measured and analysed, the same being the case with the
excreta. The blood was examined periodically as regards
colouring matter and number of corpuscles. Everything was
done to keep up the general health of the members and to
do away with all unfavourable mental influences due to the
circumstances. During the time of the experiment analyses were
made of 2550 food samples and 1175 samples each of urine and
faeces. The general results were as follows: there was no
tendency to excite diarrhoea, and the nitrogen-metabolism
was but very little influenced, if anything being slightly
decreased. As regards phosphorus the combined results of
all observations indicated that the preservative increased
the excretion of phosphorus to a small extent, from 97.3%
in the ``fore'' period, to 103.1 in the ``preservative''
period. The metabolism of fat was uninfluenced; there was
an increase of the solid matters in the faeces and a decrease
of those in the urine, from which Dr Wiley concluded that the
preservatives interfered with the process of digestion and
absorption. No influence was exerted on the corpuscles
and the haemoglobin of the blood. The effect of boracic
acid and borax on the general health Varied with the amount
administered, quantities not exceeding half a gramme (7 1/2
grains) of boracic acid, or its equivalent of borax, producing
no immediate effects, but the long-continued administration
of such small doses seemed to produce the same results as
the use of large doses over a shorter period. There was a
tendency to diminish the appetite and to produce a fooling
of fulness and uneasiness in the stomach and sometimes actual
nausea, also one of fulness in the head manifested as a
dull headache which disappeared when the preservative was
dropped. The continued administration of large doses, 60
to 75 grains per day, resulted in most cases in loss of
appetite, inability to perform work of any kind and general
unfitness. In most cases 45 grains per day could be taken
for some time, but gradually injurious effects were observed.
In some cases 30 and even 15 grains per day appeared to cause
illness, but it is acknowledged that these persons may have
been suffering from influenza. The administration of 7.5
grains was declared by Dr Wiley to be too much for the normal
man to receive regularly, although for a limited period
there might be no danger to health. Dr Wiley concludes his
report: ``It appears, therefore, that both boric acid and
borax, when continuously administered in small doses for a long
period or when given in large quantities for a short period,
create disturbance of appetite, of digestion and of health.''
Dr Wiley's conclusions were adversely criticized by Dr O.
Liebreich, who carefully studied on the spot all the conditions of
the experiment and the documents relating to the investigation.
He pointed out that the results were so indefinite and the
number of persons under control so small that ``one case
of self-deception or of forgetfulness only would throw into
absolute uncertainty the solution of the whole question''; that
no lasting injury to health was found in spite of transient
disturbances attributed by Dr Liebreich to other causes, and
that all persons declared themselves to be in better physical
condition after seven months than they had been before. On
the whole the balance of evidence seems to be that while no
acute injury is likely to result from boron compounds in food,
they are liable to produce slighter digestive interferences.
Formaldehyde.
Other chemical substances that are in use for the purpose
of preserving food materials may be treated more shortly.
Formaldehyde, coming into commerce in the form of a 40% solution
under the name of formalin, was for a time largely used in
milk. It certainly has very great antiseptic properties,
as little as 1 part in 50,000 parts checking the growth of
organisms in milk for some hours, but as the substance combines
with albuminous matters and hardens them to an extraordinary
degree, rendering, for instance, gelatine perfectly insoluble
in water, it exerts an inhibitory effect on the digestive
ferments. It injures salivary, peptic and pancreatic
digestion. A set of five kittens fed with milk containing 1
part in 50,000 of formaldehyde for seven weeks were strongly
retarded in growth, three ultimately dying, while four control
kittens fed on pure milk flourished. In even moderate doses
formalin produces severe pains in the abdomen and has caused
death. It is now generally recognized as a substance
that is admirably adapted for disinfecting a sick-room,
but quite improper and unsuitable for food preservation.
Salicylic acid.
Salicylic acid or orthohydroxybenzoic acid is either obtained
from oil of winter-green or is made synthetically by Kolbe's
process from phenol and carbonic acid. Artificial salicylic
acid generally contains impurities (creasotic acids) which act
very injuriously upon health. When pure, salicylic acid employed
as a food preservative has never produced decided injurious
effects, although administered by itself in fairly strong
solution it acts as an irritant to the stomach and kidneys,
and sometimes causes skin eruptions. It is a powerful drug in
larger doses and requires careful administration, especially
as about 60% of the persons to whom it is administered show
symptoms known as ``salicylism,'' namely, deafness, headache,
delirium, vomiting, sometimes haemorrhage or heart-failure.
It is doubtful whether pure salicyiic acid produces these
symptoms. When present in proportion of 1 to 1000 it inhibits
the growth of moulds and yeasts. In jams 2 grains per pound
and in beverages 7 grains to a gallon are considered by
manufacturers to be sufficient for preservative purposes.
It is used mainly in articles of food or drink containing
sugar, that is to say, in jams and preserved fruit, lime
and lemon juices, syrups, cider, British wines and imported
lager. Its use in butter, potted meat, milk or cream, in
which it was not infrequently met with formerly, is now quite
exceptional. It has already been stated that the preservative
committee recommended its permissive use in small proportions.
To some extent benzoic acid and benzoates have taken the place
of salicylic acid and salicylates, partly because salicylic
acid can readily be detected analytically, while benzoic acid
is not quite easily discoverable. Its antiseptic potency is
about equal to that of salicylic acid, and the arguments for
or against its use are similar to those relating to the latter.
For the preservation of meat and beer, lime juice and dried
fruit, sulphur dioxide (sulphurous acid) and some of the
sulphites have long been employed. Sulphuring of hops and
disinfection of barrels by burning brimstone matches is an
exceedingly old practice. Burning sulphur is well known as
a gaseous disinfectant of rooms, bacteria being killed in air
containing 1% of the gas. As the taste and smell of sulphurous
acid and of sulphites are very pronounced it follows that but
small quantities can be added to food or drink. About 1 part
in 4000 or 5000 of beer is the usual amount. While, in larger
quantities, the sulphites have decided physiological activity
and are apt to produce nephritis, there is not any evidence
that they have ever caused injurious effects in alcoholic
liquors. The excise authorities have tacitly sanctioned
their employment in breweries, although the Customs and Inland
Revenue Act 1885 declares that a brewer of beer shall not add
any matter or thing thereto except finings or other matter
or thing sanctioned by the commissioners of Inland Revenue,
and although sulphites are used in all breweries, the Board
of Inland Revenue do neither sanction nor interfere. An
antiseptic with a pronounced taste is obviously a safer one in
the hands of a nonmedical person than one virtually devoid of
taste, like boric, salicylic or benzoic acids or their salts.
Other preservatives.
Sodium fluoride, a salt possessing powerfully antiseptic
properties, but also at the same time clearly injurious to health
and interfering with salivary and peptic digestion, has been
found in butter, imported mainly from Brittany, in quantities
quite inadmissible in food under any circumstances. A few
other chemical preservatives are occasionally used. Hydrogen
peroxide has been found effective in milk sterilization, and
if the substance is pure, no serious objection can be raised
against it. Saccharine, and other artificial sweetening
agents, having antiseptic properties, are taking the place
of sugar in beverages like ginger-beer and lemonade, but the
substitution of a trace of a substance that provides sweetness
without at the same time giving the substance and food value
of sugar is strongly to be deprecated. The employment of
chemical preservative matters in articles intended for human
consumption threatens to become a grave danger to health or
well-being. Each dealer in food contributes but a little;
each one claims that his particular article of food cannot be
brought into commerce without preservative, and each condemns
the use of these substances by others. There is doubtless
something to be said for the practice, but infinitely more
against it. It cheapens food by allowing its collection
in districts far away, but the chief gainer is not the
public as a whole but the manufacturer and the wholesale
merchant. Our body has by inheritance acquired habits and
needs that are quite foreign to chemical interference.
Some day, artificially prepared foods, containing liberal
quantities of matters that are not now food ingredients, may
conceivably compare with natural food products, but that day
is not yet, and meantime it ought to be clearly the duty of
the state to see that the evil is checked. The intention
which has introduced this form of adulteration may be more
or less beneficent, but in practice it is almost wholly evil.
Colouring matter in food.
A similar criticism applies to the continually extending
use of colouring matter in food. Civilized man requires his
food not only to be healthy and tasty. but also attractive in
appearance. It is the art of the cook to prepare dishes that
please the eye. This is a difficult art, for the various
colouring matters which are naturally present in meat and
fish, in fruit, legumes and green vegetables are of a delicate
and changeable nature and easily affected or destroyed by
cooking. Many years ago some artful, if stupid, cook found that
green vegetables like peas or spinach, when cooked in a copper
pan, by preference a dirty one, showed a far more brilliant
colour than the same vegetables cooked in earthenware or
iron. The manufacturer who puts up substances like peas
in pots or tins for sale produces the same effect which the
cook in her ignorance innocently obtained, by the wilful
addition of a substance known to be injurious to health,
namely, sulphate of copper. The copper combines with the
chlorophyll, forming copper phyllocyanate, which, by reason
of its insolubility in the gastric juice, is comparatively
innocuous. Preserved peas and beans have been for so many
years ``coppered'' in this manner that it is difficult to
induce the public to accept the vegetables when possessed of
their natural colour only. Several countries endeavoured to
abolish the objectionable practice, but the public pressure
has been too great, and to-day the practice is almost
universal. In England the amount of copper corresponds to
from one to two grains per pound of the vegetable calculated as
