e 
OCT 2? 
Pinni Qusbmftnj. 
ABOUT SEPARATED MILK 
Does the Separator Purify 
Milk? 
Does It Destroy Disease-Germs 
Should Dairymen Be Compelled 
to Use the Separator ? 
A New Question Well Discussed. 
Never Before Considered. 
As we stated last week, 'there are many 
people who credit the separator with extraor¬ 
dinary powers and merits. Thousands of 
people who have handled milk all their lives 
have never studied intoilsphysical properties 
enough to understand why cream rises to the 
top of the pan or dish. To such people the 
work of the separator is simply astounding. 
They cannot comprehend the work that 
changes whole milk into skimmed milk and 
cream as fast as it can be poured into the sepa¬ 
rator. Like many other seemingly wonderful 
performances, the action of the separator de¬ 
pends upon a very simple mecnamca princi¬ 
ple; but we can readily understand how those 
who do not study out this principle must be¬ 
lieve that the separator is capable of perform¬ 
ing far more intricate operations than its 
advocates ever claimed for it. This mistaken 
idea as to the real place of the separator in 
dairy economy has led to many.strange ques¬ 
tions and statements. We give below a propo¬ 
sition received from a subscriber a few weeks 
ago. He evidently believes that he has made 
a perfectly logical statement and that his 
conclusion is the proper one. It has been 
referred to the persons whose remarks fol¬ 
low it): 
1 —“Milk passed through a separator as 
soon as taken from the cow , is thoroughly 
cleaned of all impurities , while it is proba¬ 
ble that many disease-germs are destroyed. 
Thus the milk is in better condition for 
drinking purposes than when not separated. 
2 .—By promptly separating his milk—as 
soon as drawn from the cow—and at once 
putting enough cream back to secure the 
per cent, of solids required by law, a dairy¬ 
man can present a cheaper and healthier 
standard milk , than by any other process. 
It is cheaper because if there is an excess 
of cream, that excess can be used for 
but ter-making. It is healthier because clean¬ 
er and freer from disease-germs. ” 3.—“// 
the above propositions are correct, it will be 
the duty of the authorities eventually 
to prohibit the sale of unseparated milk .” 
FROM DR. PETER COLLIER, 
So far as I can see there is absolutely no 
sense in the suggestions of your subscriber. 
Disease-germs could not be thus removed, and 
if they were, it is proposed to put back, say 
90 per cent, of them. You may safely con¬ 
clude that your subscriber knows little or 
nothing of the matter he discusses. 
Geneva, N. Y. 
FROM PROF. S. W. JOHNSON. 
1 —While the centrifugal process certainly 
removes mechanically-suspended “dirt” from 
milk, to assert that the milk is thereby “thor¬ 
oughly cleaned of all impurities” is claiming 
much too much. Milk soiled by manure, man¬ 
ure-liquor, or urine, cannot be cleaned of the 
impurities thereby introduced, which dissolve 
in and impart color and taste to the milk. As 
to the assumptions that “it is probable that 
many disease-germs are destroyed” I would 
say that it is certain that in case of their pres¬ 
ence, many would not be destroyed, and milk 
containing them, whether passed through a 
separator or not, is unfit for use. 
2 .—The use of the separator to prepare 
standard milk would, in most cases “cost 
more than it would come to.” Large dairies 
might thus employ it, but to enforce its use on 
small milk producers would doubtless be re¬ 
garded by them as a burden which they would 
rebel against. 
8 .—The authorities would more appropri¬ 
ately prohibit the sale of milk which has been 
dii’tied by careless handling than of that which 
has not been through a separator and yet may 
be practically clean. 
4 .—Lest some one should now illogically infer 
that I am fond of dirt, I would say that I am 
among those who much prefer clean milk to 
unclean: and if “separated” is better in that 
respect than “unseparated” milk I would be 
glad to have the separated at a reasonable 
advanced cost. 
New Haven, Conn. 
FROM PROF. S. M. BABCOCK. 
There is no doubt but that, as your corre¬ 
spondent suggests, much of the dirt which 
milk contains may be removed by the use of 
a centrifuge but that the milk is “thor¬ 
oughly cleansed of all impurities” is not true. 
Matters in solution, or those that are lighter 
than the milk-serum are retained, either in the 
skim-milk or in the cream, and it is by no 
means certain that disease-germs, or those or¬ 
ganisms which induce changes in milk, are af¬ 
fected by the process. So far as I am aware 
no investigations have been made upon this 
point. 
The chief objection to the use of the cen¬ 
trifuge for removing the mechanical impurities 
of milk is the expense involved. This is so 
great that a law demanding the separation of 
milk before being placed upon the market 
would virtually exclude all small dairymen 
from competition in this necessity, and would 
leave the price to be fixed by a few large pro¬ 
ducers. Certain it is that the price to the cus¬ 
tomer would be largely increased, without any 
probability of the product being purer or of 
more uniform quality than at present. As a 
rule the more manipulation which any pro¬ 
duct undergoes, the more opportunities and 
the more temptations are offered for adultera¬ 
tion. Persons who will remove cream or add 
water to the natural milk will not be made 
honest by a system, which, within certain 
limits, demands such practice. I think, there, 
fore, it would be very unwise to make such a 
system compulsory; rather let us strive to 
have the natural product kept cleaner, purer 
and of better quality by the exercise of more 
care in the selection of stock and in the man. 
agement of stables and dairy utensils. Only 
in this way can we hope to have better milk 
at a cheaper rate. 
Madison Wis. 
FROM W. H. CALDWELL. 
Milk, as drawn from the animal, is at the 
animal’s temperature, and in that condition is 
susceptible to odors. It should be quickly 
cooled by a cooler of some device. The prov¬ 
ince of the separator is quick separation of 
the cream from the skim-milk, either for the 
making of butter or for immediate use of the 
skim-milk for feeding. The thorough cleaning 
of milk cannot be done by the separator alone, 
and to what extent disease-germs are killed by 
the process depends on existing conditions. 
Heat is the proper means for killing these 
germs, and by heating is the absorptive power 
of milk arrested. If, however, we should at¬ 
tempt to heat milk to a temperature sufficient 
to kill the germs, the fat of the milk would be 
melted, and the high temperature would de¬ 
velop acidity. The only advantage gained by 
taking apart and putting together again the 
cream and skim-milk, in the point of health, 
is the removal of a certain amount of dirt and 
foreign matter which will gather around the 
drum of the separator. The expense of the 
process in determining the exact per cent, of 
solids would largely offset the revenue from 
the extra cream. Milk separated and put to 
gether again will not be in as good condition 
as before the process, whether first cooled or 
not, and its sale might rightly be prohibited. 
It is milk tampered with, and, if allowed to 
be sold, might influence dealers to sell only 
as good milk as they were obliged to, and 
the result would be the placing on our mar¬ 
ket of a thinner, more watery substance. 
Our laws only call for a certain per cent, of 
solids, and as long as milk comes up to the 
required standard it has a lawful place in the 
market. 
Pennsylvania Ex. Station. 
FROM HENRY STEWART. 
These propositions are based upon wholly 
mistaken ideas of the character of milk and the 
action of the centrifuge. The centrifuge does 
not separate all impurities from milk, but on¬ 
ly those which are not held in solution, and 
are merely suspended in the milk. It throws 
off such matters as epithelial scales, (the worn 
down parts of membranes) fibrine, mucous and 
other substances which render milk impure 
and produce rapid changes in it, tending to 
early decomposition, and these are fi;om either 
at the periphery of the drum or at the center 
as they may be heavier or lighter than the 
milk. All the abnormal substances in the 
milk which are foreign to it in a pure state, 
that are heavier than the milk, are thrown to 
the outside ot the separator. If there are any 
impurities that are lighter than the milk these 
go with the cream to the center, and any that 
are of equal specific gravity with the milk or 
very nearly so, will remain in it. thus any in¬ 
jurious germs, such as those of typhoid fever, 
tuberculosis, or other dangerous diseases which 
may be in the milk will probably remain in 
it, or at any rate quite enough to carry the in¬ 
fection and to rapidly reproduce themselves and 
fully charge the milk with a new crop of them 
There is nothing in the action of the machine 
to destroy disease-germs. All that is done is 
to produce the same effect that gravity would 
have done in course of time, in a few minutes. 
The separation is due wholly to the effects of 
and difference of specific gravity, and disease- 
germs are so infinitely small that they are not 
acted upon by the separator in the least de¬ 
gree and they will, of course, so far as they 
may be present, remain in the milk, and the 
cream, and in the heavier matters thrown off, 
relatively as they were originally mixed, or 
entangled with them. Separated milk is 
therefore no better or safer for use on account 
of its freedom from germsj than ordinary 
skimmed milk. 
Again, as to the second proposition, it is 
well-known that when once cream is separated 
from the milk, it is not possible to again mix 
the two as they were before. The intimate 
mixture of four or five thousand million 
globules of fat in a cubic inch of milk cannot 
be made artificially as it exists naturally. 
Moreover, it would be wholly contrary to the 
spirit of the law and honorable business deal¬ 
ings to reduce the natural quantity of cream in 
milk for the purpose of gain in selling milk. 
It is no doubt the duty of the public servants 
to watch the milk offered for sale, to detect 
anything that is dishonest or injurious in 
the management of it; but it would scarcely be 
consistent with personal freedom (of which we 
are apt to boast much) that a dairyman should 
be obliged to use a separator unless he 
thought proper to do so. On the whole there 
is too much said and written just now about 
the unhealthfulness and impurity of milk; 
and if all were true that is written or said, the 
cows, the dairy, and the dairy management, 
are the proper subjects for attention by the 
health authorities, and not so much any par¬ 
ticular method of skimming cream from milk. 
Lastly it would be impossible or impracticable 
to prepare pure milk for market by the use of 
a separator first, and then putting back a 
portion or even the whole of the cream, for 
any dishonest man could add oil or any 
suitable fat to the milk quite as easily as he 
could return the cream. 
FROM L. S. HARDIN. 
There is some disposition on the part of 
many hypercritical writers to greatly mag¬ 
nify the “disease-germs” that they imagine 
lurk in milk and man^ other human foods. 
While it is true that milk, the same as any 
other fluid, will take up the active germs of 
disease when greatly exposed to them, at the 
same time I do not take much stock in this 
supposed inherent evil of pure milk. I have 
seen and examined the residuum, left in sepa¬ 
rators, that we are now told is made up in 
large part of “fibrine,” a species of flesh of the 
cow. This residuum also I am sorry to say, 
usually contains considerable manure and 
other filth of the stable that has no business 
in the milk. That it is a nasty compound, no 
one will deny and it is probably a good thing 
to get it out of the milk, but that there are 
any “disease-germs,” any more than are con. 
tained in all filth, I think is not proven. It 
may be a wise provision of nature to make us 
all think that when an article of food tastes 
or smells badly to us it is diseased, but it 
will not do to push this notion too far, as our 
senses are susceptible of very high cultivation 
and would eventually lead us to limit our list 
of pure articles of food to an inconvenient 
margin. 1 do not believe that miln exposed to 
small-pox or fever patients could be rendered 
harmless by passing it through a separator. 
For this reason I do not agree that “all im¬ 
purities” are removed by such an act. 
2 . I do not think much of the “ cheaper” 
argument contained in this statement. The 
cheapest way to make standard milk is to get 
cows and feed them so that they will give 
large quantities of milk, just rich enough to 
satisfy the egal standard. The milk is not 
increased n bulk by passing it through the 
separator, so that there is nothing cheap about 
it, but on the contrary, running a separator 
is a pretty expensive operation. In the first 
place separators as now made, cost at least 
double their intrinsic value, and they wil] 
never get within reach of the average milkman 
until the patents expire, as was the case with 
sewing machines. Then agaiu, they are too 
slow for milkmen who must hurry the milk 
off to market as soon as it can be cooled. I 
have never heard from good authority, that 
separated milk would keep sweet longer 
than unseparated milk. I do not think many 
dairymen would be able to make money by 
the cream they would be able to save after 
the ‘legal standard requirements were met. 
Town dairymen do this in the fall and winter, 
by'saving the strippings. This process is much 
cheaper than separating. 
3. It is bard to see anything practical in this 
notion. The great mass of dairymen have 
herds of less than 15 cows. To require each 
one to purchase and set up a patent separator, 
would drive 90 per cent, of them out of the 
business, and thus allow the factories to do 
all the milk business and boom the price up 
until people in moderate circumstances would 
have to forego the article altogether. No such 
law could be enforced. I therefore think the 
above writer has greatly magnified the bene¬ 
fits to be derived from separating milk. 
*Fort Hamilton, N. Y. 
FROM T. D. CURTIS. 
There is, in this proposition, much to pro¬ 
voke thought, but there is little, I think, that 
will ever become of practical importance. 
1 . —There is the wholesale assumption that 
all milk, or milk generally, contains disease- 
germs, which I do not indorse. Milk is Na¬ 
ture’s food for the young, and in its normal 
condition is probably as wholesome as any 
food that is taken into the human stomach. 
In some instances, where cows are diseased 
it may be admitted that there are .disease- 
germs in the milk when it comes from the 
cow, but in most cases the germs of the disease 
get into the milk—as in the case of scarlet fever 
germs, small-pox germs, typhoid germs from 
the use of unclean water, etc,—from the out¬ 
side. It is difficult to see how separated milk 
would be any freer from this occasional evil 
than the unseparated milk. Another class of 
disease-germs come through stagnant and 
impure water. They enter the circulation of 
the cow, causing a feverish condition and ap¬ 
pear in the milk. These are probably the 
most common, and appear mainly during the 
hot, dry months of summer. 
2 . —It is assumed that the separator purifies 
the milk, because a greenish deposit appears 
on the inner periphery of the drum, which, as 
soon as exposed, gives off an offensive odor. 
The exact nature of this deposit is not yet de¬ 
termined. It is found to contain what resem¬ 
bles pus, some particles of dirt, and some 
substances which have not had their character 
definitely determined. It is safe, to assume 
that the albumen of the milk or at least a por¬ 
tion of it, appears in this deposit. This soon 
decomposes, by exposure to the air, and may be 
the main source of the offensive smell. But 
does it really improve the milk to deprive it 
of its albumen, which is certainly a highly 
nutritious ingredient) This question must be 
settled. But we question this improvement 
of the milk, for dietary purposes, in freeing it 
of its albumen. The question now arises 
as to what extent the separation purifies the 
milk. Plainly, it cleans it of only such sub¬ 
stances as are heavier than the milk, and it 
removes of these only such as are undissolved. 
Any impurities held in perfect solution re¬ 
main undisturbed. Only mechanical impuri¬ 
ties .are removed. 
3. Again it is assumed that the separator de¬ 
stroys disease germs. What are the grounds 
for this assumption? How does it destroy 
them? This claim is unsustained by any fact 
or argument. Certainly exposure to the air 
does not destroy typhoid, scarlet fever, small¬ 
pox, and other germs of this character—for 
they are not only exposed to the air but 
transmitted through it and take active effect. 
Possibly a certain class of microscopic vege¬ 
table germs, such as are derived from stag¬ 
nant water, may be destroyed by oxydation. 
But beyond this, I can see no ground for the 
claim that disease-germs are destroyed by the 
separator. Hence the proof that it removos 
all impurities, and the destruction of disease- 
germs, to any material extent, is seriously 
questioned. 
4. By what process would the cream be re¬ 
turned to the milk in a completely emulsified 
condition as in nature? An emulsifying ma¬ 
chine would clearly be necessitated. What 
would be the effect on the milk of first running 
it through the separator, and then reversing 
the process by running it through an emulsi¬ 
fier to reunite its parts? Think of the labor 
and expense of these two processes in prepar¬ 
ing milk for market, and the delay and ex. 
posure of the milk before reaching the con¬ 
sumer! It is hard to see where the cheapness 
comes in. An excess of cream is hinted at. 
There has always been too much disposition 
to take this excess. With the opportunities 
above indicated it may be suspected that no 
excess over the standard would ever appear 
