The San Francisco call., 1905-04-02

whose prices are more moderate. Yet
the very same people would more
cheerfully expend money for liquors
than buy this value food. Next
to bread and water, milk is prob
ably more commonly used than
any other article Of food or drink.
1t is nutritious, economical and with
many a favorite food. It contains
in easily digestible form the four
kinds of nutrients required by the
body namely: protein. fats. carbohy-
drates and mineral matter.
Vital statistics Of the Health Depart
ment show that about one-third of all
deaths are Of infants. and that very
large percentage of these die from dis
eases Of the digestive tract. These dis
eases are said to be due principally
10 impure food. The impure food in
this instance may be termed dirty
milk" and since the Board Of Health
has taken the matter in hand it can
boast that there has been a decrease in
infant mortality of at least 1s1e per
cent.
The inspectors Of the Board of Health
are not many. but the few employed by
visit the dairies daily and order the
owners to comply with the ordinances.
Constant visits are having their effect,
and where filth reigned formerly clean
Illness holds sway. Samples of milk
are taken daily and brought to the lab
oratories Of the Board of Health. A
portion of the sample is turned over to
DR.. Frederick G.. Canney. the city bac-
-
by Dr.. A c. Bottle, superintendent of
the pure food department, for analyses.
alyses.
1t Is the duty Of the bacterioiogist
TO ascertain the number Of bacteria
colonies in the milk, and the result OF
his examination causes the health au-
thorities to admonish the dairymen to
exercise greater care in handling the
milk.
Making a meteorological test is ex-
tremeiy interesting. First the sample
of milk is placed in a specially ster
ilized bottle that is wrapped in paper
so that the fingers may not contami
nate IL, and also to keep out the dust.
Sterilized tubes containing a culture
media. composed OF beef, broth and
peptone, to which is added agar-agar,
which is substance made from the
inner bark Of a tree grown in China,
and which has the property Of liquefy-
ing at a boiling heat and solidifying
when cold, is used TO feed the germs
and make them grow. Before using
the germ-food, however, one hundred
centimeters OF water are measured into
a sterile-1ask. Then one-tenth of a
centimeter Of milk is sucked up by a
glass pipette, which is not unlike a
straw, and dropped into the water.
This makes proportion Of one of milk
TO one thousand Of water and is known
as the dilution process.
Another pipette is used to suck up
one centimeter of the mixture of milk
and water, and this Is dropped into a
tube Of liquefied agar-agar and imme- |
diateiy plated out into a Petrie dish-a |
shallow glass with a cover. This dish |
is then set in an incubator for about |
thirty-six hours at a temperature of |
375z centigrade, which is equivalent to |
es1k Fahrenheit This heat, together |
with the nourishing property Of the |
media, has a tendency TO make the col
onies grow and the plate clearly shows |
the bacteria, which resemble white |
specks to the naked eye. This dish is |
placed on Wolfoegel tablet, which is
a glass marked of in one-fourth-inch
squares, TO enable better count OF the
colonies through a powerful micro
scop.
Some samples show as many as 1,600.-
900 colonies TO the cubic centimeter.
This is a sign of dirty dairy. Boston
has bacteria standard OF SOC. 900 colo
nies TO the cubic centimeter and when /
ever II goes above that figure drastic |
measures are taken against the dairy |
supplying the milk. Unfortunately, the |
Board OF Supervisors have not seen 1T |
TO enact the Board of Heaitll's recon- |
mendation Of an alike standard into an |
ordinance. and therefore the health
authorities Of this city may only ad-
monish cleaner methods 1t is the
presence OF bacteria in milk that causes