1000000030

1\°1

i, Ihe f.\lne \\'ilh

~lIlhe

olher tiq\lors iOlcnoed 10 cunOi·

tme

p~r!

~Il ~Ililll;¡t

body: Ihere is no pereep\iule aeid

in any of lhcm.

lI~nec

il may be infcrred. Ihlt one of the

princip~t

changes whidl rcr,ela!)lc'

und~q:~,

in orde r 10 Iheir be·

inS conl'ened into an al1illl'l ¡i.u!lanee,

cOIl~lIs

in litis,

Ihal lheir acios are eOl\lbinrcl,

enlangl~d,

ano O,calhed

in flleh a

m~nncr,

Ih:tl Iltey Ilccome impereepliule, and

exm nooe of

Ih~ir

propmies.

Milk lefl

ilfeif, ",i

!l.om

d!e hclp of diOillalion, Or

any addilamenl whal'crer, undcrr,llcs

fon of deeompo·

~Iion.

runs inlo a kinu of

f~onlalleous

analy!i!;

whieh dOlh nOI indw l reduce il 10 in (¡rll principies,

yel feparales il inlo three diOin{t fubflances, as Ihe pro·

e~fs

!hews; name/y, iUloeream, or Ihe butlery fal p:II't,

inlo eurd or ehecfe, ami inlo fefllm or whey: whieh

OI:WS, lhal Ihofe Ihree fubfllnces of whieh milk

eon~lIs,

are onl y mixed and blended togelher, bUI nOI iOlimalely

uuileU.

The firf! pam, bcing the lighlefl, rife gradually tO

the fmfaee of the liquor as they feparm from Ihe refl:

aud this forms the eream.

Cream, as O<immed from the filTfaee of milk, is not

howel'er

lh~

pure buttery or fal part; it is Oill mixed

",ilh I\I lny pmicles of eheefe and whey, IVhieh muf! be

fepal'.tttd in order 10 reduce it inlo bUlter. Tite mofl

flmpie,

~nd

JI Ihe f.lme lime Ihe befl melhod of dfeéling

Ihis, i¡ daily praclifed byIhe coumrypeople.

eonfifls

bea,in~

ehurnin~

Ihe eream, in a verre! eonlrived for

tllJI p,ltrofe, wilh Ihe Aal fide of a cireuiar pieee of

wooJ, in ,he eeolre of whieha fla!F isfixed. One woutd

thin't Ihat Ihe mOlion,

imprerr~d

one Ihe cream by Ihis

inllrur.1~nl,

!hould ralher ferve 10 blend more inlimalely

the particles of bumr, eheefe, and whey, of whieh il con·

fif!s, Ihao to feparale Ihem from taeh olher; as Ihis

mOlion fecms perfeélly adapled to divide and attenuale

thofe

~articles.

BUI, if IVe eonfider IVhat parres 00 Ihis

oeea~on,

we !hall foon pereeiveIhal Ihe 11)0lion by whieh

buuer is ehuroed is no,hing like Irilure , for ehurniog is

no olher, properly fpeaking, than a eonlinually repealed

compreflion, Ihe

e!F~él

whereof il to fqueeze om from a·

mongOIhe bumry panicles t.hofe of eheefe and whey

mixed Iherewilh

by whiehmeans Ihe panicles of butter

are brouzhl inlo eontaél wilh eaeh other; unite, and ad·

here tOgelher.

Milk, whelher Otimmed or no, grolVs four of ilfeif,

ano eurdles in a fewdays. When it is newly ellrdled,

the eheefe and whey feem 10 be unilcd, and 10 make but

one mafs: bUI Ihefe two mattcrs (eparale fpontaneouOy

from

e~eh

olher, wilh Ihe greatClI eafe, aod in a very

Olon

lim~.

The aeidilY, IVhieh milk nalurally eontraéls in the

fpaee of a fewdays, mllfl be eonfidmd as Ihe cffeél of

fer.neoling mOlioo, whieh difeol'er! in Ihal liquor an

aeid Ihal was nOI perceptible hefore. This, properly

fpeakinn, il an acelous fermenlalion, whieh milk

parr~s

tl, rough in it8 way 10 pUlrefaélion; and il (oon follows,

efpcei,!ly if Ihe milk be expo(eo

hOI airo

ff, inOead of

leavio~

milk 10 grow (our and eurdle of

ilfelf, in acid be mixed Iherewilh, while il is yel fweet

.and nel'lly milked, il immcdialcly coagulales

whieb

gim· rea(on to Ihink, tltat ili eurdling naturally il the

elr"ét of Ihe aeid,

WIIlC:,

difeovers ilfdf Ihmin as il

grows

lIal~.

The eoa:!ulalion of milk may alfo be eonfidcrahly ae·

ederJlCd,

(ctting il in a (aod·balh gendy hcated ; or

by mio. iog thcrewilh a littlc of owhal. in the

langu~ge

Ihe oairy, is ealled

runuel

whieh is nOlhing UUI fome

ellnllcd and half.digelled milk taken from Ihe lIomadl of

a ealf, Or both IheCe mellHlds rnay be employed al onc:,

whkh will produce Ihe e!Feél llill more

exp~dillouny.

is nOI dilliclIll to find OUI Ihe eaufe of thefe effc1h.

The runnet, IVhieh is mllk already eurdled and grown

four, is an a{tual fcrment 10 (weel milk, difpofing il to

turn four mueh more readily: for Ihough milk, when

th~s

hallily euroled by Ihe ruonel, halh nOI a manifeOly

aeid laOe, yel il is emain Ihat Ihi. aeid begins ro exen

il(elf. The proof Ihereof is, Ihal, being expoftJ 10 Ihe

fame degree of heal lVilh Dlilk equally new, Ihat is not

mixtd wilh Ihis fermenl, il tIIrns (ollr mueh (ooner. As

10 Ihe e!Feél of heal io coagulaling milk, Ihere is nOlhin"

eXlraordinary in il : we knolV how mueh il

promole~

and aeecleraces all fermenlative mOlion. The whole of

Ihis perfc,qly

agree~

withO whal we (aiJ before eoneerning

fermenlalion.

Fixed alkalis alfo eoagulale milk

but al rhe falJ1:

time Ihey fepm le Ihe IVhey from the eheefe, whieh

Aoals on Ihe liquor in doats. They gi,e rhe milk a

rurrel eolour inclining 10 red ; whieh n¡al' arife from Iheir

auacking Ihe fat parl.

The feparalion of mil

inlo buuer, eheefe, and whey,

is a kind of imperfeél analyfis Ihereof, or ralher Ihe b·e·

ginniog of one. In order to render il complete, we

muf! examine eaeh of IheCe fubflanees feparalely, aod

find Ihe

pri~eiples

of'lVhieh Ihey eonGn. This we !hall

end~avour

to do in Ihe following proeefs.

Butl"

Q"a&fod

hJ DiJlillalion.

no a glafs relOIt pUl Ibe quantity of freOI burter

you imend 10 difli/. Sel Ihe reton iD a reverbemory

apply

receiver; and lel your fire be:very gen"e at firn.

The bumr will mell, and Ihere will come over fome

dr"ps of ciear waler, IVhieh will hare the peculiar fmell

of fre!h bumr, and OlelV (ome tokens of aeidilY. If Ihe

fire be inereafed aJitt)c, Ihe bUller will feem to boil :

frolh will galher 00 ils (urfaee, and tOhe phlegm, Oill

continuing 10 run, lVill gradually come 10 (mell juf! like

butter c1:lJ'cfied in order 10 he preCerved. lis aeirlily will

be Oronger

~nd

nlOTe manifef! Ihan Ihat of Ihe lirl! drops

thal came overo

Soon afler Ihis, bf enereafinc the (¡re a lillle more,

there will rife an oil, having nearly Ihe fa:ne degm of

fiuidity as fat oils

bUI il lVill gwlV Ihieker as Ihe diHil·

lalion aovanees, and al hO will (¡x in Ihe reeeiver IVhen

il eools. 11will be aecompanicd with (ome drops of li·

quor, Ihe aeiJity whereof will ahvays inereare, while ils

Guanlily

decre~f<s,

as IheotflillJlion adr;¡nees.

While this Ihiek oil is tliflilling, Ihe bUlltr contained

in Ihe retOr!, whieh al (¡rH(¡eOled 10 boil, \ViII

e.lm

and fmoolh, wilhoul Ihe leall appemnee of eunllilioo ;

Ihough the he.\I be Ihen mueh grwer Ihan II'hcn il boil·

.d. Conlinuc Ihe diflillalion,

eonfl~ntly

inm afing Ihe

fire