Arizona republican. [volume] (Phoenix, Ariz.) 1890-1930, 1916-07-03

Pursuant to the request of DR.. H. X. /
Beauchamp, City Health Officer, | will |
give a brief account of the method of |
milk examination.
The function of the city health de-
partment is to prevent the occurrence
of those diseases which are transmit !
ted from person to person, or animal
to person, or to check the spread of
such diseases when they do occur /
Perhaps our most important single
duty is to watch over the city's milk
milk is raw food in universal use,
and CD it is an ideal medium for the
development of many forms of dan
gerous bacteria. While a sanitary in
spectiOn of all diaries is made at regu-
lar intervals, it is impossible to keep
daily watch over the various farms
which supply the city and to super
wise their methods of milking. bottling
and transporting this important food.
so the chief way to guard the citizens
from unclean milk is by continually
examining representative samples as
delivered to consumers. By such ex-
aminations. the health department can
secure an accurate idea as to the meth
cd of handling the milk and its quality
The quality of the milk is determined
by the percentages of fat and total
solids. Mixed whole milk is remark
ably constant in these constituents,
and any great variation in them means
that the consumer is not securing the
quality of milk he is entitled to, and
means, further, that, the producer Of
the milk is not delivering that which
he is supposed to deliver. namely, the
whole. mixed from one or more cows,
undiluted.
The determination of the number
and kind of bacteria in milk, as deliv-
certain picture of the cleanliness of
that milk, and is of far more impor-
lance, from the standpoint of the
health department, than is the quality
of the milk. Three factors influence
the number Of bacteria in milk:
% The number allowed to enter at
the time of milking.
| 90 The temperature at which the
milk is kept from the time it is MIXED
until delivered to the customer.
go The length of time which elapses
between milking and delivery to the
customer.
| The number of bacteria are exactly
| in proportion to these three factors:
The more dirt entering the milk, the
warmer the temperature of the milk,
and the greater the time before de-
livery, the higher will be the bacterial
count. Conversely, the less the dirt
the cooler the milk is kept and the
shorter the time before delivery, the
| lower will be the bacterial count.
Counting the bacteria, therefore, tells
the health department the exact truth
about how these three factors have
been handled.
With a reasonable degree of cleanli-
ness in milking, the milk viii contain
from 100 TO 1000 bacteria per cubic
tiers the clean milking pail. If the milk
is then properly cooled and kept cool,
at the end of twelve hours it should
never have more than 10000 bacteria
per cubic centimeter If it is found to
contain many more than this-say,
100, 600, or a million, or ten millions
this is positive proof that the milk has
been handled in such a manner as to
render it unfit for raw food.
The city health department, at last
has reached the point in its educational
campaign, where sufficient clean milk
properly produced. sufficiently cooled
and quickly delivered, is available for
all the needs of the city. No dairyman
has any more right to sell unclean milk
than butcher has to drop a steak in
the mud and then sell it or a baker has
to conceal a chunk of dirt in his LOAF
of bread. The dairyman would be the
greater offender. because in the cases
of the bread and steak the dirt would
be rendered harmless by cooking, while
the manure in the milk is offered raw
and teeming with bacteria.
Most of the bacteria in the milk are
harmless in themselves, but they are
an accurate and indisputable indica-
ton of the cleanliness of the milk. Il
the milk is clean and has been prop
erly handled, the bacteria will be few
in number If the milk is dirty, If too
much dust settled in the milking pail
. | if the COW and mixer were covered
with dirt to start with, if the milk ha'
been kept at an unwhOlesomely warn
temperature, if the milk is old wheI
| | delivered, the bacterial count will b
high-up in the millions.
I The method of bacterial examination
may be of interest. We follow the ac
curately standardized technic, decided
upon after years of investigation b.
the National Milk commission working
in conjunction with the United State
Public Health service of the nationa
government. Every step in the process
is rigidly prescribed, so that all specl
mems from one end of the year to tn
II other are handled and examined exact
II ly alike. Only after this method ca
comparisons safely be made. Ever
article that is to come in contact VIII
H the milk is first sterilized by stear
II under pressure. Then the milk is thor
oughly shaken, following prescribe
| methods. SO that all samples are shak
en- exactly alike. This shaking is i'm
! portant, not only for the bacteria
counting, but for the fat examinations
The bottles are appended and move
through the air a definite distanc
II twenty five times. One cubic cent?
meter of milk is Immediately take
II from the center OF the bottle with
H graduated pipette and placed in 80 c.
of distilled, sterile water. All the spec
linens are shaken and diluted in tn
same manner. These ! to 100 dilutior
are then shaken in the same way an
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