point of the flat pincers, 

iy '■, all round the pipe; one point only 

is u,^ ., .....L'h the eye rcmuins 6xed, It is tiien 
wsrmed equally all over, after which it ia exposed 
to I gentle heat, and whea it ngain cooU, it ia sepa- 
rated from the pipe. 




PALINGENESY. 

t ymm fiaanam't Afathrmatiriil Itrrrvntioni. t 

PiTT^CK.SMST is a chemical operation, hy means of 
t pbuit, or an animal, as some pretend, ran 
d from its ashes. This, if true, would no 
ocmot be one of the oobtcs t secrets of chemwttry and 
lUcwophy. If »orae authors are to be credited, 
meral learned men of the 17th century were in 
pOMsftsinn of it ; but at present, as this pretended 
•wrtt, m consequence of the great progress made 
la chemistry, ia conaidered as a mere chimera, we 
iMl here confine ourftelves to examining the foun- 
ixioQ of tho«e principlea which have induced some 
mpuuble authors, such as the Ahbv Vallemont 
mi otbcn, to believe iu the possibility uf lhii>> 



Accordtog to the honest Abbe, nothing is simpler 
tad KMUMit to be cxplnined. We are indeed told, 
aaya be, by Father Kirchcr, tttat the seminal virtue 
of «Kb misturs is contained in it< salts, and these 
asit* onalterable by their nature, when put in mo- 
tieat rise in the vessel through the liquor in 
L-y are diffused. Being then at liberty to 
». ' *'-— selves at pleasure, they place them- 

•rl order in nhioh they would be placed 

b> ■( vegetatiuu, or the aame as they oc- 

<bi :be body, to which they belonged, had 

b«' >ed by the fire : in short, they form n 

fiUftl, wf « phantom of a plant, which has ■ perfect 
fUtwblaACc to the one destroyed. 



This reasoning is worthy of an aothor who couU 
believe that be who robs another of his money can 
exhale corpuscles different from thote exhaled by a 
man who carries his own. and thereby make the di- 
vining rod turn towftrd<i the placet where he has 
passed, ur remnined for some time. Does it not 
show great weakness to bclirve that the mere im- 
morality of an action can produce physical eflecCt? 
It would indeetl be otTering nn insult to our readers, 
to attempt to show the folly and absurdity of the 
above reasoning of the good Abbe, and of Father 
Kirrher. \jrt tis therefore only examine the facts 
which he relates. 

An English chemist, named Coxe. asserts tliat 
having extracted and dissolved the essential salts of 
fern, and then filtered the liquor, he observed, after 
leaving it at rest for five or six weeks, a vegetation 
of sm^l ferns adhering to the bottom of the vessel. 
The same chemist, having mixed northern potash 
with au eqanl quantity uf hbI ammoniac, saw soqw 
time after a small forest of pines, and other trees, 
with which be wsa not acquainted, rising from tho 
bottom of the vessel. 

The following fact is considered by the antlior as 
more conclusive. The celebrated Boyle, though 
not very favorable to palingenesy, relates, that 
having dissolved in water some verdigris, which. 
ns is well known, is produced by rombining copper 
with the acid of vinegar, and having caused this 
water to congeal by means of artificial cold, he ob- 
served at the anrface of the ice small figures, which 
had an fxact resemblance to vines. 

Notwithstanding these facts, and others quoted 
by the Abbe from Daniel Major, Hanneman, and 
various authors, if the partisan of palingenesy oa& 
produce none more conclusive, it must be confessed 
that they support their assertions by very we«k 
proofs. Every true chemist sees in these pheno- 
mena nothing but a simple ramified crystallization, 
which may be produced by different well known 
compositions; the most beautiful of these crystal- 
lisations, call improperly vegetations, are produced 
by the combination of bodies from tbe animal king- 
dom. 

The last experiment, relited by Itoyle, might 
occasion mure embarrassment; but as it is the only 
one, of a great many, made with the essential salta 
of a variety of plants, that inooeeded, there can be 
no doubt ihut ilie figures be MW were the mer* 
eflect of chanoe ; for how many other philosophera, 
who made the same attempt, saw nothing but what is 
exhibited by the surface of frozen wster, which some- 
times forms ramificationa exceedingly complex ^ 

Tho partisana of palingenesy however quote other 
authorities, to which they attach great importancr. 
We arc cold by Sir Kroelm Digby, on the authority 
of Qttercetan, physician to Henry IV, of France, 
that a I'ole showed twelve glass vessels hermetically 
scnled, each containing the aalts of different plants : 
that at first theae salts bod the appearance of ashes, 
but that when exposed to a gentle and moderate 
heat, tbe figure of the plant, ns a rose for example, 
if (he vessel contained tbe ashes of a roee, was ob- 
served gradually to rise np, and that as the vessel 
cooled the whnle disappeared. Sir Kenelm adda, 
that Father Kircher bad assured hint, that be per- 
formed tlie same experiment, and that he communi- 
cated to him the secret, but it never had succeeded. 
The story of this Pole i« relat&l by various other 
authors, luch as Bsry, in his Physique, and Guy do 
1& Brosse, in his bonk on the Nature of Pluitl. 
(To 6v crmtinufd ) 



128 



MAGAZINE OF SCIENCE. 



MISCELI^NEOUS EXPERIMENTS. 

The lltrre Ha/oes. — The fallowing experiment, 
which iiluttralra in a pleasinit; manner the actual 
formadoD ofbulcKiif , bubeen gWeu by Dr. Brewster : — 
Take a Batur.itcJ solution of alam, and having 
eprend a few dro)t]i of it over a pUte of glaas, it 
Kvili rapidly crysiallifte ia laiall flat octobedroiu, 
scarcely visible to the eye. Wfatrn this plate is held 
between tbs observrr and tliR ntin, or a candle, with 
the eje rcry close to the smooth side of the glass 
pittv, there will be Been three beautiful haloca of 
li^ht, ut different difltancea from the lumiuouabodj. 
The innermofti halo, which is the whitest, is formed 
by the iiunges refracted by a pair of faces of the 
iKfnhedral crystals, not mach incUnod to each 
other ; the second halo, which is more colored, 
with the blue t»j% ontwardit, ii formed by a pair of 
faces more inclined ; and the third halo, which ti 
very Urge and highly colored, is formed by a still 
more tnclinrd pair of fnoes. Each separate crystal 
forms three images of tho luroinoui body, placed at 
pointK 120'' distant from each other, in all the three 
linWs ; and aa the numeroDS small crystals huve 
tliclr refracting fuctf turned in every possible 
dirtrt-tiuii, the wliolt circumference of the haloes 
will lie completely hUed up. The same effects may 
he obtained with other crystals ; aud when they 
have the pro|«,'fty of doable refraction, each halo 
will be either doubted, when the double refraction^ 
ia considerable, or rvndertid brutuler, aud otherwise 
modifird in point of color, when the double re- 
fraction ia Email. The effects may be curionaly 
varied, by crystallising upon tlic same plate of glsat, 
crystals of a decided color, by wluoh mesas we 
should hare white and colored haloes sacoeediog 
«ftch other. 

7b obtain very targe Ornamental CrystaU. — ^To 
obtain largo artificial crystals of a regular shape, 
nN|uires conxidcrable adilrcjs, and mueh patient 
attentioa ; hut the result fully recompenses the 
double. The method of M. Lcblatic is as follows: — 
The salt to bo crystallised is to be dissolved in 
water, and evaporated to such a consistency that 
it shall crystallise on cooling. Set it by, and when 
<|tiitc cold, pour the liquid part off the mass of 
crystals at the bottom, and put it into a flat-bottomed 
vessel. Solitary ciyiitBls form at some distance 
from each other, nnii these may be observed gradually 
jocrrastng. Pick out the most regular of tliese, put 
them into a flat-bottomed vessel at some distance 
from each other, and ponr over them a quantity of 
liquid obtained in the same way, by e«-s|Kiratiug a 
•olotinn of the salt, till it cryslallises on cooling. 
Alter the position of every crystal, once at least 
every day, with a gloss rod, that all the faces may 
be allemattly exposed to the action of the liquid ; 
ior the hce on which the cryElol rests never receives 
any increase. By this process, the crystals gra- 
dually ioGrease in sixe. When they have act]uircd 
such a magniiude that Oieir forms can easily be 
dislinguifibed, tBe most regular are to be chosen, 
or those which have the c^act shape which we wish 
to obtain ; aud each of them is to be put separately 
into a vessel filled with a portion of the same liquid, 
And turned in tlie same manner several times n day. 
By this treatment, they may be obtained of aluiont 
any rise we think proper. Whenever it is observed 
that the angles and edges of the crystal become 
blunted, the liquid must immediately be poured otf. 



and a portion of ne^v liquid put in its place ; oUwr- 
wisc the crystal is infullihly d—*'-'-- ■ ■' 

7*0 Bieach Priuif and P> iple 

inimcrsiuD in oxygenated min .: thr 

article remain in it, a longer or shorter space of 
time, according to the strength of the liquor, will 
be sufficnent to nhiten an engra\ing : tf it 1>e n>- 
qaired to whiten the paper of n bound book, as it 
is necessary that all the leaves should be moiatemid 
by the acid, care must be t-nken to open the book 
well, and to make the boards rot on the «dg« of 
the vessel, in such a manner that the paper aloni; 
shall be dipped in the liquid ; the leaves must be 
separated from each other, in order that they may 
be equally moistened on both sides. The liquor 
assumes a yellow tint, and the paper becomea white 
in the same proportion ; at the end of two or three 
hourK, the hook may be taken from the acid liquor, 
and plunged into pure water with the nme eare and 
precaution as recommended in regard to the add 
liquor, that the water rnny touch both sides of each 
leaf. The water most be renewed every hour, to 
extract the acid remaining in the paper, and to dis- 
sipate the disagreeable smell. 

Beani\fui Oraammi for a Room. — Dissolw {■ 
seven ililferent tumblers, containing warm 
half ounces of sulphates of iron, copper, sine* 
alominei magnesia, and potass. Ponr them sll« 
when completely dissolved, into a large evaporating 
dish of Wedgwood's ware, and stir the whole with 
a glass rod ; place the dish in a warm place, where 
it cannot be affected by dust ; or where it may not 
be agitated. When due evaporation has takni 
place, the whole will b^in to shoot out into crystals. 
These will be tntcrsperaed in small groups, and sin- 
gle crystals amongst each otlier. Their color and 
pecnliar form of crystnlization, will disitinituish each 
crystal separately* and the whole together, remain- 
ing in the respective places where they were depo- 
sited, will display a very curious and pleasing ap* 
pearance. Preserve it carefully from dust. 

7^/je Ej-jihdinf/ liubbif, — If you take up a smftQ 
qiiaatity of melted glsKS with a tube (the bowl of S 
common tobacco pipe will do), and let a drop Ml 
Into a vessel of water, it will chill and condensB 
with a fine spiral toil, which being broken, the wbols 
substance will barst with a loud explosion, withoat 
injury either to the party tliat holds it, or him that 
breaks it ; but if the thick end is struck, rren with 
a hnrnmor, it will not break. 

Threp ObjficfM, dtMcernab/e rfw/y by the um* tf 
both Eyet. — If you fix three pieces of psper against 
the wall of a room, at equal di»lancc9, at the beigU 
of your eye, placing yourself dtrectly before them, 
at a few yards distance, and close your right cye» 
and look at them with your left, you will lee only 
two of them, sapixise the first and secoud ; altar 
the position of your eye, and you will see the nrst 
and third ; alter your position a second time, you 
will see tho second and third, but never the wbols 
three together ; by which it appears, that a pervon 
who has only one eye can never see three objects 
placed in this position, nor all the parts of one object 
of the same extent, without altering the situatioa 
of his eye, 

7*tro solid Metallic Alloyt, vAich mtlt, wkem 
ruLbetl toytiher. — Make an amalgam of bismuth. 
and on amalgam of lead, rub them together in » 
mortar, they will form s componnd which is nesrly^ 
as liquid as mercury. 



i»«iiM)M : — I'rlntvtl by D. Kiiasci*. 6, Wfijre llorw hanv. WiU- End,— PubU*li«l by W. UuTtAtii, II, Fatonioatei Bop. 
CuaviDLiiitcaUom, <iibtcii are afu^>cred Moutlily.) lu be aiUlrcssfd to Ihc Editor, at Z7, Collagu i>n>v«, MUa Cnd Roa*t 



AGAZINE OF SCIENCE, 



THE 



Sn9 ^ci}ool of ^rtg. 



•] 



SATUROAV, JULY 34, 1041. 



Hid. 







FRANKLIN'S AND FERGUSONS CLOCKS. 



XT II, 



130 



MAGAZINE OF SCIENCE. 



FRANKLIN'S AND FERGUSON'S 
CLOCKS. 

Air ingenioiu clock wu contrircd hj the late Dr. 
Franklin, of Philadelphia, that showed the lioure. 
minuttia, and secundif, with only three nheeli and 
two pinions in the whole movement. A description 
of which, wc think, will please sach of our readers 
aa are not acquainted with it, whicli we believe arc 
very few. 

The dial-plate of this clock ia represente<1 by 
Fig. 1. The houra are engraved in spiral places, 
aloog two diameters of a circle, containing four 
tiniea 60 minates. The index A goea round in four 
hours, and counta the minutes from any hour it baa 
pMied by to the next foUuwing hoars. The time as 
appears in the figure ia either 24 minute* piutt 3, 
or paat 7, or past 11 ; and so on in each quarter of 
the circle, pointing to the number of minutes sflcr 
the hours the index last left in ita notion. Now, 
as one can hardly be four hours mistaken in esti- 
mating Che time, he can alwoys tell the true hour 
and minute by looking at the clock, from the time 
he rises tilt the time he goes to bed. The Bmall 
hand B, in the arch at top, goes round once io a 
minute, and shows the seconds as in ■ common 
clock. 

Fig. 2 shows the wheel- work of (he clock. A is 
the Arst or great wheel ; it contains IGO teeth, goes 
rouad in four hours, and' the index A (Fig. 1) is 
put upon its aaiR, and moved round in the same 
time. The hole in the index ia round ; it is put 
tight upon the round end of the axia, so as to be 
carried by the motion of the wheel, bat may be set 
at any time to the proper hour and minute, without 
affecting either the wheel or its axis. This wheel of 
IGO teeth turns a pinion, B, of ten leaves ; aod as 
10 is but a sixteeuih psrtoflGU, the pinion goes 
round in a quarter of an hour. On the axis of this 
pinion Is the wheel C of 120 teeth; it also goes 
round in a minute ; for there are 16 minutes to a 
qturter of an hour, and 8 times 15 is 120. On the 
axis of this pinion is the second hand B. (Fig. 1) 
nod also the common wheel E, (Pig. 2) of 50 
teeth, for moving a pendulum (by pallets) that vi. 
brates seconds, as in a common clock. • 

This clock is not designed to he wound up by a 
winch, bat to be drawn up like a clock that goes 
only tliifty hours. Fur tliis purpose, the line must 
go over a pulley on the axis of tlie great wheel, as 
In a common thirty-hoar clock. 

One inconvenience attending this clock Is, that 
if a person wake in the night, and look at the clock, 
he may possibly be mistaken in the four hours, in 
reclcoDing the time by it, aa the hand cannot be upon 
any hour, or pasi: by any hour, without being upon, 
or passing by, four houra at the sninc time. In 
order, therefore, to avoid this inconvenience, the 
ingenious Mr. Fergiuon contrived the foUowiog 
method. 

In Fig. Z, the dial-pUte of such a dock is repre< 
seated; in which there is an opening A BC D, 
below the centre. Through this opening, part of a 
flit plate appears, on which the 12 hours are en- 
graved, and diviiled into quarters. This plate is ron- 
tiguoos to the back of the ditU-pUte, and turns round 
io 12 hours; so that the true hour or part thereof, 
appears in the middle of the opening, at the point 
of an index, F, which ia engraved on the face of the 
dial-pUte. G is the minute-haoil as in n common 
clock, going round through sll the CO minutes on 
the dial in an hour ; and in that time, the x>late 



m 



seen through the opening A B C D shifts oo« bo«r 
under the fixed, engraven index E. By these meaas 
the hour and mlonte may be always known at what- 
ever time the dial-plate is viewed. In this plate to 
another opening, EFGU, through which the 
secondi ar« seen on a flat moveable ring, almost ooo* 
tiguons to the back of the dioJ-plate, and as tha 
ring turns round, the seconds upon it are ahowa 
by the top point of a flear-de-Ua I, cugraved ott 
the face of the dial-plate. 

Fig. 4 represents the wheds and pinions in tfab 
clock. A is the first or great wheel; it contUBs 
120 teeth, and turns round in 12 hours. 0& in 
axis is the plate on which the 12 hours above-awa* 
tinned are engraved. This plate is not fixed oo tba 
axis, but is only put tight upon a round part thereof* 
so that any hour, or part of an hour, may be act Co 
the top of the fixed index A, (Fig. 3.) withoat 
affecting the motion of the wheel. For this par- 
pose, twelve small holes are drilled through the 
plate, one at each lioar, among the quarter dsvi- 
aiona : and by putting a pin into any hole to ▼!€«« 
the plate may be set. without affecting any pait of 
the wheel-work. This great wheel A, of 120 toaUf 
tumfi a pinion B, of ten leaves, round in an 
and the minute-hand L, Fig. 3. is on the 
tliia pinion, the end of the axia not being 
but round, that the minate-hand may b« turned 
occasionally upon it without affecting any part of 
the movement. On the axis of the pinion B is a 
wheel C of 120 teeth, taming round in an bonr, 
and turnings pinion D, of six leaves, in three mi- 
nutes ; for three minutes is ,a twentieth part of U 
hour, and six is a twentieth part of 120. Oa tiie 
axis of this pinion is a wbet:l E of 90 teeth, going 
round in three minutes, and keeping a pendulum 
in modoD that vibrates seconds, by pallets, aa in a 
common clock, where the pendulum- wheel has only 
30 teeth, and goes round in s minute. But aa ih^ 
wheel goes round only in three minutes, if it bo 
wonted to show the seconds, a thin plate must be 
divided into 3 times 60, or IRO equal partj. and 
numbered 10. 20, 30, 10, 50. GO ; 10, 20. 30. 10, 
50, GO ; 10, 20, 30, 40, 50, GO ; and fixed upon the 
same axis with the wheel of 90 toeth. so near the 
back of the dial-plate, as only to turn round without 
touching it : and these diriatons will show the se- 
conds through the opening E F G U in the dial- 
plate, as they slide gradually round below the ponal 
of the fixed fleur-de.lis I. 

As the great wheel A, and pulley on it* faxis, 
over which the cord goes, (as in a common thirty- 
hour clock,) turns round only once in twenty'tbvr 
hours, this dock will go a week with a cord of 
common length, and always have the true hour, or 
part uf that hour, in eight at the upper end of the 
fixed indpx A on the diaUplute. 

There are two advantages which Mr. Pergasott'c 
clock has beyond Ur. FrankUn's : hat it has two 
disadvsntages of which his clock is free. For in 
this, although the twelve-hour wheel turns the mi* 
nute index L, yet if that index be turned by liand to 
set it to the proper minute for any time, it will oot 
move the twelve-hour plate to set the correapondtog 
part of the hour even with the t/^p of the index J : 
and, therefore, after having set the minute index L 
right by hand, the hour-plate mukt be set right by 
means of a piu put into the small hole in the plate 
just below the hour. It is true there is no gteat 
disadvantnge In this ; hut the pendulum -wheel 
baring ninety teeth instead of the oommon nnuibvr 
thirty, may probably make some diflereitce to ths 



MAGAZINE OF SCIENCE. 



131 



It, 00 iK-oount of tJie imallnest of the teeth ; 
U ii tierlAin thAt it will cause the peud olu m ■ ball 
la ^Mcribe tml fltnAll arra ia ita vibratiDnii. Sooie 
■VB of acMniOT thiok nn&ll arcs are beat ; but where- 
k9t «e know doc. For whether the ball dearribes 
^jMf or wnail arc, if Che arc be nearly cycloidal, 
arill be performed in equal timea ; the 
ire will depend entirelj on the length of 
-rod, not on the Itrngth of tbc arc 
.dtaenbct. The lar^r Ihcarcu, the greater 
of the ball ; aad the greater the 
i», the less will the time of the vibra- 
■fftscte<d by any anef|aal impulse of the 
b1 npon the palleta. 
ofafcction to Mr. Fer!:uaon'i clock ia, 
of the flat ring on which the seconds 
U will load the pivota of the axis of the 
tridi a great deal of frietioQ, which 
yoMihln meana to be avoided ; and yet 
docka, reoeotly made, goes very well, 
ig tbe weight of this nng. This ob- 
rr. can easily bo remedied by leaving 
Mconds are of very little use in couitnoa 
udfl for astronomical observationa ; and 
ocver have them. 



ran 



CARTHAMUS. 

v»t or safflower (earihamn* timctoriutj t 

of which alone is used ia dyeing, ia an 

plattt coltirated io Spain, E^ypt, and the 

TSrPC are two varieties of it — one which 

t leaves, and the other smaller ones. It is 

vhich ia cultivated in Egypt, where it forms 

le article of commerce, 

cootaioa two coloring matters, one 
the other red. The first alone is soluble 
tta aolutioQ ia always turbid : with re- 
cslubica ib« characters usually remarked 
odoring matters. The acids render it 
aUcalics dtepen it, giving it more of an 
both produce a liLlIe dun precipitate, 
of which it becomes clearer. Alum 
pitxte of a deep yullow, in^smdll quiin* 
tolacioo of tin and tbe other meuUic 
predpitatea which have nothing re- 

ittcr of csrtbumus ia not employed ; 
Io extract tliis portiim, tiie cartbamus 
a bag, which ia trodden under water, 
ooioT can be prcased out. The flowers, 
yeUow, become reddish, and toac in this 
I ttsrly one half of their weight, la this 
trcascd. 

the red part of certhamos, and 
'9nipo§ it to stuff, the property which 
of dissoWing it ia bad rerourse to, 
ifterwartU precipitated by an acid. 

of dyeing cooaiats, therefore, in ex- 

eoloring matter by means of an alkali, 

iog it on Uie stoif by meani of ao acid. 

which aervea for making the rouge 

^ladies. 

Aa rouge, the solution of carthamus ia 

vsh cry«taUiaed carbonate of sodii, audit 

by lemOQ juice. It has been re- 

kmoUr beginning to spoil, were fitter 

Ma tboae which were less ripe, 

nnined much mucilage. After squees- 

*»nnti juice, it is left to settle for some 

>t4t£ of carthamua U dried at a 

j.tc« of fttuue-ware ; Crou which 



it is detached and very carefully ground with talc, 
which has been reduced to a very subtile {lowder, by 
means of tbe leaves of shave-grass ffqmnetum) ^ and 
snccessively passed through sieves of increasing fine- 
ness. It is the bneiiets of the talc, and the greater 
or less proportion which it boars to the carthamua 
precipitate, which constitute the difference betweea 
the high and low priced rouges. 

Carlhamua is used for dyeing silk, poppy, nwarat 
(a bright orange-red), cherry, rose color, and Heali 
color. The process dtficrs according to die intensity 
of the color, aud the greater or less tendency to 
flame color that is wanted. But tbe carthamus 
bath, whose application may be varied, is prepared 
as follows : — c 

Tbe carthamus. from which tbe yellow matter 
has been extracted, and whose lumps have been 
broken down, is put into a trough. It is repeatedljr 
sprinkled with cendresgravetces (cnide pearl ashes), 
or soda (barilla) well powdered and sifted at the 
rote of 6 pounds for 120 potinds of carthamus ; but 
soda is preferred, mixing carefully as the alkali ia 
introduced. This operation ia called amc*trer,— 
The amettrcd carthamus is pot into a small troogh 
with a grated bottom, first Unlng this trough with ■ 
closely woven cloth. ^Vhen it is about half fiUed« 
it a placed over the large trough, and cold water ia 
poured into the upper one, till the lower becomes 
full. The carthamus is then set over another trough, 
till the water comes from it almost colorless. A 
little more alkali is now mixed with it, and fresh 
water is passed through it. These operations ar« 
repeated till the carthamus is exhausted, when it 
turns yellow. 

After distributing the silk in hanka upon the 
rods, lemon juice, brought in casks from Provence, 
is poured into the bath till it becomes of a fine 
cherry color ; this is called turning the balb (viver 
le 6aiu). It is well stirred, and tbe silk m im. 
mersed and turned round the skein-sticks in tbe 
bath, as long as it is perceived to take up tbe color. 
For poneeau (poppy color), it is withdrawn, the 
liquor is rwi out of it upon the peg, and it is turned 
through a new bath, where it ia treated aa in the 
first. After this it is dried and passed through fresh 
batbs, continuing to wash and dry it betwe«;n each 
operation, till it baa acquired the depth of color 
thst is desired. When it has reached the proper 
point, a brightening is given it by turning it round 
the sticks seven or eight times in a bath of hot 
water, to which about half a pint of Icmon juice 
for each pailful of water has been added. 

When silk is to be dyed ponceau or poppy color, 
it must be previously boiled as for white ; it must 
then receive a alight foundation of annotto. as ex- 
plained in treating of this substance. Tbe silk should 
not bo alumed. 

Tlie ntcarate, and the deep cherry colors, are 
given precisely like the p<meeaiLX. only they re- 
ceive no annotto gronnd ; and batlis may be em- 
ployed which have served for Kht ponceau, so as to 
complete their exhaustion. Fresh baths are not 
made for the latter colors, artless there be no occa- 
sion for the poppy. 

With regard to tbe lighter chcrry-reds, rose color 
of all shades of flesh colors, ttiey are made with 
the second and last runnings of the carthamus, which 
are weaker. The deepest shades are passed through 
first. 

Tbe lightest of all these shades, which is an ex- 
tremely delicate flesh color, requires a lillle soap to 
be pat into the bath. This soop lightens tbe color. 



■ 
I 



i 
4 



J 



132 



MAG^VZINE OF SCIENCE, 



end prerenU it from Ukini^ too ipeedUy, and be- 
coming unevrn. Tbe lUk is then washrd. and « 
Uulc brightening iti giTcn it, iu n Ualh which hu 
Bcrfc4 for the dcepf r colors. 

AU these baths are rmplojed the moment thry 
sre made, or as ipeedily as ))Ofl«ibIe, becatue they 
lose much of their color upon kn'ping, by which 
thry arc cren entirely deatruyed at the end of q cer- 
tain time. Tliey ore, moreover, u«d cold, to pre- 
sent the color from being injured. It must hove 
been remarked in the ei}>erimentA just descritMd, 
that the csuntic alkaliRs attack the extremely deli- 
cato color of cartfaamus, making it pass to yellow, 
lliis is the reason why cryitslt of soda are pre- 
ferred to the alkaline matters. 

la order to diminish tbe expense of ttie cartha- 
mns, it is the prnctice in preparing the deeper 
shades to mingle witli the first and the second bath 
abont one-fifth of the bath of archil. 

Dobercincr regards the red (»Ioring matter of 
carthamua as an acid, aiid the yullovr as a base. — 
His carthamio acid forms, with the alkalies, color- 
ks* ults, decomposed by the tartaric and acetic 
adds, which precipitate the acid of a bright rose- 
nid. Hrjit has a remarkable inflarnce upon rar- 
Uiamns, rendering its red color yellow and dull. — 
Hence, the colder the water is by which it is ex- 
trocted. the finer is the color. Light destroys the 
color very rapidly, and hitherto no means have be«a 
found of counteracting this effect. For this reason 
this brilliant color mnst be dried in the ahadc, its 
dye must be given in a shady place, and the silk 
atuffs dyed with it mast be preserred as mnch as 
possible from the light. Age is nearly as Injarioua 
as light, rspecially upon the dye in a damp state. — 
He color is very dear, because a thousand parts of 
carthamua contain only five of it. 

In preparing the flnrst roage, the yellow coloring 
matter being separated by wssbing with water, the 
red is then dissolved by the aid of alkali, and ia 
thrown down on linen or cotton rags, by saturating 
ttte solution with vegetable aeld, Tbe color is hosed 
oat of thr^e rags, dissolved anew in alkalis, and 
once more precipitated by lemon juice. The best 
and freshr»t carthsraus mast be selected. It is put 
into linen bags, which are placed in a itream of 
water, and kneaded till the water rans off colorless. 
The bags are then put into water, soared with a 
little Tioegor, kneaded till the color is all expelled, 
and finally rinaed In running water. By this treat- 
ment the carthamua loses nearly half its weight. — 
6633 cwts. of sofllower were imported into the 
United Kingdom in 1835, of which 2930 cwU. were 
retained fur Internal consumption. 



ENGRAVING. 

Enoratino is understood to be the art of cutting 

the Kurface of wood, or smooth metal, so thai the 

lines formed may be coTcred or fiUai up with ink ; 

then being sobjccted to an oppropriste pressure, 

the ink shall he left nn the surfnce of the paper 

printed upon, forming whot is called an etching, a 

^Vood, copper, or steel cngrnTing, according to the 

material worked upon, or else the manner in which 

K work is executed. In the Utter sense. engrsTing 

primarily divided into three great acctioiu, each 

tally disliact from tne other. 

Engraving on wood, or wood engraving, in which 

Hnes are left even with the surface, the rest of Uie 

wwd b«u»g cut away ; thcM are printed at the 



common printing press, alone or attended with 
iy]ic, sach as illustrate this and other similar worktt* 
To dcM:ribc the mannrr of et^rhini; aud copper* 
plate engraving, in general terms, so that it may ba 
understood without entering into minate particidBrs, 
it may be said to be performed thus:— First, tho 
copper or other plsta ia covered evenly and thulT 
with a certain compositioii, called eiehing ffrtnam^ 
The design or drawing is then transferred to i(< 
then in the case of etching, the lines tbni smb 
on the ground, ore scratched with on etching needle^ 
so as to lay lure the aarCace nf the eopper benesih 
the ground : then, a waxy substance is made to 
adhere to the piste, so as to form a border arooad 
the picture, as it may be called, shout half an inck 
high ; the plate has then aji acid poured upon tt, 
which eats or corrodes away the exposed lines o( 
copper. 'When sufficiently corroded, the bordmuj 
wax is taken away, and the plate washed with opaila 
of turpentine, which removes the etching ground, 
sad ahuwa the cop|ier- plate, bright aa when first 
taken in hand, but with at least an outline, and ui 
most instances a drawing considerably shaded. U 
will be remarked that no tool whatever has beca aa 
yet nsrd, except a needle. This then, coostitatea 
an niching, which is merely a plate of metal widt 
lines corroded in it by means of an acid. Those 
etchings which are afterwards to be made iaCo 
engravings, ore bit in very faintly, but the linos vv 
afterwards cut deeper or wider, by a amatl tool» 
called a prefer, or burin. 

Etchings and engravings, having lines, or, tBKRfti 
cases, dots below the general surface, the printing it 
conducted as follows : — ^Tho whole plate is covoad 
with ink, and the surface then cleaned, leaving only 
the ink in the lines ; passing this through Hm 
coppcr-plste printer's rolling press, with a l^ijlft 
pressure, the paper adheres to and brings the ink- 
out of tlie lines, forming what is called ayiroq^tf 
of the best quality, and a yriiU, if of nvandatf 
value. The illustrative figures in the present NOb 
will give an idea of the difference between engravioig 
on wood and on metallic plates, altbuugh in this 
instance both are executed on wood. i^Thr. side-cula, 
and alao a port of the others, consist of lines i^, 
the rest of tbe wood being cut sway ; but in the 
clock faces, the general surface is left nnton 
and the lines only are cut away. The sa 
these is blackened with ink end printed 
copper-plate prinCiog, tlie letters, figures, and 
only would appear : thus, our leading rata 
the engraved plate or etching, and not a print 
from that plate. 

This being clearly understood, the next thiofl l». 
be considered are the requisite tools and 
and we would premise that tbe same are lued 
every style of metallic rngmving. modi6ed 
a trifling degree to suit the material to be 
or perhaps one or other of them may not be 
except in fwrticular cireumstanoea. 

Tbe only tools required, are a hand vice, a ami 
euihion, two or three ^orers of different sixea. ■ 
etching neeHU, a bumiahffr, a Merger, a rsdi^ 
with a straight edge, two /itch ptnciU^ or brutfm, 
(one QS small as possible, the other obont as large as 
a small goose-quill,) a dabber, an oi7 rvbber, aud a 
piece of Turkty ttone : and if mathematical or 
similar engravings ore to be executed, a case of thv 

* A Tall acMiUDi or ttio art ol Eny ravin( lo Wood, li glna 
In Vol. I. rutilitininit aiteicri^na ot the varinu* tociU. Ic« W* 
lber»tiire ili^ n.ii (alrod furutvr In allutV l<> thnt fArticuloi 
act, bul c«»Gmv uurvclvca al prt.'tent lo engravnig ua nwiai. 



MAGAZINE OF SCIENCE. 



133 



drawing InBtnimcnU mOAt be added. The 
misrUlc reqaired, arn »ht«U qf copper or tteei, 
lo mgrmvc upon, ftchuuj rfrounti^ hardering iriu*, 
«ttknir «eidt Brunxwick black vartiith, tpiritt qf 
tarp^ntine, a yjojr tnptr, come o//, and a fine piece 
of dear charcoai, with the bark scraped off, and 
en* end made stunotb. 

Hm aamdcuMhiun ia a flat leather bag, made in the 
fix^ inatvocQ like ibe two sidea of a leather cricket 
hall. It ia formed of sheep leather, and when the 
fidra are tewed together, leating bet a small hole in 
the Afving. it is filled with sand ; the sewing is then 
cocDpicied — tbe whole soakrd for a day in water, 
od then prraaed with a great weight, or in a acrew 
praaa, when it aunmea the flattened form, which it 
ralUiM afterwards. The sixe most convenient fur 
DM moat be according to the ai«e of the copper, 
to be engraved. The und cusUion is not re- 

io etching, its uc being to support the pUte 
itoadUr, and to allow it to be tamed round euilj 
wbcD being cot with the grarer, according tu the 
ri^irementA of the artist. 

Thm iuokd vice ia used to bold the plate b^ one 
■Orsor or edge, during tbe time it is heated and 
Mdk«d, aa afterwards to be described. It is auf- 
M l ll y large if yoa ran hold up the plate by it with 
mlnad three or four minutes when it is fastened 
mtlHcdge. 
" OrVffcn are small tools, formed of a handle, about 
n bch long, Bod a blade or cutting part, about 
} imdies long, such cutting part being formed of a 
loaeDgc-shaped piece of steel, ground to a bevelled 
edge. For audi gravers as are to cut thin lines, 
Ac bhule is narrow ; for others the bUde is ne4u-Iy 
•^fUre, arid the point eoniequently of a more ob. 
taw angle. For steel angmvings, the gravers are 
l«(]airrd lo be tempered harder than for copper. 
As aitv*dj remarked, gravers are not required in 

Nmtlle, Hching needJV, or dry point. — Thia useful 
teatran^ent may be compared to a round, fine-pointed 
ta*d awl, aet at the end of a handle, a quarter of on 
hefa tfatrk, and 4 or & inches long. An excollcnt 
■batltnle may be easily made by any person by 
tdjng a thick short needle, such as ia used by tailors 
mtl bcmparreisea, called a htuni, (No. 3 and No. 5 
Ant rtfprtipriateO »nJ inserting them into the end of 
« ooHmon pencil, so that it shall bo firmly fixed ; 
(fee poiat not projecting above a quarter of an inch. 
Whni one needle gets blunt, another is easily made 
lOTrpIncc it. Tbe use of the etching nt^edle is to 
KFstch throui;h tbe surface of the ground that the 
ovpper may be laid bare in places prpvious to bUiny 
^ B9».d «lio to scratch any faint lines on the copper 
• rw«rds, to throw in a shade or make a line, 
■2 dune with mnch less labor than with a 
mfcr. Jc is in tlte latter use that it ia called a 

A fcwwMAer.— This is a straight piece of §lee], 
^dvalty tapering to a point, and made everywhere 
pmtuAy imooth and bright. The use of it is im- 
^btA by the name ; it is to burnish or rub out lines 
made, or else to suflen down such iis 
bern made too deeply, and oonsoqucotly print 
too dark. 

ISie tcraper iaa triangular piece of steel, fastened 
l» « bAudlfl, ch« edges being ground sharp. The 
Ma of thit tool is to scrape out such parts as re- 
qoiffe lo be removed, and are to deep that the hur- 
ts not aufiuient to remove them. 

tt\t bt roniinvtd ) 



PALINGENESY. 

CSaumed/remt poffr 127, and conclwifd.) 

We are told by Kirober himself, in his " Ara Mig- 
netica," that he had a long-necked phial, hermeti- 
cally sealed, containing tbe ashes of a plant which be 
could revive at pleasure, by means of heat ; and that 
he showed this wonderful phenomenon to Christina, 
queen of SwL'dtrn, wbo was highly delighted with it; 
bat that having left this valuable curiuailjr une cold 
day in his window, it waa entirely destroyed by the 
frost. Fatlier Schott also asaerts, that he saw this 
chemical wonder, which according to his account, waa 
a rose revived from itsusbes; and he adds, that a 
certain prince having requested Kircher to make him 
one of the same kind, he chose rather to give up 
his own than to repeat the operation. 

The process, indeed, as taught by Kircher, is so 
complex and tedious, that it would require no imali 
patience to follow it. Father Schott relates it at 
full length, in his work entitled " Jocoseria Naturse 
et Artis," and he calls it the imperial secret, bcc^uso 
the Emperor Ferdinand purchased it from aohemist, 
who gave it to Kircher. 

This em[M:ror was exceedingly fortunate; for it 
was to bini that the philosopher, who had the 
secret of the pliilosopher's sloue, addressed himself, 
and gave a proof of his art by transmuting, aa ifl 
said, in his presence, three [touods of mercury into 
two pounds and a half of gold. 

We most however content ounelvee with point- 
ing out the phicca where the curious may find thia 
singular procuba ; for besides the length of the de- 
scription, nothing seems leas calculated to succeed. 
Digby, therefore, and many others who followed 
this method, did not obtain a favorable result ; and 
there KB reaaon to^ believe that their seal fur iialinge: 
neay would induce them to omit nothing that was 
likely to insure them success. 

Dobreaensky. of Negropont, has alto given « 
process for t!ie resurrection of phints. which seems 
to have been attended with not better aucvcas. We 
are at Icujit told by Father Schott, that the attempts 
of Father Conrad proved iuefiectoaJ, and he there- 
fore lapposea that Dobrezensky did not reveal all 
tlie circumstances ot the process^ but kept Che most 
important to himself. 

M^haC then can be sud in opposition to all these 
authorities ? Undoubtedly, the IMiah physidao 
was a quack, and we shall describe hereafter a 
method of prodociog a false paliugenray, which, if 
performed with art and in a prupL-r place, may im- 
pose on credulous persons. To be convinced that 
Dobrexenaky, of Negropont, was a mere impostcr, 
we^need only read the "Technica Curiosa," or the 
"Jocoaeria NatufE et Artis." of Father Schott; 
for he had the impudence tu pretend that he could 
pull out the eye of an animal, and in the course of 
a few hoars restore it, by means of a liquor, which 
he no doubt sold as a remedy fur sore eyes. He 
even tried it on a cock. A person who could assert 
such an impudent falsehood, in regard to one iset, 
would do the some in r^ard to anoUier. 

The authority of Father Schott will certainly be 
of little wt'ight with those wbo have read his works. 
In regard to the testimony of Kircher, we confess 
that we find some embarrassment : a Jesuit cer- 
tatnly would not wilfully hsffo told i falsehood. 
But KirchiT was a man of a warm imagination, pas- 
sionately fond of every thing singular and extraor- 
dinary, and wbo had a strong propensity to U-lieve 
to the monrcllous. What can bo expected from a 



134 



MAGA2INE OF SCIENCE. 



man of that character ? He often ihmkt he sees 
wbiit be iloet not tee, and if be deceives otheri he 
ii first deceired faimaetf. 

Some persoos go still farther, and assert that oh 
animal may be nnrived from its ashes. Father 
Scbott, in his ** Pbyslca Cariosa," eren gives the 
figure of a sparrow thoa revived in a bottle. GafTarel* 
ill his "Unheard of Cariosities/' beUeves in this 
fiftct, and coniiden it as a proof of the possibility of 
the general resurrection of bodies. This pretended 
revival, however, is a chimera, still more absurd 
than theformer; and which, at present, it would be 
ridiculous to attempt serioustj to rtifute. 

In short, what reasonable man can with Kircher 
believe, that if the ashes of a plant be scattered on 
the jp^ound, plants of the like kind will spring up 
from them, as he says he frequently ex|»erienced ? 
Wlio can admit as a truth, that if crabs be burut, 
and thcD distilled, according to a process given by 
Digby, there will be pruduccd in the liquor small 
crabs of the size of a grain of millet, which must be 
nonhshed with ox's blood, and then left to them- 
selves in some stream ? Yet we are told by Sir 
Keoelm that this he himself esperienced. It ii 
therefore impossible to clear him from the charge 
of imposture, unless we suppose that by some meana 
or other be was led into error. However, it ie cer- 
taiu that Digby, with great zeal and s considerable 
share of knowledge, had a strong propensity to all 
the viaiona of the occult and cabalistic sciences. 
In our opinion, he was one of those visionaries 
known under the name of Rosicnuiatu. 

An iUwtory kind of Paligenesy. — We have 
already mentioned a kind of sleight of hand, by 
means of which, credulous people might easily be 
imposed on, and induced to believe in the reality of 
p&lingenesy. We shall now discharge our promise 
by describiog ic 

Provide a double glass jar of a moderate size, 
that ii a vessel formed of two jars placed one vrithin 
the other, in such a nuniiar, that an interval of 
only a tine in diameter may bo Icit between Ibem. 
The vessol may be covered by en opaque lop or 
lid, so disposed, that bjr turning it in ditferent di- 
recCioDa,the inner jar may be raised from or brought 
nearer to the bottom of the exterior one. In Lbe 
interior jar, on a base represeotiDg a lieap of ashes, 
place the stem of an artificisl rose. Into the lower 
part ol the interval between the two jars introduce 
a certain quantity of sohes, or some solid sub^stance 
of a biiuihir appearance ; and let the remainder be 
filled with a composition made of one part of white 
wax, twelve parts of hog's lard, and one or two of 
oUrifted Unseed oil. .This oily compound, when 
cold, will entirely conceal the ingide of tlie jar ; but 
when brought near the fire, if done with dexterity. It 
will dissolve, and by shaking the lid, under a pretence 
of hastening the operation, the compound may be 
made to fall down into the bottom of the exterior 
jar. The rose in the interior one will then be seen ; 
■nd the credulous spectators, who must not be suf- 
fered (o approach too near, will be surprised and 
astonished. When you wish to make the rote dJB- 
appear, remove the jar from the fire, and by a new 
aleight of hand make tlie dissolved semi-tronspsrc^nt 
wax flow back into tlie interval between the jam. 
By accompanying this mancenvre with proper words, 
the gaping spcctaton will be more easily deceived, 
and will retire firmly jiersaaded that they have seen 
one of the moit curious pbeuomeoa tliat con be ex- 
hibited by the united efibrts of chemistry and phi- 
luMipby. 



ANALYSIS OF MINERAL WATERS. 

TnK examination of mineral waters with a new |« 
ascertain their ingredients, and thence their medical 
qualities and the meana of compounding them arti- 
ficially, is an objoct of eonsiderable importance to 
society. It ti, likewise, a subject which deatnw 
to be attended to, becaose it affords do mesa op* 
portunity for the agreeable practice of chemifld 
skill. But this investigation is more espedaUy of 
importance to the daily purposes of life, and the 
soccers of manufactures. It ronnot but be an m- 
tcreiting object, to ascertain the componrat parts 
and qualities of the waters daily consumed by tha. 
inhabitants of large towns and vicioitica. A. 
minute portion of unwholesome matter, daily 
may constitute the priadpal cause of the diffi 
in salubrity, which are observable io different placs. 
And with regard to manufactures, it it well knows 
to the brewer, the paper-maker, the bleacfaoTa Ul 
a variety of other artists, of how much oooseq^enot 
it is to them, that this fluid should either be pan, 
or at least not contaminated with such principles m 
tend to injure the qualities of the articles they makSb 
This analysis has accordingly employed the atCH^ 
tion of the first chemist. Bergmann has wrictaa 
an express treatise on the subject, which may b9 
found in the first volume of the EngUab tmntiUrina 
of his Essays. Kirwan published a valuable volu^t 
on the analysis of wateri. 

The topography of the place where these 
rise is the first thing to be cunsiderBd. By 
ing the ooze formed by them, and the 
itones through which they are strained and 
soma judgment mayjbe formed of their coni 
In filtering through the earth, and meaaden 
its Borfooe, they take with them particles of 
kinds, which their extreme attenustion rendera 
blc of being suspended in the fluid that 
their vehicle. Hence we shall sometunei 
these, water; siliceous, calcareous, or 
earth ; and, at other times, thoogfa less 
sulphur, mdgneflion earth, or, from the 
tion of carbonated iron, ochre. 

The investigation of mineral waters 

1, In the examination of thorn by the 

2. In the examination of them by reageats 
the analysis properly so calk'd. 

The exaniinution by the senses consists in 
ing the effect of the water as to appearaaoe, 
and taste. 

The appearance of the water, the instant in 
it is pumped out of the well, as well as after 
stood for some time, affords several indicationa, 
which we are enabled to form a judgment 
ing its contents, if the water be turbid at 
the BuhBtances sre suspended only, and 
solved ; 'but if the water be clear and 
at the well, and some time interreoea before 
comes turbid, the contents are dissolved 1^ 
of carbonic acid. 

The presence of this gas is likewise ind 
small bubblei, that rise from the bottom of 
and burst in tlie air while they are ma 
escape, though tlie water at the same time, 
hoB not an acid taste. This ia the case, 
to Count Razoumowiki, with respect to 
spring in Vallois, and the cold vitrioUted 
beate iprings at Aatracan. But the 
proof of n dpring containing carbonic acid 
generation of bubbles on the wster beiag 



MAGAZINE OF SCIENCE. 



135 



bunting vrith more or lets noise, while 

ent deposited by the water in the well 

t to be examined ; tf it be yellow, it indi- 

oe of Iron; if blftck, that of iron 

with vnipbur ; but chalybeate watera 

lom inlphurettcri. the latter occurs Tery 

is to the color of the water itself, there 

latanrea where ttiia can give atiy inilica- 

B coDtents, as tbera are not many sab- 

t color it. 

ar of the water serrrs rhicAy to discover 
e of solpburetted hydrogen in it ; such 
oontaia this 8ubBtaaL'« have a peculiar 
I, aomewbst resembling rotten eggs. 

of ■ spring, provided it be perfectly 
i by repeated trials, may afford some 
Uons with respect to the contents. It 
very sensible by tasting water, tu which 
I salts that are usually found in such 
diMolved in Tarioas proi>ortions. Ttierc 
depeudrnce, however, to be placed on 
of inrestii(tition ; for in many springs, 
aolpbate of soda is disguised by that of 
united with it. The water iao is not 
lMt«d It the spring, but after it has 
time. This precaution must be par- 
with respect to such waters as 
with carbonic acid ; for the other 
eontained in them make no impression 
ipie, till the carbonic acid has made its 
pd it is for the same reason that these 
lit be eraporated in part, and then tasted 

the ipecific gravity of any water contri. 
little towards determining iu contents, 
not be entirely useless to know the spe- 
of the water, the situation of the spring, 
Ind of sediment deposited by it. 

ination of the water by means of re- 
what they contain, bat not how much 
■iociple. In many inatances this is as 
inquiry demands ; and it is always of 
the proceedings in the proper analysis. 
■olutely necessary to make the experiment 
r just token np from the spring, and after- 
i neh as has been exposed for some hours 
air; and sometimes, a third essay is to 
rith a portion of the water that has been 
afterward filtered. If the water cou- 
•aline particles, it must be evaporated ; 
be moat sensible reagents do not In the 
it, if the salts, the {ircsence of which is 
orered by tbera, are diluted with too great 
f of water. Now, it may happen, that a 
iU be impregnated with a considerable 
f nline particles of different kinds, though 
kcm mty be present in too small a ijuan- 
Vrhieh reason the water must be examined 
time, after having been boiled down to 

of which the presence is discover' 

are:— 

add. When this ii not combined 

or not with sufficient to neutralize 

}n of lime-water will throw down a 

aolttbte with efTervesoence in muriatic 

infusion of bimua Is reddened by it ; — 

color gradually disappears, and may be 

> by the addition of more of the mineral 

boiled it loeci the property of red- 

td Utuut. A«cording tg PlaS, 



tlie most sensible test of this acid tt acetate of 
lead. 

3. The mineral acids, when present uncombined 
in water, give the infusion of Htmos a permanent 
red, even though the water has been boiled. Berg- 
maun has shown that paper stained with titmos is 
reddened when dipped into water containing jjf^ of 
sulphuric add. 

3. Water, containing sulphnretted hydrogen gu, 
ia distinguished by the following properties ; it ex- 
hales the pecnliar odour of sulphuretted hydrogen 
gas. It reddens the infusion of litmus fugaciuusly. 
It blsckena paper dipped into a solution of lead, 
and precipitates the nitrate of silver black or brown. 

4. Alkalis, and atkoUne and earthy carbonates, 
are distiogaished by the following tests: — the Infu- 
sion of turmeric, or paper stained with tumieric, n 
rendered brown by alkalis ; or reddiah-brown, if 
the quantity be minute. This change Is produced 
when the soda in water amounts only to y^xr P^rt. 
Pajver stained with Brazil wood, or the Infusion of 
brazil wood, is rendered blue; but this change Is 
produced also by the alkaline and earthy carbonates. 
Bergmauo ascertained, that water conuining p^ ^j^ 
part or carbonate of soda, renders paper stained 
with Brazil wood blue. Litmus paper reddened by 
vinegar, is restored to its original blue color. This 
change is produced by the alkaline and earthy car- 
bonates also. When these changes are fhgucioai, 
we may conclude, that the alkali is smmnnia. 

ii. Fixed alkalis exist in water that occasions a 
precipitate with moriste of magnesia after being 
boiled. Volatile alkali may be distinguished by the 
smell ; or it may be obtdned in the receiver by 
distilling a portion of the water gently, and then it 
may be distinguished by the above testa. 

6. Earthy and metallic carbonates are precipi- 
tated by boiling the water containing them ; except 
carbonate of magnesia, which Is precipitated but 
imperfectly. 

7. Iron is discovered by the following tests : — 
The addition of tincture of galls givc« water, con- 
taining iron, a purple or black color. This test in- 
dicates the presence of a very minute portion of 
Iron. If the tincture have no effect upon the water, 
after boiling, though it colors it before, the iron is 
in the state of carbonate. The following oboerra- 
tions of Weatrumb on the color which iron gives 
to khIIi, OS modified by other boflics, deserve at- 
tention. A violet indicates an alkaline carbonate. 
or earthy salt. Dark purple indicates other alka- 
line sAtts. Purplish. red indicates sulphuretted hy- 
drogen gaa. Whitish, and ihen black, indicates 
sulphate of lime. Mr. Pliitlipe has lately ascer- 
tained, that, while the iron is little oxided, the pre- 
sence of lime rather facilitates the application of this 
teat ; but the lime prevents the teat from acting, 
provided the iron be considerably oxidized. The 
Prussian alkali occasions a blue prectpitate in water 
containing iron. If an alkali be prL-st-nt, the blue 
precipitate does not appear unless the alkali is satu- 
rated with BU acid. 

fl. Magnesia and alamino. The presence of 
these earths is ascertained by the following tests :^ 
Pure ammonia precipitates them both, and no other 
earth, provided the carbonic acid have been pre- 
viously separated by a fixed sikali and boiling.— 
Lime-water precipitates only these two eartba. 
provided the carbonic acid be previously removed, 
and the solpbaric acid alto, by meana of nitrate of 
barytes. (To be amltitmti,} 



136 



MAGAZINE OF SCIENCE. 



MEMORANDA. 

To Hlkitm Ivory that Aaifiecome Red or Vellow. — 
DoU iilam in water ; ;into this immerse your ivory, 
And let it remain in sn bvur ; then rub the ivory 
with a cloth, wipe it clean with wet linen rag, and 
]ay it in a moistened cloth to prevent its drying too 
quickly, which causes it to crack. 

Bwiporation qftht Sea, — In the beginning of the 
]ut ceulury the phlltrtophical world was agitated 
with an inquiry into the origin of rivers, the vast 
waten of which are unceasingly being discharged 
Into the iea. One party contended for the exist- 
eoce of a large mass of water within the bowela of 
te earth, which supplied not only the rirera but 
ettie ocean itself. Another party anerted, that the 
vaten of the ocean were eonreyed back by some 
mbterrancoua passages to the land, and being fil- 
trated in their paasage, returned again to the sea in 
the course of the rivers ; this opinion was however 
too absurd to be long maintained, being contrary to 
all the known principles of bydroftatios. In oppo- 
sition to these hypothrses, our celebrated country- 
aojin, Ilolley, contended that the immense deposi- 
tion of water iu consequence of evaporation was 
folly adequate to the whole supply, which opinion 
ma oOBfirmed by the following experiment. He 
took a retacl of water, made of the average saltoess 
of the ocean, which he ascertained by an hydro- 
meter ; and having placed a thermometer in it, he 
brought it by a chafiug-dish to the heat of the air 
Sn our hottest aammer. This Teasel witli the ther- 
mometer in it, be placed in one icale, which he 
lucely counterbalanced by patting weights in the 
opposite scale. After two hours he found that 
about the sixteenth part of an inch in the depth of 
tbe sorface had escaped in vapor, and cotise- 
qaeatly, that in twelve bourn, the length of a natural 
day, one-tenth of an inch would be evaporated. 
It follows from this experiment that every ten 
square inches of the surface of the water yield a 
cubic inch of water in vapor per day, every square 
mite 6.914 tons, and every square degree 33 millions 
of tons. Now, calculating the Mediterranean at 
4(f long, and 4 broad, we have a surface of 160 
sqTiare degrees, from whence will evaporate 3,280 
millions of tons per day, a quantity, which renders 
it highly prolwble that tlie rivers msy be supplied 
by the deposition of water raised by the proceaa of 
evaporation. 

New Mod* ((f Preparation qf the Daguerreotype 
Plstttf by which portraits can be taken in tbe 
abort space of time from five to fifteen seconds, ac- 
cording to the power of light, discovered by A. 
Ctaudet in the beginning of May, 1841. — ** My im- 
provement,"' aaya the author, "coosiats in using 
for the preparation of the plates, a combination of 
chlorine with iodine, in the ntate of chloride of 
ioftinc. I follow the preparation recommended by 
Daguerre. After having put the plate iu tbe iodine 
box for a short time, and before it has acquired any 
appearanco of yellow color, I take it oat, and pass 
it for about two seconda over tlie opening of a bottle 
containing chloride of iodine ; and immediately I 
patitigiin in the iodine box, where it acquires 
Tcrytoon the yellow color which showi that the 
plate ia ready to be placed into the camera ob^cura. 
I have substituted for the chloride of iodin*-, chloride 
of bromine, and have found nearly the same result ; 



but I prefer chloride of iodine as produdog a 
ter effect ; and besidei. on aeccnnt of the 
sraell of bromine. The result of my pi 
such that 1 liBve operated in ten aeconda, 
same apparatus which, without any ohlonac^ 
quired four or five minutes ; when using oolt-i 
original preparation of Dagverre, I have ol"^ 
an image of clouds in four tecondt." — Aihem 
Snltmff Meat. — ^The method for which a 
has been lately taken out by Mr. Payne, is 
scribed.— The meat to be salted is placed 
atroog iron vessel, which is dosed in an «ir-t 
manner, and the air exhausted from it by men 
an air-pump ; a communication is then opened* 
a brine vessel, whence the brine flows into the 
ceiver, until it Is about half filled ; the afr-pamp 
then again worked to draw off every partick eCl 
from tlie meat, Slc. The brine ia then permitted > 
flU the receiver, and a farther quantity ii inj* 
by means of a common forcing-pump, the pi 
being regulated by a safety-valve loaded witbH 
100 or lOOIb. upon the square inch. After 
ing under this pressure for about fifteen 
meat is cared, and may be taken out of tbe i 

£.Ttraordinary Phenomenon at Derby. — ] 
a heaTy thundcr-Btorra, which happened 
the rain poured down in torrents mixed wil 
melted ice, and, incredible as it may appear, 
dreds of small fisbes and frogs in great abt 
descended with the torrents of rain. The ftA ' 
from half an inch to two inches long, and afeiP4 
Biderably larger, one weighing three ounces; 
of the fish have very hard pointed spikes on 
backs, and are tcommonly called Btickle-ba£fct| 
Many were picked up nlive. The itogi were 
the size of a hor«e-bcan to that of a garden- 
numbers of them came down alive, and 
away as fast as they could, but the bulk vrer^j 
by Che fall on the bard pavement. Wa ha "* 
some alive which appear to enjoy thamaoli 
gloss with water and leaves in it. — Ske0Md, 
Engrarittff in Krtiefhy mean* qf Voltme 
city.— Mr. G. H. Hoffman, of Margate, 
certain modifications of the processes at 
use, the result of which he conceives will btfl 
grently superior. A flat copper-plate, sudk^ 
used by engravers, is to be covered with 
etching-ground ; in this grooves are to be 
or cut, or dots stippled with a Want or sharpj 
down to the copper, as in common etchii 
plate is then to be immersed, and the copper< 
■ited in the usual manner, and the electric 
to be continued until the deposit forms 
sheet. The compound phite is then to ba! 
over a spirit lamp, so that the etching grooi 
be melted and run out. The plates are IheiLJ 
separated ; and, after carefully washing with ' 
of turpentine, the engraving will appear, poU 
sharp and 'perfect. 

Stood.— Vt. Carbonel. of Barcelona, ba 
ployed serum of blood on an extcnsiTe scale in 
ing. Mixed with powdered quicklime or alokc 
to a proper consistence it is easily applied on 
to which it thus gives a coating of stone t '" 
dries quickly without any bad smell, and 
action of sun and rain. The wood abonld 
covered with a coating of plaster, the 
mu?t be rabed as it is used, wjd the 
not be stale. It may be also used as a cement 
water pipes and for stones iu building under 



LoMDoM.— Pnntad by 1>. Fra*cu, «. While lloru Laoe, Mkls End.— PnblUhwl by W. BairfAiif. 1 1 ..,„., 

ComoiUBicaUoaa, (ivblcli are aaJwcrcd MooUUy.) to bf addrcaied to tbe Editor, at ST. Coltaga Grova. JUle c-mJ 



S^GAZINE OF SCIENCE, 

■ ^nH ^cgool of <3Lvt9, 




MAGAZINE OF SCIENCE. 



BTGROMETeKS. 

fttf Ifa* ^ ii Mt oHly suerptibk 

It ^gkmf^Hmdonj to pki. 

■• ^i^Re of noiftare, c*pe- 

• CRM aiiaace •■ the kuuB body. 

cfipcts of BaUiro^ 

«€ tt« Ayyrvaef er, 

tW tomuhty ol 

of portia- 

tkii pcoftrtf to tbe 

F«r thu 

■r bovo w pIsoM aoroov 

Omu. ■• tttf Kkefifano 

isritiimihekanBl 

firaMiotfacv 

hj ■ohfii. Th< 

AoaU Uftimcd of piBceoof 

oaife lifiidr bel««a 

*7. Aa tW botfd goto «c£, 

tkerfcsrao 

tfao Ai^iii of hcod^. Thu n- 

k W«^aH« 7«t of kttl' fcadicol vtiGtT. 

s toDK IBM okr tW 

it !• cb«r|ed; be. 

A«ho«4 ■WJMJTlirilWM kH OMUbfetO 






if • ««l «rik. iw^ o« • omB ealMK. pk»d ■ lb« 
«afr«of ftMM^ bM^tho oCbor otfnaiiyof tbt 
karlMBM ifawHfc Idbi ««Mn of tbooovcrgf tbo 
>■!, ifc /ii Liii I liwaii^»yA »JmAM»te »smI 

K; M(bt bi(|^o«»flJltiAamo^of ipopcr 
Vt«4l»ih»0KtnHX|of«h*boarl. U ordor 
•i ^bt4 oc«M» to «ho tttr, Ik k ■■liii Hbot lb* 
riite of tk* bM ftbovU bo|oribnlv4 irttk bisli^ 
tfWI Ibo ^ «M ^"v* * f< >< * r»MI* tbtoocbft. 
Wb<» ^fc^^tiiiBwl k m— i » Ar or mtimm 

faH^ji wfciibJte u ^Nk t w iii l» >— Ak F f "<y i 
fniiMiotiiW>s •» ift % ««»7 ba^M«l bMlrtMoaL, 

9. «i«y«o4 ftMtoMMK'tlw fbM bfoiftrkcor 
plwo of «m*( »iHioil «o ill ffottbn of gnvity. ■»! 
M Ikt ot^ fo4 f4 «b» otHOf bo oIlMlwrf !• • book. 
JUmHI^ m Iho Mr Ii »art or hm aofat. fov will 
Mi Ikl iMiA H^i« tif» tOM>4 fai OM direecioa or 
to iMitbn TVi taott »oriuo« may b« corered 
witb ibittcW«, h>p«Tt«li«i beUM;dof»ncod by the « 

St»Hoauflb« »u>*ltbebflIwii»tbeeieT«t«l abow 
a baao Ukat iK* M' w*y havrnrcrM to the slrinf. 
4, ir« |'i<^v v^*»t4[Ut iv whipcord bi" ni»He fait 
tt oiw ralf»«vitt. K. ^ t^mtrirJ o^cr dilfprtnt pul- 
liM. ai B,t\ b, K, F» «. (r»«. »>. «<•« to make 
Mvvrat luma bocbwMtb utd forwards ; sind if a 
^,l»Ki \' t^ ■ubiM'ntWil fnMu Uitf other extremity, it 
ip,^ -cOf fiiU iu a more 

^„, .<f tbc nooisture or 

i>i iht« Mir, AiOMuiii^ 4A tbo nnmbef of turns 
•U ami fi>rwftnU la |rrt«tar. But ihia will 
' •« iiulri H K, tuminjt on a 
kucit a mannrr that the |>art 
<ritf«r than I II. br made fast 
' tba oonl U. Tbe aligfateat 
( of th« air will be maoifeftttd 
tndfix. 
. tuay b« ooutructed alio in ifae 




tocr. 

4 



bUowing manner : — Extend k eord, & or 6 feet ia 
kogtb, between the lopportfl A and B, (Fif. S,) an4 
auapcnd &Dni themiddleof it C, a weight P byo thraod 
PC, the weight will as before aaccod or dttctod 
■eoordiBf to the degree of humiditj of the air acta* 
•ting tbc index attached to it, in a similar manner 
to tfae former inttruroent. 

6. Mouc may also be employed to indfcate tfao 
dryneaa or mouture of tbe sir. The aound of a 
ilito ia higher daring; dry (ban darini^ wet weather 
So alao stringed inttrumenta l^t in tune are w 
known to require tuning again each day or 
ihey arc pUyed upon, not merely because of 
itretcb'ing of the utringi, but btcanae of (to 
weather. Let a piece of catgut then, extended bcv 
t»eeo two bridge*, be put in a state of vibratioa 
lo aa to agree with any certain note in music, oe- 
oordiog to a tuning fork, ^^'hen tbe weather be* 
cornea moiater, the string will emit a loirer sound, 
and the contrary will be the case when the sir bo« 
eomes drier. 

7. Tbe balance hygromeitr is well known ; it 
litU of a acaie beam, suspendtrd on a proper 
bearing at oae end a sponge dipped in salt and 
and afterwards dried in the oir, nnd at the other 
ft weight which is exactly equivaJent to it. £ro 
may put into the scale of a balance any aalt 
attract* the moisture of the air, and a correa; 
ing weight into tbe other scale. In the casta 
of the sponge and tbe scale of salt, this part 
sinfc down during damp weather, and thereby 1 
coto tbo atate of the atmosphere. An iodcx, 

out tike different degrees of drought or 
ttay be easily adapted to it. This ioat; 
ia* hoverer. worse than any of the rckt ; for salt, 
iiBMsrifd in moist air, becomes charged with a 
great deal of humidity, but loses it very slowly. 
when the air becomes dry ; iioCash* the chloride of 
Haae, ood BUmeroua other salts, eren imbibe moit- 
laic, omtil they arc reduced to a liquid state. 

ft. Tbo hygrometers commonly aold at tha toy 
ifcopo oro eonatrocted on the principle of that d*. 
oarJbe4 ia poiagraph No. 3. One of them coasisiBof 
a kiad of box, the fore part of which repreaenls • 
•Aid« with two doon ; on one side of the metid 
plalo vbick toras round, or aa ia substituted het% 
■■ilj a doable arm or suspended balance beaas, 
flmdi the iguri <rf a person with an umbrdb aa* 
defeaca froa the rain ; and ou tbe other, a peraoi 
vtlboot a hat, or in gay attire, as if aware of the eon- 
tjaaapco of fine weather. The appearance ul one 
of theae indicates damp, and that of the other, dry 
weather (see Fig. &). Another toy hygromoltf^ 
upon the same principle, is made to repreaeat a 
fiiar, with a large moveabia coal orcr his bead, aid 
beariog in one hand a theriDomeicr, that tbe iaatni> 
meat may scrre the double purpose of an hygfO* 
meter and s thermometer (see Fig. 6). The bygn- 
netrical part is very easily cooatnicted. Behied 
tlie neck of the figare projects a thin tin tube, about 
2 inches long, this tube comes quite through tha 
thin board upon which tbe figure is painted. Oa 
the bock part of the hood is a hole, wbicfa AH 
loosely over tbe tube, so tbst, as ftir aa thia is eoi^ 
cerned, the hood may move round in any direotXda* 
To the front side of the hood, at a part correapood- 
ing with the end of tbe tube, is glued the end of a 
piece of cat^t, the other end ia drawn through tbe 
tube and fastened by paasing through the m-dllr of 
a cork, which fits tbe backward end of tbe luU \— 
thus, the catgut being fixed at one end, aa it twitts 
or oalaiBtl with cbangei of the waatherf the hood 



-J 



MAGAZINE OF SCIENCE. 



139 



if tbe monk'* brad if wtt, or rnts upon 
bni when dry. These pret«ndrd bygro- 
\ttTTe for no other purpose than toomuAe 
the pbiioiopber mu»t observe itnt u the 
|ef btnaiditj ira tranimicted to thia in- 
Wf degrees, it will indicnto mottture or 
jffaeo the state of tbe atiDoa[>here nmy be 
^t. Tbe circumstance, too, of these 
p9 being genemlly |]lnct-din a room where a 
1^ dou not coDtribute to their luefnlnew. . 
bee a perfect hygruraeter, na well as any 
|BophioKi inttrument, we must call in the I 
Ice, and with its unerring prindplea aa ■ 
|nl perfect hygrometcTi bafe been con- 
fevfl shall Bt preaent dejcribe two of tbe 
b — those of Profewor Daoiell, of King's 
Itondon, and of Mr. F^ge. To under- 
pnndptes upoa which these instruments 
Icted, it is to be premised that " the tem- 
fc which dew ittffina to be dejKisttcd, ia a 
r the moisture of tbe air." Referring to 
llrfaich ia a rqiresentaltoo of DanieU's by- 
Hht ball A ia of black glass, about V2b 
taicter, and connected with a transparent 
P of the same size, by a bent tube C C 
I of 10 inch in diameter. A portion of 

rier, sufficient to fill about three-fourths 
A, is introduced ; a amnll mrrouriHl 
ber. with an elongated bulb, is fixed inside 

rB, and the atmospheric air being ez- 
vhole ia hermetically- sealed. The ball 
iRd with muilin, and the whole ii sap- 
I a brass stem P G, on which ii another 
IhErmomeier. The tube can be removed 

ring tube H ; and the whole instrument, 
of ether, neatly packed in a box, which 
iMed ia tbe pocket. 

Ib-poiot, sttd, consequently, tbe humidity of 
i ascertained thuf. The ether being all 
bto the ball A, by Inclining tbe tube, the 
placed tterpendicularly, the temperature 
F It noted by the common thermometer, 
klacfaedto the centre iftand FG, and ether 
ly dropped on the mtiilin cover of I) ;— 
\ produced by the evaporation of the 
0ein«a the elastic ethereal vapor within 
l^d if tbe thermometer inside tbe Umb C 

re that Instant, we obtain the true dew- 
Mi the temperature ibuwn by tbe other 
Icr. To ascertain the degree of humidity, 
i»ve recourse to a set of tables constructed 
lrpo«e, whirb may be found as originally 
P by Dr, DaltOD, for every degree of the 
ier, in the fifth volume of th? ** Man- 
psBsactions," or by the following for- 
ascertains the moisture contained in a 
Its weight in grains will be equal to 

where / is the temperature of the ex- 

'■nd p the elasticity of the ethereal vapor, 
itare shown by tbe interior thcrmo- 

inent invented by Mr. Jones, is de- 
the "Tracts of the Society of Useful 
" U being on exactly tlie same prinrJple 
invention of Dsniell, bQt simpler in 
more compact, and less expensive. — 
ice would certainly scirccly imply as 
seen ia Figure 4, and consiftn of s de- 
ial Cliermometer, with its tube at A U, 
bring its cylindrical ball C parallel 
JUtle distance from its item. The 




bulb is one inch Ions, and is terminated by a sur- 
face of black glass which projecln somenhit beyond 
the sides of the bulb. The bulb below l}ie ilattened 
surface is covered with black silk, llie instrument 
is supported on the wire £ F. which is attached to 
the scale by a pivot at top, that allows the bUck 
surface to be inclined to the light, and the whole aa 
in the case of the former instrument, is, with a phiil 
of ether, contained tn a smnll CAse. When used, 
the temperature of the air is first noted ; tbe ether 
is poured on the lilk cover of the bulb, and the 
condensntion of the dow is seen on the bUrk ex- 
tremity of tbe bulb. The calcolstion to find tbe 
degree of humidity is the same as before; an ordi* 
nnry thermometer must be used along with this In- 
itrument, — Danietl's hu one attached to it, 

CALOTYPE PICTURES. 
Mm, H. F. Taldot, so well known for his re- 
searches and dificovrries, relative to photographic 
drawing, and of which art wc have, from time to 
time, recorded the progress, has been and u itUI 
occupied with the iuterestiog subject, snd seems to 
have brought it to o degree of perfection hitherto 
unknown, which Uie following paper, read st the 
last meeting of the Royal Society, will show. Our 
resdcrs wilt, by comparison, remark that there are 
so many points about it so entirely different from 
the old process, that it may justly be ci^risidered a 
new art altogether ; and as such, Mr. Talbot has 
given it the new name of Calotype, Wc give Mr. 
Talbot's paper entire, and nearly vrrbotiin. 

Preparation qf the Paper. — Take a sheet of the 
best writing paper, having a smooth surface, and « 
close and even texture. The watermark, if any, 
should be cut off, lest it should injure the appearance 
of the picture. Dissolve 100 grains of crystallised 
nitrate of silver in six ounces of distilled water.— 
Wush the paper with this solution, with u soft brush, 
on one side, and put a mark on that side whereby 
to know it again. Dry the paper cautiously at a 
distant fire, or else let it dry spontaneously in a dark 
room. Wlteu dry, or nearly so, dip it into a solution 
of iodide of polaet>ium, containing 500 grains of that 
salt dl^^solvcd ill one pint of water, and let it stay 
two or three minutes in this solution. Then dip it 
into a vessel of water, dry it lightly with blotting- 
paper, and finish drying it at a fire, which will not 
injure it even if held pretty near ; or else it may be 
left to dry spontaneously. AH this is best done in 
the evening by candlelight. The paper, so fur pre- 
pared, the author calls iodized paper, because it has 
a uniform pale yellow coating of iodide of silver. It 
is scarcely sensitive to light, but, nevcriherless, it 
ought to be kept in a portfolio, or a drawer, until 
w&tited fur use. It may be kept for any length of 
time without spoiling or undergoing any change, if 
protected from the light. This is the first part of 
the prepurstion of CtUotype pa[>er, and maybe per- 
formed at any time. The remaining part is best 
deferred until shortly before the paper is wanted for 
use. When that time is arrived, lake a sheet of the 
iodiied paper and wash it with a liquid prepared in 
the following manner :— Dissolve 100 grains of crys- 
tallized nitrate of silver in two ounces of distilled 
water; add to Ibis solution oae-sixth of its volume 
of strong acetic acid. Let this mixture be called A. 
Make a saturated solution of crysUlltxed gallic add 
in cold distilled water. Tbe quantity dissolved U 
very small. Call this solution B. When a sheet of 
paper is wanted for use, mix together the liquids A 
and B in tqutl volamcs, but only mix ■ small quso- 



5 



140 



MAGAZINE or SCIENCE. 



tity of them it » time, bectute the mixture does not 
keep loa^ without Bpoilin;. I ihall call this mijclure 
the f7ollo-nitrate of W/rrr. Then take a sheet of 
iodurti paprr aod wAsh it over with thii gaih-Httrate 
qfnirrr, with & toft brash, takiog can to waah icoa 
the side which has been preTioutit}' marked. Tliia 
oprnitian ahoiUd be performed by candlelight. Let 
the paper rest half a minute, and then dip it into 
water. Then drr it lightly with blotting paper, and 
finally dry it eauiionaly at a fire, holding it at a con- 
aiderable distance therefrom. When dry, the paper 
is 6t for use. The antbor has named the paper thus 
prepared Cahtype paper, on account of iu great 
utility in obtaining tbr pictorea of objecta with the 
camera obscura. If this paper be kept in a press it 
wUl oft<-n retain its qualities in perfection for three 
months or more, being ready for use at any moment ; 
but this ia not uniformly the case, and the author 
tticTtffure recommends that it should be used in a few 
hours after it bss been prepared. If it is used imme- 
diately, the last drying may be dtspemed with, and 
the paper may be used moist. Instead of employing 
a solution of crystallized gallic acid for the liquid B, 
the iinchtre of galU dilated with water may be used, 
but he does not Uuuk the resulti are altogether bo 
satiafactory. 

Pie <iftht Paper. — The Calotyp§ paper ii sensi- 
tire to light in an extraordinary degree, which 
transcends a hdndred times or more that of any kind 
of photographic paper hitherto described. This may 
be made maDifest by the following experiment : — 
Take a piece of this paper, and hmving covered half 
of it, expose the other half to daylight for the space 
of one $econd in dark cloudy weather In winter. — 
This brief moment safiices to produce s strong im- 

Ereuion upon the paper. But the impression is 
iient and invisible, and its existence would not be 
suspected by any one who was not forwamed of gt 
by previous experiments. The method of causing 
the impression to become visible is extremely aiiuplc. 
In rnosiits in washing the paper once more with the 
fjaUo-uitrate of niters prepared in the way before 
described, and then warming it gently before the fire. 
I n a few seconds the |iart of the paper upon which 
the light has acted begins to darken, and finally 
grows entirely black, while the other port of the 
|>aper retains its whiteness. Even a weaker im- 
preseion than this may be brought out by repeating 
the wash of gallo-nitrate of silver, and agiun warm- 
ing the paper. On the other band, a stronger im- 
prcssion does not require the warming of the paper, 
for a wash of the gallo-nitrate suffices to make it 
visible, without heat, in the course of a minute or 
two. K very remarkable proof of the sensitiveness 
of the CaloC)-pe paper is aiforded by the fact stated 
by the author, that it will take an impression from 
limple moonlight, not concentrated by lens. If a 
le&f is laid upon a sheet of the paper, an image of it 
may be ohbuned in this way in from a quarter to 
half an hour. This piper being posaesaed of so high 
a degree of sensitiveness, is therefore well suited to 
receive imagea in the camera obacura. If the aper- 
ture of the object-lens is one inch, and the focal 
length fifteen inches, the author fi nd]> that one minute 
is amply sufficient in summer to impress n strong 
image upon the paper of any building upon which 
the sun is shining. When the aperture amounts to 
one-tliird of the focal length, and the object is very 
white, as a plaster bust, &c., it appears to him that 
one eeeofid is sufficient to obtain a pretty good 
image o( it. The images thus received upon the 
Caiotyjw ps^ier are fur the must part iuviaiblo im- 



led with 



preasiona. They may be aaade ▼iaibte by the pR»- 
cesa already related, namely, by washing theoi willi 
gallo-nitrate of silver, and then warming the paper. 
When the paper is quite blank, as is genetmlly tba 
case, it is a highly curious and beaotiful phaaoae- 
OOQ to see the spontaoeous commencement td tf» 
picture, first tracing out the stronger outlinca, aad 
then gradually rilling up all the numerous and com- 
plicated details. The artist should watch the pio- 
ture as it dcvdopca itftclf, and when, la hla jodf-* 
ment, it has attained the greatest degree of streogOl 
and clearness, he should stop further progreaa by 
washing it with the fixing liquid. 

Thefjcing procett. — To fix the picture, it ahoold 
be first washed with water, then lightly dried with 
blotting paper, and then washed with a solnl 
brotnide of potatfium, containing 100 graioa 
salt diuolred in eight or ten ounces of water. 
a minute or two it should be again dipped in 
and then finally dried. The picture is in this 
ner very strongly fixed, and with this great adrtzt* 
tage, that it remains transparent, and that, there- 
fore, there is no difficulty in obtaining a copy froa 
it. The Calotype picture is a vegafive one, in which 
the lights of nature are represented by shades ; bnt 
the copies are poniive, having the lights conforma- 
ble to nature. They also represent the object im 
their natural position with respect to right and left. 
The copies may be made upon Calotype paper in ■ 
very short time, the invisible impresaions beitf 
brought out in the way already described. BoC the 
author prefers to make the copies upon photogra- 
phic paper, preiuu-e^ in the way which he orifinaUf 
deacribed in a memoir read to the Royal Society tn 
February, 1339, and which is made by washing the 
beat writing paper, Jirvt with a weak soluboa td 
common salt, and next with a solution of nitrais of 
silver. Although it takes a much lunger time IQ 
obtain a copy upon this paper, yet, when obtainedr 
the tints appear more harmoaioua and pleaaii^ to 
the eye ; it requires, in general, from three minatoa 
to thirty minutes of sunshine, according to cdicsm* 
stances, to obtain a good copy on this sort of phe* 
togruphic paper. The copy should be washed and 
dried, and the fixing process (which maybe deferred 
to a aubsequent day) is the same as th«t already 
mentioned. The copies arc made by placing tM 
picture upon the photographic paper, with a board 
below and a sheet of glass above, and pressing the 
papers into close contact by means of screws or 
otherwise. After a Calotype picture has for* 
niabcd several copies, it sometimes grows faial* 
and no more good copies can then be made from it. 
But these pictures possess the beautiful amlexiraor- 
dinary property of being susceptible of rerival. U 
order to revive them and restore their original tip- 
jMrarance, it is only necessary to wash them again bjf 
candlelight with gallo-nitrate of silver, and ww 
them ; this causes all the shades of the pictum Itt 
darken greatly, while the white parts remain ■»- 
affected. The shaded parts of the paper tfatu ac- 
quire an opacity which gives a renewed apirit and 
life to the copies, of which a aecond seriea may now 
be taken, extending often to a very considerabla 
number. In reviving the [licture it sometimea h^u 
pens that various detaila make their app 
which bad not before been seen, ha1lt1^ been 
all the time, yet, nevertheless, not destroyed by 
long exposure to sunshine. The author termii 

these observations by stating a few expenmenta 

culated to render the mode of action of the sen>Ilt«» 
paper more bmiliar. — 1 . Wash a piece ut Uie iadtsed 



MAGAZINE OF SCIENCE. 



141 



i the gmUo-oitrate ; expote it to lUylighl 
»nd or tivo. and then withdraw it. The 
L toon brKiD to darken spontaneously, and 
quite bldi:k. — 2. Tht name as before, bat 
per be warmed. The bUckeniof will be 
' in coasctjueiue u( the warmth. — 3. Put 
ftp of the gaJlo-nitrate on one port of the 
BWifCcn mother part of it more sparingly, 
it exposed to a Terf faint dnylight ; it 
that the leaser quantity produces the 
bet ID darkening the pajwr ; and, in ge- 
n}l be seen that the most rapid darkening 
at the moment when the paper becomes 
also, if only a portion uf the paper is 
it will be obserred that the edges or 
of the moistened part are more aoted on 
an any other part of the torCace. — 1. if 
lifter being moistened with the gallo- 
washed with water and dried, a alight 
daylight no longer inlficei to produce 
discoloration ; Indeed it often produces 
Uut by subsequently waabing it again 
•nitrate and warming it, the lune de- 
lormCion is developed as in the other 
ents 1 and 2). The dry paper appears, 
be equal, or superior in sensitircoeaa 
only with this differeuce, that it re- 
tttal instead of an actual impresaioa 
Kgbt, which it lequires a subsequent pro- 
pdope. 



»VE)i£NT IN THE DAGUERRO- 

TVPE. 

bey with which the artists of Paris have 
ttrom yi. Daguerrc information respecting 
iDTery of his relative to the Daguerrotype. 
I hare forced a communication from him 
tt he would, himself, have chosen to make 
»esiiDenta not being complete — not having 
I yet, perfect eridences of the extraordi- 
lie results which he expects from tbcm. 
(St the sitting of the 2Ktb June, explained 
Idemy the new principle of which the dis- 
■iats, but on the ttutb<jrity of M. Daguerre 
I witboot the production of any specimens 
■i his BSMrtiooa. Contrary to what we 
^unagined, M. Arago withholds the sanc- 
b anthority, declaring that he has not. 
Bra any of the experiments or results ; — 
inciple itself ts one of greater importance 
•ific bearing, than for any orlistic appti- 
Irbich it ia Bosceptible. The history and 
I of the discovery is as follows ; — Aban* 
B search, in which so many have been 
ber some fresh substance more senaitive to 
of light than those hitherto employed, 
rre submitted bis plate, merely washed 
t, in the ordinary manner, to the inftaence 
tty ; and found that it had attained such 
Ne d^rec of aensibility, that no mechttoiam 
Ideatly nipid in its action to exj>o«e it 
to the impression of light — that is, a plats 
td and placed \a the camera obteura an- 
turing the one unapprecinblc moment 
b opening and shutting the diaphragm 
m the objective glass> such varied degrees 
ion, that the portion first brought into 
lUi the light i« already too prutbuudly 
I it c&D touch the )atf r portions. The re- 
V&fuaed and clouded image. To meet the 
H. Uaguerre states, that he has employed 
(which, however, he does not name,) 



leu seositire than the ordioary combination of io- 
dine with Kilver ; and, in the next, instead of sob- 
jecting his plate to the continued action of the 
electric fluid, be admits the intervention of this 
mysCcriotts agent for a single instant only. In more 
precise terms, the plate so prepared and disposed in 
the camera, may be exposed, without injury, to the 
notion of the light for a certain time ; and to cotn- 
monicate to it the exquisite sensibility in questioo, a 
single electric spark suffices ; after which, the plata 
resuming its inertness, time Is afforded to withdraw 
it from the influence of the light — and the operation 
it complete. It U not easy to imagine the artistic 
effects which will result from this remarkable dis- 
covery ; — from the rapid action of the electric spark, 
vast assemblages of men, in the moment of ani- 
mation and impulse, may be caught for eternity, with 
the gesture of the moment in the limbs, and its ex- 
pression on the lips of each. History may be writ- 
ten, by picture, even while its deeds are acting ; and 
nature, in her subtlest movements, be painted by 
herself. M. Daguerre, however, is not satisfied 
with such results as he has yet obtained ; and, in 
yielding to the demand for his secret, bos declined 
confirming it by his specimens, till he has succeeded 
in making them perfect, l^leantime, the important 
part of his communication is the scientlBc pheno- 
menon, itaelf — this wonderful effect of electricity 
on the chemical combtoation, exposed to the action 
of the rays of light. 



LIGHT. 
Tub cause of those senaalions which we refer to the 
eyes, or that which produces the sense of seeing. 
The phenomena of light and vision have always been 
regarded as one of the most interesting branches of 
natural science ; though it is only since the days of 
Newton that they have been examined with such earo 
as to afford grounds for any safe speculation re- 
specting the nstnrc uf light, and the mode of its 
propagation through space. But the solution of 
tbest; two qupations Is involved in very great ditficolty, 
for notwithalonding the splendid discoveries of that 
immortal philosopher, and the long train of inte- 
resting and important facts which have been invea- 
tjgited since bis time, and more particularly since 
the banning of tlie present century, the true theory 
of light still remains an enigma. This docs not arise 
from any difficulty there is in framing an hypothesis 
which ahall afford a mechanical explanation of the 
various phenomena, but from the circumstance that 
more hypotheses than ona have been imagined by 
which all the phenomena can be explained, not 
merely in a general way, but with the precision of 
numerical calculation. 

Properties tif Liffht, — Experiments of the simp- 
lest and most familiar kind suffice to show that light 
is propogated from luminous bodies in nil directions. 
Provided nothing intervenes to intercept the light, 
tbey are seen in ail situations of the eye. Thus, 
the flame of a lamp is visible from every part of the 
sphere of which it occopiea the centre ; and the 
same is the case with respect to a phosphorescent 
body, an electric spark, a ball heated red-hot, or 
light having any other source. The nun throws its 
light, not only on the cartli, but on the ptanela and 
comets, and every other body in the firmametLt* 

Auuiher property of light is, tliut iu a homoge- 
neous medium it is alwtiya propagated in straight 
lines. This 15 evident from various considerations. 
The forms of shadows correctly represent the ont- 
Imes of tbe objects which produce them, as seen 



1 



U3 



MAGAZINE OF SCIENCE. 



from the lamiaou body, which could not bo anle«< 
the light proceeded In ■tratght Udci from the ex- 
tremities of the objects to the borden of the Rbwlow. 
If three plates of metal, each pierced with a smalt 
hole, are placed at Mue distance beluod each other, 
aad iu such positions that the three holes are eiaotly 
in one straight line, the light will pass freely through 
them i but if the holes are not exactly in a itmigbt 
line, no Ugbt will pass, in like manner, if a nnm- 
bcr of simiUr objects are placed bebiad each other 
in a atraight line, the first renderi all the others in- 
Titible to «n eye plsced in the ume line. We 
cannot see through a bent tnbe. 

A third property of light is, that it requires time 
for its propagadoB. The velocity with which it 
passes from one point to another is, however, bo 
greftt, tfaftt. with respect totnytamttri&ldistttnces, 
the passage may be romiderod as instanlaneous. 
Bat astronomy fumishea the means, not only of 
detectiof its propagation, but of measaring its Te- 
locity with grest precisioa. The eclipses and emer* 
lioDB of Jupiter's aatelUtes become Tislble about 
IG min., 26 see. earlier when the earth is at its 
least distance from Jtipitrr, than when it is at its 
groatest. Light, therefore, occupies above s qnar- 
ter of an hour in passing through the diameter of 
the earth's orbit. Now. the sun's diittjincc from the 
earth being nearly 95,0(H>,000 of miles, it foUowi 
that bght mutit travel through space with the pro- 
digious, though finite, velocity of 192,500, or nearly 
200,000 miles, in a second of time, and cooie- 
qucntly would pass roand the earth in the eighth 
plot of a seooud. Astounding as this conclusion Lsj 
no result of science rest* on more certain eridence. 
It is also proved, by the phenomena of nberration, 
that the light of the sun. planets, and all Che fixed 
stars, travels with one and the same velocity. 

When light in ita progress encounters an obstacle, 
or eut«rs a different medium, it undergoes certain 
modi fi ca t ions, depending on the nature of the body 
on which it falls, or the medium into which it enters. 
When it fsUs on a smooth polished surface, a |)or- 
tion of it is regularly reflected ; that is to say, it is 
returned from the surface at an angle equal to the 
angle of incidence, and pursues its course in a 
straight line as before the reflection. The quantity 
of bght thus reflected depeoda on the nature and 
polish of the surface, and on the angle of incidence, 
being greatest when that angle is small : but it is 
calculated that even tlie brightest, and most opaque 
Burfaces, mercury for example, do not reflect more 
than three-fourths of the incident light. Another 
portion of it enters the medium, and <hcre (if the 
medium is homogenous,) pursues a rectiUnear 
coarse, bat diflfering from its former direction. In 
tUb oaae it ii atid to be refracted. The angie of 
refraction depends on the nature of the mcdiucn, 
each diiTerrnt medium having its own peculiar law of 
action on light. In many media, comprehending 
the liquids and most of the uncryitalUzed substances, 
the whole of the refracted light is bent frum its ori- 
ginal direction at the same angle. In many othera, 
as in roost crystallised media, pert of the refracted 
light folluwa one coarse, and another part it a dif- 
ferent one ; the two portions acquiring, at the some 
time, dilfereut physical properties, hi this case 
the refraction is said to be double. A third portion 
of the light fklling on a body is neither reflected 
Bor refracted regularly, but is scattered in all direc- 
tions ; and it is this portion which renders bodies 
vlsUtle. All bodies on which light fulls obsorb a 
certiaa jurt of it; more or less in proportion to 



the opacity. In perfectly opake bodies the absorp- 
tion is total, and the light does not penetrate to 
a sensible depth under the surface. In others it 
penetrates fertber ; but even in the most trans- 
parent it ia gradually stified and lost. A depth of 
only seven feet of pure water ia required to cxtia- 
gnish one half of the incident light. 

Solar light, rrfracled by a prism or other body, k 
separated into a multitude of rays of diflerent colort* 
each of which afterwards proceeds in ita ootsrae to* 
dependently of all the others. The«e difieready 
colored rays possess different physical propertiea* 
and different degrees of refrangibility. It ia to this 
dispersion or separation of light by refraction ihH 
we owe all the pleaaore derived from the vari^atei 
baea of natural bodies. The inveatigalion of ikM 
laws of the dispersion of the oobred raya fformi tfc* 
subject of chromaticw. One of the principal fiuti 
connected with it is, that the dispersion of the raya 
by diflferent refracting aubstances is not proportioued 
to the refraction ; the dispersive power of aoa* 
subsUncea being greater than that of otfaen, vbUi 
their refracting power is less. This fact led tchtfc* 
important discovery of the acAromieiie Ulmeoptm 

Light, on being regularly reflected or refraete^ 
undergoes a modification termed pvtari^atum^ hi 
virtue of which it presents, on encountering aoMhcr 
medium, difTereot plmoaieuof reflection and t^ 
fraction from those preaented hf light which ha« 
not undergone such modification. When a rsy of 
light, having acquired tills modification, ia made t9 
to fall on a plane rejecting surface under a oertai^ 
angle of incidence, no portion of it will be refledad} 
the whole ia transmitted or absorbed. But, in th* 
ease of ordinary light, some portion is always re- 
flected from a polished surface, whatever be tha 
angle of incidence ; the light has therefore acqutfW 
the property of being acted upon in a partiookr 
way; whence Malus. who first investigated tUl 
subject in a philosophical manucr, gave tl*e phinc^ 
mena the name of polariiaiion, from ita analoif |» 
the effect produced by a magnet on a senea ti 
needles. 

The lut property of light which we shall ootSoi, 
as important towards formwg a theory of lis proplk 
gation, is that to which Dt. Young gave the naoi 
of interfertnce. Under certain circumstasaeB* Chi 
rays of light exercise a mutual iofiaenoe on eacdk 
other ; increasing, dimiuishlng, or modifying oaob 
other's clTects according to certain laws. This 
mutual action of the rays on each other, givea titf 
to a great number of the most intricate phenocofM 
of optics, and aifortls a sufficiently simple exploi* 
lion of them, in numerous oases where no other ci« 
planation has yet been found on other hypo 

ThrorifM of Ltff/tt. — Two different theonea 
long divided the opinion of phiiosophera, rea 
the nature and propagatiou of bght. One of 
cnnsiats in supposing it to be compoaed of particki 
of excessive minuteness, projected from the ianl- 
nous body with a velocity eqaal to nearly . 20(MMtt 
miles in a second. This hypotheaia 
by Newton, and, till recently, has been acq 
in by the greater number of writers on optica. 
otlier hypotheaia supposes light to be pn 
the vibrations or undulations of an ethereal 
great elasticity, which pervades all space and 
tratea all aubsiaoces, and to which the lam. 
body givea an impulse which is propagatnl with In- 
conceivable rapidity, in sphehoal superficiea, by a 
sort of tremor or undulation, oa aound is conveyed 
through the atmosphere, or a wave along the sur* 




MAGAZINE OF SCIENCE. 



143 



Both of these hjpotheacs »re ren- 

tla by the great aamber of phenomena 

\cy atford a mechanical explanation ; bat 

also, attended with very great iliffi- 

Ither theories hare alio beeo proposed ; 

ire not met with such general attention 

»phen u to make it necessary to explain 

fTia hr itmtiniwtt. J 



MOSAIC PICTURES. 

Iknovn tliat Mosaic-work constfts of rari- 

piecej oF colored gtoM eitamel ; anj 

these pieces are cemented to|fcther, they 

tegnUr and other beautiful Agures which 

teaaetlated pavements. These pavements, 

of the ancient Romans, have freqnently 

England and other cotuitnes. The 

ictory of Mosaic pictures, in the 

at Rome, and belongs to his Holi- 

in which the establishment is sitn- 
and contains a collection of enamels 
Che form of sticks. These ore arranged, 
to their colors, in on ejctensive suit of 
number of shades of color is 17,000. 
consisting of glass mixed with me> 
ing matter, is heated for eight days in a 
eadi cohr in a separate pot. The 
id is taken out with an iron spoon, and 
tished marble placed horizontally ; and 
rble slab is laid upon the sur^ce, so 
cools into the form of a round cake, 
of -^^ths of an inch. 

the cake into smaller pieces, it 
sharp steel anvil, called tagUolo, 
[idge appennost ; and a stroke of on 
Is given on the upper surface of the 
is tbos divided into long parollclopipcds, 
whose bases ore iS^ths of on inch square. 
ipeds are again divided across their 
tigUtlo and hammer, into pieces of 
of an inch, lu b« used in the 
Sometimea the cakes are made 
places larger. 

\, the enamel, whilst fused, la 
psraUelopiped, or quadrangular 
■re divided across by the tagliolo 
or by a file ; s(»raetimes, also, these 
divided by a saw withost teeth, oonsist- 
blade and emery ; and the pieces 
polished on a horixontal wheel of lead 

Mosaic is formed by applying the gold- 
hot surface of a brown enamel, imrae- 
tbe enamel ts taken from the furnace ; 
is put into the furnace again for a short 
wbisa it is taken out. the gold is firmly 
tihe surface, lu Che gilded enamel, used in 
Rome, there is a thin coat of trojutparent 
the gold, 
it Romans, besides tlie enamel for Mosaic, 
works in enamel. WinVlemonn men- 
titles of a kind of gloss or enamel, for 
t/ifion of rooms ; and be dmcribes a small 
of filaments of cnemdof difTerent 
together by Tuition, emrh tnins« 
of this gave a picture like that at the 
The antique pa^, or artificial gems^ 
lucts of art allied to enamel, 
ly, the paste in which the pieces of Mosaic 
li GoUcd, in lt«iyr ituccoi was oom- 



]>osed of a neasnn of quick-lime quenched in wateTf 
and three measures of pounded marble ; these were 
made into a mass with water and white of eggs ;— 
and this was called Mannoratum : but this paste 
hardens too rapidly, bo that it is bard before the 
workman has time to insert the pieces, and it is in* 
jurcd by damp more readily than the cement made 
with oil. 

The paste now used, is composed of a measure of 
ooenehed quink-Ume, and three measures ot pow- 
dered travertine stone ; tlicse are mijied with linseed 
oil, and ore stirred and worked up every day with a 
trowel. The mass is at first levd on the surface, 
but afterwords swells up. Each day some oil is 
added, to prevent the moKS from becoming dry and 
Intractable. The mass is ready in a shorter time in 
warm weather thsu in cold ; iu summer the mass is 
at its perfection in twenty days ; this is known from 
its ceasing to swell, the water that was in the lime 
having evaporated ; the mass is then uniform 
throughout, like on ointment. In winter, and when 
the air i£ moist, it requires a month to bring the 
paste to perfection. 

The wall to which the Mosaic is to be applied, 
must have the lime taken off its surface ; then fur* 
rows, an inch deep, are formed on the wallf to fix 
the cement. For the same purpoae large-headed 
nails are driven in. and wire is stretched from one 
nail to another. After this, the wall thus prepared, 
is painted over with linseed oil. Then the cement 
is hud on, to the extent of a surface of as many 
inches as can be executed before the cement dries. 
The plasticity and softness of the cement lasts about 
twenty days ; ofler that the oil exudes, and the Ume 
and travertine become a hard maas. The cement 
mode with linseed oil is ycUow \ that made with 
white of eggs is white, and the white cement is con- 
sidered to be a character for distinguishing the old 
Mosaic from the modem ; hut some of the modern 
ia also made with white cement. 



MEDICAL QUALITIES OF SEA-WATER. 
Two very important agents, endowed with peculiar 
virtues in refercooe to the human consHtn H nn , barc 
of late years been mneh comznendad aad employed 
in the practice of median*. I allodb to iodine and 
bromine — both of which have boen detected by recent 
analyaea in sea-water. Independent of these, there 
are otlier very active IngredieiUs in sea-water. The 
first is chloride of sodium, which exists in the pro- 
portion of 1 to 35. or, in otlier words, a pint of sea- 
water contAins 21 6^ grains — that is to oay, some- 
thing less than i os. of common salt. The seoood 
is what medical men call muriate of magnesia, which 
is a combination of chlorine with magnesiuu— 
a salt endowed with well-marked proportiea oo tho 
human frame, and which constitutes one of the active 
ingrcdienU of Fnllna water. To complete this 
analyots, it should be stated that the same pint of 
sea-water contains also 18 grains and i of Epsom 
salts, 1 1 } grains of sulphate of lime, with a very tri- 
fling quantity of carbonate of lime. Aft«r this ao- 
coont it will be readily admitted that sea^water ia, 
in fact, a mineral water to all intents and purpowa, 
and that we may. therefore, look with as mudi con* 
fidenoe for beneficial effects from its employmenU 
whether externally or internally, provided it be judi- 
ciously recoouneuded , as from the employment of 
other mineral waters— proportionate to* and la ao- 
cordaoce with, their respective chrmic al oompOfi- 
tion. — QroHviUe't ^m» if Bnffimtd* 



144 



MAGAZIKE OF SCIENCE. 



NOTES ON THE UONTB OP JOX*Y. 






w»^k^ai ^ftroito/tht Jrtnge^lMe Qitaniiljfqf 



LaxDON ... 
DnLm . . . . 



7 Atft^MOllMlAr' 



MS 

CMS 



Banrntngr. 



1944 



Mmi 



i\'M tncb. 
S>M 



TBB AKIHAL KINOOOM. 

Birdi. — About or before this Mason most long 
birds become aileiit. The Blsckbird, the Pippet 
Lark, the Willow Wren, and aereral otber birds 
tbongh they become silent now, resume their notes 
in September. The Cuckoo leiivcs off its curious 
note. The Qusil, however, begins to make itself 
heard. Mole hlUa msf be observed, some very 
much larger than others : when a hill of enlarged 
dimennions is discovered we may bfl almost certain 
of finding the ue«t beneath. Suppofting the weather 
CiTorable we And the Snake basking on ^the bank, 
the Hedgehog sleeping on the common, and the 
pretty tittle lizards nimbly mnning through the 
brake. The insect race is in ita full vigour, and 
ftboundi iu all situations. The Dragon Flies skim 
■long the margin of the streams and ponds, settling 
from time to time on the water planta around. 
The Cuckoo Spit, the Plant Louse, and the Frog- 
bopper are everywhere in abundanre. It is in this 
month that the Caterpillars of most of the Hawk- 
Moths are to be sought for. That of the Poai- 
Moth may be found on the lower branches of Wil- 
low trees, and must bo sought by the eye, for beat- 
ing the branches will not moke them qidt their hold 
as it does the Noetua. 

THK VKGETABLB KINGDOM. 

PUats indigenous to our climate are now in their 
gnatest number and beauty. The whole of nature 
■eemt but a witdemeaa of flowers. In June they 
were but struggling into existence, now they arc 
Imuriant. To enumerate even a hundredth part of 
the long list of plants in flower would be extremely 
tedious ; yet there arc some whole tribes which 
seem to choose July as their season of blossoming ; 
thus in the early part of the month, the Grass&t and 
the Uosea are almost all in blo&som. The umbel- 
liferous planta and the Brambles moat now be sought 
for. The extensiTe family of the Cnwiiene or Cab- 
bage tribe arc, during this months more particularly 
In perfection, tliough a few of them are in blossom 
at a much earlier season. The Sedums or Stone 
Crops, the House-Leeks, the Rock Rose tribe and 
the Saxifrages, and numerous others, deserve par- 
ticular altentioa at this season. These remarka 
relate but to our wild plants. The garden flowers 
an BO leas abundant and rich, showing the luxuri- 
ance of summer without the incipient decay of the 
aucoecding month. If wc have lost the Peony, and 
the Like, and the Tulip, we can, instead of them, 
admire the Rose, the Pink, and the Honeysuckle, 
and a thousand others equally tweet and beautiful. 

OAaDBMSO OritRATlONS. 

The gardener begins to witueu the success and 
reap the benefit of hU toil in the precedmg winter 
and spring. His cliief employment wiU be in 
gathering his Peas, and his eariy ripe KruiU, his 
Goosoberriea, CorranU, Cherries, Strawberries, and 
Baapberries. He will not, howerer. neglect to pro- 
pagate from cuttings of such planU as arc going 
oat of flower j nor forget to pipe and lay the Pink 
tribe, and gather the seeds as they ripen of such 
planta as may have flowered early. 



NOTES ON THE MONTH OP AUGUST. 



LOHDOII ... 

EomiraoB. 
DoMLia . . . . 



rkermometer. 






UarxHiteier- 



90-OC 

l»8S 

aoiT 



Jtaim. 



S-tt* 



AKUIATXD NATUUE, 

Inhbctis no less abound now than they did In Jtilp 
Piies are well known to swarm in the hooses. 
Wasps, Hornets, Gnats, and God-Fliea in the Gdda. 
Flying Ants appear — Bees kill their Drones — Cha 
Swallow-tailed, and the Ulack-Eyed Macbia 
Butterfly appear. Swallows, Martins, and 
other birds of passage, begin in Uio Utter 
the month to congregate, prcrions to 
their distant migrating expeditions, and 
already are departing. Various birds reaume tbdr 
spring notes. The Nuthatch clutters — the Stone 
Curlew whistles at night — the Goat-Sucker and 
young Owls make a noise in the evening, and the 
Robin Red-Breast sings. The young of animala, 
born in .\pril and May, are in Tigour, and tapiilly 
attaining tlie tut. of their parenta. Rabbita and 
Hares so prolific in the spring begin to cesise thtii 
parental duties, their three or four brtXMls hajing 
grown from under their care, and there being none 
others to succeed them. Young Partridgea ud 
Pheaaanta have attained to nearly their fuU tin and 
strength. 

THK VCnaTAHLS KINGDOM. 

The observations applicable to July, are no \em 
appropriate here on the abundance of floweri ; still 
aa the season adTaoces, we find some fading fj^m 
our sight, and othera of a more autumnal chlrafter 
making their appearance. Wc lose the besutiAU 
Roses, and find but Hipa in their place ; we iHidl 
see the scarcely less beautiful Bramble Flower, hul 
it is joined with the young Blackberry. Trees hava 
lost their flowcra and show more or leaa ripe fruit 
These are the general effects of the chaoge of ata- 
son, yet it is said, and with perfect truth, that the 
first week in August is, if fine, the best in all the 
year for the botanist, aa he will then find the greatac 
number of rare plants, in almost any situaboo h« 
may search for them. Mountainous districts are, 
previous to this, loo cold to yield many flowcn, 
the marshes have till now been too much overtlowed : 
the waters too cold, until the beats of July rs- 
awakens the r^etable cneigy, dries up the auper- 
abnndaoeeof moisture, and Uivigorates the plant so 
aa to produce ita flowers now. Another odvuitscs 
the botanist now enjoys whiiii he did not previoaaly. 
he can in moat cases procure the seed and seed-nsMl 
of his spedmens, and such is in very mimBWW 
tribea absolutely neceasary. 

GARDKymC OPKRATIOXS. 

The gardener will have to attend to lus crops af 
vegetables and fruit, for roost kinds grown in gar- 
dens are now in perfection, as well as his hot-house 
productions. His forced Fruits should all be 
ready early in the month. Peaches, Ncctarioea, 
and Grapes, Plne-AppIes, and Meloni. In the 
open ground, besides culinary vegetables, be will 
gather Plums, Apricots, and the earlier Pean and 
Applea for the use of the table ; while, at intervals, 
he will not forget to sow Mignionette for winter 
flowering, and such biennials is may have been be- 
fore neglected. 



L«aDO«<— Pnatc4 by U. Fkanci*. «. White Hon* Lana. Miln Kml.— f ubli«fa«<l by W. BBiriAUt. 1 1 . Pil«mu«ter Rm>. 
(which aze auiwoiad Hoalhlyjlo be wldicssed lo On EtUWr, at V. CotlaK« Grove. Mils Cad fiM«, 




THE 



MAGAZINE OF SCIENCE, 

"SLnti School of ^m. 
123] 



SATURDAY. AUGlfST 7, 1841. 



\Ud. 





w X 



^.U 



f^j^ 



NEW ELECTRO-MAGNETIC ENGINE. 



L. lU.-^-MO, XIX, 



i 



14G 



MAGAZINE OF SCIENCE. 



Steam Supttrtedtui, Am Anount iff iht nrmly- 

tMmtteH Etectro.mnynf'tic Eupine, for the PfO- 
fminon nj Jjirttmultveji, SlitjtM, MUlu, i,'c. : and 
cho apftUcabie to the Ptttcc*»m nf Syinniny^ 
TStming, Ormdimg, Saving, PoliKfiing, Vi*., 
mid every Speciet qf Methaucai Moretnent. 
Price 2m. , jHign 36. 
Such is tbe lille of « tery small vork, pretty (fcne- 
rftlly dUtributcd throughout London, h is a truni- 
Ution from the Germin. Ufwn lookiog into this 
work we expected something exceedingly new, and 
■t the same time exroedingly excellent. We were 
•oinewbut disop{Hjtuted, therefore, in findinf^ that it 
gives a deacription of the first mschinc, invented 
two or three years ago by M. Jacobi. Without itit 
describing other inachiooi of more simplicity, grcBter 
power, and of h:ss weight and expense ; besidea 
wholly lenvtng out the account of Sir. Sturgeon**, 
and whatever else has been done in this country, re- 
lative to the tnnving of macfainea by cleclrD-mag* 
nelinn . This might hsve been eicosed in the original 
German work, but it is in some degree to be regretted 
that this small treatise was not made more useful by 
introducing various matters of thia kind in notes by 
the truuUtor, who ia well able to bafc supplieU 
them. 

With this drawback the work Is good, giving on 
account of the princtjial parts of the reasouijig and 
experiments of M. Jncobi, who, whotevcr may be 
^e merits of others, must always hold a distinguished 
nnk among electricians. WV give some of the il> 
Ittstrattvo cuts, and iho fallowing extracts, explana- 
tory of thrm. from the book iUelf, trusting that 
those who are interested, will, by purchasing the 
work, (which may be had of any bookKllcr in 
London,} glean from it those unerhog principles of 
science and fact, which will assist in thpir own en- 
deavours to understand, and it may be to construct 
some simpUficaiiun of M. Jacobi's invention. 

** The ppneipal figure of the cut, (No. 1,) repre- 
sents A magnetical apparatus, in which eight bars, 
(four bars of soft iron in the shape of horse-sboei.) 
are symmetrically attached to a wooden frsme, re- 
volving round a horixontal axle. A, and eight others 
similar, arrnnged on a sufficiently strong fixed frame. 
The arrangement of tbe bars admits of every |>oa- 
aible variety, it being only nerewary that they he 
oymmetrically arranged, and that their poles shall 
past each other as cloacly os )Kissible. Since iu all 
probability tiio centre of the mogneticaJ gravity is 
situated at some little distance from tlie extremity, 
as is the case with the ordinary magnetic bars, it 
would be better to arrange it so that the axes of the 
oylindrical bars should be at right angles to ouo 
another, instead of parallel, as in the figure. The 
form given in the plate is attended with some other 
inconvunicDces, as regards the formation of tlie spi- 
ral line* of copper wire, which must be first bent 
over another cylinder of the some dimensions. 
These spirali must be quite close to the cylinder, 
but be preserved from contact with it by being 
wrapped in silk, for tbe sake of isolation. 

'■ The several bars attached to the moveable and 
stationary frames ore then converted into electro- 
magnets, by being encircled by the wire of a voltaic 
battery, and their extremities are north and south 
poles alternately. If, then, a slight impulse be 
given to the moveable frame, it will continue to re- 
volve in the direction given, nnlil the contrary poles 
come opposite one another; after a few oscillations 
the iQotioa would be snspcndeil, were it not, that, 



by means of an ingenious contrivance t>f Jaca^K 
which he terms the cfrMrNU/tf/or, the moment di»- 
similar yoWt rotuc oppusitr one another, the |)ohM 
of the moveable or stationary bars arc rcverasd, 
and thus the original conditions of motion on n* 
newed. 

** The cnt No. 3. gives a front new of the bara. tad 
No. 2, a side view of tlu; commutator. There ar* 
four plates of copper attachrd to the rotatory axlo, 
which likewise bears the frame on which the electiv* 
muf^iets are fastened ; the plates are connected fary 
coppur tulxrs, two and two, and each pair nf pUtM 
perfectly separated from the other by the interposU 
tioQ uf ■ hollow axle of jupnoued wood, or any similar 
isolating substance. The edge of each plate la oo- 
curately divided into eight parts, foar of whidi, 
U H U 11, (No. 2.) arc cut out, and duly filled with 
ebony, so that the sectors and the metal present a 
perfectly even surface. The plates are so arraogeU 
on the axk, that the sectors of wood and metal alter* 
nately correspond, as exhibited by the figure, No. ]> 
C C ore copper levers, very moveable round their 
axes, and servmg to conduct the current of the TolBsie 
battery. Each lever is shaped like a bammvol 
the end, which rests on a corresponding pUlcr* 
The shorter arm is bent, and dips into the vessel K 
filled with mercury. These Te«ecls (for thero on 
four of them) are, as appears by the pUte, con* 
nectcd with one another by means of a copper win. 
*' The action of the cOTWiwufa^or will be uuw rtaJUy 
understood, llie levers are in constant cooueiioa 
with the plates, but touch the metallic and isolating 
parts alternately. As they readily move roand their 
axes, they Hy from the slightest mequality of stir- 
face, and the friction which is therrby cauard is very 
trifling. The spiral coiU, which encircle the move- 
able bars, are nnited to one wire, branches of wbteh 
ore soldered to the pairs of pUles uf the commo* 
tator. The other spirals, endrcling the fixed ban, 
are similarly joined, and the ends dip.* the one Into 
a vessel uf quicksilver, which is connected with lb* 
voltaic apparatus, and the other into one of tbs 
vessels of the commutator. Thus, by means of lbs 
commutator, the whole sixteen spirals form bwtoM 
connecting wire. The voltaic apparstoa cooaisU ttf 
four troughs of copper, into which four ploCva el 
xino dip. As soon as the lai^ wooden fnmt is 
turned by the power of the voltaic pile, the con- 
mutator, which is attached to the same axis, wiUbf 
likewise set in motion, ami thus the reversal of 9kt 
poles effected by raeans of the modune itccif, pro- 
vided that the commutation plates be so coostraclal 
that the extremities of the levers shall pass tnm 
one sector to the other. 

" In September, 1837, by advice of the Mloistef of 
Pablic Instruction in Kuseia. a commission, cua- 
sistingof RearAdminUvoo iCruseostrnt, the Acadv- 
micians. Fobs, Ostragrad^ki, Ktipfer, and Ijoatt 
Colonel Sololewak), and Licutenant-Culonei Bnnl- 
aphock were appointed, under the guidance of Pro- 
fessor Jacobi, of Dorpat, with a view to endeavgor, 
by experiment, to render electro-magnetism appli- 
cable to the working of machinery, and particularly 
to tbe propulsion of ships. The object of this com* 
miaitiiiu appears in part obtained, as on the 2otb of 
September, lH3ti, a vessel was set in motion on ths 
Neva, An eight-otred gtlley, such oi is osool im 

In oar rul we iisvc omltlad tbs galvsole b&U«ry, it prn- 
•«nl)n| nulhlnjf pi>ruIUr, The two wire*. N and V. ar> tli«H« 
which profiM'd to U. od« of tbmm ramUif rroni lite fitAl tiw, 
theoLhirr frvra Ibe CKiDtnutstar, oc Irmn Um siovval»t« ban 

througb the CDniniutuiur. 



MAGAZINE OF SCIENCE. 



147 



the Ti«rr, WIS placed at the disposal of the commiit- 
' ' rii Irntfth, an<l "J in breadth; it wna 
J ii paddlM flimilnr to those of a itrom- 

1-^' > i. ..ti.i till! vnrioul flpparstiif vcre put cm 
botrJ. 'I"he insufficiency of many of the arranf;e- 
mencs which had beeo made, was then, for the first 
tftau, sp}>«rentf and io consequence, tbs first ex- 
penment was in n measure proportion ably nnsac- 
orvafui. It had been intandcd to moke experiments 
only in atiU water, but they succeded in propelling 
the veuci on the Neva, eren against the stream. The 
rpeed otttiiDed ia itill water was three Engltih mites 
per hour, ftnd would have been (greater liad the 
weight on board, which waa largo, \>ecn properly 
dbtrilmtetl throughoot the boat, which drew 2^ feet 
of water. The machine, when on board, occopied 
a vpace 12} feet Id breadth, and 2} in length. 

"Th< butit-TT consisted of 320 pairk of platea, ar- 
rtag«d along the sides of the boat, leaving imffictent 
room for tweWe persona. The whole battery could 
b« bromght into play only for a abort time, in con- 
nqftcnce of a trifling fauit in the connexion, which 
h wma im[>oHtible to correct on the spot. The con- 
moiptjon of zinc, or rather tbe production of vitriol 
of ttii£ per horse power, could not be exactly as- 
textaintd ; but it would appear from the ezperi- 
aaeala, that this ooald not be very considerable, in. 
aamach as the original weight of the zinc, being 4(K) 
•oanda, and presenting a surface of 'Jti sfiuare feet, 
ud decreased but 2( pounds in weight, during from 
two to tfaree months that the experimenti were 

ti'd. 

>vided tbo health of Professor Jaeobt allow 
Itim, he intends conatnictinK^ au electro- magnetic 
saiditne of 40 to SO-faonw power, and to adapt it to 
Ibe fkropaUion of a TeaaeL • • * 

** Dawt/npon, who has constnicted the moat pow- 
Wfol maehines propelled by cltfctro-mogDetism, ia 
•■id to have already applied some imalier ones to 
objrctfii such as the working of printing- 
principally of a few horse power. Daven- 
fOtt'a machines are, at preaent, the miMt powerful 
•■d aavple. (\ description is in a former part of 
lUrn'Maimne.) 

'• U'**r- rndebted foragrratimproTcmentin elec- 
ti rnachinea, to tlie mechanician 8tnehrcr, 

V' "bo bait constructed a macbine oi a 

mode), the perfect simplicity and easy construction 
of which will, In all probability, ensure its applica- 
tSnn in tiie room of all ulber moving poweni. It is 
worked at present but by four elements, each con- 
•^ a copper cylinder filled with vitriolic acid, 
a tine plate is hung, and sets a lathe in 
which is applied to the turning of small 
artirles. The expense of this power for twenty- 
foiir hours is one shilling, one hflf of which ia fully 
by the pore metallic copper which ia ob- 



** Sloehrer eonstTDCted this model last year on the 
plnriplct Laid down by Jacobi; and some time 
•fker, Wagrner, of Frankfort, constructed n similar 
Model, for which a reward of 100,000 (lurins was 
^aamntcred him by the German Diet, as soon as the 
plan -hould be carried out on a loi^ scale. 

" This execution on a large acale has, according to 

-*t icrounts, sutxecdrd most brilUiinlly ; for 

nil) is at present worked by cleclro-mng- 

:i Bftvaria, and this new power has alreudy 

. :he moat sanguine expectations. A loco- 

-:-„.... IS alao propelled by it. 

" It Is. thcrcfure, to be expected that eleotro- 
BSfaettam will soon play au inporCuiit part, and 




unrioestionably sapcrscde steam, which Is so much 
more dnogcroua and expensive, and «very other 
power witli which we are as yec acquainted. — 
Stoehrer is convinced that, with 100 sine elements, 
as above mentioned, (equal to 4b hor^c power,) he 
can propel a train of waggons with the usual num- 
ber of paBscngers, from Letpaic to Dresden on the 
railroqd, at an expense of hue six shiUinga, whilst 
the expense at present la about five pounds sterling. 

** Wc thus arrive at a standard of the extraordinary 
economy and power of these new mnchines : noC> 
withatauding Uieir immense power, thry can, never- 
thelefi«, be instantly stopped by a child ; nothing 
further bring necessary to btop the machine than to 
lift the connecting-rod out of the veaael. 

" The extent by which Uiia power may yet, and 
nuat in time, be perfcirted is sufficiently clear, from 
the fact of its being applicable, with the greatest 
advantage, for grinding, turning, spinning, and in* 
numerable other mechanical procesccs. 

"We feel, ilicrcfure, justified in calling the atten- 
tion of meohooica to thia novel power." 



ANALYSIS OF MINERAL WATERS. 

( Hemmed frvm pofje 1 2$. > 

9. Sulphuric acid exists in waters that form a 
prrripitate with the following solutions : — murifttc, 
nitrate, or acetate of barytes, strontian, or lime, or 
nitrate or acetate of lead. Of these, the most pow- 
erful by far is muriate of barytes, which ia cap&ble 
of detecting the presence of sulphuric add uncom- 
bined, when it does not exceed the uiillioiith part 
of the water. Acetate of lead ia next in point of 
power. Tbo muriatea are more powerful than the 
nitrates. The calcareoos aalts nre least powerful. 
All these tests are copable of indicating a moch 
smaller proportion of unoombined sulphuric acid, 
than when it is combined with a base. To render 
muriate of bnrytes n certain teat of sulphuric acid, 
the fullowiDjj; precautions meat be observed :— The 
muriate must be diluted ; Che alkalis or alkaline 
carbonates, if the water contain any. must be pre- 
viously aaturatod with muriatic acid ; the precipi- 
tate mast be insoluble in mnriatio acid ; if boraelc 
acid be suspected, muriate of strontian miut be 
tried, which is not precipitated by boradc ai^d.— 
The hydro -sulphnrets precipitate barytic solutioni, 
but their presence Is easily discovered by tire smell. 

10. Muriatic acid is detected by nitrate of silver, 
which occasions a white precipitate, or a cloud, in 
water rontnining an exceedingly minute portion of 
this acid. To render this test certain, the following 
precautions are necessary :— The alkalis or car- 
bonates must be previously saturated with nitric 
acid. Sulphuric acid, if any bo present, oaust be 
previously removed by means of nitrate of barytes. 
The precipitate must be insoluble in nitric ocid.— 
PfafTsayv, that the mild nitrate of mercury is the 
motl senaiblt^ test of muriatic acid ; and the. preci- 
pitate is not soluble in an exc&ta of any acid. 

11. Boracic acid is detected by means of acetate 
of lead, with which it forma a precipitate insoluble in 
acetic acid. But to render this test certain, the 
alkalis and earths must be previously snturulcd with 
acetic acid, and the sulphuric and muriatic acids 
removed by means of ocetate uf strontian and acetate 
of allvcr. 

1 2. Barytea is detected by the insoluble white 
precipitate, which it forms with diluted sulphuric 
acid. 



^ 



149 



MAGAZINE OF SCIENCE. 




13. Lime is detected by meaos of oxalic acid, 
which occuioDS a white prvcijiitate in water con- 
taining a very minute proportion of this eitrth. To 
render this teat deriilve, the following precaations 
are necenary : — ^The niiDeral oclils, if any be piv- 
sent, moat be previously saturated with an alkali. 
Barytei, if any be pre«ent, roust be previously re- 
moTed by means of sulphuric acid. Oxnlic acid 
precipicatea magocsta very slowly, whereas it preci- 
pitatei lioie instaally. 

M. Silcx may be adcertained by eraporattng a 
portion of water to dryness, and re-disiulving the 
precipitate iu muriatic acid. The sUex remaius be- 
hind undiMolved. 

By these means we may detect th« presence of 
the different substances commonly found in waters ; 
but 05 they are generally combined so as to form 
salts, it is necessary wo should know what tbeee 
combinations are. This is a more difficult ta»k, 
which Mr. Kirwon teaches us to accomplish by the 
fbllowiog^ methods : — 

1. To ascertain the presence of the different sul- 
phates. 

The sulphates which occur in water are seven ; — 
hot one of these, namely, tnlphate i}f cupptr, is so 
uncommon, that it may be excluded altogether. — 
The same remark applies to sulphate of ammonia. 
It la almost onneccssary to observe, that no sul- 
phate need be looked for, unless both its acid and 
base have been previously detected in the water. 

Sulphate of soda may be detected by the follow- 
ing method : — Free the water to be examined of alt 
earthy sulphates, by craporating it to one-half, and 
adding lime-water as long ej any precipitate appean. 
By these means the earths will nil be precipitated 
except lime, and the only remaining earthy sul- 
phate will be gulphnte of lime, which will be sepa> 
rated by evaporating the liquid till it becomes con- 
centrated, and then dropping into it a little alcohol, 
ami, ntitx filtration, adding a little oxalic acid. 

V^ith the water thus purified, mix solution of 
lime. If a precipitate appear, either immediately 
or on the addition of a little alcohol, it is a proof, 
that sulphate of potash or of soda is present. Which 
of the two may be determined, by mixing some of 
the purified water with acetate of hurylea. Sul- 
phate of barytes precipitates. Filter and evnporata 
to dryness. Diigest the residuum in nloohol. It 
will dissolve the alkahoe acetate. Evaporate to 
dryness, and the dry salt will deli([ue8ce if it be 
acetate of potaab, but effloresce if it be acetate of 
loda. 

Sulphate of lime may be detected by evaporating 
the water suspected to contain it to a few ounces. 
A precipitate appears, which, if it be sulphate of 
lime, is soluble in 500 parts of water ; and the 
solution aifords n precipitate with the muriate of 
barytea. oxalic acid, carbouute of mu^csia, and 
alcohol. 

Alum may be detected by mixing carbonate of 
lime with the water suftpe[;tc:d to cuutaln it. If a 
precipitate appear, it indicates the presence of 
alum, or at least of sulphate of alumina ; provided 
the water contain<f no muriate of harytcs or roetaUic 
sulphates. The tint of these salts is incompatible 
with alum. The second may be removed by the 
alkaline prusBidtea. M hen a precipitate is produced 
in water by muriate uf lime, carbonate of licne. and 
murinte of maj^nL-sia, we may conclude that it con- 
tains nlum or sulphate of alumina. 

Nulphate of magnesia may be detected by means 
of bydroculphuret of sLronlian, which ocouioos an 



immediste precipitate with Oils salt, and with no 
other ; provided the water be previously deprived 
of alum, if any ho present, by means of carbonsto 
of lime, and provided also (hat it contains no ob* 
combined acid. 

Sulphate of iron is precipitated firom witter by 
alcohol, and then it may be easily recognised by &M 
properties. 

2. To ascertain the presence of the different 
muriates. 

The murintcs found in waters amount to e^fat, 
or to nine if muriate of iron be included. The most 
common by f»r is muriate of soda. 

Muriate uf soda and of potash may be detected 
by the following method: — Separate the sulphuric 
acid by alcohol and nitrate of barytes. Decompow 
the earthy nitrBtcs and mariatca by adding sal- 
phuric acid. Expel the excess of muriatio aai 
nitric acids by heat. Separate the snlphace* tbu 
formed by alcohol and barytes water. The watsTi 
thus purified, can contain nothing but olkBlino 
nitrates mid muriates. If it form a precipitate with 
ocetste of silver, we may conclude, that it coutaiu 
muriate of soda or of potash. To ascertain which, 
evaporate the liquid thus precipitated to dr7n«ift.'— 
Dissolve the acetate in alcohol, and again evaporate 
to dryness. The salt will deliquesce, if it be sretHe 
of potash ; but efRoresce if it be acetate of sods. 

Muriste of barytes may \k drtected by snlphurie 
wad, u it is the only borytio salt hitherto fonad \m 



Mnrinte of lime mny be detected by the following 
method : — Free the water from sulphate of lime 
and other sulphates, by evaporatiog it to a few 
onnces, mixing it with alcohol, and adding lut of 
all nicrate of lurytes, as long as any precipitate ep- 
pears. Filter the water; evaporate to drToeu?^ 
treat the dry mass with alcohol ; evaporate Cfao el- 
oohol to dryness ; and dissolve the residuum 1« 
water. If this solution give a precipitate with oo^ 
tate of silver and oxalic acid, it may contain muriate 
uf lime. It must contata it in that case, if, after 
being treated with carbonate of lime, it give vo 
precipitate with ammonia. If the liquid in the rt- 
ceivcr give a precipitate with nitrate of silver, mu- 
riate of lime existed in the water. 

Muriate of magnesia muy be detected by sepe* 
rating all tlie sulphuric acid by means of nitrate of 
barytes. FUter, evaporate to dryness, and treit 
the dry mass with alcohol. Evaporate the alcohoU* 
Bolutioa to dryness, and dissolve the rcsidDnai ta 
water. Tbo muriate of magnesia, if the water am* 
taiued any, will be found in this solution. Leive 
suppose that, by the tests formerly described, the 
presence of muriatic acid and mogneeia, in llui 
Bolutiun, has beett ascertained. In that caae» \i 
carbonate uf lime afford no precipitate, and if s«U 
phuric acid and evaporation. togi:thcr with the ad- 
dition of a little alcohol, occasion uo precipitatO, 
the magnesia is to be separated by the oxalic add 
and alcohol, and the acid with which it was uniXcd 
is to he distilled off. If the liquid in the reiorv 
give a precipitate with nitrate of silver, tlic water 
contains muriAte of magnesia. 

Muriate of alumina may be discovered by Hta- 
rating the water, if it contain on excess of alkaH, 
with nitric acid, and by separating the sulfihurut 
acid by mcaus of nitrate of barytes. If th'' li >ii»4 
thus purified, give a precipiUile with eaii 
lime, it contains muriate of alumiua. TbL 
of iron or of mnnganese, if any be presvnt, i* «a«i> 
decomposed, and ihv icon prccipitAtod by this salt. 



MAGAZINE OF SCIENCE. . 



149 



MUt« may be diwiilTed ia muriALlc acid, 
imiiia. iroHt and mnDgrine<e, if they be pre- 
be leparstcd by the rules laid down below, 
■accrtata the pretence of the different 
U The iiitratei but seldom occur in waters ; 
en tbey do, they may be delecUd by the ful- 
rcaiilta : — 

.line nitrates may be detected by freeing the 
examiocd from Hilphurio acid by mcana of 
of barytcs, and from tauriatjc acid by acetate 
r. Evaporate the filtered liijuid, and tn'aC 
mau with alcohol ; what the alcohol leaves 
uisC only of the oJkaline nitrates and acetate 
}. Dtuolre it la water. If carbonata uf 
da occasioo a precipitate, lime is present.— 
le the lime by means of carbonate of mag. 
fMter and evaporate to dryness, and treat 
)5d mass with alcohol. The alcohol now 
only the alkaline nitrates, which may be 
racogoiied, and distingmsbcd bj their re- 
B properties. 

■Ic of Umc. To detect this aalli conceotrate 
W« and mix it with alcohol to separate the 
HL Filter, and distil off the alcohol; then 
e the muriatic acid by acetate uf silver.— 
eraporatc to dryness, and dissolve the resi- 
a alcohol. Evaporate to dryness, and dis- 
se dry mass In water. If this last solulion 
t the presence of lime by the usual teats, the 
vmtxtuetl oltnitc of lime. 
rtcct nitrate of magnesia, the water ts to be 
rom sulphates and muriates exactly as de- 
la the last pangmph. The liquid, thus 
l« ia to be evaporated to dryness, and the 
■1 Created with oIcohoL The alcoholic solu' 
to be evaporattrd to dryness, auil the dry 
bftolved in water. To this solutiua potash 
I added, «s long as any precipitoCe appears. 
lution, filtered, and a^oin evaporated tv dry- 
I to be treated with alcohol. If iC Icuve a 
m considtuig uf nitrate (the only residuum 
iK can Icare;, the water contained nitrate of 
HU 

fTobeeontinutdJ 

THE PHILOSOPHER'S STONE. 

lilosopber's stone (formerly called tAe trori, 
of ejccelleoce, or chty^opta, the IrauBmula- 
the bas« and imperfect mctiUs into guld ur 
has, since time imiuemorial, beeu au object 
:h the attention of miiltitadcs of peu[tlc, 
reraed in chemistry or scarcely initiated in 
ence, has been directed, llie vulgar once 
t tliat it was the sole object of chemistry ; — 
vast, indeed, be allowed that it was in some 
e the fault of those who first cultivntcd that 
mtieh of philosophy : there were few of them 
1 aot sufler IhemicUes tu be bliudeil by the 
of attempting to make gold. 
at pre«euc very few people ore Infatuated 
le philosopbcr'a stone ; at any rate none of 
ij[htencd chemists employ themselves with 
ins of making gold ; but formerly there were 
lersoDS who, though tbey have scarcely an 
tha simplest oiH.Tatiuu^ of chemistry, wsj^tcd 
ma in vain attempts to regenerate tiiat pre- 
Bctal. Tbcy are often seen proceeding ot, 
and stiU imagining themselves on the point 
in the midat of poverty consoling 
with the sgreeuble idea, that this iudi- 
vucBcdcd by the posacasiou of im- 




mense treasures. They called themselves adrptt, 
because they pretend to have reached to the summit 
of philosophy, yuati mrntnam tapientiam adcpti ;— 
they spoke enigmatically and in an unintelligible 
manner, because mankind in general do not deserrv 
to possess such a secret. Filled with empty pride, 
they coat a sardonic smile of cootempt on the ra- 
tional chemists, and on those who endeavoured to 
deduce phenomena from clear and established prin- 
ciples. 

We might say tu the searchers after the philoso- 
pher's tttuoe, before attempting to make gold, first 
decompose and re-composo it ; for if there be any 
method of ascertaining and demonstrating the con- 
stituent principles of any substance, it is that of de* 
composiUuu and re- com position. We might say 
aUo to those alchemists, before you make for us 
the precious metAls, such us gold and silTer, make 
for us lead ; fur before you proceed to the most dtf- 
ticult, method re^iuires ttiat you should execute the 
easiest. But we are acquunted with no chemical 
operation whicli resolves either of these problems. 
Gold, as stubborn in regard to decomposition, as to 
compmilioD, always remains the same, in whatever 
manner it bo treated ; it is only more or less at- 
tenuated, but is never in the state uf calx. It Ims 
been kept for several years in fusion, without losing 
the least part pf its weight. 

But let OS near the alchemists, and learn what 
are their proteukioos ia regard to the formation of 
metals. 

According to them, metals are all formed of an 
earth, which they coll mercurial, but more or less 
mature, more or less mixed with lieturogeaeoua 
matters, so that tu convert the imperfect into the 
perfect metals, nothing was necessary but to free 
them from these heterogeneous mattertf and Co 
mature them. 

Ail this is rery fine : but who has proved the ex- 
istence of this mercurial earth ? who has proved 
that the dilTerence among metals consist* lo this 
greater or less maturity i by what means ia it to be 
produced? To these questions no solid answer can 
be giiven. 

According to other alchemists, mercury contains 
Ln principle all the perfect metals ; it has the 
sjilendourof them, and nearly the weight j it is even 
heavier than silver. If it is fluid and exceedingly 
volatile, it is because it is alloyed with impurities 
which degrade it. The question, then, ia to fix the 
mercury, by freeing it from thoHo properties. We 
should then have the mercury of the philosophers, 
which would require only a certain degree of baking 
to be brought to a red heat, and tlie re&ult would 
be gold ; brought to a white beat, it would furnish 
silver ; nay, this matter would have such an activity 
ou the impure parts of other metals, that by throw- 
ing a pinch of it into a crucible filled with melted 
lead, it would transmute it into silver or gold, ac- 
cording oji it had been carried to a white or red heat. 
Uut the great matter is, how to destroy the impuri- 
ties by which quicksilver ia debased, Aristeua, a 
celvbrated adept, tcadics us the process in the 
clearest manner, in his '* Code de Veritc.*' " Take,*' 
says he, "king Gabertin, and the princess Beyo, 
his tiiittrr, a young lady, beautiful, fair, and exceed- 
ingly delicate ; marry thera together, and Gobercin 
will die ulmo:it immediately. Be not, however, 
alarmed ; after eighty days, Gabertin will revive 
from his ashes, and become mure beautiful and 
more perfect than be was before bis death ; wiQ 
beget with Ucya a red child, more beautiful and 



150 



•MAGAZINE OF SCIENCE. 



i|>erfect than thcmMlres/' After this, mil uiy one 
pretend to *aj that the alchetntsti explain tiiem- 
flelves obBcnrrljr ? ^\llBt true adept, for there are 
true and ftlse* aud erery one thlnki himulf among 
the formrrt will uot evidently »ee in tliii allegory 
the whole proceaa of the fixat^n of mercury and of 
the powder of projection ? 

This Un^^e. and tbif aflectatton of obacnre 
■liegoriei, are no doubt very proper for making 
Ithese pretended adepta be cgniidered as finished 
•nd contemptible quacki, or, perhapi, as people 
vhose brains have been deranged by the beat of 
Ihnr fumacea. But the partisans of their researrhei 
iftnd foUiea allege pretended facta ; and It ia our busi- 
nrss to make them known. 

It is reluted that llelrctius, a physician and cele- 
brat4:d professor in UoUand, having declaimed one 
day with great Tiolcnce, in one of his lectures, 
•gainst the vanity and absurdity of pretending to 
nuke gold, was visited by on ;adept, who gave him 
a certain powder, a pinch of which, thrown into a 
crucible, filled with melted lead, would transform 
it ioto gold : that the learned Dutchman did so, 
and obtained from hia lead a considerable quantity 
of that metal. Hclvetias then hastened to find the 
adept ; but the latter had given him a false address, 
and woa not to be found ; for the chemiirta of this 
order never fail to disappear at the noment when 
tbey have given a proof of tbeir profound knowledge. 

The same thing occarred, it ii said, to the em- 
peror Ferdinand. Ao adept came to lum» and of- 
fered to transform mercury into gold. Mercury 
was pat into a crucible in the presence of the prince, 
and the adept having performed certain operations, 
[• button of gold was fonnd in the bottom of the 
veuel. Bat while those present were employed in 
examining aud astnytag the gold, the adept disap- 
peared, to the great regret of the emperor, who 
\«Ircady beheld in idea the immense treasures which 
'lie hoped to obtain by the acquisition of this grand 
aecret. 

At the Raic of the effects left by M. Geoffroy, in 
1777, thrre were three nails, which, as it was said, 
were a proof of the possibility of at least transmut- 
ing silver into a common metal, inch as iron. — 
They were the work, as aasertcd, of a celebrated 
adept, who wished to prove to Gcofrroy the posxl- 
bility uf the tntnsmatatioo of nietals. One of these 
nails was converted into siWcr, by being dipped in 
an appropriate liquor ; the head of the other only 
Fliaving beea dipped, the remainder of it was iron ; 
and the point of the third having been dipped, that 
part was aiWer, and the head iron. 

Notwithstanding these authorities, no one, of or- 
dinary judgement, can hsve a beUef in the philoBO- 
pher's stone. It is very probable, that in all 
these pretended tran a mutations, there was some de- 
oeption, even if the above accounts were true. 

However, tbenlchrmisU pretend that all the fnblee 
of antiquity are nothing else than the process of the 
grand work explained eymboUcally. The conquest 
of the golden fleece, the Trojan war, the events 
which followed it, and the whole mytliology. are only 
emblems of the cbryaopea, pntdently vtrilcd by the 
ancient philosophers, who did not wish that their 
■ecret, become common, should be employed to pro- 
duce on immense increase of the precious metals, 
which mast then have lost their value, and have 
ceased to be the medium of commerce among man- 
kind. The reader may sec, in « curious work by 
Dom Pernetty. entitled '* Lcs Fables Egypticnnes 
etCrecques," 3 voU. 8vo., including the " Dicti- 



onnaire Mjtho-hermetique,** how far baman 
maybe extended, to find an ecplanation of such 
But every thing muy be explained in the sa: 
ner. We have heard of an adept, in the Fi 
Saint Marceau, who, being pursusded that tl 
Koman history was a fiction. Intended Co 
chemical explanation of it, which would 
supplement to the Fables Egypticnnes et G 
We have even heard that the hiiitory of tlia 
of the Horotii and the Coriatii w&a'exp 
with an appearance of truth, capable of 
doubt whether that famous circnmatance 
Roman history ever really took place 





form 

thill 



PRINCIPLES OF CRYSTALLIZATll 

CnrsTALS occur very frequently in the 
kingdom, and have long attracted attention 
count of their great beauty and regularitj. 
the greater number of the salts likewiae 
crystalline form ; and as these substances are moSSf 
aolnbte in water, we have it in our power to gtvd 
the regnlar shape of crystals in some measnn l| 
pleaimre. It hu long been observed by cbeeotili 
and mineralogists, that there is a partscnlar (fan 
which every individual substance always affectawfaril 
it crystallizes : this indeed is considered as one dj 
the best marks for diatinguishing one sobalnGl 
from another. Thus, common salt is observed t| 
assume the shape of a cube, and alum that of tl 
octahedron, consisting of two four-sided pyramidij 
applied base to base. Saltpetre atfects the 
a fiix-fiided prism ; and sulphate of magnesia 
s four*sided prism, whilst carbonate of lime ii 
found in the state of a rhomboid. Not that 
individual substance always uniformly 
the same form ; for this is liable to co 
variations from accidental drcumatances, 
are a certain number of forms pecolior to ei 
stance, nnd the crystal of that anhstnnce, 
case, adopts one or other of these fonoa, 
other; and thus comoioQ salt, when 
has always cither the figure of a cube, or oct 
or some figure reducible to these. 

To explain the caase of regular figures is a i 
task. Newton remarked, tiiat the particles of 
while in a state of solution, are imaged ia 
solvent in regular order, and at regular dist 
the consequence of which most be, that wb< 
force of cohesion becomes snfficicntly strong^ 
parate them from the solvent, they will 
combine in groups, composed of those 
which are nearest to each other. Now all thfti 
tides of the same body must be supposed taj 
the same figure; and the combination of a 
minate number of similar bodies must pt 
similar figures. Hauy hns made it exc 
probable that these integrant particles always 
bine in the same body in the Mme way ; that 
say, that the same faces, or the same edges, 
attach themselves together ; but that theae 
difi^erent crystals. This con scarcely be acconi 
for, without supposing that the particles of boAMl 
are endowed with a certain palarity which mska 
them attract one particle of another body, wl 
they repel the other parts. This polarit] 
explain the regularity of cryatalliiatiou, but] 
itself inexplicable. 

There are, however, Bome circnmstancw 
phenomena of crystallization, which llsny's 
docs not well explain, ond his viewf of the 
forou of crystalliccd bodies ore not tn ever] 



MAGAZINE OF SCIENCE. 



152 




tfootrovertibty established. Thus, a slice ofjtuor 
\mr, obtAined bf making two succesiive and 
kr&Uel Bcctioos, may be dividetl inio acute rhom* 
lids : bat these are Dot cbe phmitiTe forms of the 
Wr, becatur by the removal nf a tctrahe<lron from 
th extremity of the rhomboid, an octahedron is 
)tjuned. As the vbole mass, tlien, of the spor 
«y be divided into tetrahedra and octahedra, it 
■y be doubted which of these forms is to be coo- 
3c*<d u the jiritnittve one, espectaUy as neither of 
aoi can fill a ^trcn space without leaving vacuities, 
jt can they produce any arrangemcot sufficiently 
ftbl« to form the basis of a permanent crystal. 
Dr. WulUstou has given an eipoiition of another 
i«ir of cryitallixxtioo, (Philosoph. TransacL 1613.) 
t« bas proposed, that the primitive particles of 
iScA should be considered as spheres, which, by 
i«tual attraction, have assumed that arrangemeut 
hub brings them aa near as possible to each other. 
■ oumoer of similar balls are pressed togechsr 
Mmc plane, tliey form equilateral triangles 
other ; and if balls so placed were 
together, and afterwards broken asunder, 
gbt Uses in which they would be disposed 
,te, would form angles of CO'' with ea<^ 
bsr. A aioglt bull placed un this stratum would 
nA tbrw of the lower bails, and the planes 
IMlUag tbeir sarfaces would then include a r^olar 
tahedron. A square of four balls, with a single 
lU resting ofi the centre of each surface, would 
krvi an octahedron ; and on applying two other 
paU at opposite sides of tliis octahedron, the group 
bO represent the acute rhomboid. By this view, 
ibicft is highly ingenious, the difficulty of the 
vimitive form of fluor spar, above alluded to, is 
ibrikted. By oblate and oblong spheroids other 
arms may be assumed. 

Richard Phillipa. in treating on cohesive 
n. Bays :— The experiments of Mr. Donieli, 
Hauy, M. Link, and others, prove incon- 
, that all solids are varieties of crystallized 
while it requires a very slight exertion of 
to perceive that crystallized forms arc 
conscqucucss of atoms being packed 
by the action of the atoms of any elastic 
in which they ore immersed. The powers 
V art: varied only by the variable form of 
which are its patients during the process 
on and reduction of bulk. The patient 
therefore, are packed as it were by the in- 
activity of the elastic or fluid medium Id 
process takea place ; and they are dove- 
or bound together by the atoms in other 
ich mingle during the process, thereby 
united cryktahi, which crystals connUtuta 
dl ioUds, whose density, impenetrability, 
CQ of foreign action or motion, are 
•coOfding to the original form of their atoms, 
forms, and tho relative action of other 
acent atoms are, therefore, the sole causes 
hoa« phenomena of cohesion in bocUes. 
principles on which crystallization depends, 
seljr given by Cbaptal, as follows :— 
y docs not crystallizCi unless, by a previous 
the cohesion is broken, and tlie particles 
led fully and freely to exercise their re- 
at&nibcs. 

division may be edected by solution; the 

operated in water for salts ; in caloric 

and in alcohol for resins and certain 

• body Is disaoU ed in ono or the other of 



these fluids, the re-nnian of the particles dissolved 
in ejected by evaporation, or by lowering the tempe- 
rature of the liquid. 

Id those cases in which the soiutioo is performed 
by water or alcohol, evaporate till small crystals 
arc formed at the surface, or on the sides ; thcu 
suspend the operation, and as the liquid cools, a 
great quantity of salt in crystals will be precipitated. 
By evaporating the Liquid which lemaini, after re- 
moving the crystals on the top, you may obtain 
a second quantity of crystals, and extract all the 
liquid from tbe salt by successive operations. Bat 
if the dissolution is efleoted by caloric ainne, as in 
metailic fusions, and those of sulphur and pboft- 
phorus, other precautions arc necnasary to decido 
tbe crystallization. If you suffer a melted metal 
to cool, it will not fail to appear again, in codw- 
quence of the refrigeration, in its primitive form; 
exhibiting at the 6ame time some confused traces, 
or imperfect lineameots of crystallization, such as 
are observed in antimony and zinc. But if at the 
moment when tbe melted metal begins to harden, 
yon pierce the crust, and let out the metallic liquid 
contained within, the vacancy will be lined with 
regular crystals, which almost always present the 
cubic or octahedral form. Ueoca we may infer, 
that the metal in a moss is in reality an aggregation 
of orystals, and that the only method of giving it 
the reqcusite cohesion and ductility, is to beat it 
with the hammer, and to vWrf it. 

From what has been said concerning crysUl- 
lixation effected by evaporation and refrigeration, 
we may conclude, that, after having saturated a 
boiling liquid with any saline substance whatever, 
nothing more is necessary to obtain a deposit of 
crystals than to let it cool. We shall easily com- 
prehend all these phenomena, if we consider that 
there are then two liquids acting upon the salt, 
(water and caloric;) by taking away one of them, 
we cannot fail of having the whole of the salt, 
which it held in solution, for a precipitate. 

When the evaporation of the solvent proceeds 
slowly, the crystallization ts always more regular { 
the particles then unite and arrange themselves by 
virtue of their affinities ; but, on the contrary, 
when the evaporation is rapid, tho particles are 
precipitated ou each other, and there is nothing 
but confusion in their assemblage. 

The slowness of the evaporation not only deter- 
mines tho regularity of the forma, but likewise con- 
tributes to give volumn to the crystals. This wc 
observe daily in the saline solutions which we leave 
in a corner of our laboratories : it is dumoostrated 
too by all the operations of nstare, which forms in 
time, and by insenaiblo evaporation, saline and 
stony crystals, which it is impossible for us to 
imitate, because it is not in our power to cause ages 
to enter as elements into our operations. 

Rest is cqaalty necessary for the liquid, in order 
to obtain forms of great regularity ; uninterrupted 
agitation prevents all symmetrical arrangement ; it 
precipitates the orystals as fast as they are formed, 
and you obtain nothing, if £ may ao express myself, 
but the integral partidea of crystals. 

In tho arts we avail ourselves of the disturbance 
produced by agitation in liquids to procure crystals 
of extreme fineness. It \i by this method thuwe 
precipitate, in very small and delicate needles, the 
crystala of sulphate of soda, those of nitrate of 
potass, &o. 

It freqoeutly happens, thst a solution, though 
I complete, refuses to cry9t4llij[e ; in this case a 



152 



MAGAZINE OF SCIENCE. 



slight a^ution of the vessel somettmn decides tbe j 
crysUlliz'itioQ. Fahrenheit obflcrred, that, io tbii i 
circumfttonce, heat etcaped at the momeat of < 
agitation, which leenis to prove that the caloric 
was interposed betwwn the particles, and that 
notluDg but the alighce&t motioo waa wanting to 
disengage it. 

A crystal formed in water alwaja retains a more 
or leaa considerable portion of the liquid, and this 
is called the wafpr of cri/Atalh:afion. 

Tbe only cause of solution is, that the affinity of 
tbe liijuid overcoroea the cohesion which connects 
the particfes of the salt; but in jiroportion as the 
mass of the liquid diminishes by evaporation, its 
affinity of msis decreases, and tbat of the particles 
of the body dinolved increases, since they br^in to 
cotnbine with each^othrr. There mast. consc<|Upntly, 
be a moment at which the affinity of the salt over- 
pow^n thai of the liquid; and from this moment 
the salt which forma itself into crystals mast retain 
• portion of it. This water of crystal liution enters 
u a principle into the combination, dnce that 
liquid cannot be discovered either by the eye, or by 
Che touch, or by faygrometriral testa. 

This water of cry «talliia lion contributes to give 
to the crystal its form, tmnyiisrency, and cohesion. 
When it is disengaged by beat, these three characters 
almost always disappear. If, for example, you 
expose to heat a traniparent crystal of sulphate of 
Umc, you will instantly perceive the water to be* 
come volatilized and dissipated in vapour ; the 
crystal will lose its transparency, and be rendered 
friable and pulverulent. 

Simple lubstances, such as metaJa, certain earths, 
nlphar, phospborua. resins, and, in genera], nil 
inch bodies as are simple, and not soluble In water, 
crystuUize without retaining n seniiibic qusnttty of 
their solvent. Bat compound substances require 
to be dissolved in a liquid, that they may there 
acquire the portion necessary for tbe formation of 
their crystals. 



MEDICAL RECEIPTS. &c. 

JXsoh'f AniibilioHa Pith. — A nostrum com- 
posed of equal parts of aloes, scammony, rhubarb, 
and a little potaseio-tartratc of antimony made op 
with Castile soap, and of course, a powerful ca- 
thartic, and dcobstruent. 

l^rfyjropi.— a' nostrum obtained by distilling 
oil of nrpentiae in a glass retort till a red balsam 
reaoaina, which has also been called Balsam of I'nr- 
peDdDB. Or by distilling resin till a thick red oil 
comes over. Or by dlasolving 4 drams of flower of 
auljiliur in B ounces of oil of turpentine. 

Edinburtih Ointmfnt, for iU:b, and tetter, is pre- 
pared with laid, white hellebore, and h^drochlorale 
of unmoaia. 

Fincham't Purifying and DitinfecHnff Liquid. — 
A lotutton of chlunde of lime, requiring to be di- 
faited for use with -10 parts of water. 

Fiath. — A preparation sold by brewers* druggists, 
to color brandy and rum, and to give them Acti- 
tiow slnDgth. It is prepared by making an ex- 
tract of csyeune pepper or capsicam, and adding to 
it bornt sugar. 

Ford's BaUam of Horehtjvnd it a cough nostrnm, 
of which opium is the basis, being composed of 
•qua] parts of horehound and liqaonce root, infused 



in water, strained, and a double portion of aplril 
added to nine pints, to which liquor add 7 draiM df 
pure epiora, I oance of dried squills, C drams 
benzoin, 9 drams of camphor, 8 drams of anise* 
■eed, 1 f pound of honey ; digest and atrain. 

Pbiherffilt't Pilh. — A purgative noitrum, 
with equal proportions of aloes, acammooy, 
cynth, oiide of antimony, and aromatic 

Friar't BaUam, Compmmd Tincture of BensoSn, 
JfsuiV* DrApt, U'ade'M Drapa. — Take 2^ ounoM 
of benzoin. 1} ounce of storax strained, 10 drami 
uf balsam of Tolu, 5 drams of alol^, and 2 pints of 
rectified spirit; digest fourteen days, and filter.— 
It was long celebrated ai b styi^tic for the speedy 
cure of fresh wounds, cots, &c. ; hut nothing conU 
be more Improper, as it is stimulant and irritatlug. 

French R^, or Rouge, for the toilette. Tafcj 
1 ounce of genuine carmine, light in weight ai 
strong in color, mix it with very tinely-sifted 
powder, according to the shade irqnirod, and 
per the color by tbe eye, which will be 
laying the powder on aheeta of black paper. 

German Paste, for cage birds, is prepared by 
beating together 2 poont^ of poaie floor, 1 ptiaa) 
of blanched sweet almonds, 3 oances of freu I 
ter, and adding the yolks of two fmh tggt, an 
little honey and saffron ; then heat the mass gpsl!^^ 
and pass it through a sieve, to form it into frtim. 
If properly made it will keep good for half a ffsu. 

GilberVt AntUcfurbutic Dropr. — A di^wd 
preparation of bichloride of mercury. 

Godhold's Vegetable Baltam.—K noatrum eon* 
pMed of oxymel. with some coloring matter ■ 
perfume tn disguise it. Ttie specification of Go 
hold's patent, however, directs aeparate syrapl 
be made of 12 difierent herbs, many iif them ; 
ous, and then to be mixed with four different 
vini^r, oil of cinnamon. &c., and kept three^ 
before It is administered HI By a late trial it 
pears that the proprietor's profits have fallen frooi 
3,000/. to 50/. per annum. 

Oodfretf^t Cordial, — A popular nostrum, tka] 
basis of which is opium. Infuse 9 ounces of « 
fras, 1 ounce each of cartway, coriander, and ai 
seeds, in 6 pints of water, simmer till redneed Iftl 
4 pints, add 6 pounds of treacle, or coarse fU|Wt 
and boil for a few minutes. When cold, add 3 oi 
of tincture of opium or laudanum. 

Godfrey** Smelling Salta. — A nostnim pi 
by re-subliming sesqai-earbonate o( ammonia, with' 
carbonate of potass and alcolwl to moiacen it, m^xich 
forms carbonate of ammonia, of a very pt 
odour. 

Gregory^* Pounder. — Made with eqnal 
ginger, rhubarb, and calcined mogneda. K ll 
good stomachic in doses of 1 scruple or more* 

Grrn^ie't Cough ]>rnpn are a tincture of 
prepared with rectified spirit. A very onsafW 069- 
trnm. 

Gum Paste for Com^/s.— Soak an oance of gum 
tragacanth in half a pint of water, stirring it fr»- 
quently, till quite dissolved, which it will be io 3< 
hours, squcexe it through a coiu>e cloth by twist- 
ing, pat it into a mortar, and add four onncvi of 
Ireble-refined sugar, work it well till quite whitCi 
put it in a glazed earthen pan, with a wet doth ovtf 
it; when wanted, take some of this paste, workf 
and knead in it fine sifted sugar, till it Oecom 
without slicking to the fingers. When scented 
or colored, the aromatic materials arc worked in. 



ciJi^;rr"°*!^ w' iP" *""**•«"■ 5- ^^'l*"* H«i»t Lai*. Mil. E<id— Kubltalud by W. fiairriui. li. rsUrauvtot 
VtMWBuotMUdoi, (which are auwtred MouUily.j to be addrcucd to Uic Editor, at H. Cullaje Grow, Ulli- !;i« 



imI H<»n!. 



THE 



AGAZINE OF SCIENCE, 



^nd ^cdool of ^rt?. 



4.] 



SATUSOAT. AUGUST I< IB4I. 



[Urf. 




MAGAZINE OP SCIENCE. 



■ 



' EGYPTIAN AUCHITECTURE. 

Ik h work uf tlie nature of a geot^ral iniigaxtne it is 
im possible to treat effectively of so esteutfive s nib. 
j^ c( u vrcbitectuTc, without eiigrosniiti; too mach 
*(itcc, and diaiippointing those of our friends who 
look for far diffwcnt matter. We have, therefore. 
Ion); hesitated whi^ther to introdura the subject, 
and are still in doubt, if right, to iiursue the subject 
tfaroafb the Greek orders. Whether we do so or 
not, the noble and gignntic muses of masonry. 
niicd by the ancient Copts or Egyptians, during 
the time of the Pharoahs, with all their rode yet 
■pleodid ornaments, cannot but be intcrcsCin^, 
MpeciaUy upon reflection, that with, perhaps, the 
exoeption o( the cavern temples of India, of the 
times of which we have no account, the structures 
of Nitbia, of Thebea and Mem]ihiB, are the most 
•ncifnt records of human strength, skill, and taste, 
and those to which even the refined Greeks them- 
selves owed their fir»t ideas of architectural gran- 
deur and imposing outline. 

Well may the traveller of our day be astonished 
at the mogniAcence of the vast structures of an- 
cient Egypt ; its huge pyramids and proud tombs, 
which have long outlived the memory Cif the mif^hty 
kings whose oshea they contain; granite temples, 
OS extensive as towus, which inclose in their courts, 
or support upon their roofs, villages of the present 
Inhabitants: obeUslu covered with hieroglyphics; 
colossal statues; long avenues of sphinxes, &c. ; yet 
the art of huildhig aoujng them conaistcd of but few 
prlndiples ; far they did nut »eem to understanil thu 
use of the arch, all the apertures of thetr walls wrre 
covered with a single block of solid stone. Their 
domes or vaulte-d chambers (as in the great pyra- 
mid) were formed of stones, in horizontal courKe», 
projecting equally over each other, like inverted 
flights of steps. The roofs of some of their temples 
ore iodoed arch-shaped, but these ore only excava- 
tions out of the Bohd rock. Their walls were built 
of stones of enormous size, without cement. The 
removal and placing; of these huge materials would.. 
even at thifl day, almost bid dettaiice to the boldest 
and bi'st constituted of our mechanical inventions, 
thoi^h conducted with all the science of modem 
times. The stones of their edifices are for the roost 
part jointed and squared with the greatest accuracy ; 
the hieroglyphic carvings with which iheir walls 
and ceilings are charged, are all recessed, but pro- 
jecting in xplief from the bottoms or backs of the 
recesses. The forms of £gyi>tian temples and gates 
are generally truncated pyramids, crowned with a 
cove or large hollow moulding, and 611et above. — 
Bat tbe cut, illustrative of the present subject, will 
gire. perhaps, a better idea to the general reader of 
the details of Hgyptisti architecture than any verbal 
description. In the foregmiind of the right of the 
cat is a superb column, taken from the ruins of 
Dendera. or TVn/yrti. It will be seen how much 
labor has bei-'n expended upon a single column, yet 
the interior uf a temple might be called a forest of 
colnmnsi so numerous were they. The abacas (the 
capping stone nt the top) is very ]>ecuUar, bang 
nearly a cube in shupe; it is elaborately carved with 
filtolft and Rcrolls, and crowned with the winged 
globe, the emblem of eternity. The capital is four 
sided, each side braring the f4ce of Isis, the presld* 
ing deity uf tbe temple. Tbe shaft of tbe column 
is also richly curvett in compartments of hierogly- 
phics, of reeded work, and towards the busr. of the 
favorite lotus oroaineut, the emblem of beauty, and 



of the Nile, — in truth a national flower, as the 
is of England, snd the Uly of France. The 
purple, fragrant water lily called the lotus, may wail 
be the pride of the Egyptians, and if their repre- 
sentations of it have not an English artiat's tasted 
they at least show that these ])eopIt- could appredaU. 
if not express the beauty of their votive flower. The 
following is a more accurate detail of the lotoa m 
an architectural ornament: — 




It mast not be thought that all tbe columns of 
their buildings are formed upon one model. Ukr 
those of one of the Grecisn orders. In truUi lltfy 
vary both in proportion and ornaments The sltaft 
is often plain, more frequently retrded, or with round 
projecting ribs along it, and occaeionally fluted. Tbft 
abacus is often thin and iiiconsplcuuus, fometimeaa 
flat sculptured block. The capital is even yet mor« 
varied — a fine bell shape is extremely common, 
covered either with leaves or with hitToglyphics. 
The following examples, from tbe temple o( Coniatii 
may illustrate this ubservatluo. 




Immediately umler the column in the forej^rooMl 
ia A lion sphinx, for the sphinxes of Egypt mm 
various in character, sometiraes reprraeoting the 
lion simply, occasionally uniting the brute and The 
human forms -, and at other times being compoouded 
of different animals, or monitrous altoi^ther. Thry 
were placed in parallel rows, forming avrnnes «f 
great length, and constitating. together with tbt 
coloasi and the obelisks, tbe chief ritrrnal apprn* 
dsges of the Egyptian temple. In the left hand of 
the cut you see one of these obelisks. It is the 
representation of one uf the celebrated ones at Luxor, 
covered with hieroglyphics, and which was brought 
to, and is now erected in the French capital. At* 
thongh the baseless obelisk be not in its effect a 
striking object, when viewed in conjunction witii a 
large mass of buildings, it has paramount clumsi 
when regarded as a nnytp t/one, and con^derrd with 
reference to tbe labor and great meclianical skill. 
which must have been employed in detaching il 
from ila native quarry, in transferring it to its 
destined basement, and in raising it to its vertical 
position. 

At the back of the obelisk is a building com- 
posed of twin masses, riving on each side of t hr central 
door, which may be received as the ectabli^hed 
model of the gate that formed tlic entrance to any 
Egyptian buildings of considerable extent ; sad 



MAGAZINE OF SCIENCE. 



155 



whvrh from iu npenor loftmeo was by far the most 
' iK-iit md impoclng feature of tltc temple's 
r. The mott rnriom circumKUncc rt^pecling 
«t n liie dttplicate cbarnctcr, ghown in the Cwtn 
nolai or towers, (to which we hive already alluded,) 
file eotrancti being between th^m, lo ns to leave 
tbfUr individual solidity nnJiDpaircd. Thif ^te is 
not nierely to be considered u such, but it u also 
tiM nauai form ia which the front of the tcmplo 
SImI/ vat constructed. Two immeDBe piles of 
loUdtng tkperin^ upwards, with a gate between 
tlHon ; the salient angles or orriaea fioisbed with a 
large round torus or bead ; the suuinitt crowned 
with a drep hollow entablature or cornice, finiahed 
with a Bllct at top, and carved with longitudinal 
dMUinelfl, often arranged, aa in oar figure, like the 
Grecian Irigylph, constituted the characteristic form 
oT outline and proportion ; while the whole was 
oftentimes completely cohered with hieroglyphics, 

«n :' •! -Tinted with v&rions colors, so virid and 

i" that they remain fresh even in oar day, 

ari 1 - f^t ages of their construction and finish 

Boat tuTc been monDmrata equally of taste and 
labor; sod showing, in their contour and mojeaty, 
ttne of the greatest charms and requisites of archU 
Ucture, nmplicity. 

ORIGIN OF SPRINGS AND FOUNTAINS. 
It wuuld appear that the origin of fountains and 
•ftrinps craght not to have occaiioaed such a diver- 
aaty at opinions, as baa, for tome lime, prevslled 
BfDoag philosophera. An attentive consiileration 
of tbeae phenomena is sufficient to show that the 
ori^n of them '\& entirely owing to the raina wliicb 
cootioually moisten the surface of the globe, and 
whicJ], running over beds of earth, capable of pre- 
vrnting them from penetrating deeper, at length 
furre a passage to places which are lower. Every 
person, Indeed, must have observed, tliat the greater 
part of springs decrease io a considerable degree, 
whra a louff drought has prevailed ; that some of 
tiwtn ab»olnt<.')y dry up when this drought contiimt-i 
teo long ; that when the surface of tjic esrth has 
boen moistened with snow or rain, they are re- 
newed ; and that they increase almost in the same 
ynrgry^Ton as the waters become more abundant. 

"«0| hers, howerer, have ascribed the 
L' irtuns to a sublimation of the waters of 

tbr v^, Aiijcii, flowing into the bowels of the earth* 
lisc Dp in vapor, in ttie fissures of the rocks, and 
tlii>n.f tn, Ll^ down into cavities and reservoirs pre. 
are, from which they make their way 
Some have evtru gone so far as to 
i> H sort of subterranean alembics. 

nnjectures are entirely void of founda- 
water of the sea produced fountains 
r, it would lung ago have cboaked up, 
>™.i, the subterruoean conduiu through 
: is supposed to pass. Besides, the connt^r* 
-;ioh ia observed between the abundance of 
.J thst of the water of the greater part of 
.III, would not subsist ; as the internal dis. 
tiiUUon would take place whether it rained or not. 
It t* io be observed, alao, tliaC the water of springs 
aiwaya distils from above beds of clay, and not from 
Mmt them ; hut as these beds intercept the pas- 
aveof raponand water, the latter must necessarily 
come from above them. A sure method of destroy- 
tig a spring, is to pierce this bed ; but if the water 
eune fron below, ■ contrary effect would be pro- 
duced. 



\^*hat induced philosophers to have recoVt'^e to « 
cause BO remote, and so false, no doubt was their 
ima{;tning that rain water wa« not tutficirnC lo feed 
all the springs and rivers. But they were ccrl&^uly 
in an error ; for instead of rain water being .too 
amnll in quantity to answer that purpose, it sfet&.t 
mthcr difficult to conceive in what maancr it ia ei-» 
pended. This will be proved by the foUowaig cal- 
culation of Mariotte. 

This author observes that, according to eiperi- 
meittf which bavn been made, there falls annually 
on the fiurface of the earth about 19 inches of water. 
But to render his calculation stilt more convincing, 
he supposes only 15, which makes per square totae 
45 cubic feeti nod per square league of 2300 toisea 
in ench direction, 23BO&0000 cubic feet. 

But the rivers and springs which feed the Seine, 
before It arrives at the Pont-Royal at Paris, com- 
prehend an estcnt of territory, about fiO leagues in 
length, and 50 in breadth, which makes .1000 Icagnfs 
of superficial content ; by which, if 23yor)0000 be 
multiplied, we shall have far product 7H150f)OOOOn, 
for the cubic feet of water, which falls, at the lowest 
estimntion, on the above extent of territory. 

Let OS now esamine the quantity of water anna> 
ally furnished by the Seine. This river, above the 
Pont-Hoyul, when at itd mean height, is 400 feet in 
breadth, and ;) in depth. The velocity of the water, 
when the river is in this state, may be ealimaCed at 
100 feet per minute, taking a mean between the 
velocity at the surface and that at the bottom. If 
the product of 400 feet in breadth, by 5 in depth, 
or 2000 squnre feet, be multiplied by 100 feet, we 
shall have 200000 cubic feet, for tlie qtiantity of 
water which passes in a minute through thnt section 
of the Seine, above tho Pont-Royal. The quantity 
then in nn hour will be 120(10000 ; in 24 hours, 
288000000; aud in a year, 10.1120000000 cubic 
feel. But this is not the seventh part of the water 
which, as above eeen, falls on the extent of country 
that supplies the Seine. 

But how shall we dispose of the remainder of this 
water ? The answer is easy : the rivers, rivulets, 
and ponds, lose a considerable quantity of water by 
evaporation ; and a prodigious quantity is employed 
for the nutrition of plants. 

Moriutte mokes a calculation also of the water 
which ought lo be furnished naturally by a spring 
that issues a little below the summit of Montraartre, 
and which is fed by an extent of ground 300 toisea 
in length, and 100 in breadth; making a surface of 
30000 square toisea. At the rate of 18 inches for 
the annual quantity of rain, the quantity which falls 
on tliAt extent will amount to 1620000 cubic feec 
But a considerable part of this water, perhaps three- 
fourths, immcdiatrly runs off: so that no more than 
40^000 forces its way through the earth and eaody 
soil, till it meets with a bed of clay at the depth of 
two or three feet, from which it flows to the month 
of the fnunluin, and feeds it. If 405000 therefara 
be divided by 3G.'>, the quotient will be 1 1 00 cubic feet 
of water, which it ought to furnish daily, or about 
3Hr>UU French pinU ; which makes about 1600 
pints per hour, or 27 pints per minute. Such is 
nearly the produce of this spring. 

An objection, founded on ho ftperiraent of 
M. de la Hire, described in the mtmoirs of the 
" Academy of Sciences,*^ for the year 17011, is, com- 
monly made In thia idea respecting the origin of 
springs. This philosopher having canaed a pit to 
be dug in a field, to the depth of 2 ftret, found no 
traces of moisture ; from which some conclude that 



MAGAZINE OF SCIENCE. 



the nln witer flowi only over tbe lurfttce, tad doc* 
not, in any manner, contribute to the origin of 
BpringB. 

Bat this experiment 1b of no weight, aa it ii con- 
tradicted by a thousand contrary instance*. EvBry 
one VnowB that water, in Yorious pUcea, ooxea from 
the roofa of caverns and subterranean passages : it 
is this water which, after penetrating the earth, and 
flowing between the joints of stones, produces stn- 
loctites, and other stony cnncrctions. It is, there- 
fore, fiilae that rain water never penctrntes beyond 
the depth of a few feet. The fact, ohserred by M. 
de la Hire, was a particular case, from which it was 
wrong to deduce a general consequence. 

Il ia objected also, that water is sometime* col- 
le^rted at heights at which it is impossible that the 
rain water could give birth to a spring. To tliis it 
may be replied, that if the ground, where theae 
coUecliona of water exist, be eiamined, it will 
always be fonnd that they are produced by rain or 
melted snow ; that these places on the sunimiu of 
mountains are only a kind of funnels, which collect 
the waters of aome neighbouring plain, continually 
maintained by the rain or snow, oifiisted by the 
Itnall eraporation which talcee place, in consequence 
of the rarity of the air. It is, therefore, evident to 
every rational mind, that the origin of springs and 
fjnntains can be ascribed to no other cause, than 
t*u nin water and snow which have been collected. 

BOTANICAL NOTICES. 
nirnoDUCTiTK organs of pLA>rra. 
Tii« reproductive organi of pbiraogamous, or 
flowering pluU, are the flowers and the fmit. 
beoanae theae parU are of necessity in the prepa- 
ration, the maturing, and defending the seed. 

Both tbe flower and the fruit consist of serveral 
parts : for example, in the common primroee tiierc 
is outside of all a green cup, which incloses the 
rest of the flower— this is ihe calyr. Within tlio 
calyx is a colored leafy part, called the cortiUa. 
These two partfl together ore the Jloral enrelopeM. 
Still more inwards are a number of colored threads, 
with a knob at the cod of each— these are Mtametta, 
Innermost of all is a green swellcd-out body, called 
B jfointal or putU, which is either the young seed 
vessel or leads to it ; and the part of the stalk upon 
which the whole of these organs are placed is tbe 
receptecle. The manner in which flowers grow 
together or upon the stalk which bears them, is 
called their infioretemee, and the folding up of the 
diflercut parts of the flower before oi)ening ia called 
their ipxiivation. 

Tbe following cut will enable tlie student clearly 
to understand the namre.iwsition.and usual character 
of the reproductive organs, as eiempUfied in tbe 
cowshp : — 



A. Show* the Influcvaccoce Of mode of (loweriin. B. Tim 
nUvatlov or foldlof op of Uwcalyx C. 1 he caIvi nrour^ 
I>. ThP nstivation of lli» corolla. E. Tli*' i-inoll* i»BKr»w. 
F ThfcornlUopeii«ltoihowtlwllve«tajDnrf «i. AMaa^ 
mnpufuKt. with sooM gnUu of poMca »»> tb« ittW w( IL 
IL Tbe pbuL I. Tbe tUflma or top of tb« ityltt, niagnlftM 
J. Tha atad vwstl cot opan lenjAiriit. K- A w«d col oiW> 
to ibow tba aiabryo lyiof acroai IL 

The re-prodoctJTe OT:gana vary in shape, relntife 
itse, and method of attachment to each other, oo 
leas tlian do the roots, leaves, 0tc. Sometime! ooa 
or other of them is deficient — in different easea mors 
than one : thua a flower may want calys or corolbl, 
or both, when it would be called incomplete^ or ft 
may have all theae organs, and be complete. Ocoa- 
sionally one part is redundant, or of onnatunl 
form or riae, in which case the flowera become 
monitrowt. Tbua cultivation, injury, exccM of 
food, and many other causes, make such grast 
alteraliona in the structure, and stiU more often 
in the habit or appearance of a plant, that It b 
sometimes scarcely possible to recognise the altered 
form. However greatly variations of this kind may 
contribute to the beauty of the flower, or the utility 
of the fruit, yet by the botanist such changlinga 
must he disregarded as unnaturaL The hen and 
chicken daisy, the hosc-tn-hose polyanthui, a.nd all 
doable flowers, are in this condition. Even " tbe 
queen of our gardens,** the elegant rose Itself, is to 
be considered but as a vegetable monster, uo- 
courteous as the term may seem, becanae cnltaxt 
has increased its moss, multiplied Its petals, bedglil- 
ened its colors, and it therefore no longer bears in 
OUT gardens those simple 6owcrs with which natuic 
investefl it. 

Calyx. — The outer part of every complete flower 
bears the name of calyx, whatever may be its fllie, 
form, or color, The general use of this organ it 
to defend the more delicate parts of the flower from 
injury, when in their young and unfolded state. 

A calyx consists, in its usual state, of a leai^ 
green cup, more or less cut and divided. Hit 
different partfl or Icavea of which it connats v* 
colled sepals, and it often takes its name firom &■ 
number of these aepals. Thus, in tbe primroae It 
is jHonosepalotui, (1,) — that is, oue-leaved. In tbt 
poppy, disepalouM, (2,) — or conMsting of two 
leaves. It may also consist of three sepaU, (3.) u 
in the pUewort. Pour sepals, as in the cabbw(e, 
((.) It is 5, 6, 8, to, sepalrd in ntbcr plants, 
when its name would be appropriate to thcM 
numbers. 





1 s » 

It ia tuboUr, lipped, puffed out, ribbed, api 
notched, or entire. If it fall off when the ' 
opens, it is fugacioug—'-d it drop with the rest 
the flower, it is eaducotie—M it remain until the 
fruit is ripe, it is pertitteut. When situated abort 
the fruit, ss in the rose, it is coiled eupehor, (I,) 
when under tbe fruit, as ha the mallow, U 
ir^erior, (2.) 





MAGAZINE OF SCIENCE. 



157 



OQgk penutent csljrcca remain afu^ tbc time 
-erin^a it U gcDcrelly in a dry and withered 
»artkalarlj in those which ore suptrior ; and 
iaieniir, although they retain their green 
nd liTiBg texture longcri yet it ia not often 
ej coQtinae growing ahcr that period. In 
tlanta, however, it is diiTerent, for the calyx 
r« during all the time of the fruit rii>eniag — 
iitration of which tbc curioiuly-eolBrged 
i of tlie nictmdra phyaafodrt, and tlie bng- 
cutjx of the winter cherry may be referred 
reciaUy as they add «o greatly to the beauty 
fruit of theae and limilar plants. The calyx 
beobane Is another of a most beantiful and 
r form. It is also to be observed, that the 

• ofbm colored, as in the fuschla it is of a 
letDtiAil scarlet. When a flower has but one 
pe to its stameni, we must consider that a 

whaterer may be its color or form. The 
lily, the gsndy tulip, and the golden crocos, 
icir beaatj to thrir colored calyces ; nnless 

• as some botauists have doDCi we consider 
M fieriantAif, that is, a covering, which par* 
if Che position of a calyx and the character 

otlA. — The corolla is that part of the flower 
is next within the calyx, and between that 
le ttamena. It is generally the most brightly- 
d of the floral envelopes ; thus, the red leares 
i rote, the yellow of the buttercup, and the 
tt tbe bell flower, constitute the rarious 
K of those plants. A corolla may consist of 
oe leaf or petai, as it is more properly called, 
the form ^ this gives it an appropriate name ; 
nay be of •erenl petals, when their arrange- 
■nd thicVnem serve as marks of distinction. 
the Tsrions petals or divisions of a corolla 
lite, jt is said to be rtffutat — if noti irretptl^r. 
wumopetaiotu or onc-petaUed coroUc, the 

rU called the tu6e — the upper expanded 
Kmh, and where these join one another, 
Oii^JI or ikroai. They are either campanuhte 
^t-tAaptd, (1.) as in the bl uc -be 11— yunneV- 
it (2.) as in the bell-bind — tmrnpet-ahaptd, 
i in the tobacco flower — rotate or wheel-ahaped^ 
Ilis is flat and without a tube, as in the speed- 
•mhfT'tkcpHi, (5,) or flat, with a tube, as in 
rimrose — tipped or deeply divided into two 

at the limb : this variety may be either 
U or gaping, (6a,) where the two lips stand 
r opeUp u in the white nettle — or pcrtonate, 
when they close op like a mouth, aa in the 
dragon. The corolla is tirap-thaped, (7,) 

daodeliunf tad tultuiar, (8,) in the thistle. 




potjfptlalouM or man) -petallcd coroUx. 
Aimed— 




Cruei/orm, (I,) which have four petals arranged 
in the furm of a croas, aa in all the pUiuts of llie 
fifteenth class, lucb as the wall-flower, stock, 
cabbage, 8cc, Hen the outer part of the petal is 
called the margin, and that part covered by the 
calyx la the elaw — (a, a petal scpuratcd.) 

Papiiicmaceoiu, (2,) when five petals are arranged 
so as to look something like a butterfly, fm Latin, 
papilio,) as in the sweet pea flower. The upper 
petal, which covers over the rest, is called tbc 
veritlum or aiandard, (a,) — the two side petals arc 
alte or wiogs, (&,) — and the two lower and inner 
ones, when joined iagelher, form what goes by the 
name of the carina or keel, (e.) 

A corolla is rosoreAia, (3,) when the petals are 
thin, like those of the rose — and liliaceouit, (4,) 
when tbc petals ore thick, like those of the lily. 




1 X S 4 

The use of the eorolls, spparently, is to defend 
the inner parts of the flower from some injuriea 
they might sustain from wind or damp, and so to 
coUeot and oonoentrmte the sun's light and heat 
upon those parts as to ripen them, and old in the 
more rapid exercise of their functions. 

Necfary. — There Is often found sttaehed to the 
corolla, or situated near it, Tariously shaped and 
colored parts, not contributing to the regular 
formstion of a flower, nor yet apporently necessary 
to its structure. These are the nectaries, parts ao 
called becaose of the honey which some of them 
secteCe— the use of which sweet fluid seems to be, 
that the insects being attracted to the flower, and 
fluttering aboot within it, may aid in distribatiag 
the pollen from tbe stamens to the stigma — a pro* 
cess which is necessary to the well-being of the 
future seed. 

Every flower does not contain a nectary, not eva 
all those which secrete honey, as, for example, tbe 
coroUa tube of the white nettle is sweet, but has no 
particular organ to collect the honey within it. So 
also, many parts are for convenience considered 
nectaries, which fasve no such use. In fsct, every 
part of a flower, which is neither calyx, corolla, 
stamen, nor pointol. Is classed under this general 
term. Tbe nectary, therefore, has the same mesU' 
ing when applied to flowers, as the word fulcrum 
has to the preservstiTe organs. 

fTo he rtmlnwutl.^ 

LIGHT. 

r St'iumed /rvm pcge 143, and cimelutU\i.) 

Corputcuiar Theory qf Light. — Sir John Her- 
schel, in his sdmirable Esiay on Lirjhi in tbe Ency- 
eiopirdia Metropoiitaiui, states the principles of the 
Newtuoisn or corpuscular theory as follows : — 

1, " That ligbt consists of particles of mottcr 
poiiessed of inertia, and endowed with attractive and 
repulsive forces, and projected or emitted from all 
luminous bodies with nearly the same velocity, — 
about 200.000 miles per Moond. 

2. *' That these particles differ from each other 
by the intensity of the attractive and repulsive forces 
which reside in them ; and in thetr relatiooa to the 
material world ; and also in their actual nukiscs, or 
innrtia. 



158 



MAGAZINE OF SCIENCE. 



3. " That Clicse puticlea, impinging on the 
retina, stimulate and exdic vision ; the particles 
whofo inertia ts greatest prodticiitg the sttuBnttoD of 
red, those of the least inertia of riolet, and those in 
which it is intermediate the intermediate colors. 

4. " That the molecules of material bodies and 
those of Light ciert a mataal action on cacl) other, 
which consists in attraction and repalHion, accord- 
ing to some law or function of the distance between 
them ; that this law is auch as to admit, perhaps, of 
several altematioos of cKsoges from repuJaive to at- 
tractive force ; but tbnt when the distance is below 
a certain very small limit it is always attractive ap 
to actual contact, and that bejond this limit residoi 
at least one sphere of repulsion. This repulsive 
force is that which caust's the reflection of light at 
the external surfaces of deaie media ; and the iiite- 
rior attraction tliat wbicli produces tlie refraction 
and interlur reflection of light. 

&. " That these forces have different absolute 
ralnes or intensities, not only for all different ma- 
terial bodies, but for every different species of the 
lominous molecules, being of a nature anolagous to 
chemical sffiuitieA or eJa:tric altroctious ; and that 
hence arises the different refrangibilities of the 
rays of light. 

6. *' That tlie motion of a particle of light, nnder 
the inflnenoe of these forces and its own velocity, 
u related by the same mechanical laws which 
govern the motioiu of ordinary matter ; and that 
therefore each particle describes a trajectory, caps, 
ble of strict calculaliun as soon as the forces which 
act on it are assigned. 

7. "That Che distance between the molecules of 
material bodies is exceediiu(ly imall, in comparison 
nrith the extent of thrtr spheres of attraction and 
repulsion on the particles of light. 

8- " That the forces which produce the reflection 
ud refraction of Light are, nevertheless, absolutely 
insensible at all measureable or appreciable distances 
from the molecules which exert them. 

9. *' Thst every luminous molecule, during the 
whole of its progress through spa?e, is continually 
passing through certain periodically recurring states, 
called by Nrwcon fits of easy reflection and easy 
transmission, in virtnc of which they are more dis- 
posed, when in the former states or phas2B of their 
periods, to obey the inflnence of the repulsive or 
reflective forces of the molecules of the repulsive 
or reflective forces of the molecules of a medium ; 
and when in the latter, of the attractive." 

Soch are the postulates on which the corpuscular 
theory of light depends. Most of them may be ad- 
mitted withont difficulty ; and they afford data for 
the application of malhematical reasoning to the phe- 
nomcna, which may be investigated by the same 
tort of nnalyfiis with which mathematicians are 
already familtar in the theories of heat, capillary at- 
traction, and molecular forces. 

Undulatory Theory. — The principles of the un- 
dulatonr theory ore thus stated by Sir J. Herschel: — 

1. "That on excessively rare, subtle, and elastic 
medium, or e'/Aer, fills all space, snd pervades all 
material bodies, occupying tlie intervals between 
their molecules ; and either by pa»<nng freely among 
them, or by Its extreme rarity, offering no retustance 
to the motion of the earth, the planets, or comets, 
in their orbits, appreciable by the most delicate 
astronomical observations ; and having inertia, bat 
not gravity. 

2. ^* That the molecules of the ether are Buscep* 
tible of being Kt in motioo by the ogitatiua of the 



particles of ponderable matter j and 
one is thus set in motion it oanmunicae 
motion to those adjaccot to it, and thas 
is propagated further and further in all 
according to the same mechanical laws whh! 
late the propogationa of undulations in otUvi 
media, as air, water, or solids, aocordii 
respective constitutions. 

3. "I'hat ID the interior of rcfractinf^i 
ether exists in a state of lets elasticity^] 
with its density, than in vacuo (i. e. in 
of all otlier matter) ; and that the 
the medium, the less, relatively 
elasticity of the ether in its interior. 

4. *' That vibrations communicated 
in free space are propagated through 
dia by means of the ether in their interic 
a velocity corresponding to its iaferiori 
elasticity. 

&. " That when regular vibratory 
{iroper kind are propagated dirough the 
passing through our eyes, reach and 
nerves of our retina, they produce in at { 
tion of light, in a manner beariDg 
close analogy to that in which tlte vibratu 
air afleot our anditory nerves with that of aoi 

G. " That as, in tlie doctrine of sound. 
qnency of the aerial pnlses, or the nnmb< 
sions to and fro Uxyax the point of rest 
molecule of the air, determines the pitc 
so, in the theory of light, the frequency of 1 
or number of impulses made ou uur 
given time by the ethereal moleciilei next 
tact with them, determines the color of ib 
and that as the absolute extent of the motion 
fro of the particles of air detcrmioes the A 
of the sound, so the amplitude or extent ^ 
cursions of the ethereal molecules from 
of rest determines the brightness or int 
light." 

M'hirhever theory we adopt to explain tl 
nomena of light, we are led to conclusions 
strike the mind with astonishment. Accor 
the corpusculsr theory the molecules of lii 
supposed to be endowed with attractive ana 
sive forces, to have poles, to balance thai 
about their centres of gravity, and to 
physical properties which we can 
pond(;rablp. mutter. Inspeaking of I 
it is diflicult to divest one's self of 
ble magnitude, or by nny itrain of tbeimi 
conceive that particles to which they bcU 
so amaxingly small as those of light 
are. If a molecule of light weighed a sii 
its momentum (by reason of the enoi 
with which it moves) would be such, thai 
would be equal to that of a cannon-ball 
projected with a velocity of 1000 feet 
How inconceivably small must they 
when millions of molecules, collected by \t 
mirrors, have never been found to pro^ 
slightest effect on the most delicate appi 
trived expressly for the purpose of rem' 
rauteriality seuslble. 

If the corpuscular theory astonishes 
extreme minuteness and prodigious T( 
lumiuouB molecules, the numerical 
from the nndulatory theory are not leas 
ing- The extreme smalluess of amplit 
vibrations, and the almost inconceiTabl 
measurable rapidity with which Ihoy ii 
other, were computed by Dr. Touog. 



tbB« 

mt ^ 

itenm 



MAGAZINE OF SCIENCE. 



159 



view, it mast Bjipeor singular that 
«, fouuded on uaamptiona so easeo- 
ot, tlioolJ concur in affording themMiw 
gmC ft number of facta with equal 
Oft equal facility. Tbif , boweTer, 
ect to the corpuicolar and udJu. 
ei of light, frotn both of which the 
lawa to which the phcoomeaa are 
be deduced, though not in all cases with 
ree of facility. So fur as the corpua- 
atailable for the purposes of de- 
on. it poftse^aes all the charac- 
d theory. It luppoaca the opera- 
vith which we are in some meaanre 
fWe are accastomed to contemplate the 
traction in the grand phcDonieDa of aa- 
«e perceive them at every Instunt in the 
tendency of all heavy bodies ; and though 
in the small bodies of natnre, tbej 
d in the phenomena of electricity, 
capillary attraction, electricity, and 
ical aetiooi, where they can be not 
ty traced, but reduced to mathematical 
d submitted to accurate calculation.— 
torr hypothesis is not seized by the 
the same facility; yet it also possesses 
least equivocal characteristics of philO' 
Ch. No phenomenon has yet been dis- 
,y at variance with any of its prin- 
contrary, most of the phenomena 
principles with remarkable ease ; 
pMrous irutaocea, consequences deduced 
theory by a long and intricate analysis* 
ao sagacity could possibly hare tiiviQed 
have been found to be aaturately true 
t to the test of experiment. Hence 
begins to be generally adopted by 
and. in recent times, by far the most 
lumei in the annals of optical discovery 
in the list of its supporters, 
sensation of light is produced by the 
4rf an ulxemely rare and subtle fluid, is 
|l was maintained by Descartes, Hooke, 
but it is to Huyghens that the 
of having reduced the hypo- 
shape, and rendered it available 
mechanical explanation. Owing 
of Newton in applying the cor- 
to his splendid discoveries, the 
Haygbens were long neglected ; in- 
theory remained in the same state in 
left by him till it was taken up by our 
the late Dr. Voung. Ky a train of 
I reasoning, which, in point of ingenuity, 
been equalled. Dr. Voung was con- 
very remarkable numerical relations 
e oi the spparently most dissimilar phe- 
Optici, to the general laws of diffraction, 
trae principles of the coloration of crys- 
ces. Malus, so late as ISIO, made 
bant di!ieovery of the polnritation of light 
CM), and succeflsfully cxplainird the phe- 
i^ the hypothesis of an undulatory pro- 
The theory nub-tequently received a great 
from the ingenious labors of Kresnel ; and 
ore recent resr-*rches of Arago, Poisson, 
Airy, and others, have conferred on it so 
Urae of probability that it may be almost 
I ranking in the doM of demonstrated 
Ic Is a theory." says Ilerfchel, ** which, 
ikled in nature, is certainly one of the 
Kmmm that the gcntua of man has yet 




invented to group together natnral phenomena, as 
well as the most fortunate in the support it has re- 
ceived from whole classes of new phenomena, which 
at their discovery seemed tn irrccoocileable opposi- 
tion to it. It is, in fact, in all its applications and 
details, one succession o( /eticitie§ : insomuch that 
we may almost be iadaced to say, if it be not true, 
it deserves to be so." 

Helationa of Light and Heaf. — Light and heat 
are so intimately related to each other, that philo- 
sophers have doubted whether they are identical 
principles, or merely coexistent in tbe luminous 
rays. They poHSess numerous pro[>erties in com- 
mon ; being redected, refracted, end polarized ac- 
cording to the same optical laws, and even exhibit 
tbe same phenomena of interference. Most sub- 
stances, during combustion, give out both light and 
beat ; and all bwUea, excepting the gases, when 
heated to a high temperature become incandesc4>nt. 
Nevertheless, there arc many circumsUncea in which 
they appear to difier. 

A thin plate of transparent glass interposed be- 
tween tbe face and a blazing fire intercepts no sen- 
sible portion of the light, but most sensibly dimin- 
ishes the heat. Light and heat ore, therefore, not 
intercepted alike by the same substances. Heat is 
also combined in different degrees with the different 
rays of the solar spectrum. A very reniarktble 
discovery on this subject was made by Sir William 
Herschel, which would aecm to establish the Inde- 
pendents of the beating and illuminating effects of 
the solar rays. Having placed thermometers in 
the several prismatic colors of the solar spectnun, 
he found the heating power of the rays gradually in- 
cr^cd from the violet (where it was least) to the 
eimme red, and that the maximum temperature 
existed at some distance beyond the red, out of the 
visible part of the spectrum. The experiment was 
soon after repeated with groat care by Berard, who 
con6rmed Herscbers conclusions relatively to the 
augmentation of the calorific power from the violet 
to the red ; but he found the maximum heat ex- 
isted at the extremity of the red, and not beyond 
the spectrum. This discovery of tbe inequality of 
the heating power of the different rays led to the 
inqairy whether the chemical action, produced by 
light on certain bodies, was merely the effect of the 
heat accompanying it, or owing to some other cause. 
By a series of delicate experiments, Bemrd found 
that this action is not only independent of the heat- 
ing power, but follows an entirely different law ; iCa 
intensity being greatest in the violet ray, where the 
heating power is the least, aod least in the red ray, 
where the heating power is greatest. We arc thus 
led to the conclusion that the solar rays puasess at 
least three distinct powers, — those of heating, illu- 
minating, and effecting chemical combinations and 
decompositions; and these powers are dislribated 
among the differently refrangtbh; rays in such a 
manimr as to show their complete independence of 
each other. 

Light acts a very important part in the vegetable 
economy. The green color of plants and the hue 
of flowers entirely depend on it ; and il is found 
even to influence the form of their leavps. lu ef- 
fects in developing the forms of wome of the lower 
claises of animals hare also been proved by various 
experiments ; and there are probably many other 
powers resident in the same wonderful agent of which 
we can at present form no adequate notion. 



9 



160 



MAGAZINE OF SCIENCE, 



MEMORANDA. 
FitrmatioH 'tf RockM. — Though seveni] of tbe 
agencies which operated during the carliett eru in 
the phycicol hiitory of oar i^lobe either now exert a 
comjiaratiTely diminished iu0uence, or have ceased 
altogether, yet the general Uw of nature unquestion- 
ablf continues the same, and rocks ore in course of 
formation by various causes, and under dlTeraified 
circunutanceB, at the present daj. Not onlj do 
tbe coral formadoas continue in the southern ocean 
to produce rcefi, ialands, and by the connexion and 
jncrease of thes«, to form coDtlnents ; but, in our 
own Islands, accumulations of sand, mud, and shells, 
are producing fresh layers in tlic bed of the sea, 
and constituting fr(»h deposits, which add to the 
cnut of our globe, and will form a subject of in- 
terest to the future inquirer into its history ; but 
every river and every stream is in like manner con- 
verting ita bed into rock, and the operation is often 
assisted by causes of an extraordinary and singular 
kind. A very remarkable instance of this nature 
was brought to light a few years since. Daring the 
unhappy and distracted reign of Edward II. several 
of the English barons took up arms against the 
monarch and his favorites, tbe Gavestooes. One 
of their insurrections was headed by the Earl of 
Leicester, whose associate in the enterprise was the 
Earl of Lancaster, tbe litter nobleman taking charge 
of the military t^est, and the paying the troops, 
&c. &c. While the insurgent army were crosalng 
the river Dooe, in Derbyshire, in the night, they 
were attacked and routed by the king's troops ; — 
and, in the confusion, the military chest, with its 
contents, was thrown Itito the stream, and sunk to 
the bottom. The Earl of Lancaster was ah^y 
after beheaded (iu March, 1322). and all trace of 
the tre:asure was lost light of. After the lapse of 
half a thousand years, on some ezcavaiions being 
made a few years since for the purpose of deepen- 
ing tlie bed of the river, masses of ferruginous brco- 
da— that is, of pebbles, gravel, &c., cemented into 
rock by tltc mst of iron, were found, many of them 
containing coins of tlie period, silver pennies of 
Edward L, \c., evidently funning portions of the 
lost treasure. It would socm that the box contain* 
ing tbe money bad been bound or otherwise fitted 
with iron, and that the decomposition uf the metal 
had produced a cement aufficient to convert these 
pebbles into rock. The circumstance is not alto- 
gether unique ; and the efficiency of iron to pro- 
daoe Bneh a result ia perfectly weU known ; but the 
prescrration of these cotus by so remarkable a rauise 
constitutes a highly remarkable and interesting fact. 
Bhiith Queen. 

AVic ftrtife qf Iron. — This combination has been 
obtained by M. Fremy. It commnniciitea a violet 
color to water, and possesses a powerful dyeing 
principle. It resembles manganese diamcleon. It 
decomposes readily when boiled with an alkali or 
organic subst.tnce having an aifioity fur oxygen, 
and is converted into oxygen and scsqni-oxide of 
iron, of a yellow color. This combination is a pcr- 
ferrnte of potash, which may be procured by calcin- 
ing peroxide of potassium and peroxide of iron. — 
Fremy has shown that tbe appearance of a chame- 
leon color ia no proof of the presence of man^ncsc, 
as it maybe confounded with the new oxide of iron. 
Fremy forms this oxide by igniting a mixture of 
potash and peroxide of iron ; a brown mass ia the 
result, which, by digestion in water, gives a beau- 



tiful violet'rrd solution. This compound is very 
soluble in water. A large quantity of water dccoro* 
pose* it In the couneof time. It beeoraea insolabk 
in very alkaline water, farming a brown premnitate, 
which readily dissolves in pure water, and alorde ■ 
fine purple solution. It appears much leas stahlc 
than manganate of potaah. A temperature of 111^ 
decomposes it immediately ; all organic substaacw 
decompose it. It is consequently impossible hi 
filter the solution. It is impossible to isolata tUa 
compound, for when the red solution is treated bf 
an acid, when the potash is saturated, ozygm U 
disengaged, and peroxide of iron predpttated. I( 
the acid is In excess, it dissolves ue peroxide, and 
gives rise to the formation of peroxide salt of inm. 
GUug Church'BelU are among modera «oodfln» 
One has just been cast in Sweden ; iti '"■'■*i*it fa 
six feet, and its tone is said to be finer than soy 
metal bell. — Tyne Mercury. 

U»e of Lime in Planting TYftt. — A large planta- 
tion has, within the last two or three years, bean 
formed in the neighbourhood of InTemess, without 
the loss of a single tree, and this has been achieved 
by a very simple process. It is merely putting a 
small quantity of lime in the hole with the plant ; 
about four bushels of lime will suffice for an acrtL 
It must be thoroughly mixed and incorporated with 
the mould before the plant is inserted. The 
of the lime Is, to push on the growth of the 
in its first and most precarious stage. New 
begin to form and ramify from the top root | 
not only is the safety of the plant ensured, b«t 
growth is advanced in double ratio. — /i 
Courier. 

Kalorama. — Under this title an exhibitioB of • 
novel kind has been thrown open in Bond StrefC 
It consists of Isndscapea on a large scale, and pKw 
senting trees, water, animals, human figures, 
every variety of scenery ; but instead of cauvai 
color, being composed of paper cut out with 
and by disposition and gumming together, m 
represent all these features in a very effective 
nrr. In some points the distances are 
having the materials on different horixontal 
in others, by painting tbe baekground. As obj 
curiosity, these Kaloramic products deeerre a 
Muiie uf Liffht. — Dr. Buchanan, of Ken 
conceives that he haa found some affinity 
the different rays of light, as presented iu a 
bow, and the Dot«8 of music. Following up 
theory, real or imaginary, be proposes to 
concert for the eye ; that is, that tfie eye 
experience the same pleasure by an harmonic 
and fall of the different rays of tight, as the 
does by the accordance of sweet sounds. How 
this plan is practicable, ia a thing resting on exj 
mpnt. Something analogous to this may have 
birth to the fable of Memnoo's harp, which 
said to havr uttered delightful strmixis of 
when touched by the solar rays. 

Th Demlruy Caterpillarf, — A mode of d 
caterpillars has been discovered by accidcnL 
piece of woollen rag had been blown by the 
into a currant-bush, and when taken out was : 
covered by these leaf-devouring insects. VUtm 
wooUen cloth were immediately placed on 
hush in the garden, and next day the cai 
had universally taken to them for shelter, in 
way thousands were destroyed every motningi 
National Advertiser. 



LVKOON. 



-Pruned hy U. I nA^cti. 6. Whlu- Jlurw Une. Mil* End.— Poblifibe*) by W. UmTUtix. H . PatCisoitcr KtfW. 
Eaiaburuli, J Msksiss.— OJugow. O. Daici and J. DAaim.'^UvcrjiwI. J. Fsmr. 



16*2 



MAGAZINE OF SCIENCE. 



BATE'S POLYANGULAa KALEIDOSCOPE. 

Itf the common kalctdoscopcA, the reflecting planes 
are Axed in an invariable an; le, whiL'U la aotuti even 
aliquot part of 360"^ ; and, therefore, though the 
forms or patterns which they create are literally in- 
finite in number, jet thej have all the oanie chft' 
racter, in so far as they are compotcil of as many 
palrf of direct and inverted images as half the num- 
bcr of times that the inclination of the rcflecton is 
contained in 360'^. 

U is of the greatest importance, in the ■ppUra- 
tion of the kaleidoscope to the arts, to have it con- 
structed in such a manner, that pnttema composed 
of any number uf [laira of direct and inverted images 
may l>c created and drawn. With this view, the 
instnintent may be fitted np in various ways, with 
paper, eliith, and metallir joints, by means of which 
the angle ran be varied at pleasure j but the must 
convenient metliod is shown in the polyangular ka- 
leidoscope, the construction of which is as follows : — 

The three figure*, viz. I, 2, 3, represent the 
polyangular kaIeido»cnpe «*ith mftoUic reflectors, 
■1 made by Mr. Bau. optician. Rg. 1 shows the 
complete instrument, when mounted upon » Htand ; 
fig. 2 is a section of it in the direction of it» Irn^th ; 
and fig. 3 is a transverse section of it througb the 
line ST, fig. 2. The tube of this instrument is 
compofted of two cones, MM, NN, fig. 2, con- 
nected together by a middle piece or ring R R, into 
which Ihey are both screwed. These two cones 
inclose two highly-polished metallic reflectors A O, 
BO, fig, 3, only one of them, viz. IH) E. being 
seen in fig. 2, One of these reflectors UOE. is 
fixed to tbe ring R R, by the intermediate piece 
K G L. The reflector is screwed lo this piece by 
the adjustable screws K L ; and the piece K G L is 
again fixed to the ring RK by two screws seen 
atwve and below G, in tig. 3. Hence the tube, 
cortmistiiig of the cones MM, N N, and the ring 
R R, are tnimoveably connected with the mirror 
B O K. The surface' of the reltector B (> E is ad- 
justed by the screws at K and L. till it passes ac- 
curately through t)ie axis of the cooes and ring as 
seen in fig. 3. The oiher reflector A O, is fixed 
to an outer ring X X, by means of an intermediate 
piece, similar to K G L, the srm P of which, cor- 
respondinj^' to G, pluses tKroush on onnulor space. 
or open arch, of more than 1(0', cut out uf the clr- 
runifcreuce of the inner ring R R, Tlie arm F is 
fixed to the outer ring X X by two screws, seen 
above and below F, iu fig. 3 ; and the reficctor 
A O is filed to the bar corresponding to K L, by 
simitar screws, for the purpose of adjusting it. 

The lower edge O E of tbe reflector B O E ex- 
tends about the ISlh of an inch below the axis of 
the coues, as represented by the dotted line in fig. 
'2 ; but the lower cUrc O E of the other reflector 
A O E, which is finely ground to an acute angle, 
forming a perfectly straight and smooth line, is 
placed exactly in the axis of tlie cones, so as just 
to touch a line in the reflector A O E. which ootn- 
eides with the Btia of the eones, and to form a 
juction with that line in every part of the two mret- 
ing planes. Tbe very nice adjustments which are 
necessary lo produce so exact a motion are etfcctcd 
by the screws corresponding to K and L. 

If wc now fix the outer ring X X into the ring of 
« stand ST, so as to be held fast, and turn the 
cones with the hand, we sball give motion to the 
reflector BO, so nj to place it at anv angle we 
please, from O"* to 90'^; and, during 'its motion 



through thb arch, the junction of the two rrflrctort 
must remiUn perfect, if the tootbiiii; lines are ad* 
justed, as we have described theni. to the asi* of 
motion, which must alao be the axis of th« nwa 
and ringa. If. on the conlrarr, we take away die 
stand, and, holding the instrument to the hand ky 
either of the eones M, N, turn the ring R with thi 
other, we shall ^ive motion to it# reflector A O, aad 
produce a variation in the angle in tbe same man* 
ner as before ; or the same effect may be produoed 
by an endless screw working in Ceeth, cat upon Che 
circumference of the outer ring X X, 

In order lo enable the observer to lost the rt- 
flectora at once to any even alit|UOt part of a rirde, 
Of so as to give any number of pairs of direct and 
inverted iraagrs. the most convenient uf the e^ett 
aliquot parts of the circle ore engraven uj»on t^r 
ring X X ; so that we have only to »et the tndn lo 
any of these parts, to No. 12 for example, end tte 
reflectors will then bo placed at an angle of 3<r, aatf 
will furm a circular field with ttreire Inminoua see- 
tors, or a star with Hx points, and, consequently, a 
jiaitem composed of tix pairs of direct and inTtrtari 
images. 

As the length of the plates is only aboat Alv 
inchrs, it is necessary, excepting for persona ytn 
short-sighted, to have a convex lens placed at 1L 
A brass ring, containing a plane glass, screws Ial9 
the outer ring C D, when the instrument la aotiv 
use ; and there is on object plate contaimng Iraf- 
menU of difTerently colored glau. This object 
plfltc consists of two plates of glau, one gnraiail» 
and the other trauiparent, set in brass rims. IW 
transparent one goes nearest the reflector, and the 
brass rim which contains it screws iuto the other, 
so ss to inclose Iwtween them tbe colored fn{- 
ments. and re^^lar figures of colored and twisted 
glass. A loose ring surrounds this object pUte ;— 
and when this ring is screwed into the circular rfai 
C D. the object plate can be turned round vj *^ t/> 
produce a variety of patterns, without any risk of 
its being drtacbed from tlie outer oone. 

In applying this instrument to opaque objetfts. 
such as engravings, coins, gems, or fragments of 
colored gloss laid upon a mirror, tbe aperture of Ibt 
mirrors is laid directly over them, the large cone ^ 
M M having been previoujily unscrewed, for the 
purpose of allowing the light to full fnrly upi>u the 
objects. Tilts property of the kaleiiloscope is of 
great importance, as in every olber form of tbe In- 
strument, opaque objects mukt be held obliquely, 
and, therefore, at such a distance from the rrflectun 
as must affect the symmetry of tbe pattern. 

As the perfection of the figures depends on tliJ . 
reflectors being kept completely free of dust, parti- 
cularly at the angles, where it naturally accumulatM. 
the greatest facility is given by the preceding con* 
sCmetion in keeping them clean. For this purpoo?, 
the large cone must be unscrewed ; the reflcctAfi 
having been previously closed, by turning the ind« 
to 00 on the ring. They are next to be opened tt 
the utmost, and the dost may in general be removed 
by means of a fine point wrapped in clewi and dry 
wash leather. If any dust, however, alill odherVt 
the small screw in the side of the rini; oppoiltt la 
the index should be removed, and the snc'iT i .'iic. 
K N, olso unscrewed. By casing the ■ 
screws of either of the reflector*, thru 
sides will separate, so as to allow a piece i»r ili; «»ii» 
lenther to be drawn between them. When crwy 
ptrlicle of dust has been thus removed, the metih ' 
should be re-adjusted and dosed before tbe conei 



MAGAZINE OF SCIENCE. 



\G3 



rrpltcrd ; both of which should he icrewed 
■ < Uic ring K R. 

<\i« of m>ition in the prrc^din; conftruc- 
'sjurily the axis of the cones and ring*, 
'■r of l)ir*e coiK'fl and riiif^a must everj 
double the breadth of the retlpctor*. — 
frnn thU caiue, the tube, and con«eqaentl; the 
pbjttf pUU>t arr widr, and the inaCmmcut is, to a 
r«rtain dufree, nopartable. 

Tijtf sdvuitogea which th« polyangular kaleido- 
>pM poaaesa over all uthers, are— 
1. Tbat pattema of an; Dumber of eectort, from 
|}ii> HimnU^t to tho most Complicated, can be ca&iljr 

>'- the reflector! can be let, with the moit 

rrf«ct M'ruraey, to an even aliquot part of a rirclc. 

i. That the rcflectari can be, at any time, com- 

' 4nrd and freed from all the diiitt that ac- 

bctv^eo them, and the instrument ren- 

v.. ~. jKxfacC aa when it cane from the Jundi of 

m»ker. 



(SIECTS AND THEIR CLASSIFICATION. 

CT4 Are animuU which have a bodj coRM«tin)( 
w or more divisions, articulated feet, and a 
,k«a ■-■^"-picnoualy distinct from the boiW, un whiuh 
1 two moveable horns, called anlennK. 
.the through airholes, which are situated 
liic atdcfl of the body; the greater number have 
wi]r» in iheir perfect state, and only a propurtion- 
"1 number are entirely without them. With 
ion of certain groopa, all perfect inspcta 
(i9»T Bii (Vet, and their bodiea are divided into a 
bead, thorax, und abdomen, by notches or incisions; 
brncr the name iiufct, derived from the I^tin word 
«*fC«re, to cut or notch. Before they attain their 
perfect »tate they arc subject to variooa transforma- 
ttuna, whic}i are called metamor})huses. For the 
lake of penpicoity tlie very numerous class of in- 
■ct«, the tnoit extensive in the whole animal king- 
dom, faai been dtvirlcd into two principal dtviaiuni 
- fh,- aini^, and the winglesa. 

■I ifutctt ure divided into the following 

tl.J CoMptFva (Boetlw; Sheath- wings). Six 
^, and mostly four wings, Uie anterior pair of 
*hieh arc homy* in the form of a covering for the 
t»o pokterior wings, which are sometimes wanting. 
Utey haxe tijipcr and lower jaws (uianilibK's and 
•uaillc) for giiAwing or chewing : their under wiugs 
vt trwisTcrfely folded. Exanipin — the may-bug, 
the long-horna (Ccnimbycidie), atag-bcetles. ground- 
lioclles iCarabidse), weevils, &c. 

(2.) Orth6pUra (Straight-wings.) Six feet ; four 
•ingi, the two anterior of a leatliery aub&tance, 
tarring as covcm to the pusterior, which are folded 
ioCh loDgitodintliy nod tmnsrersely, but m^rc gene- 
n^ only loDgiludinally (whence the name straight- 
■Ifligvj, aud which lie, when at rest, couccaltd un- 
der Ihe others. They have upper and luwj-r jaws 
(or Bandibles and ooaiilla:) fur chewing. Examples' 
—^kif f^^rwig, the black-b<wtlr, the cock>roach, the 
^et, the migratory locust, and llic green 

^....( iiruapifra (Half-wings). Six feet; four 

viofS, the two anterior forming hard coverings with 

lartnbrauotu ends, or recembliog the lower ones, 

Larger and stronger. Instead of upper 

j4Ws, the organs of the mouth are furnii'd 

• incloacd in an ortirulal^-d klicath, nf u 

J oc oooicdl ahitpe, jnd funning u ]iil>;cc1- 



in% beak or nieker. Examples— the field and tree 
bugs, house bags, cicada;, and aphides. 

(4.) ftitur6ptffra (Net-wing*). Six feet; four 
meuhrnnons naked wings, upper and lower jaws 
for chewing ; the wings are delicately veined, the 
under nearly the sise of the upper, or even broader 
in diameter. Examples — the dragon-fly, or Libi'I- 
lu)n; lace-fly, or Hemerobioa -, and day-fly, or 
Ephticnera. 

(j.) f/jrmeH6piera (Membrane- wings). Six feet; 
four membranous wings, upper and lower jaws ;— 
the posterior wings smiiUer than the upper. In tlie 
abdomen of the female of most species is n sting, or 
ovipositor. Example! — the aaw-flwa (Tcntbredt- 
nidai), Sirex gigai, gall-fly, bcea, wasps, humble- 
beea, and anta. 

(G.) Lepidoptera (Scale-wingi). Six feet ; fbnr 
memhrannna wings, covered with small, rolorcd, 
mealy, shining scales or feathers. Instead of the 
upper and lower jaws, two hollow ftlamenla exist, 
which tOj;ethcr form a spirally rolled tongue. Ex- 
amplea — butlerfliei, moths, and bawk-moLlis. 

(7.) Rhipipiera (Fan-wings). Six feet ; two 
membrantnta wings, folded like a fan; oa the an- 
tertur part of a thurax are situated two fmall, bent, 
hard, moveable bodies, like wing-covers. Tha 
mnFticatory organs consist of simple briatle-shaped 
mandihles, and two palpi. To this order belong 
two gcuern of parasites living on wasps and heea. 

(_H.) jyiptera (Two-wiogs). Six feet ; two mem- 
branous expanded wings, generally with two more- 
able organs, called poisers or balancera, and which 
are situated behind the wings. The organs of the 
mouth consist of a sucker, formed of a variable 
number of bristles, which are inclust-d in an un- 
nrticulated sheath ; terminated in a double lip. 
Examples — gnats, midgei. house-flies, ox and horae 
breexe-Hiea, \c, 

Jnatct* wUhout winffs consist of the following 
orders: — 

(9.) MyridpoJa (ThouMnd-fert. Millepedes). — 
They have more than six feet, twenty-four at least, 
□ nd upwardn, whir.li arc plnrrrl on a series of rings, 
extending the whole length uf the body ; each ring 
has gt-ncrally two pairs. The ftr»t, and sometimea, 
also, the second pair, form parta of the month. 
Examples — the centipede, iulua, and scolopendra, 

(10.) Thymnitra (I'ringe-UiU;. Six feet; on 
the under aides of the abdomen are situuted flat 
niovenble appendages like pro-legs, and at the ex- 
treuiity is a forked apparatus, by which the body 
can raise itself and move by leap:*. Example — the 
sugar-louse (Lrpisma sacchnrinam). 

;ll.) Para»tfa (Varasites). .Six feet j no other 
organs of sight except aimple (instead of composite) 
eyes ; the mouth is mostly internal, and conaltta of 
a snout, which contains a retractile sucker, or it 
forms a clrft with two lips, two mandthici, and 
hooka. Examples — the ditfcrcnt spccie-» of lice. 

(12.) Sncturia (Suckers). Six feet, of which 
the posterior are the longest, and adapted far jump- 
ing. These undergo a transformatiou, and actptirc 
organa of motion which they had not at first. The 
mouth conaittts of a sucker, which )& inclosed in n 
cylindrical aheath, and is formed uf two articulated 
piecea. Example — the flea. 

CVflA* and npidct'i, which Linnreui included 
among insects without wings, arc now formed into 
two distinct claaiMts — CruBtacea and Arachoida. 

The arranij/fmrftf Mere tjhmt i* thnt of KollNr; — 
but other nulhorsdilft'-T in thfir \iKWftof the aubjed. 
Uy some the earwig is formed into au order distinct 



MAGAZINE OF SCIENCE. 



Irom the Ortb(jpterft. The Tbrfpi ii leparated u 
an order from the Hemfptrra, the CAddice*fli«« 
(Phryg^eA) rrom the Neuruplera and the horse- 
flies (Hippobosca) firom the Diptera. la a popular 
point of view the arran^ment of KoUar may be 
cODiidered ai lufficiently detailed. 



ANIMAL MAGNETIS.M. 

Tbis Bobject haa lately attracted so mnch of pnbUc 
attention, that we ibould not be joBtifted in wholly 
omitting an account of it, more eBpetrislly as it 
pretenda to be intimately connected with subjecta 
which we have found occasion to treat of ratber 
fully. Before, howeTCr, we allude to the present 
operations of the cbarlattms or eothuaissts, wbieh 
ever tbey may be, who now impose upon the cre- 
dulity of the public, it will, we doubt oot, be inte- 
resting to present to our readers tlie authenticated 
proceedings of the original magnetiser, M. Metmer, 
with the fundamental principles upon which the 
pretended idence was originally contrived. 

On the 12th of March, 1781, Louis XVf. sp- 
pointed Messrs. Borre, LalUu, Darcet, andGaillotin, 
members of the faculty of Paris, to examine tbe 
animal magnetism, practised by M. Oeslon and 
Meamer, and to give in a report to him on tbe sub- 
ject ; and in conscqncnce of a request made by 
these physicians, His Majesty appointed live mem- 
bers of the Academy of Sciences, Messrs. Franklin, 
Leroi, Bailly, De Bory, and Lavoisier, to scsist them 
In this exaniinatioD. As M. Bory died when tlie 
commissioners began their labors, His Majesty made 
choice of M. Msjanlt, member of the faculty of 
medicine, to succeed him. The following is an 
eitract from their report : — 

" Doctrine. — Tbe agent which M. Meamer pre- 
tends to have discovered, and which be has made 
known under the name of animal magnetism, is a 
fluid diffused throughont the whole universe. It is 
the means of a mutual ioflnence between the celes- 
tial bodiea, the earth and animated bdngs. It is 
continued in such a manner as to leave no vacuum -. 
its subtlety is beyond all comparison ; it is capable 
of receiving, propagating, and communicating nJl 
the impreasioDi of motion, and is susceptible of a 
flux and reflui. Animal bodies experience the effects 
of this agent, and it Is by insinuating itself into the 
tabatonce of the nerves, that it immediately atTects 
them. The human body, io particular, possesses 

Eropcrties analogous to those of the magnet, and it 
as alio its dllTeretit and opposite poles. 
** The action and virtue of animal magnetism may 
be communicated from one body to other bodies, 
either animate and inanimate, and even at a con- 
aiderable distance, withont the aid of any interme- 
diate body. It is increased and reflected by glass ; 
it is commnnicaled and propagated by sound— io a 
word, this virtue maybe occumnlated, concentrated, 
and transmitted. Though the fluid be universal, all 
animated bodies are not equally susceptible of it ; 
there are some even, though few in number, of a 
nature so hostile to it, that their presence alono 
destroys all the effects of it in other bodies. Ani- 
mal magnetism can cure immediately all diseases of 
the nerves, and others it cores mediately ; it 
Btrengtheni the action of medicines, and it cxrrts 
and directs salutary ones in such a manner that 
they may be overcome. By its means the phy- 
sician can ascertain each individual's state of health ; 
and can speak with cert^nty respecting the origin, 
nature, and progress of the mo»t complicated 



diseasea. He can prevent their increase, and be 
able to cure them without ever expostng the paciot 
to dangeroiu effects, or disagreeable oonaequeaesa^ 
whatever be tbe age, the temperature, or the •«. 
In animal magnetism, natare preaents an vuvrnsj 
medium for curing and preserving mankind. Suh 
is the agent which the commiauonera were charged 
to examine, and anch tbe properties warranted by 
M. Deslon. This physician, when he explained to 
the commissioners the doctrine and nature of aiiiiiwl 
magnetism, taught them also the practice, and 
made them acquainted with the poles, by ihowlttg 
them the method of touching the patients, and of 
conveying to them the magnetic fluid. 

" Treatment, — Af^r having procured informidoD 
respecting tbe theory and practin: of animal mag- 
netism, it was necessary to see its effects. For this 
purpose the commissioners attended, and each of 
them several times, to observe tbe manner in which 
M. Deslon treated hia patients. In the middle of 
a large hall, tbey saw a circular box, made of oak, 
rsiscd to the height of a foot, or a foot and a half* 
which was called tbe tub ; tbe upper part of tiris 
box was pierced with a great number of holes, bom 
which proceeded iron branches, ba\'ing moreihle 
elbows. The patients were placed in rows aronad 
this tub, each opposite to one of the iron brancbesi, 
which by means of the elbow could be applied di- 
rectly to tbe diseased part. They were all united to 
each other by a rope that went round their hoSa ; 
and sometimes tbey formed a second chain by layii^ 
bold of each other's bands— -that ia to asy, by each 
applying the thnmb between the thumb sod fore- 
finger of the next person. In a comer of tbe baD 
stood a piano-forte, on which various aire were pl^ycA 
in different time ; and these airs were sometimas 
accompanied with tbe voice and singing. All the 
magnetised persons held in one of their hands la 
iron rod, about 10 or 12 Inches in length. TU« 
was called a niftatlie tractor, M. Dealoa declared 
to the commissioners — First, that thia rod was t^ 
conductor of magnetism ; that it posseased the pro- 
perty of concentrating it at its pofait, and of ren- 
dering its emanations more powerful. Second, Ibat 
sound, according to the principles of Meamer, wM 
also a conductor of magnetism, and to commanlaMi 
tbo fluid to the piano-forte, notliing waa DeeoMVy 
but to bring the iron rod near it ; those who tooctwa 
the instrument furnished It also, and tbe mognetiaB 
was transmitted by the sounds to tbe s 
patients. Third, the rope which went 
patients, as well as the joining of bands, 
ttned to increase tbe effects by commnnicatiM. 
Fourth, the inside of tbe tub was couatructed in 
SDch a manner, aa to concentrate the magnetism. 
It wns a large reservoir, from which it was propa- 
gated by meaas of tbe iron branches Axed in it. 

" The patients arranged in great numbers, and iB 
several rows, around the tub. received the magnet' 
Ism at the same time by all these means— by the 
iron branches which transmitted to them the 
msjenetism in the tub — by tbe rope twisted wanS 
their bodies — by tlie joining of hands, which com- 
municated to those of their neighbours ; and by 
tbe sound of the piano-forte ; or of an sgreeable 
voice. The patients were magnetised also 
by means of tbe finger, and of an iron rod 
before tbe face, or behind the head, and on 
eased parts, always observing the distioctioa of thi 
poles : the person who performed the operatiM 
acted upon them also by }be look, and by 
at them ; but they were magnetised in ■ 



^M 



MAGAZINE OF SCIENCE. 



165 



bj* Applying the fingers to the hypochon- 
druc regions, and aometlmefl coDtuiumg to du to 
tat MTfral hoars. 

" J5E^«t/*. — The paticmts exhibited a highly-varied 
yieUuv, ttccording to their different ftatea. Some 
flf them were calm and tranquil, and experienced 
BO «flect whatever ; other* cou|^hed, spat, and felt 
MBA tUght pain, a local or a universail beat, and 
titM of penpiration ; others were agitated and tor- 
mented nith conruliionf, which were remarkable 
§or their number, their duration, and Tiolcnoc. Aa 
•DOB *a one conrulsion begaSt aereral others inani- 
tatad tbemselres. The commijAoners saw some 
«faidh lasted three hours ; tbey were accompanied 
'Vidi the expectoration of a turbid, viscous liquor, 
loreed ap by the violence of the efforts. Sometimes 
atreaka of blood eamo np ; and one young wan in 
ptfticvUr, one of the patients, tlirew np a great 
deal of it. These convulsions were characterised 
Vf sudden and involuntary movements of all the 
Kmbs, or contraction of the throat, snbsultus of the 
kfpocbondrta and the epigastrton, uneasiness, a 
vUfaen of look, piercing cries, weeping, hiccups, 
■id bDmoderate laughter; they were preceded and 
Ulomd by a state of Inngoar, and often a sort 
of d^ection and even lethargy. The least unex- 
Doise produced in the patients a tremour ; 
it was observed that changing the tone and 
of the oin played on a piano-forte had an 
iftflaence oq them, so that by lirelier tonea they 
vere more agitated, and the vivacity of their coo* 
mlsions was renewed. 

*'A hall, lined with matUng, had been at first 
dcptined for patients afflicted with these convulsions. 
aad on that account waa called the chamber of 
criea ; but M. Deslon does not think proper to 
saake use of it, and all the patients, whatever bo 
their symptoms, are collected together in the public 
han. 

** Nothing can be more astonishing than the ap- 
Maraoc-e exhibited by these convulsions ; none but 
nOM who have seen them can form any ideji of 
then : and those who sec tfaem are not a little sur- 
prised at the prnfound tranquility of one part of the 
patients, and the agitation experienced by another; 
Umt varioos symptoms which are rep'tated, and the 
■ympathetie emotioos produced. Some patients 
themselves to each other exclusively, rush 
each other, langh, address each other in an 
tone, and mutaally poften each other's 
Tbey are all subject to him who magnetises ; 
ftcmgh III an apparent state of stupor, the sound of 
Us Toic«, a look or a stgn, is sufficient to rouse 
tkem from it ; and in consequence of these constant 
It is impossible not to acknowledge some 
power by which the patients are agitated and 
tobdned, and of which he who magnetises seems to 
he the depository. 

*' Qmc/iuion. — The commiastODers hnving asccr- 
taJDad that this animal>mag:netie fluid c&nnot be 
fSvelTcd by any of our senses ; that it has no 
Mlion either on them, or on the patients subjected 
to U ; and liaving assured themselves that pressure 
Md lOMching occasion changes seldom favorable in 
ttSBiiDsl economy ; and in the last place, baring 
dBDOMftiBted by decisive experiments, that the 
faHfiAaUuD, without magnetism, produces con- 
walnoas, and that magnedsm, withoat the imagt- 
Mfion, produces nothing, have unanimously con- 
riadtfd. in regard to the question of the existence 
and utility of the magnetic fluid, that nothing 
protvs its existence; that the violent effects oh* 



BCrved on those subjected to public treatment, arise 
from touching ; from the imagtnaUuD being put in 
action ; and from that mechanical imitation which 
impals OS, in spite of ourselves, to repeat whatever 
strikes our senses. At the same time, ihey think 
themselves obliged to add, as an observation of im- 
portance, that frequent touching, in*^ the repeated 
action of the imagination to produce a crisis, may 
be prejudicial ; that the sight of these crises is 
equally dangerous, on account of that imagination 
which nature seems to have imposed on us as a law, 
and consequently that all the public treatment, 
where thetaeons of mugneUsm ore employed, most 
in the end produce disastrous effects.** 

i'nru, March Hlk. I7fr4. 

MUSICAL STRINGS. 

If a string be stretched between two pins, and then 
be struck or pulled to one side, it will move as far 
to the other side, and then nearly as for back again, 
and that vibrate for a considerable time ; — each vi- 
bration diminishing till they finally cease — though 
the time occupied in each vibration, from beginning 
to end, is exactly the same. Two atrings in every 
respect the same, will pruduce exactly the same 
tone, and arc said to be in unUon. A string half 
the length of another will \ibrate in half the time, 
or make two vibrations for the other one,— each 
second vibration of the shorter one commencing 
with each vibration of the longer one. A string two- 
thirds the length of tiie long string will vibrate 
three times to its twice. Should we suppose the 
long string to consist of 120 parti, and to vibrato 
sixty times in a second, then we may have seven 
divisions of it, with their according vibrations, and 
the number of times which each one vibrates in A 
second, u in the following table : — 



NaniM of 


DiTlsioni of 
the t^iig 
Sarlii«. 


According 

VlOiaLiHis. 


Iloni in a 
SocomL 


First 


1 or 120 






60 


Minur Third 


^ — 100 


« . 


5 


72 


Major Third 


i — y6 


5 . 


4 


75 


Fourth .... 


1—90 


4 . 


3 


flO 


Fifth .... 


y — 80 


3 . 


2 


90 


Minor Sixth 


f - 75 


8 . 


5 


96 


Major Sixth 


f - 72 


5 . 


3 


100 


OcUve .... 


i — 60 


3 . 


1 


120 



These strings, when struck, will produce different 
sounds ; but the vibrations of each will accord or 
commence together at the above stated intervals 
with the original long string ; and they ore, there- 
fore, said to form a concordance, or to bannonise. 
When the strings have not those proportions, nnd, 
consequently, not these periodical concordances, 
they form disconls by the vibrations continually in- 
tercepting each other, and thus jarring or checking 
each other's momentum. 

The above proportions ronstitnte the diatonic 
scale, and are the foundation of all music ; pro- 
ducing the greatest number of recurring vibrations 
or concords that can he had at the Itn^t intiTvals ; 
and, with the addition of five inti;rveninf strings 
that produce half tones, each one being a sharp to 
the one below, and a flat to tlie one above, consti- 
tute ihe mnsical alphabet. AH the stringa together 
form one octave. But tht same diviainns muy be 
repeated on the short string or CO. when its octave 
tvill be 30 ; and this may be again divided, as also 



I 



its octave. Some InBtnimenU contain ten octaves, 
riling one above another j ypt, constnirted on a 
rc^ar acalc, so as to preserve the proportions. — 
The pianu generally baa five, but samrtimca seven 
octave*. 

The strings are not tfana exactly meaanred in all 
inntnimenU ; oecauM the least difTerence, either in 
tbe matcriala of which strings are made, (heir thick- 
uesR or trniion, which is continuiiUy varying with 
the weatlier, makes a dtffcretire in the tone. Tbej 
are, therefore, fixed according to the sound it- 
self, aa determined by the accuracy of the ear ; — 
which is called tuning them. The conitrtictioo of 
most instruments must connequeutly depend on the 
ear; for in many wiad-instruments, in musical 
glassea, and even in a great many utringed instru- 
ments, no actual proportions can bo npphed ; aiiJ 
tlie only means we have of producing the above seta 
of harmonics or octaves, is, by alteriog and adjust- 
ing the instramcnt or tension of the string tiU the 
right tone is produced. In the violin the lengths of 
the strings are varied by the disposition of the fin- 
gers ; and in the flute, the octaves are chiefly pro- 
duced by the manner of blowing. 

1l\w vihratinn of strings is on the same principle 
as that of pendulums ; each string being confidered 
as two pendulums joined together at the points of 
otdllation, and as describing very small arcs. Now. 
«• pendulums of the same length oscillate in the 
same time, whether the area which they describe be 
great or small, so the vibratioa of equal strings will 
be )>erformed in the same time : hence, though one 
string be violently struck so as to produce a loud 
aound, and nnothcr in unison, so gently as scarcely 
to produce any sound ; yet, aa each vibration is 
performed in the same time, the tones will have the 
same pitch, or the strings will be in tune. 

If a pendulum of a certain length vibrate in a cer- 
tain time, then one that is one-fourth the Icnj^h will 
vibrate in half that time ; the time of vibration being 
as the square root of the length. But to produce 
the seme effect in the string, or double pendulum, 
we must work with hslf the length, — or as the pen- 
dolum decreases in the ratio of 1 — 1, the whole 
string must deoreaac as 1 — 2, Now, as the lengths 
of pendulums are measured from the point of sus- 
pension to tlie point of oscillation, this point of os. 
dltatioti in Htrings mustdtpend an the tension of the 
String. When the string is slock, the distance 
between the point of suspension and osnillation, or 
between one of the pegs to which the string is fast- 
ened, and the middle of the string, must be greater 
than when the string is tight. Uut perhaps the 
true principle is, that each string possesses elasti- 
city only to a limited decree; and Ihit when 
stretched tight, a certain portion of its clastic power 
is exerted lengthwise; ond. therefore, when struck, 
there will be less to exert laterally in the vibration 
— it will consequently vibrate in less time. It may 
be poBsible, therefore, to make n string so tight, 
that all its elasticity shall he exerted longitudinally ^ 
BO that when struck it will not vibrate but break. 

" If the lengths ond weights of two chords are 
the same, their times of vibrstions will be inversely 

the square roota of the forces with which they 
are stretched ; and the number of vibrations which 
they perform in the same time, directly as those 
square roots. So also the tension and the weight 
remaining the same, the celerity of the vibration ia 
inveraely aa the sijnare root of the length, or the 
tcDSiOQ and weight, per inch remaining th- sumr, 
the celerity uf vibration is inversely as the length. 



If eight strings be such, thst the number of vibn- 
lions KJiifh thry perform in a given time be aa llie 
numbers 24. 27. 30, 32. 3G, 40. Ah. 48. the aoonds 
of the tint seven will be perceived aa intirc«stn:g fa 
acutcnrsR one above another from (he first to Uia 
last, and will yield the notes from tlic combination 
of which all musical effects are produee/l. Tha 
tone la not aflected by the eitent of the vibrstloai. 
but merely by tbeir time. The loudneaa of their 
sound is supposed to depend on the greater extvnt 
of vibrations. The last of the eight strings will 
sound what is called the octave above the first ; and 
the ssme series may be repeated again between the 
number 48, and its doable 96, and esch note will 
be the octave to its corresponding note tn the first 
inter\'al ; the numbers of vibrations will be 54, GO, 
C4. 72. 80, go. 9G, and it is evident that this senea 
may be continued either down or up without limit. 
All musical sounds are computed to be contataod 
within ten octaves ; so that the number uf vibrm* 
tions in a given time, that yield the gravest notp, 
is to that which yields the most acute, as I to 2-^. 
or 1 to \^2i.*' ^Piaafair't OutiiM* of XatUfH 
PAHiMopAy. 

Large instruments, and long, tliicV, and alack 
strings, therefore, vibrate slowly, or only once ; — 
while instruments of diminutive siie, and very short, 
small, and tight strings vibrate ahote a Ibooaaod 
times ; the former pruducitig grave and deep tones, 
and the latter sharp and acute ; hence that screw- 
twisting and ear-torturing process that attends the 
tuning of stringed instruments ; — and all the variety 
of contrivances seen in musical instrumentJ, which 
are, first, for producing the a1>ove octaves ; and, 
secondly, for playing the tonea longer or shorter, 
when they are called notes, so as to produce sncb 
harmonioos combinatiuua of r^pilarty recurring 
aounds, as we call a /une, an air, or a mtl&djf. 

The above divisions in the length of the origin^ 
long string are fnr from Iwing arbitmry — they are 
even poiuted out hy Nature herself; fur, should a 
rope of 30 or 40 feet in length be stretched 
very tight, and struck, it will not vibrate uuiformly 
between end and end, but will divide itself iaM 
portions ; some vibrating and some at rest,— the 
latter acting aa bridges, or stops to the former. — 
Soppose the length of the rope to be OU ; then the 
IpngtliA of the vibrating parts most be 30, 20. snd 
12. Pur the sounds emitted are the octave, the 
twelfth, or otrlavo of tlte fifth, and the srvrntemth 
major or double octave of the third major of titf 
principal sound produced by the whole rope. It ift 
supposed to be the tendency of strings to more in 
this manner that produces the wild and mc'lodioiu 
harmony of the Eolian harp ; for we not only hear 
the natural &ound of each string, but it-s octavf, 
twelfth, and scventccnlli. " Harmouy (says a 
writer, in the " Edinburgh Review,") is not ao ad> 
vectitiouH quality in sonorous bodies, but is in some 
sense inherent in every sound, however produced. 
Every sound is aa much made up of three compo- 
nent parts as a ray of light is compulsed of seven 
(three) primary colors. In many sunorons bodies 
these sounds may be made distinctly andthl?, as in 
the toll of a great bell, where, amid the vihrvtinns 
of the primary or fundamental note, its 1 2th, and 
17th are distinctly heard ; that is, the note with its 
3rd and ^th, composing the full harmony, are gene- 
rated by the vibrations of what ajipean, to itiaUen- 
tive cirs. to be only a siiiiide sound." S^mriiiing 
of the same kind maybe observed in tlie report trf 
cannon when heard from a distance. When near, 



MAGAZINE OF SCIENCE. 



167 



aU accnniUnr vibrations nre confounded in one cnek ; 
bat wh^D beard from the distance of ten or iwentj 
■dies, " it iti a grave sound, wbich may bt! com- 
^red to A dettrminate muBicol sound, and loslesd 
of being lnsUnt<uieou«, it begins softly, sneltg to its 
rnutiMtt loudorss, snd tbcn dies away growling.— 
Nearly the same rosy be observed with respect to a 
clap of thundt^r/* 

Another remarkable circumstance in the nature of 
wand is. tbdi when >a elastic propaUion of tlie air^ 
pntdacinj; K rfrtnintooe, strikes any sonorous body 
or Btasiesil iusirumenl, which, if struck iu any other 
aaoner, would produce that tone, it communicates 
the sound to that body or initrument. while it 
breaks si^inst, ur passes orer ocberi not in unison, 
vithout producing^ any clfcct. The string! of the 
EoUaii harp are of the same length, and arc tuned 
ia unisun ; if one string is, thcrefure, struck, the 
*hoI« will Tibrate or produce sound ; but if only 
two are iu onison, and one of them be struck, the 
other imlr wilt vibrate. This may be proved by 
v,.--;^,. pi^ea of paper on all the striugs; when, 
'- struck, the paper will immediately fly off 
1 in unidon with it. but will remain nn- 
1 upon the rest. Though the Btrings all 
:tie some combinations of natural concords ; 
fct, «« ibe wind that plays upon them is perpetu- 
ally rmrying its intensity, its sportire sweeps '*pro- 
J — vjiriety and awectff^ss of liormony. which, 
the stillness of evening, may almost be 
._ ., ;i for an unrarthly muair." 
To (his sympathy in the claatic pro)>erties of 
BuUrr it is owing that one thing, and perhaps only 
that one in a room wilt begin to danr^, vibrate, or 
emit sound to one particular note of on organ, or 
any other instrument, while all the other notes have 
ao effect upon it. These corresponding notes are 
Called the key notes ; and such foundation has thb 
n nature, that it is not confined to inanimate ob- 
jects. A dog will begin to howl at one particular 
QOtr. though iodifTcrent to all the rest uf the gamut ; 
tnd nen man himself has the key-note to each of 
tils pAisions : and hence it is, that his soul is so 
noirii nith music, and that he is often compelled, 
c«cn iQ deftancfl of himself, to laugh with those 
Ihit laugh, and weep with those that weep. 






f 

t 



ANALYSIS OF MINERAL WATERS. 

iRjftttMfl/rom pagt 1-49.) 

Tiuic is flonetimes found in water a quantity of 

Uhuncn combined with alkali, and in the state of 

MU. In such waters aeids occasinn a rnagulation; 

M the rosgulum collected on a ftlter discovers its 

klaminous nature by its combustibility. U'ater, 

■U9, somrtlmes contains extractive matter ; the 

pRKOee of which may be detected by means of 

HtnU of silver. The water iuspeoted to contain 

knoaC be freed from sulphuric and nitric acid, by 

Mtts of nitrate of lead ; after this, if it give a 

*nwn precipitate with nitrate of silver, we may 

cnotlude that eitractiru matter is present. 

R':t it is not sufficient to know that a mineral 

r.uins certaia ingredients: ft is necessary 

tin the proportions of theie, and thus wc 

■ complete unclysifl. 

tent .-luriaJ duids ought to be 6rst 

' r ktimaled. For this purpose, a reC 

filled two-thirds with the water, 

- with a jar full of mercury, standing 

rcufiul trouBih. I^et the water be made to 

A quarter of an hour. The aerial fluids will 



^gUglgl^ 



pass over into the jar. When the apparatus is coot, 
the quantity of air expelled from the water moy bo 
deteruiiiied either by bringing the mercury wilhia 
and without the jar to a level ; or, if this cannot be 
done, by reducing the air to the proper density by 
calculation. The air of the retort ought to be core- 
fully subtracted, and the jar should be divided into 
cubic inches and tenths. 

The only gaseous bodies contained in water are, 
common oir, oxygen gas, nitrogen gas, carbonic 
acid, sulphuretted hydrogen gas, and sulphurous 
acid. The lost two never exist in water together. 
The presence of either of them must be ascertained 
previously by the application of the proper tests. — 
If sulphuretted hydrogen gas be present, it will be 
mixed with the air contained in the gloss jar, and 
must be separoted before this air be examined. 
For this purpose the jar must be removed into a tub 
of warm water, and nitric acid introduced, which 
will absorb the sulphuretted hydrogen. The rcsi- 
dnnm is then to be again put into a mercurial jar 
and examined. 

If the water contain sulphurous acid, this previous 
step ia not necesory. Introduce into the air a solu- 
tion of pure potash, and agitate the whole gently. 
The carbonic adtl and iulphurous acid gas will be 
absorbed, and leave the other gases. The bulk of 
tlii« residuum, subtracted from the bulk of the 
whole, will give the bulk of the carbonic acid and 
sul))hurouii acid absorbed. 

Eraporate the potash alowly, almost to dryness, 
and leave it exposed to the atmosphere, Sulphate 
of potash will be formed, which may be separated 
by dissolving the carbonate of potash by means of 
diluted muriatic acid, and Altering the solution.— 
)UU grains of sulphate of potash indicate 36.4 grains 
of sulphurous acid, or 63. G6 cubic inches of that 
acid in the statu of gas. The bulk of sulphurous 
acid gns ascertained by this method, subtracted 
from the bulk of the gas absorbed by the potash, 
gives the bulk of the carbonic acid gas. Now 100 
cubic inches of carbonic acid, at the temperature of 
GO^, and barometer 30 inches, weigh iQ.6 grains. 
Hence it is easy to ascertain its weight. 

When a water contains sulphuretted hydrogen 
gas, the bulk of this gus is to be ascertained in the 
following manner : — Fill three-fourths of a jar with 
the water to be examined, and invert it in a water 
trongh, and introduce a little nitrous gas. This 
gas, mixing with the air In the upper part of the 
jar, wrill form nitrous acid, which will render the 
water turbid, by decomposing the sulphuretted hy< 
drogeu and precipitating sulphur. Continue to add 
nitrous gas ut intervals as long as red fumes appear, 
then turn up tlie jar and blow out the air. If the 
hepatic smell cootinne, repeat this process. The 
sulphur precipitated indicates the proportion of 
hepatic gas in the water ; one grain of sulphur in- 
dicating the presence of nearly 3 eubic inches of 
this gai. 

2. After having estimated the gaseous bodies, the 
next step is to ascertain the proportion of the earthy 
carbonates. For this purpose it is necessary to de- 
prive the water of its sulphuretted hydrogen, if it 
coutain any. This may be done, either by exposing 
it to the air for a considerable time, or trcatiog it 
with litharge. A sofficient quantity of the water, 
thus purified if necessary, is to be boiled for a 
quarter of an hour, and filtered when cool. The 
earthy carbonates remain on the filter. 

The precipitate thus obtained moy be carbonate 
of Umc, of toBgncsiD; of iron, of alumiuo, or even 



168 



MAGAZINE OF SCIENCE. 



sulplwte uf lime. I^et lu 8U)i[)ofl« all of tlieae aub- 
tUncet to be prcKDt tofcthcr. Treat the mixture 
with ililuted muriatic acid, which wiU dissolve the 
whole pxrrpt thr alaminx and sulphate of lime. — 
Dry tbi« residuum in a red-heat, and note the weight. 
7*heu boU it in cmrbonate of Boda, saturate the soda 
with murifttic acid, and boil the mixture for half an 
hour. Carbonate of lime and alumina precipitate. 
Dry this precipitate, and treat it Kith acetic acid. 
The time will be dissolTcd, and the alumina will re- 
main. Dry it and wci^h it. Its weight subtracted 
fram the original weight, giret the proportion of sul- 
phate of lime. 

The muriatic solution contains lime, ma^esia, 
■nd iron. Add ammonia as loog as a reddish pre- 
cipitate appe&rv. The iron and part of the mag- 
oeaift are thus separated. Dry the precipitate, and 
expo«e ic to tJie air for some time in a beat of 200" ; 
thea treat it witb acetic acid to dissolve the mag- 
nesia, which solution is to be added to the miiriatic 
solution. The iron is to be re-diisolvcd in muriatic 
acid, precipitated by an alkaline carbonate, dried 
and weighed. 

Add sulphuric acid lo the mariatic solution as 
long as noy precipitate appears \ then heat the 
eolation and coooeatrate. Heat the sulphate of 
lime, thus obtained, to redness, and weigh it. lOO 
grelDS of it are eciolvalent to 74.7 of carbonate of 
lime dried. Precipitate the magneida by means of 
carbonate of sodn. I>r7 it and weigh it. But aa 
|>art remains in solution, evaporate to dryness, and 
wash the residuum witb a sufficient quantity of dis- 
tilled water, to dissolve the muriate of snda and 
•niphate of lime, if any be still present. What re- 
mains behind is carbonate of magnesia. Weigh it, 
and add its weight to the former. The sulphate of 
Ume, if any, must al^ be separated and wciglied. 
^TuU coniinMrilJ 



MISCELLANEOUS EXPERIMENTS. 

Into a large glass jar, inverted upon a flat brick 
tile>, and containing near its top a branch of fresh 
rosemary, or any other such shrub, moistened with 
water, introduce a flat thick piece of heated iron, 
on wUch, plac« some gam benzoin in gross powder. 
The benzoio acid, in consequence of the heat, will 
be separated, and ascend in white fumes, which will 
at length condense, and form a moat beautiful ap- 
pearance upon the leaves of the vegetable. This 
will aerre as an example of tui/limatioa. 

Introduce a little carbonate of ammonia into a 
Florence Aosk. and place that port of the flask which 
contains the salt on the surface of a basio of boiling 
water : the heat will soon cause the carbonate of 
ammonia to rise nndeoomposed, and attach itself to 
the upper part of the vessel, affording another ex- 
ample of ahnji/e gnhlimation. 

Pill a glass tumble half full of Umc water ; then 
breathe into it frequently; at the same time stirring 
It witb a piece of gloss. The fluid, which before 
was perfectly transparent, will presently become 
quite white, and if suffered to remain at rest, rtat 
chalk will be deposited. 

Mix a little acetate of lead with an equal portion 
of sulphate of zinc, both in fine powder; stir tbem 
together with a piece of glass or wood, and no che- 
mical change will be perceptible ; but if they be 
rubbed together in a mortar, the two solids will 
operate upon each other ; an intimate union will 



take place, and a Jtuid triU hf pnnlvrfi!. If alum 
or Glauber salt be used instead of sulphate of tine, 
the experiment will be eqoally iocccnfat. 

Put a little fresh calcined magnesia in a tea-cnp, 

upon the hearth, and suddenly pour over it as uoch 

I concentrated sulphuric acid aa will cover the mag* 

Dcsia. Id an instant sparks will be thrown oat, and 

the mixture will be cumpUtety ignited. 

Put a little alcohol in a tea-cup, set it on fire, 
and invert a large bcU glass over it. In a short 
time an aqueous vapour will be seen to condeoae 
upon the inside of the bell, which, by means of a 
dry sponge, may be collected, and its quantity as- 
certained. This may be adduced aa an example of 
the formation of vo/rr by combustion. 

Pot a small piece of phosphorus into a crucible, 
cover it closely with common chalk, so as to fiU tho 
cracible. Let another cnioibU be inverted upon it, 
and both lubjeoted to tbe Arc. When the whole 
has become perfectly red hot, remove them from 
the fire, and when cold, the carbonic add of the 
chalk will have been decomposed, and tba kiatJk 
ek«rc<Ml, the bans of the acid, may be eaailj par- 
ceived amongst the materials. 

Let sulphuric acid be poured into a aancer npoo 
some acetate of potass. Into another saucer put a 
mixture of about two parts quick-lime, and one of 
sal ammoniac, both in powder, adding to tbcae a 
very 9maU (juantJty of boiling water. Both saucera 
while Btpanite will yield hmtible gases ; but the 
moment they are brought close together, the ope* 
rator will be enveloped in very vitidle roposirs.— • 
Muriate of aoda, in this experiment, may be aob- 
stitnted for acetate of potass. 
Take a glass tube vrith a bulb in form of a oom- 
^ mon thermometer ; (ill it with cold water, and su- 
pend it by a string. If the bulb be frequently and 
continually moistened with pure Bolphuric ether, 
the water will presently be^oren, even in nrmner. 
Dissolve five drams of muriate of ammonia, and 
five drams of nitre, both finely powdered, in two 
ounces of water. A thermometer immersed in the 
solution will show that the temperature is reduced 
below 32^. If a thermometer tube, filled with 
water, bo now suspended within it, the water will 
soon be a» tjfectually frozen as in the last experi- 
ment. 

Procure a phial with a glass stopper accurately 
ground into it; introduce aome rapper wire, tbn 
entirely fill it with liquid ammonia, and stop the 
phial so aa to exclude all atmospheric air. If left 
in this state, no solution of the copper will be ef- 
fected. But if the bottle be aflerwards left open far 
' some time, and then stopped, the metal will dis- 
solve, and the solution will be colorless. Let ttu 
stopper be now taken out, and the fluid vrill bccoma 
blue, beginning at the surface, and spreading grsda- 
aliy through the whole. If this blue solution hal 
not been too long exposed to the air, and fresh cop> 
per filings be pat in, again stopping the bottle, the 
fluid will once more be deprived of its color, whiA 
it will recover only by the rc-admikiion nf air.— 
These efi'octs may thus be repeatedly produced. 

Take a phial with a solution of sulphate of xbir, 
and another containing a little liquid 9mm< 
both transparent fluids. By mixing them, a on 
phenomenon may be perceived : — tbe line 
immediately precipitated in a white aanai, and 
then shaken, almost as iniiantly rg'di u chfed. 



toNKiiK — l»tlnl«d by U. F»a>ci». G, Wliilo H,ir»e Laii?. Mll« Ku-l ^PubllolioJ by W. BimAiK, 1 1 . l*altfniQtli>t Hv^ 
Commumeaucof. (wtiuh nrc auiwercU .Monliily.) to b« acldrctsed lo ^h^ Editor, at IT. ColtS|[9 Grvw, MUe Eiid Koad. 



THE 



MAGAZINE OF SCIENCE 

R^nd Scf)ool of Srtg. 




170 



MAGAZINE OF SCIENCE. 



• 



c. 



ELECTUICAL EXPERIMENTS AND 
APPARATUS. 

TnK object of the preient paper it to prove, by cj- 
prriment. the identity Iwlwrcn the electric Huid and 
lightniDg. We have already stJttcd thnt they are 
identicml, and in Vol. I, page 333, adduced nume- 
roaa reAsona in cxinfirmation of tht; fact. We shall 
now show upon wliat direct proofR the identity of 
the two rest; am), at tlie same time, explain the 
nature of tome useful electrical apparattts and ci- 
perimentJ. 

It is nec£SMry that when we operate with ac- 
cumalatcd electricity, nud deairo to pa^i a shock 
through a tuhfclauce, that we alioold hnve HOme 
means of holding it steadily, and dlrrrting the fluid 
in the exact line which we deaire. No apparatus is 
80 wrU adApted for genernl purposes of this nature, 
as Ifenlet/'« f^niversal DijiJiar^er, represented in 
Fig. I. A A are two thick brass wires, each termi- 
Dated at one end by a ring, and at the other by a 
ball and socket, which slips on and off, so that the 
inatrament may be naed with or without the balls, 
as required for particular experiments. The wires 
may be drawn out or in by slidinj; tliem through the 
Bockcta B n ; they may be lifted up or down by the 
joints C C, and they have a motion sidcwAys by a 
hall and socket, or other joint nt IJ D ; aU thi» part 
is of brass. The wires are supported upon the two 
glass pillars E G, which fit by their lower ends into 
the wooden feet F F, these lust screwing into the 
stand. The centre part uf the inatruiueiit consists 
of a small table of wood, with a piece n( ivory let in 
the top of it, G, and with a spindle below, fitting in 
the support H, and bound ut any required height 
by the screw 1. The letter J shows a amall presa 
of two pieces of baked wood, with screws to hold 
them together, and a spindle similar to that of the 
tiiblc, for which this pres« is sometimes sabatituted. 
When the uniTcrsal discfaargt*r is to be used, the 
two rings of thr wires are to be connected with the 
opposite sides of an electrical jar or battery. The 
object through which the shock is to be passed, is 
to be placed on the ivory which ia upon the table, 
one ball or wire touching each side of the object. 

Having described this instmmcnt, we proceed to 
prove that nil the etfccts of lightning can be easily 
imitated by tlie ordinary electrical machine and ap- 
paratus ; and, in doing so, it will be necesaary to 
recapitalat« the chief effects of lightning. 

First — Lightning destroys animal and regetable 
Ufe, 60 does electricity. 

Kr. 1. — Procure a mouse and send a strong shock 
khroQgh his body, from head to tail, and the pr>or 
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 form part of the circuit. 
We may be allowed to caution the yonng experi- 
menter, when amufiing himself in electrifying his 
frieucta, never to paaa a shuck along the back-bone, 
it often causes distressing synijUoms fur a long time, 
and may even occasion partial or general paralysis. 

Kr. 2. — The same sudden death will sciae upon a 
Bounder or other small fish, if a very trifling shock 
be passed through it, or a stranger one through 
the water in which it is placed. 

Bjt. 3. — Pass a strong shock from tlie top to the 
root of a balaam or geranium, and although no im- 
mediate efTect will be apparent, yet the plant will 
be effectually kiUed, ti will be evident after a few 
days. 




Seeond-' Lightning often renders 
and disturbs tlte magnetism of such at' 
magnetized. That this is the c 
notoriety. The compau needles on 
often seriously injured from this cause ; 
doea not always occur when a sb( 
through a magnetized needle depends 
cuiTisUince tlwt thn electrical and ma( 
act the one tangential to the other, ai 
lightning potscs close to the magnetic 
in a direction tangential to it, or across 
effect will Uke place. This is fully ex| 
the method of making a magnet descril 
29t^. of Vol. II, in an ardde on electro- 
,^ Third — Lightning destroys metals, ao 
trinity. 

Lightning condncton. the leaden pi| 
and churches, and nther metallic sut 
often seriously injured, if not totally 
when lightning has struck them. Tliii' 
the metallic 5ub»tnnce has not been stifl 
convey awsy the passing duid. There ■ 
experimenta which may be conducted nitk 
electricity, that show the same effect aa wm 
reduction of metallic oayde* ; among 
conducted of which are the following : — 1 

Ex. 4. — Procure two pieces of flat 
about 3 inches long, I^ inch broad 
them a strip of gold-leaf, i an inch or 
Dud long enough to bang out at each moi 
these glasses together with a piece of 
fasten them ia the tittle press belonging' 
vertal discharger, provioualy describeiT 
press in its phioe, and the two balU of ih« 
OS to touch tbe projecting ends of the goh 
psss a strong shock through the leaf and i 
melted, oxydated, and dnven into the surb 
glass. This experiment is illustrated 

Er. b, — Elevate and separate from 
the two balla of the universal dischi 
very Bne iron wire from one to the other; 1 
a shock through them and the wire, and if 
be strong enough the wire will immcdi 
red hot, or be melted. 

£x. 0. — Paint one side of a card 
moo water color called vcrmillion, and 
the tabic of the discharger, re^t the ball 
the diatancc from each other of about an inc 
ing the shock the fluid will run along th« « 
the painted card, and its paaaoge be 
strong black mark on tbe red 
from one hall to the other. If tiw 
off and the points of the wires rested 
the effect will be tbe aane or even 
than when the balls ore ii5cd. Occaaioi 
line will be seen. 

Fourth — Lightning rends to pieces 
and other bodies opposed to ha 
electricity. 

Ex. 7. — Rest upon tbe table of the 
piece of white paper, 4 or 5 inchea 
plncing the two ImHs about 'i iocbes from ea 
send a shock along the surface of the 
it will be rent in pieces along the 
fluid travel*. 

Bt. 8. — Piss the shock throngh a 
the balls of tbe discharger on each tidal 
to it, a minute hole will be pierced thi 
and what is very singular, a l/urr or pi 
is fomit'd on eoch side of the curd, 
stance hns been alleged as a proof that 
two electric fluids : ouc of which crvuei 



'A 

ih« 
goli 
ndi 
e surb 
dby 1 
am M 
targefl 
her; 1 
ndiri 

ndfl 
lalUl 




MAGAZINE OP SCIENCE. 



171 



, and Dtrh praduring tUown burr. It 
I Bmiril. ihiit the pBtMHige of tiic fluid in one 
' is from the poattivc to the nega< 
•Juce but one burr, in the same 
L> ^ piu wuuld da Cliriut tlirough tlie card. 
I ui quwIm; inference, bccaune a Jrili or indrcd 
wl tf fort.'rJ through fl yielding substance, like 
I, by « rarrtiUr motiDii, leavct a durr on IxHb 

M may be evtily proved by a taper bitt and 
>(Ml|i ; or by « «crrw forced througit the cover 
i9ok. or a rtm^r turned round i<t a piece of 
r. That tbis electric fluid is forced forward 
b the ocgntiTC lurfacc is evident from the very 
I of ■ thoclt, and that it hat a circular moUon 
e time, the whole science of electro- mug- 
to prOTC. A shock may be patted 
;li tbrre or four cards at once, and each have 
iWe burr. 

9. — Uang to the celling four or five sheets of 

paper, and pan a shock through it ; the wliole 
< paper will be pierced, without the paper being 

Alixbl(-st degrre oHived. Upon smeUing tbe 
i ttti- paper wlitch has been pierced, it will be 
J Uj\c a combined scent of sulphur aud phos- 
» ; a scent exactly analogous to tliat perceived 
'tuning haa atmck an abject close at hand. 

10. — Place betweeo the two bolls of tho dis. 
ST a amall tump of sugar, and und a shock 
[hit; the sugar will perhaps he broken, if not, 
I •er.ond and a third shock through it, when 
I the shocks have been very weak, and the 
UiT^c, it will not fail to be broken into many 
I. If this experiment be performed in the 

the sugar will give out at the time of the 
y aod fur half a minute afterwards, a strong 
iMriclighL 
. II. — TAe TMmnder Hi/use is oa apporatoi 

ahiiws the cfl'crts of lightning and it^ imj- 
^ Jt is represented in Pig. 3, and consists of 
B^ piieoti of baked wood, made like tbe gable 
Imat, placed upon a wooden stand. A strong 
wltJb a boll at one end and a hook nt the other, 
lowo the upright piere ; it is interrupted in 
r two places, by a hole cut in the upright, 

one inch square and a quarter of an inch 
be aurfocc ; into these holes are fitted fif|0Ares 
od. tbat take out and in very easily. They 
I wire running across them in one direction, 
ai if the squares are placed in one way, tbe 

upright is furuisfaed with a continuous wire ; 

other way, the wire is interrupted, because 
in \a tbe small piece or pieces runs across. 
ttd so as to be continuous, a shock may be 
i di^wti the whole boose, without injiu'y ; but 
her of the pieces ore placed with the wire 
, that pircc upon passing the shock through 
ire would be ihrawn out, showing a close 
jj with the effects of lightning, when it passes 
•a NBpeffect, or rather on interrupted con- 
r. 

, 12.— Pig. 4 reprcsenU T&e BUetricat Obe- 
LAj^i, ^..^. -'a of four pieces of wood, standing 
■h I- tlirt*e Mjip<-r onea resting on 

pftU J lit ball is supported by a moveable 

Af woixl, hke that in the thunder liouse, aud 
Ifae fthodt is passed, the piece is thrown out in 
laoner, and of course lets the obelisk fall. 
h — Lightning sets fire to stacks, ships, build- 
>ko. 

liATe already, in a paper showing the healing 
^f tlrctricity, (in Vol. tl, pogL* :i22.) seen thai 
Mob»t«Dcet may be readily iulluiuvd by the 



spark and shock ; we need not, therefore, dwell 
long u[Kin tliis, yet tbe present notice would be in- 
complete were we wholly to omit an iUoatration or 
two. 

Rx. 13. — iZosin F^rtd. — Tie loosely round one of 
the balls of the universal discharger, or round the 
ball of a common discharging rod, a little loose tow ; 
when tied on, roll it in powdered rosin, and oend a 
sudilea shock through it, when the rosin will be 
infiomed. 

Ex. II.— Fig. 5 shows The Eheirie^l fhrt .■ we 
bare shown it with three cannoDS, but itis more con- 
venient and effectiTe witb four. The cannons and f*»rt 
are of ordinary make, obserring only tbat the fort 
should be of very dry baked wood, nod tlic canuoiia 
hove extra touch-holes made of a piece of paper, 
sh'iped like n funnel, and fixed on with sealing wax , so 
tliat there may he a grealer body of gunpowder than 
they would otherwise hold. The passage of the 
fluid is MS follows : — One side of the charged Leyden 
jar is connected with a chain that dips in a basin of 
water. The chain F also dips in the some water 
by one end, and is connected with the outside of 
tbe cannon A. The 6uid then passes through the 
gunpowder of this cannon to the wire U, and runs 
along this to the next cannon B. It passes through 
the gunpowder here, and inflames it, as it did the 
former ; it has now reached the outside of this can- 
non, end passes by a wire E, under tbe platform of 
the fort to the outside of the lost cannon C, and then 
goes through the touch-hole to a wire G. that may 
lead it away to the Lcydcn jar again ; thus com- 
pleting the circuit, and proving, at tbe same time, 
tbe inflaming effects of the electric Huid and Ita 
great rapidity of motion, as it will be fuuiid that the 
cannons, however numerous, or however far apart, 
all go off so simultaneously as to be beard as but 
oue report. 

CONVERSION OK CARBON INTO SILICON. 
A oiscovBKY has been Utely made, which is likely 
to extend widely the bnnndaries uf chemical science. 
The views of the alchymists, with regard to the 
transmutation of metAls, are now shown to be of 
possible realisation. Chemists have ceased to draw 
any line of distinclioo between those bwlics ordi- 
Dsrily termed metals, and other elirroentary sub- 
sUncea ; j. e. in proceeding throngh the list of 
elements, from oxygen to platinum, we cannot say 
where the metallic property commences. Now 
Dr. S. Browu, of Edinburgh, bos given proof, in 
a paper read before tbe Iloyol Society of that place, 
that the elemetitary body, carbon, can be converted 
into silinon, whirh last substance was, not long ago. 
considered metallic. Observe, this is not the de- 
composition of silicon, or rather the formution of 
it, from n new base, but the proof of tbe absolute 
convertibility of one elementary body Into snother, 
which we must still regard as simple. Tliis grand 
discovery, second to none that has ever been made 
in science, and likely to prove of vast benefit in its 
results to the resources of the arts, is the work of 
a young man — who hnd, however, given proof of 
the greatest powers — c.r j/ede firrculcm. Like 
other great discoveries, it has been preceded by 
such indicative facts as might gradually induce us 
to regard it as possible. We allude to the doctrines 
and facts of isumerisra, which showed that some 
compound bodies, presenting on analysis tbe same 
chemical composition, might yet ditfcr greatly in 
properties. In tliesu cases it was cunceived that 
the atoma might be difr«jrtnlly arranged, or that the 



172 



MAGAZINE OF SCIEKCK. 



compoBiUan of the one body miglil be rcpresentctl 
hy duubliog the Moms of tlic olber, and to furth. 
Tfans. if we bave a body whose compoflition may be 
represented by a b, we may write it i a, or twice 
a h. Now, as our only reason for bclicTiog any 
body Co be simple is, that we are anable to decom- 
pose it, it is quite possible that some of the bodiea 
which we coU simple mij^ht really be compound 
ftod isomeric- But to sum op the fdcts prrseoted 
by Dr. Brown : — Hia late communication is purely 
of a practical character, the author baring retrained 
from presenting what he conceives to be the rntionale 
of the aiDgnlar facu be baa dincovcred, until furthrr 
inTestigntiuni of a similar kind shall hare been 
executed by himself or others. The manner in 
which the author cstabliahes the Isomerism of car- 
bon, and iilicon la Tery simple, and cousists in 
giving a great many processes by which the former 
may be converted into the latter. These are coa- 
Uined in a scries of fire sections. The first treats 
of tbtj production of silicon from free paracyanozen ; 
Uie second, of Uie formation of mixed siUdureta of 
copper, iron, and platinum, by the re-action of 
parecyanojcn ; the third, of the ijuantily of nitro- 
gen Bfp.inited from paracyanozen, when it ia changed 
into nitrogen and silicon ; the fourth describe* pro- 
cesses for the preparation of transparent crystallised 
liliciuret of iron from the poracyanide of iron and 
the ferro-cyanide of potassium ; and the fifth gives 
easy procesacs for the extraction of silicic add from 
ferrocytnide of potnisium by the action of car- 
bonated putau. The last of these processes baa 
been rrpcatLd in the laboratory of the Newcustle 
Medical Sdiool. .ind found to give the result de- 
aoribcd by Ur. Brown.— A/iK»ny Jonmuf. 



ON CHLORINE. 
CilLORi?rB was discovered by Schccic in his experi- 
ments on oxygen, in 1774; be colled it dcpblo- 
gisticated muriatic acid, but it afterwards obtained 
the name of oiy-muriatic add. 

Its specific graiity, compared to hydrogen, Is 
33'3 to 1 ; 100 cubic inches weighing 73-375 grains. 

It ia a permanently elastic gaseooa fluid, liaving 
a pungent and disagreeable odour, and being highly 
iiijarious whtn respired, ercn though it be largely 
diluted with atmospheric air. lu color is a greenish 
yellow. Cldorine is not altered wlien expuscd to 
the highest temperature, which wag proved by Sir 
U. Dsvy, by means of the foUowiug experiments : 

Er. 1. — Provide ■ gloss globe of about \ inches 
in diumcter, baring at its upper port a sliding wire 
passing air-tight through a ground collar, to the 
lower end of which is attached a piece of well 
burned charcoal. At the bottom is a stop-cock 
supporting n pair of brass pincers, in which tlierc 
ia another piece of charcoal. The globe is I'xhaustcd 
upon the air-pump, filled with chlorine, and the 
aiop-cock and sliding wia attached to the extremities 
of a galvanic battt-ry. The charcoal poinU are 
then pushed down, aod retained as long aa necessary 
iu igniiiuu. 

Kr. 2.— To obtain cldorine from bliirk oxyde of 
manganese and muriatic uctd ; provide 4 ounces 
of the osydc, aitd oild as much muriatic acid as 
will make it of the consistcuce of thick cre^m. 
Mral it in a glaM retort, and collrct the ^as at the 
piitwmatic troush. but observi! thnt it is absorbable 
by fold water, and only pattiuUy so hy hot. 

Ki. 3. — From blaek o»yile of mnng'mesc, salt, 



water, and sulphuric acid, lake 6 porta of ttmxmaa 
salt, '^ of the osyde, 1 of water, aud 6 of sttlpboHc 
nctd. 

Ex. A. — Take one volomn of water aati tww of 
chlorine, and the water will absorb the gas. This 
solution is of a pale ytllow color, has an sslnngvol 
taste, and destroys vegetable colors ; hmce its use 
in bleaching, though the gas ii^rlf, when pvrfEctlj 
free from njoisture, has hardly any cflect on then. 

Ex. h. — Take a small piece of phosphoma ami 
pat it in a deflagrating ladle, aod immerse it la 
a jar of chlorine, when it will bttra with gmi 
brilltaoer. 

Ex. G. — Provide a wire, and attach '« pieec «f 
a taper, aod immerse into chlorine ; when Ihr 
brilliancy of the flame becomes impaired, it appear* 
red, throws oR* much carbon, and is nearly ex- 
tinguished. 

Ex. 7. — Vary Ex. 5 by iotrodiicing copper leaf, 
antimony in powder, and a finr other mctala. 

Er. 8.— To make oxyde of chlorine, prooeed w 
follows: — Upon 10 or 12 grains of cbloraie of 
potash, drop a small quantity of sulphuric aiil, 
and stir the mixture with a platinum knifs, hstffaf 
so adjusted the relative quantities of the »a1t aii4 
acid ttiat they may form together a yellow liquid. 
Put thic into a small retort, and heat it by meaoa 
of a water bath to IfiO". Oxyde of dilorine will 
pass ofl'i and may be collected over quicksilver In 
small jars or tubes. The oxyde has nn odonr aome- 
what resembling that of chlorine, but mnch IcM 
irritating and disagreeable. Its taste ta astringeat, 
and not at nil acid. It dissolves in water, formifij 
a lemon-yellow colored solation. 

Ex. y. — Heat gently some oiyde of cbl< 
and it will he decomjtoscd vrith explosion ani 
panslon. Two volumns are enhrgnl into thrrc, 
which two consist of oxygen, and one of chlortac 
it is therefore com]>ofled of 33*5 parts, by 
of chlorine, combim.'^d with 30 of oxygen* 
gas was originally cnllcd cuchlorioe by Sir H. 

Ex, 10. — To obtain chloric add, take a 
of oxyde of silver and water, and pass a ci 
chlorine through it. Chloride of silrrr is p 
which is insoluble, and may be separated by filtri 
The excess of chlorine, which the filtered 
contains, is separable by heat, and the chio 
dissolved in water, remains. It is a soar, 
liquid, producing peculiar compotmdfl, 
chlorate of potash. It fbrms uo predpl 
metallic solutions. 

Ex. 11. — Muriatic acid, (or accordiag lo 
new nomenclature hydro-chloric add,) la a 
pound of hydrogen and chlorine. Mix 
volumns of these gues, and eiposc then 
light, aod the add will be formed. Having aae^te 
portion ready, expose it to tlie direct lolar rays, 
and u detonation will ensue. The same rrsalt U 
observed if it be exposed to the light of the volttie 
discharger. 

Ex. 12.— Chloride of nitrogen. Chlorine tnt 
nitrogen do not nnite directly; hut the coBD|Kmai 
may be obtained by exposiug a solution of nitral* 
or muriate of ammoaia to the action of a currMt 
of chlorine at the tcin|K:rKlure of tlU" or 70^. 1^ 
gas is nbsorbcd, and an oil-like fluid heavier thai 
water Is produced. This ^wuld be experiiaenlsd 
U]H}n with great care, as it is very exploiive. 

Ex. 13. — Ammonia and uhlorinr. >\'hen (hOM 
gnses are mixed, a partial dccumjiosiLion of ths 
furuier cnsuco. Take of amuioniu 10 |i.irt0v ana 
mLx with 15 of chlorine ; 3 parts of nitrufO an 



l:i 



MAGAZINE OF SCIENCE. 



fttnl mumcc of acnmonia is formed. U 
htf iterievliy drj, beat is eToIred, ntid a 
U MJd to traTCne the resad in ivhlch the 
It fonnvd. 

Rr. 14. — CliIortd« of sulphur. Heat ntplivr in 
A£0rinc ; it iibaorin rather more than twice its 
vwjglit of Iho fu, and formi a grtKnub yellow 
i^fidi. cxit^atsting of 15 iiu]j>hur and .'\3'.'i of chlorine. 
U vximlrt nlTocatiog and irrltAtin^ fumet when 
crpOMtt to the air. Ita cpccific gmvity is 1'6, anil 
4ut>Irea aolphnr and pbosphoms. 

Kr, \S. — Chloride of phusphorus, consisting of 

II fhospbonu *nd .'i3-r» chlorine, is procored by 

totlTiBf K mixture of phosplionis and corrosive 

i^btiiialg, or |KrchIoride of mercury. Csloroel or 

pntoddoiridc is left in the retort, and the phos- 

oeabities with one proportion of chlorine 

iftpttiM* over. 

Ar. 10< — Take a jar of chlorine nnd immerse in 
a |«{«cr ^ftitcd in oil of tarpentiuc, and the gas 
i-II btflaine the tnrjienline. 

C mit tn, — CUlurinc must be experimented upon 
Mk frrit care, from its jiangent odour and 
Ltittf; pfDpcrtici ; and it is advisable for 
^rciiinrrs not to cxpcrimeut with tiacb things 
L|d£ of chlt^rine, chloride of nilrogun, \c. 

CUEMlCUa AUATOH. 



AyAl.YSrS OP MINERAL WATERS. 

f Jif^tmmcii/rom pa^ 168, ami concbuUxLj 

ri;-jct to ascertain the proportion of 

iilkalis, if any be present uncora- 

1 j-.r ,1. ..I.-* which may be present, omittinif the 

t, 5UT iliC salphuHc, muriatic, and the Iwracic. 

prop'irttnn uf sulphuric acid is t:aKiIy dcter- 

Satamte it with barytes water, and ignite 

Itate. 100 ^:raiui of sulphnte of barytes 

tndieate 34.0 of real sulpharie acid. 

lie ibc muriatic add with burytcs water, 

precipitate llic barytea by suljihurie acid. 

of the ignited prei'ipitatc arc equivalent 

t ^,Ai-,-: ..f real muriatic acid. 

borocie acid by meaoa of acetate 

>j>ose the borate of lead by boiling 

acid. Evaporate to dryness. Dis- 

ic nHd in nicohol, and tvaporate the 

:" I may be neighed. 

I of ulkalinc carbonate 

^ rxi,^ . L....L^..w<,|^ it, Batiimtc it with 

•crd, and note the nciglil of real acid 

Now 100 gmini of re-ai sulpharie acid 

I21I.0 potash, and 80.0 soda. 

T- 3^1 'lino jralphnte* may be estimated by 

\r snid by means of nitmte of bn- 

vinualy freed the water fiom all 

' ' '' grains of ignilwl sul< 

I Ains of dried sulphate 

:, . Lc of barytes indicate 

ol poioah. 

.i''< U easily irstlmated by cmpora- 

•"g it, to a few ounces (hav- 

I the earthy carboDstes n-ith 

I', ftiiLt {•:>-i'i]>iuting the »ulpliate of lime 

iA weak alcohol. It may then be dried 

■ rilu'H miy be cstimnted by prcci- 

lina by carbonate of lime or of 

^if uu lime be present in the liquid).^ 

(Taint uf the sluniioii, hctited lu tiu-sn- 

IwtfaLe loo of eryBlallixcd alum, or 05 of 



1 

is. 
to 



Snlphate of ma^esiu may be estimated, prori* 
no other sulphate be present, by predpitating t) 
nciti by mt^mis ot a barytic salt, as 14. 7j porta of 
ignited sulphate of barytes indicaLe 7. lli of sul))hat 
of magnesia. If sulphate of lime, and no othi 
sulphate, occompnny It, this may bo dcetim|K>«e( 
and the lime precipitated by carbonate of magnesia. 
The weight of the lime thus obtained, enables us to 
ascertain the quantity of inilphate of lime cantaint 
in the water. The whole of the sulphuric nt^id 
tbrn to be precipitntrd by barytes. This gives tl 
quantity of sulphuric -, and subtracting tho portion 
which belongs to tht sulphate of lime, there remains 
that which was combined with tlte magnesia, from 
which the sulphate of magnesia may be estimated. 

If sulphate of soda be prest*ut. no earthy hitratj^l 
or muriate can exist. Tbcrct'orc, if no other eortll^^l 
sulphate be present, the magnesia may be precipi^^ 
tated by sods, dried and weighed; 2.iC groins of 
which indicate 7.1G grains of dried iulphote 
magnesia. The «.ame process succeeds when st 
pfaato of lime accompanies these two sulphates 
only in this case tlic precipitate, which consist* bt 
of time and magncflla, is to be dissolved in sulpht 
acid, evaporated to dryness, and treated with twl( 
its weight of cold water, which dissolves the sul- 
phate of magnesia, and leaves the other salt. Let 
the sulphaCci of uiagnesia be evaporated to dryness, 
exposed to a heat of 4U0', and weighed. Tbe same 
proce&ses succeed, if alnm be present instead of Ba|S 
pbate of lime. The precipitate in this case. prfllH 
viously dried, Is to be treated veith acetic acid^ 
which dissolves tiie mairnesia, and leaves tlic ulumina. 
Tbe magnesia may be iigoin precipitated, dried, and 
vreighed. If salj^hate of iron be prcient, it may be 
separated by expobing the water to tbe air for somc^ 
days, and mixing with it a portion of alnmina.-^fl 
Both the oxide uf iron, and the sulphate uf aluminiq| 
thus formed, precipitate in the stjite of an insolable 
powder. The sulphate of magnesia any then bo 
estimated by the rules above given. 

Sulphate of iron may be estimated by prccl] 
tating the iron by means of pruasic alkali, havi 
pre viouAly determined the weight of the preciplt 
produced by the prussiate in a solution of a givi 
weight of sulphate of iron in water, if muriate of 
iron be also present, which is a very tore case, it 
may be separated by evaporating the wuter to dry- 
ness, snd treating the rvsidonm with alcohol, which 
diisoKes the muriate, and leaves tbe sulpliate. 

A. If muriate of jiotaah or of soda, without any 
other salt, exist in water, we have only to decom - 
pose them by nitrate of silver, and dry tlie precipl^^ 
tate; for 18.2 of muriate of silver indicate 9.& *^| 
muriate of potash; and 18.2 of muriate of silver io- 
dicnie 7.5 of common suit. 

The same process is to be followed, if the alkl 
line carbonates be present ; only these carbouat 
must be previoosly snturstcd with sulphuric kci< 
and we must precipiUile tbe muriatic acid by memit 
of sulphate of silver inttoad of nitrate. The pre- 
Bcncc i>f snIphatK of soda does not injure the sue- 
oesa of this process. 

If rouriste of ammonia oocompany either of the 
fixed lUkalint sulphates, vrithout the presence of any 
oIh«r snit, decompose Che &nl amuioiiiac by baryl 
wnlcr, expel the ammonia by boiling, prcclpiti 
by diluted sulphuric acid, and saturate the murint 
acid with soda. The sulphate of bttrjtes thus 
cipttate<l, indicates the quantity of mnriute of at 
moni'j, I4.7ri gmins of Miiplmte indicdtini; 07^ 
graiua uf this salt. If any sulphate* br present ~ 



a uo 

m 



i<tfl 



^^ik 



MAGAZINE OF SCIENCE. 



the ftolntion, they ouglit to be previously separHted. 
If common salt be accompaoied by mDriale of 
lime, mariate of nos|^eii8, muriate of aluniJua, or 
inoriate of iron, or by all thcac together, without 
any other salt, the cartba may be precipitated by 
borytes water, and r«dis8ol?cd tn muriatic acid.— 
They are then to be separated from each other by 
tlie ruin formerly laid down, and their weight, be- 
in^ determined, indicates the qaantity of CTcry par- 
ticular earthy muriate contained tn the water. Fur 
50 grains of lime indirat^ 100 of dried muriate of 
lime; 30 grains of magnesia indicate 100 of the 
muriatic of that earth ; and 21. H grains of alumina 
indicate 100 of the muriate of alnmina. Tttc barjten 
ij to be separated from the solution by sulphuric 
acid, and the muriatic acid npelled by heat, or 
saturated with loda ; the common salt may then 
be ascertained by evaporation, subtracting in the 
last ease the proportion of common salt indicated 
by the known quantity of mDrintic acid, from which 
the eartlis had been separated. 

'%'hen sulphatf?9 and muriates exist together, they 
ought to be separaled either by precipitating the 
snlphales by mcana of alcohol, or by evaporating 
tlie whole to dryness, and dissolving the earthy 
muriates in alcohol. The salts thus sepnratcd may 
be estimated by tlie rules already laid down. 

When alkaline and earthy oioriatca and sulphate 
of lime occur together, the lost is to be decomposed 
by means of muriate of barytes. Tbe precipitate 
ascertains the weight of sulphate of lime contained 
in the water. The estimation is then to be oon- 
dnctod as when nothtug but niuriutrs are prearnt, 
only from the mnriatc of lime that proportion of 
muriate must be deducted, which is known to have 
been formed by adding the muriate of barytea. 

When muriates of soda, magnesia, and oluniLaB, 
are present together with sulphates of lime and 
magnesia, the water to be examined ought to be di- 
Tided into two equal portions. To the one portion 
add carbonate of magnesia, till the whole of the lime 
and alumina is precipitated. Aacertain tbe quan- 
tity of lime, which gives tbe pro|H)rtion of sulphate 
of lime. Precipitate the sulphuric add by muriate 
of barytes. This gives the quantity contained in 
the sulphate of magnesia and sulphate of lime ;— 
flubtroctiog this last portion, we have tbe quantity 
of sulphate of magne&ia. 

From tbe second portion of water, precipitate all 
the magnesia and alumina by means of lime-water. 
The weight of these earths enableii us to ascertain 
tbe weight of the muriate of magnesio and of aluminu 
contained in water, subtracting that part of the 
magnesia which existed in the state of sulphate, as 
indicated by the examination of the first (wrtiun of 
water. After this egtimotion, precipitate the suU 
phuric acid by barytes water, and the lime by car- 
bonic acid. The liquid, evaporated to dryness, 
leaves the common salt. 

6. It now ouly remains to explain tbe method of 
ascertaining tbe proportion of tbe nitrateH which 
may exist in waters. 

When nitre accompanies sulphates and muriates 
without any other nitrates, the sulphates are to be 
decomposed by acetate of silver. The water, after 
filtration, is to be evaporated to dryness, and the 
residuum treated with alcohol, which disaolves the 
acetates, and leaves tbe nitre, the quantity of which 
may be easily calculated. If an alkali he present, 
it ought to be previously saturated with sulphuric 
or muriatic acid. 

If nitre, oommOD salt, nitrate of time, and mu- 



riate of Lime or magnesia, be present together, tlM 
woter ovght to be evaporated to dryneaa. and tlin 
dry moss treated with alcohol, which takes np tha 
earthy salts. From the residuum, redissoWed la 
water, tbe nitre may be separated, and i^lcnlated as 
in the last case. The alcoholic solution is to be 
evaporated to dryness, and the reaidumn redlsaolred 
in water. Let us suppose it to contain muriate of 
mogncaia, nitrate of lime, and muriate of lino^ 
Precipitate the muriatic add by nitrate of 
which gives the proportion of muriate of 
and of lime. Separate the magnesia by means of 
carbonate of lime, and note its quantity. This give* 
the quantity of muriate of magnesia ; and sabtnct- 
ing the muriatic acid, contained in that salt, fnm 
tlie whole acid indicated by the precipitate of ulver. 
we have the proportion of mnriate of lime. Lastly, 
saturate tbe lime added to precipitate the magnesia 
with nitric add. Then precipitate the whole of tha 
lime by sulphuric acid ; and subtracting from the 
whole of the onlphate thus formed, that portion 
formed by the carbonate of lime added, and by the 
lime cx^ntained in the muriate, tbe rcaiduum gives 
ua the lime contained in the original nitrate *, and 
35 grains of Ume form 100 of dry nitrate of Ume. 



ENGRAVING. 

rAuuoNM/ /rum pag* 111^ 
Next to the tools necessary, it is advisable to 
olfer H few remarks npou the materials employed. 
The chief of these is, of coarse, the subat&noe to be 
engraved upon, cither copper or steel. Plates u( 
thcsi; metals, of various sizes and Uiickxteaseo, ore 
prepared ready for the engraver by persons who 
make it their sole employment ; and those who ore 
able to procure them thna prejiared, will find It 
infinitely better to do so than to prepare the plates 
themselves; but ^oald they live far off in the 
country, or for other reasons desire to prriwv 
their own copper-plates, (for steel, tliey will, per- 
haps, not attempt,) the following observationi msy 
guide thcra : — Let them procure a sheet or piece of 
thick copper, the thickness (if a small plate) bong 
about equal to that of a thin mill-board, or (bv 
cards pasted together. Let them carefully 
and polish both sides with und, emery and 
or charcoal ; wiping this off carefully that do 
may remain, let the plate be paased two or tbrta 
times through a flatting mill, or wanting this, let it 
be planished by a tinman, directing him to keep U 
perfectly flat. When this is done, and the oopfer 
thereby hardened, let one surface be rubbed oU 
over with a piece of «nake stime ; a piece of Aom, 
Jiiw slate, or lithographic stone will do as wrll. 
When tbe plate is thus made smooth, and the 
inequalities of the hammer arc removed, mb U 
over in the same manner with a piece of fine diar* 
conl and oil; any bark, knot, or grit in tht 
charcoal being first carefully rasped off" it. Inolead 
of charcoal fine washed emery may be used. Finally, 
the plate is smoothed around the edges with a pUne 
or file, and pulisbed with whitening. It will no« 
be tit for use: a great deal of tbe success of tbe 
after operation will, however, depend upon <h( 
quality of the copper, as well as the prvporatioti of 
it. Another method by which a plate may be mods 
at once, is by the electrotype process. A plate, ii 
a pattern, being first procured, another pUte cnsf 
be deposited ujion that, which being removed, I 
secuiul ajid a third plate la like maniker lusy (S 
CA&ily be made, and if the opcraboD has been wtU 



10 jHF 



MAGAZINE OF SCIENCE. 



175 



la AC 



conducletl, nil will be of excellent quolityi and 
ciMt but a trifle i (the whale procesn of the elertro- 
t|pe will be foand ia Vol. I;) indeed thou&ands of 
pUtev are now made in Ijondon by this process. 

The next material is ticking yruund. The oae of 
it b to Uj a ground ujwn the pUte prcTious to 
clcMog it, oj afterwards desaribed. It may be 
bottf hi along with the platea. or it may be made by 
tW following receipt, and which, by experience, we 
kaow may be depended upon. The prescribed 
qaauUty will make enough to laiC for a long period, 
ftud co^er a great nainber of plates: — MeU together 

1 oaxice uf white wu, 1 ounce of aiphaltum, and 
ft qoiirteK of an ounce each of commoa pitch and 
Bargundy pitch ; let tlic wboto boil ten minutes, 
tb«n pour it into cold water, and mould it into a 
ball with the hands ; when cold^ tie it up id a piece 
of tilVi or tafTeta. 

Bordrring wax la • substance oaed to form a 
ridge around the plate when it hat been etched and 
ia about t^i be biuen iu by the acid. Ita only use 
to prevent the actd from running off at the edges 
ttie plate ; common slioo-makers' wax will do 
well ; so will glaxters' putty, though the 
ftkU<ming ia most naiully employed. Aa it ia not 
mat^d when in use, a stock of half a pound will 
last for yean : — Melt together 2 ounee« of rosin, 

2 ouncca of common pitch, and I ounces of yellow 
bBtei'<wax ; when melted, pour the mixture into 
edd water, and as icon as it is sufficiently cooled, 
Imead it well with Uie bands. 

Aadt required. — It is adrisable in procuring a 
•apply of add for biting in, to chooae the stroDg 
Bitric acid, and not the common aiptaforti* ; atrength 
lur strength, it is but little dearer, and the en- 
gmTer knowing the article he is operating with to 
be of first quality, can proceed with greater confi- 
dence. It should be diluted only when wanted, 
•nd ID a degree according to the nacure of the 
subject— this practice atone can teach. 

Brutunrirk blark vamiMk is purchoseablc at most 
Mspectable oil shops. Its use to the engraver is to 
tt^p otti, that is, to cover over false lines, and other 
daisetaf previous to bitine in ; and alto during this 
part of tbe process, when a portion of the plate is 
Utiea in enough, the rest of it rerjuiring a further 
iOtioa of tbe acid. To be good, Brunswick black 
aboold dry in three or four minutes ; it may be made 
by diaaolving aspholtum in spirits of turpentine. 
If too thick at any time, it is to be diluted with 
»I>ints of turpentine. This Liquid must therefore be 
in readiness, not only for the above, but other pur- 
poses, olterwardi described. The Brunswick block 
rsmiah is to be laid on with a camel's-hair |>cncil. 

A irax taper Is the last material required. The 
intention nf it is to smoke the ground of the plates, 
preriooa to transferring the picture which is to be 
eicbed upon them. The taper adapted to this pur- 
pose is that which ii white, very long, and about 
the thickness of a goose quill, sold nt oil-shopi for dd. 
Procure one of these tapers ; if the weather be cold, 
soak it for a few minutes in luke-warm wotcr, draw 
it out in length, wipe it dry. and fold it up or else 
rut it into eight equal pieces, which are to bo twisted 
together, furming us it were a candle with eight wicks. 

A dabber is also wanttrd ; this may very easily be 
made by the artist, as it consists merely of a hand- 
fel of wool or cotton wadding, tied up in a piece of 
silk ; some persons put inside and behind the wad- 
ding a piece or two of ttiff card, cut of a round 
ism, in order to make the dabber keep its shape 
betteff bat this is bjr no means necessary. Tbe 



dabber is used In llie Arst process of laying tbe 
ground evenly upon tbe pbte to be etched. It is, 
therefore, indispensable. 

Ad oil rubber is made of a long strip of woollen 
cloth or flannel with the sclrage to It. Take about 
two yards in length of this list, and roll it up tightly 
tike a ribbon on Its roller, so that tbe selvage shall 
form an even flat surface. Tie it tightly together 
and keep it for use ; it la Taluable in cleaning off a 
plate, after the scraper, burnisher and charcoal has 
been used upon it, it is rubbed over the psrt of the 
plate requisite, together with a little sweet oil. 

Tbe writing engravers, and those vrbo execute 
mathematical engravings, often require little trifles 
in addition to the above, but as they urc only of 
partial use, and not even absolutely necessary, we 
have not (thought it requisite to mention them. 
These are, indeed, all the materials requisite for the 
most extensive business, costing, with the cxcepiiun 
of the copper and steel pUtcs, altogether, both tools 
and substances, not more than 6t. or 7». The next 
paper will explain the process of etching. 

AWe- — Coppsr and *iw\ plale« for sngravcn, and alK> cU^li- 
tDg iroimd, may b« purcbasvd of Mr. I)ugbe«, Slio« l^n*. 
l^mcTin ; or uf Mr*. L^rgc. DttSiiSlr»el, Fetter LaDC, Londoo. 
A plAto of cop|N*r. the itM of the (iruilleat card. eo«tf t^U. 
Next iiu cord. Id. A plot* Rboai iho tiiv of oa« P^ss of 
this liook may b« Xi. or 3#. tJ. The avTieral pric* U 3«.lr tb 
weiglii. SU>el double the price. A ball of etcbtag graund 
coatji If. Engraverft' looiii may b» boaght of Mr. Kntghl, 
Koilar Loiw ; Mr. Fenn and Mr. Buck, Newfal* Slroet; nml 
Mr. HolUalTr). Charing Crosi. HravcrB are from Zit. to &(. 
pocli . haiidlea to ditto. Id. A tfamisbtr. Ij. ScraiMr. 3$. (kl, 
HtclilRf Deedlo, Bii Saod cuihlon*. of varkraa piiois— oua 
coitius ti. la ftl for ordinary occailoiis. 

FLAT mON WIRE ROPES. 
Round iron wire ropes have for upwards of two 
years been successfully used in the collieries on the 
Continent. Another improvement in these ropes 
has been mode, which will render them still more 
useful. M. Louis Goens, manufacturer at Ter- 
CQondc, in Belgium, has obtained a patent tor Jiat 
iron wire ropes. This cordage, which resembles in 
a great degree flat hempen ropes, possesses extra- 
ordinary strength. When properly applied, it will 
last twice or three times as long aa the ro{>cs in 
present use, snd yet the new rope costs a fifth less. 
Independently of these advantages tbe flat iron wire 
cord is more flexible, leu bulky, and a great deal 
lighter than the ropes now used. The latter fact 
deserves the serious attention of mine proprietors 
espedally, for a great quantity of power is now un- 
protitably employed in deep shafts in bringing up 
the weight of the rope alone. The first of tliese flat 
iron ropes manufactured by M. Unens, were applied 
by Messrs. Picard, Davigiton, and Co., proprietors 
of the coal mine of La Bonne Fortune, near Ans, 
where they are now working, and give great satis- 
fscLion. Those gentlemen were the first mine pro- 
prietors who employed the round iron wire ropes. 

POLARIZATION OP LIGHT. 

To tki Bditvr, 
Sin.. — In the interesting article on the polarixation 
of light, recently published in your Magafine, 
there are two or three obserrations which ba»c in- 
duced roc to solicit further Information ; in doint; 
so, I would remark that it is a subject to which I 
have given some atlenlion, and that I have had con- 
aiderable experience in the use of an oxy-hydrogen 
pulariscoiw. I make these remarks that it may not 
be supposed that I ask idle questions, or that I seek 
lufoxmalion tg be procured, by reading the ordl- 



176 



MAGAZINE OF SCIENCE. 



narjr trcatiiifs on the subject. In the artick in 
quuHon it is stated tbnt ■ Nicol'iv prism is the best 
ttiulyziDg medium, uid a Jnwinf; is ^iveii in illus- 
trmtion. 1 am foWj awaro that it \a far superior to 
erery other Gualyiin;; npparstuA in ordinnry csprri- 
iu«nt, but I cannot conceive how it ia applied to the 
oxy-hjrdrogea polari scope. 

Now >vbat 1 would particnlarly uV l«, irAe/An- 
or not such an ntitrument hat been constructed ? 
And if ID. where can it be seen, or a particular de- 
scription obtained ? 

]t is also stated that polarization ib best cffboted 
by reflection ; but I bare beard that oxy-hydro^n 
polariicopes are mndc hy Carry, in the Strand, in 
which the light ia polarized fay tranamisEion through 
a bundle of glass pUtea, and that the colors are 
morr brilliant than those produced by the reflecting 
polariscopei. Can ycni infnrm me if this is correct ? 

Agnin, it is stated tliat the light is also annlyzM 
by being transmitted through sixteen plates or Alms 
of mica ; liut tlii« mica is not the mineral in its 
natural condition, it is prepared in some way be- 
fore it is fit for experiment. Can yoa inform ms 
in what way it is prepared ? e. w, 

r.S. — Is the drawing (Fig, 1. page 113) made 
firom an instmment, or ia it ■ design for one ? It ia 



I rery onlika the instrameots I hare seen. Wliy is 
the light made to pasa through three leases ? 

[The article on the polnrisatioa of light we atated, 
I in the comfflenccment of it (sec pSge 3?). to be 
written by Mr. Guddard. the inventor of the polari- 
acope afterwards described. The original wiU lie 
' found in a recent part of the *' Transsctions of the 
! Society of ArtP." A Nicol'a pijura is not men- 
tioned in connection with the pobrisrnpr, but as 
explanatory of the general remarks which precede 
I the deacription of that instrument Tlie polan- 
I scope has been constmcted, and was oscd far a 
considerable time fur public exhibilioa at "The 
Adrlaidc Gallery." Whether reflective or traoa- 
{ niitting poloriscnpes, He, ore best, ia a mere matter 
^ of opinion. The reason why two lenaes arc often 
combined to act ai one in rarioua optical inatru- 
I meota, is because the sphcricnl and chromatic 
j aberration of two lenses is one- fourth only of that 
produced by a single lens of the aame focfu ; 
I therefore Mr. Goddard has very Judiciously doublMl 
' the lenses in the eye>piecc of the instrument : iha 
lens nearest the light is the better to conccntnte 
the light upon the sclcnite or other poUriaing 
medium . We regret that wc do not know the prepa- 
ration that mica undergoes, or if any, but from th« 
natora of the auhatance «c ahould think not. — kikX 



NOTCa ON THE MOITTB OF flBPTBMBER. 



rreatkeral 


ThfrtmmiHer- 


Jrmget^flfk- 
liarvmeter. 


Rtiin M 
iiwhet 


LOKMHf 

Kpiitaraea,,.. 
PvWIK 


59 63 

at 


aoo9 

iQtti 


4»e 

1470 

3^1 



ANIUATRO NATUiLK. 

In the eariy part of the month the Swallow sines, 
in the latter part of it it Ukfta its departure to 
warmer rlimrs. The other sommer birds are also 
gone from us — broods of youn^ Goldfinrhes nppear 
— the Linnets congregate. Few T^-inter birds viiit 
«s till the fnllowinK month, yot we may see In Sep- 
tember tlie Woodcock, the Fieldfare, and the Ring 
Onael. The Stormy Petrel ventures furtlier south 
than is her wont in bri|>hter and milder weaUier ; 
while many other sea birils change their habitation, 
the Sea Gulls— the Manx Puffiu, and the Solan 
Goose. Owls are more noisy in this month tlxan 
before. Mnny of the songBtcrs of the spring re- 
sume their vernal notes, though with lees brilliancy 
and conatancy tlwn at an cariier pcriwi. The note 
of the Woodlark ia now in its greatest perfection. 
The Robin, who has been emphatically called the 
Brumal Songster, begins his sweet song on the ap- 
proach of the cold. The insect race begins to feel 
the cessation of summer's heat; Butterflies and 
Mothaarc Ic«s abundant ; the Beca, AnU. and Wasps 
more languid. Many Flies b«!come blind and die ; 
yet a few other tribca of insects abound still more 
than during the hot weather. The Earwigs ore 
found in every garden, and the Spider'* weba hour 
on every bosh. 

VBCETAnLK KINGDOM. 

This dejMirtmcnt of nature feeU the cflTecU of a 
dechnmg and varying temperature, of heavy deira. 
und prolonged darkness. The gardena and the 



L«oo«..Pria.PJ l,y » K..„-;. S. Wh.,. „.>« Uo«. M,.p K„j._ra 



hedge-rows are still gay, bat their gayncwtsofa 
different character. Red. white, and blue colors ta 
flowers are much les« abundant than at an earliir 
season, and yellow flowers take their place. By flv 
the greater number of the compound flowers ar« 
yellow, and this is the seaman of their greatest 
abundance. Tlie Hawkwecd — the Marigold anJ 
the Aster are well known. The splendid Uohlla, 
(pronounced Dal-e-n, not Dale-c-a,) is now in Call 
flower, and there are no lesa than a thousand «•• 
rieties of it, of almost every color j a bhic, a green. 
a brown, and a black excepted. Of native plants wg 
may collect, among others, the Clematis Til 
common in the chalky coantlea ; Ballotta 
abundant in the south of England, but rare, if 
unknown in Scotland — Pamassia palustrim a beaa- 
tifut snow white mountain plant. The Iryolsoll 
in flower, so are the Foxgloves — the tribe of tbs 
Mints — the Thyme — the Vervain, and Uie Arbutus. 
The trees put on their autumn tints, their fine grim 
chanties to the sickly yellow, or the go^^couar«Jt 
and intcnninglud as those colors often are, poitico- 
larly in the Horibr-cheennt. render bjr contn«t dit 
grove almost as beautiful as in the apnng. 

OARHKNIKO OPEnATIOXS. 

In the decline of the year, the chief occoptr__ 
of the gardener is to gather his riiwoing crops, and. 
to clear away the plants as they decay in lh« 
borders. It \\ luirdly yet time to be^n pruning 
and transphintlng. Watcting the borders will, om 
account of the dewy nights, be leas neoessary ; baC 
covering the melon beds in the evening, and taking 
care to close his conservatories, will require his 
attention. The cuttings of nnmeroas shrubs msy 
be planted out, nnd the seeds of many biennials 
sown, that they may blossom during the foUowia^ 
year, snch as columbine, agrimony, and chelooe. 
LawQB and grassy glades shoold now be repaired 
where necessary; and towards the end of th* 
month evergreens transplanted and prtmed. 



wytfafflh-j «>i^.v.~a.;:t7.rs:is:z::;rn:'::-^:i^iT.^^;T^^^^^^^ 



THE 



AGAZINE OF SCIENCE, 

and ^cbool of ^xt«. 



SATUBDAV, 5EPTEUBKR 4. 1641. 



[Ud. 



Cj 



1 y 




LEGGETT'S CHEXflCAL COLOR PRINTING. 
Fig, 1. 



Z2= 



n 



^=^ 




ia.-~Ko. XXI II. 



17S 



MAGAZINE OF SCIENCE. 



t-EGGETT'S CHEMICAL COLOR 
r PRINTING. 

Most of ub hare admired the beontifnl coloretl 
cardit show boards, nnJ imall arliclcs of a similar 
de«cripttoo, which bAve appeared within this je^ror 
two in London, iu which the colon are graduiJl; 
Mtftened into each other, nnd made to harnmDixe to 
exquiuiely with each other. Aa the method by 
which such an effect is produced has jiiixzled many 
a ooc. and iff besides a singalar. ti novel, and per- 
fectly scientific appUcnlion uf chcmittry, wc arc gtid 
to accede to the rrquest of several correspondents. 
Rod give the process entire ; and to do this the 
more accurately, we arail oorselrea of the word« of 
the patent, and have beaidea figured the machinery 
described in it. It is the patent of Mr. L<-Kgctt. 

" This Invention consists, first, in a new printing 
ink, to he applied to the purpose of printing in co- 
lors -, to ifiiicb the required color ia given by certain 
^emicftl re-agents. Secondly. — In the mode of 
applying the said re-agenU to prints or patterns, 
printed with the said ink. Thirdly, — Certain oia- 
chinery for that purpose. 

" A quantity of logwooil chips are boiled, for one 
hoar, in eight times their weight of water, (soft 
water is brat ;) tlie liquor ia tbrn drawn oflf, and 
■trained through a hair sieve. The chips are again 
boiled, for two hours, in another portion of water, 
of the same weight as the first, and the liquor is 
■gain drawn off nnd strained. Tlie two decoctions 
■re then mixed together, and a quantity of English 
verdigris, one-thirtiuth tlic weight of the logwood 
chips, is mixed with water, to the consistence of 
cream; the whole, or part of it, it then poured 
gradually into the decoction, adding it till the co< 
loriog matter sinks to the bottom ;'~-thc precipitate 
being of a dark grey, or blue-blark color, and tlie 
anperuatant liquor is clear and colorless. Tlie au- 
peruotant liquor ik now drawn off by a syphon, and 
the precipitjite is placed on a filter, made of fine 
cotton or woollen, in order to drain off and evapo- 
rate any moisture that may remain. When dry. it 
may be ground with oil, or any other liquid, ao- 
cording to the usual method of making printer's ink. 

*' The print or pattern, whether on copper, steel, 
wood, or stone, is printed in the usual manner witJi 
this ink. Then, to those parts of the print or pat- 
tern, which, if it were a painting, would be colored 
yellow, is applied a weak sululion uf vcgetabit acid, 
or any acidulous salts, (bi-tartrate of potash, or 
tartaric acid, is best,) which will cliangetbe neutral 
grey of the ink to yrlluw. To thoae parts which 
are to be red or orange, a weak solution of vegetable 
acid, or any acidulous salts, is appUed. (oxalic acid 
is best.) which will change the neutral grcj of the 
ink to red or orange. To those parts intended to be 
pink or crimson is applied a solution of very dilute 
mlphuric, or other uiioeral acid, which will change 
the nentral grey of tiie ink to pink or crimson. To 
those parts which are to be colored tiluc or riolet is 
applied a solution of nitro-muriate of tin, or of 
alum, which will chongc the neutral grey of the ink 
to lilac or riolet. To those parts which are to be 
blue, n solution of bi-corbonate of ammonia, or 
other alkali, is applied. To those parts which are 
intended to be purple, a dilute solution of bi-tartrate 
uf potash, or other vegetable acid, is applied first, 
and afterwords a solution of thu alkalies, above 
mentioned. If a very delicate pink is required, 
the ink may be made of Brazil chips, instead of 
logwood chips. 



** The chemical re-agent* nay be applied with* 
common hair pencil, or by either of the foUuwing 
processes, which constitute the second part of thia 
invention : — 

" Blocks are formed, similar to those used by paper 
stnint-M, for printing silks, fltc. A bloi-k being pro- 
vided for each color, those parte of the drawing, 
which arc required to be of the same color, are left 
In relief on the block set apart for that color ; aui 
blocks, being provided with the re-agents above men- 
tioned, are applied in succession to the print or pit- 
tern . The following is the second of theie proceuea : 
The print or |»attern is copied on thin aberta of 
metal, paper, or other substance. A sheet uf netal 
is provided for each color ; and those parta wbi^ 
are required to be of the same color, are cot out 
with H graver, knife, or other instrument. Tlir 
sheets arc placed over the prints, and the re-agent 
is applied with o roller — a separate roller being pro- 
vided for each re-agent. The roller is a cylindrical 
block of wood, covered with felt, of the kind con* 
monly used for hatting-blocks ; it is fastened to the 
block by smoll metal pins, or by dissolved ibell-Ue. 

** The tiiird part of tiua invention in the macU* 
nery for applying the re-agents, which is 
applicable for original colore ; and the paten 
dettcribing the machinery, oses the word * coli 
in place of ' re-agent5.* 

*' Pig. 1 ihowB the machinery, with the roller R| 
receiving color. Fif. 2, shows It passing over tttf 
metal plate. There Is a platform, upon which 
workman stands. B is a vrinch handle, that 
the pinion C, which ia fastened ou the wi 
shafY, The pinion C turns the lorge wheel D, 
teeth of this wlicel take into the pinion E, an4] 
this means the wheel F is turned. The whi 
works tlie rack G, by which tlie irregular rod 
moved. Another pinion ia on tlie same axis 
pinion E, and the wheel F : which pinion has 
teeth, which are dividrd into seta of four, a 
being left between each set ; it turns the whi 
by which means the pinion J, on the same axis, ii 
also turned. The pinion J turns the toothed «h«>| 
K. which tarns the Urge dram or narrow cyliadarif 
by the connecting rod M. 

*' The prints or patterns to be colored ore ptsat 
on the cogs N of the dram L. The metal plata 0« 
(shown in Fig. 2.) is fastened totheft.ime V- TbH 
frame ia raised by the quadrant Q, after the colons^ 
roller R has passed over the metal plaU.*. in or^if 
that a fresh cog may come under it ; and diumi;tlis 
time occupied in raising the frame P, the culuniij 
rolltir is moved, (by the irregular rod II, to nhaik 
it is attached,) on to one of the tables S, io onW 
to take a fre»h supply of color. The color is spr*d 
over the tables S, by the feeding rollers T T. wtorb 
are moved backwards and forwards by studs on tbs 
irregular rod H, which wnrk in the guides U of ibtf 
feeding rollers. The feeding rollers take the oobl 
from the colora beds over V V. 

" It will be seen that theooloring roller Knnaol 
descend so low as the metal plate, eicept uhea thr 
raiacd parts of the irregular rod rest ou the fsp- 
porta X ; sufficient pressure is g:iveu to the coloriii| 
roller by the weight W. 

" The quadrant Q. is worked by the rod Y, »ltf 
rod is moved one way by the'spriog Z, and 
other way by the lever A and B, which lerert 
moved by two tappets on the wheel F. 

" The cobring frame is supported by rods, pW 
vided with pins, which step into grooves in the ru- 
lers 1 and 2 ; motion being giveo to the roller t 



MAGAZINE OF SCIENCE. 



179 



9 nf treth, nn the side of the Urge wbcel D, 
to the teeth of thitt roUer, nad are lo tr- 
uit tbey commcQro acting on the teeth of 
'f u soon as the lut of the series 4. quit 
of the pinion K. Tlie motion ii comniu- 
kom the roller 2, to tbo rolter I, by an 





CTING THE ORK IN LEAD MINES 
UTAiNlNG GOLD AND SILVER. 

Dttifol riperimrnti of M. Becquerel on the 
of elecCro-chcmical action to elfcct the 
I tii IcJid anil silver in the galena, containing 
nUer, have deinonstrateti the possibility 

6^ electricity in the mauagement of the»e 
\it vmluable discorery bu indeed been 
dopted OD a Urge aode by M. Decqucrcl, 
Mrimentol manufactory that he baa eatAb- 
Ptria; hot, aa ia often the case in inven- 
;reat importance, mnnj yejira will probably 
Coro bis system is nniversally adopted in 
Sag of lead mines containtug silver. M. 
b1 observtis, in reference to the method of 
the metal at present pnriued : As a pro- 
tbe anriferouH and ailver lead mines in 
' of Baden, I have carefully attended to 
proceaaes that are generally adopted, 
DOfiTicoed of the possibility of obtaining 
prodace from the mines by impruv- 

lenralioni tbat I have made, may be of 

to the icMcra or proprietors of lead minra 
silver or gold. I will mention them in 

, puraiting in detail the method of work- 
mines that I have superintended for ten 

[any of these mines are very rich in silver 

to the manner of washing the ore. By 
in which the process is now executed, it 
that a cooaideroble quuiUty of the ore is 
the portion lost is that whicb is of the 
rilue, the snlphurct of silver. 
Hd and lilver galenas have in general for 
a very hard qunrtx, in which are irregu- 
Kdded sutphnrets of silver, \&id, iron, sul- 
tMrytea, or cwbonate of iron, iiiiJ also ^uor 
be raricty of aulphurets that 1 have just 
contain gold, but Ln such a state of 
t it is invisible in a microscope, and 
rcry attempt to analyse it ; yet gold does 
it is found in considerable quantity in 
the silver. The ore broken into pieces of 
to five centimetrea, ^Is by degrees into 
in which the stampers work. A current 
pBBHt through this trough, which is 
front by a very close iron grating. The 
of the stampers must be continued for a 
lo reduce itie ore sufficiently small to 
passing through tlie grating, and being 
long canals calted Ubycinths. where it 
at a distance further or nearer in pro- 
•txe. 

examining what takes place during 

of waiihiug. it is remarked, that the 

of ore, owing to the great hardness of the 

Bt the percussion of the stampers for a 

ble length of time, and that they only very 

ditnintflb in size (ill they are completely 

Tlie ore thus successively reduced into 

es, is gradually carried sway by the 

«ntcr beyond the labyrinth, where it 



ta 



ita 

itively 



ought to be deposited ; and the loss of this part of 
the ore i* more to be regretted, as the sulphuret of 
silver being very friable, it is the snlphnrct that \$ 
first carried away ; none remains but what i* con- 
tained in those pieces of the ore, which, from their 
size and weight, have had power to resist the in- 
fluence of the onrrent. 

I ara well assured that the loss which 1 have jost 
stated, is but too certain, as at the extremity of ■ 
labyrinth which readied for '200 roetrcs, 1 took up 
water that was impregnated with the dtposits of or*. 
This sediment, on being put to the test, yielded ia 
the lame weight« a proportion of silver equal to 
that of the sediment in the water at the entrance of 
the labyrinth. Tlie particles of gold disseminated 
in the aulphurets of lead, iron, and stiver, not in a 
BtJile of cnmhinntion, bnt only united mechanically, 
escape in the same way. 

Many ingenious men have tn their vritinga indi- 
cated as a method of collecting the gold contained 
in minerals and in auriferous sands, the levigation 
of these very finely comminuted substances ; but I 
cannot inppose that in this manner they imagine it 
poi^sible to obtain the whole of the gold ; this could 
only be done by means of chemical analysis. A 
very simple experiment will sulHce lo prove how 
very inefficient the levigation is for this purpose. 

Take two discs formed of an alloy composed of 
lead, silver, and gold, and girc them a circular 
motion against tbesnrfaces of each other, by keep- 
ing them immemed in a vciutel full of water. The 
water will very soon be rendered turbid and cloudy. 
If, in the same water, two discs of the mineral, in 
which the ores are imbedded (qusrti fur instance), 
are afterwards rubbed against each other, long 
enough to add new particles to those already con- 
tained in the fluid, all the metallic and earthy par- 
ttclrs will not be i>rttled lill after eight days, and 
no trace will be perceived on the outer aurfaoe of 
the glaas vase tbat the particles have been deposited 
according to their specific gravities. They will 
appear all mingled. Hence it mny be coucladed 
that when metals, ores, minerals, and sands in a state 
of extreme divihion are mixed, levigation is an ineflec- 
tual means of producing their complete separation. 

The next operation to be considered is that of 
EimcltinK the ores. The products of the mines are 
also greatly diminished at present by the loss of 
lead, silver, and gold, in the operation of smelting, in 
either reverberating or other furnaces generally used. 

In tlio former case the roasting of the slag ia a 
long and difficult operation, and with many ores 
almost impossible ; those of Baden for instance, of 
which the matrix composed of quartz, of sulphate 
of barytes, and of tluor spar, is fusible to such a 
degree, that in making use of the reverberating fur- 
nace it would be necessary to smelt without pre- 
viously roasting, and to let the first meliiog run oat, 
which it would be necessary aftewards to calcine 
before re-smelting in another furnace, which ma^t 
also be reiorted to, to extract part of the refractory 
scorise. The loases in smelting are occasioned — 

Ist, By the volatilisation of a great quantity of 
sulphuret of lead, and sulphuret of lilter, before 
their reduction. 

2d, By the action of the flaxes, and particnlarty 
by the silex on the lead at ita different degrees of 
oxydatiun, from whence is produced the siUciureta 
of lead which unite with the scoriir. 

3d, By the alkaline aolphureia and pcrsulphnrets, 
which, in a great degree, absorb the gold contained 
in the ore to be smelted. 



IdO 



MAGAZINE OP SCIENCE. 



4lh, By the great quantity of fael neceMary to 
be need to retain id a itAto of constant fluidity the 
enonnoui proportion of the KcoriN: of forges nod 
fumNCci obliged to be added to the melted ore, in 
order to secure the metal from being redaccd by 
^ oxydation aud Tolatilisation during the time it la 

rassing into and remaining in the furnace, where 
believe the Icmperatare ia raised to a much higher 
degree than is necessary. 

5th, Finally, because, inetesd of obtaining by 
one smelting in which there ii so great a consump. 
tion of eombnstible, the whole of the lead contained 
in the ore, only half of it ic at first extracted, and 
the other half most be afterwards calcined, which 
if only an impure metal or sulphuret, in order to be 
■melted again. 

I make no obserration on the manner in which 
the operation of cupelling it ia done at Baden, be- 
cause 1 beliere it is impossible to be managed better. 

The consequence of the inconveoiencea that 1 
bare ennmerated is, that though the prodnce arising 
from the gold and rilver lead mines is quite equal 
to what might be cipected in their present condi- 
tion, it is yet capable of being considerably increased 
by improving the method of washing and smelting. 
— A/oni/tKr indiutriet. 



SYSTEM OF EARTHENWARE PAVING. 

BY M. rOLONCBAU. 

NoTWiTiiBTAKDiNG the Improvements that have at 
various times been introduced in the method of 
paving, the roadways of our high roads and the 
atreets of our towna continue more or less uneven, 
which occiuions those frequent jolts which ore 
80 destructive to carriages and boraes. This state 
of the pavement is atlribatsble to many causes, the 
principal of which are the general formation of the 
paving stones, the wont of regularity in their 
forfaccfl. which does not admit of a good jiuta.jrosi- 
tion, aud the great difference in the hsrdnebs of 
the stuues, which, although taken From the same 
quarry, are aome of them worn out much sooner 
than others. This latter inconvenience exists not 
only with rejpect to the dilTerent kinds of slonc 
regularly made use of, but oUo, and in a greater 
degree, with respect to vegetable substances, so 
that the method of paving in wood, which has 
bcsen recently proposed, would, considered with 
reference to this, be inferior to stone pavement. 

So long ns stone pavementa are used, M. Polon- 
ceau Bays it will be impassible to adopt any difTe- 
rent form for the blocks than the one they have at 
present, which is that of a rectangular prism, for 
by substituting cutting for the ooramon method of 
breaking, the expense would be considerably in- 
creased, while at the same time the resistance of 
the stone would bo diminisbed in consequence of 
the repeated percuflsio