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poured out like oil; with us it is cut and spread. 
Their butter was probably much inferior to ours, 
and its use very limited. 
Butter has been usually thought to be a mat- 
ter naturally distributed through the milk, and 
existing, along with the caseous and serous parts 
thereof, in a state of mechanical suspension, 
similar to that in which oil is when suspended 
in water by means of syrup or mucilage. But 
though a mixture of this sort—commonly called 
an emulsion—puts on a white colour like milk, and 
its oily parts by rest rise to the top and form a 
cream similar to the cream of milk, yet the ex- 
periments of Messrs. Deyeux and Parmentier 
seem to have proved, that butter does not actually 
exist in the cream, but that it is formed from it, 
during the process of churning, by certain che- 
mical changes which then occur. These gentle- 
men were led to form this opinion, by observing 
that butter could not be produced in any other 
way than by agitation; whatever substances or 
means they employed to detach either the cheesy 
or buttery part of the cream, they always found. 
agitation or churning necessary. Fourcroy con- 
siders the butyraceous matter of milk as quite 
distinct from butter; and says, it is a white li- 
quid oil, suspended in the serum, by means of 
the muco-saccharine and cheesy parts, which, 
combining with oxygen, forms butter. The oxy- 
gen he conceives it to,obtain partly from the at- 
mosphere, and partly from the milk itself. He 
is of opinion, that butter in a small quantity can 
be obtained without agitation; and says, that 
the oily particles of the butyraceous matter, 
which, from their greater levity, float, when the 
milk is allowed to rest, on the surface of the ca- 
seous and serous fluid, absorb oxygen from the 
atmosphere, and become real butter. 
That important chemical changes take place 
during the operation of churning, there can be 
no doubt ; but the nature of these is still, how- 
ever, imperfectly understood. Farther experi- 
ments seem necessary to elucidate the subject. 
In all cases, there is a considerable extrication of 
gas; Dr. Young affirms, that there is likewise a 
rise of temperature equal to four degrees; and 
Professor Traill found from experiment that the 
rise of temperature is greater than Dr. Young 
supposed, and ranges from five to eight degrees. 
In the Mid-Lothian agricultural report for 1795, 
it is stated, that cream churned in contact with 
atmospheric air, absorbed a considerable quantity 
of it. But Dr. Young has shown, that butter 
may be obtained from cream by churning, with- 
out the contact of air. These two statements, 
however, are not irreconcilable, since, according 
to Fourcroy, the butyraceous matter takes its 
oxygen partly from the air, and partly from the 
milk. That this matter should absorb oxygen, 
_ and thereby acquire the consistence of butter, is 
quite analogous to what happens to other oily 
bodies, which all become thicker by absorbing 
the oxygenous principle. The gas disengaged is 
* 
_ BUTTER. 
probably the carbonic acid gas ; for every person 
must have observed, that when even sour cream 
is churned, the butter obtained is perfectly sweet; 
and the milk remaining in the churn, called the 
butter-milk, is always much less sour than the 
cream had been. 
Though butter is obtained usually by agitating 
cream, it may be also got by agitating milk as 
drawn from the cow, and even in greater quan- 
tity than from the cream alone of the same milk 
—a fact well known to those who superintend 
dairies. The result of a series of experiments 
by Professor Traill, upon the churning of sweet 
cream alone, of sweet milk and cream together, 
of slightly soured or acidulated cream, of soured 
milk and cream together, and of scalded cream 
or “the clouted cream” of Devonshire, showed, 
in the first place, that the addition of some 
cold water during churning facilitates the pro- 
cess, or the separation of the butter, especially 
when the cream is thick and the weather hot ; 
secondly, that cream alone is more easily churned 
than a mixture of cream and milk ; thirdly, that 
butter produced from sweet cream has the finest 
flavour, when fresh, and appears to keep longest 
without acquiring rancidity,—but that the but- 
termilk, so obtained, is poor, and small in quan- 
tity ; fourthly, that the scalding of the cream, 
according to the Devonshire method, yields the 
largest quantity of butter, which, if intended for 
immediate use, is agreeable to the palate and 
readily saleable,—but if intended to be salted, 
is most lable to acquire, by keeping, a rancid 
flavour ; fifthly, that churning the milk and 
cream together, after they have become slightly 
acid, seems to be the most economical process on 
the whole, because it yields a large quantity of 
excellent butter, and the buttermilk is of a good | 
quality—a point of some importance when but- | 
termilk is largely used as an article of diet, as it 
is in Lancashire; and sixthly, that the keeping 
of butter in a sound state appears to depend on | 
its being obtained as free from uncombined albu- 
men, or caseine, and water, as it can be, by means 
of washing and working the butter when taken 
from the churn. Even whey, by churning, yields 
butter. In the agricultural report before quoted, 
it is stated, that 27 Scotch pints of whey, that is 
about 108 English, afford at an average one pound 
of butter. The oily part of the milk appears to 
have so strong an attraction for the other ingre- 
dients, that it never completely separates from | 
them. 
Butter can by no means be equally well-ob- 
tained from the milk of every sort of animal: 
indeed, the milk of some of them can never be 
made to yield any butter. No length of churn- 
ing will produce it from the cream of woman’s 
milk, or of mare’s milk; while, on the contrary, 
the cream of goat’s milk, and ewe’s milk, yield 
it in abundance, and with as much facility as the 
cream of the milk of the cow. The cream of 
ass’s milk, when long agitated, yields a soft, 
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