POISONS IN FOOD
Poison in Beer—Poison in Food—Poison in Honey—Poison in Cocoa and
Chocolate
In the latter part of the year 1900 a fairly widespread epidemic of
peripheral neuritis of the extremities and its attendant symptoms was
noted by medical men in certain districts of Manchester. In addition,
many of the sufferers complained of swelling of the legs, weak
circulation, vomiting and pigmentation of the skin. It was noted by the
medical officers of the various hospitals who examined these patients
that in every case they were heavy beer drinkers, and patronized
public-houses supplied from certain breweries.
The mysterious epidemic spread and cases were reported from different
parts of the north of England. In Manchester and Salford there were five
hundred and twenty-two cases, in Liverpool seventy-one, fifty at
Birkenhead and fifty at Stourbridge; at Darlaston, Staffordshire, there
were upwards of fifty cases, forty were reported from Chester,
thirty-two in Birmingham and thirty in Leeds and district.
Many deaths ensued, and the whole train of symptoms and circumstances
were such that, had they happened two or three hundred years ago, they
would have created consternation.
The beer was the clue, and scores of samples were purchased at
public-houses miles apart, and the ingredients used in the manufacture
of the beer in breweries spread over the North of England were carefully
examined. Dr. Hitchin, the Medical Officer of Health for Heywood, Lancs,
stated that two or three hundred persons were attacked, and he
discovered arsenic in stout as well as beer.
The result of the analysis was startling, as in the majority of the
cases it led to the discovery of arsenic. This was first detected by Dr.
Reynolds, of Manchester, and at his instance the public were warned
against drinking cheap beer.
Meanwhile, research into the whole mystery went on. That large
quantities of the beer were contaminated was certain, but how the
poisonous substance got into it was the question which had to be
determined.
A clue was found when certain experts who were engaged in investigating
the materials used in the brewing of certain kinds of cheap beer,
discovered that in every instance glucose had been used in the
preparation, and on analysis of the glucose it was found to be
impregnated with arsenious acid. This was followed by still further
examination of the materials employed in making the glucose, and it was
found that the sulphuric acid used for this purpose was brown in colour
and contaminated with arsenic, showing that it had been made from iron
pyrites containing arsenic as an impurity, and thus the ring of evidence
was complete and successful.
This opened up possibilities of even more widespread poisoning. Samples
of jams and golden syrup were obtained for analysis, but all gave
negative results when tested for arsenic. It appears that there are only
about a dozen manufacturers of glucose in England, a great deal of it
being imported from America. It was therefore concluded that the makers
of the contaminated glucose must be some particular firm who sold their
product to brewers only, and that within a certain area. Some samples of
glucose that were subjected to test showed in one instance a proportion
of arsenic that was absolutely deadly, and this was located to one firm.
They instantly sent out telegrams to their customers stopping the use of
this ingredient. Everything was done to prevent further mischief, and
the output of the poison-impregnated material was stopped. Heroic
measures were taken by one brewery, which placed an embargo on all the
beer in the cellars of their customers, until it was certified as pure
by analysts deputed to visit them in turn. Some brews were recalled
wholesale, and the loss to the firm amounted to several thousand pounds.
The next thing was to discover how the arsenic got into the glucose
during the process of manufacture, and this was traced down to a Spanish
copper mine from whence pyrites was imported by a firm of manufacturing
chemists in a northern county for the purpose of making sulphuric acid.
The sulphuric acid in question was of the ordinary commercial variety,
generally used in works for dyeing and similar purposes. It was usually
of a brownish colour, and even though it was contaminated in any way for
the purpose of such manufacture, no harm could ensue. If, however,
without having it tested to see if it was free from deleterious matter,
the manufacturers should then use glucose containing this ordinary
commercial variety of sulphuric acid for their product, a considerable
amount of arsenic would remain in it. In this way it was sold to brewers
who used it in the manufacture of their beer, and this mineral poison
was thus carried on through the various processes till it reached the
consumer with the dire consequences already described.
It is stated that brewers thought they could obtain a better-coloured
and more satisfactory beer by treating the malt with invert sugar and
glucose. Invert sugar is cane sugar boiled in solution with diluted
sulphuric acid, and glucose is starch boiled in a similar manner. It was
obvious therefore that the only ingredient which could have been
contaminated with arsenic was the sulphuric acid.
The manufacturers of the glucose had, of course, not the faintest idea
that the mysterious poison which had caused so many deaths emanated from
them. Although it was said that the sulphuric acid was tested, curiously
enough it was admitted it was never tested for arsenic, and the
explanation was put forward that the pyrites sent from the mine in Spain
had been obtained from a new lode which was charged with an undue
proportion of arsenic. After a full investigation had been made, special
precautions were laid upon brewers to examine all ingredients used in
making the beer, and since this time no similar cases have been
recorded.
The epidemic had developed into almost a panic in and around Manchester,
and several cases of ordinary illness were put down to arsenical
poisoning. The hospital wards were filled, but the prompt measures taken
had their effect. It was said by the Manchester coroner at one inquest
that the only pleasant feature of the epidemic was for the temperance
people. The consumption of fourpenny ale was not a fraction so great as
it was a fortnight previously. Arsenic had proved a temperance argument.
Within the last few years many cases of food-poisoning of one kind or
another with fatal results have been reported. It is probable that in
spite of every precaution such cases will occasionally occur. Some may
have been due to the fact that bacteria were actually living in the food
at the time it was consumed, or as probably in the case of the Loch
Maree fatalities, it may have resulted from toxins left by bacteria
which once lived in the food. The former type of food-poisoning which is
most common in this country results from the eating of food which has
become contaminated by certain bacteria, whose presence may be due to
disease in the animal before it has been slaughtered, or if they have
gained access to the food in course of its preparation.
The heat used in cooking is generally sufficient to kill such organisms,
and no doubt it often does so. Again, it may be introduced from the
outside, as in a recent case when the instrument of infection was found
to be a contaminated knife used in cutting ham for sandwiches.
In cases of food-poisoning due to a toxin formed by organisms, these
probably being dead, the organism concerned is what is known as
_Bacillus botulinus_, so called from its having first been discovered in
German sausages. The bacteria thrive especially in a medium in the
absence of oxygen, and so breed with rapidity in air-tight tins or
inside sausage skins, and are to be found even in vegetable matter. They
form a very powerful poison, acting upon the nerve centres in the brain,
causing paralysis of the muscles which move the eye and eyelids and
those concerned in speaking and swallowing. The resulting disease known
as botulism has fortunately been rare in England, where there is not a
very large consumption of tinned meat or vegetables, but it has been
frequent in both America and Germany.
Botulism and food-poisoning, therefore, must not be confused, as the
former is a poisoning by a specific toxin and the latter may be called
an infection.
A very curious case of poisoning was brought to light some years ago at
an inquest held on a woman who had died with symptoms of poisoning after
attending a wedding breakfast. The guests, after regaling themselves
with wedding cake, had finished up with kippered herrings, and shortly
afterward one of them was taken ill with severe pain and died.
During the inquest it was pointed out, that it was possible that some of
the ingredients used in curing the kippers, when brought into contact
with almond paste on the wedding cake, would possibly liberate prussic
acid, if the almond paste had been made with bitter almonds, in
sufficient quantity to cause death.
The poisonous effects produced by honey gathered in certain districts
has been known for centuries, and the story of some of Xenophon’s
soldiers having been poisoned by this means more than two thousand years
ago is well known. This poisonous property was formerly attributed to
the bees having gathered the honey from the flowers of henbane and
hemlock, which grow largely in the neighbourhood of Trebizond, but it
has now been proved that the poisonous principles may be extracted by
the bees from other plants, according to the locality in which the honey
is found. Thus American honey has been found to contain poisonous
ingredients derived from gelsemium or golden seal.
A serious case in which fourteen persons were poisoned from eating
honey, one of whom died, is reported from Princetown, N.S. The honey was
found to contain Andromedo-toxin, a poisonous principle obtained from
certain ericaceous flowers.
There are other instances on record of poisoned honey which has been
contaminated by bees which have carried poison from certain flowers, but
cases in which poison has been introduced into honey for criminal
purposes are rare.
Some years ago a young man was arrested at Coire, in Switzerland, on his
own confession of having murdered two young women, to whom he had been
engaged to be married, by introducing strychnine into the cells of some
honeycomb which he presented to his victims. In each case the girls died
in great agony on their wedding eve, after a visit from the man. One
victim had been buried two years, and the other some months, before
suspicion was aroused and the bodies exhumed for examination, and the
man was convicted of the crime.
Within recent years the contamination of food substances with arsenic
has come into some prominence, not only in connection with certain cases
in which chocolate sweetmeats have been used as a medium for the
administration of arsenic, but also in substances in common use, such as
cocoa. Towards the end of November, 1922, the Public Analyst, acting for
the Reigate Town Council, reported on seven samples of cocoa that had
been taken under “The Sale of Foods and Drugs Act,” and he found that
one contained arsenic (arsenious oxide) to the extent of ¹⁄₇₅th grain to
the pound of cocoa. It was obvious that such a report could not be
allowed to remain unnoticed, as, according to the Royal Commission on
Arsenical Poisoning, it is illegal for an article of food to contain
¹⁄₁₀₀th of a grain or more of arsenic per pound.
The matter was reported to the Minister of Health who took a serious
view of it, and it culminated in two summonses being issued by the
Surrey County Council against the vendor and the manufacturer, the
charge being that the cocoa was “adulterated with arsenic (arsenious
oxide) to the extent of ¹⁄₄₀th of a grain per pound.”
The cocoa had been purchased at a shop in Richmond and was labelled
“Pure Cocoa Essence. Guaranteed absolutely pure Cocoa.” On analysis this
sample was found to contain ¹⁄₄₀th of a grain per pound, but on inquiry
from the manufacturers it appeared to be a mystery how the arsenic was
introduced into the cocoa. The investigation was rendered more difficult
when it was found that the actual sample purchased was a blend of seven
different cocoas; however, samples of these were taken, and one was
found to contain arsenic to the extent of ⅒th of a grain per pound.
On tracing back the source of contamination it appears that an alkali
such as potassium carbonate is mixed with cocoa to render it more
soluble, and in this case the impurity was discovered in the potassium
carbonate, which was found to contain a substantial quantity of arsenic.
The manufacturers, on finding this out, sacrificed three hundred and
fifty tons of cocoa and did everything they could in the interests of
the public to stop the sale. The retail firm, directly they heard of the
impurity, also withdrew sixty-five tons from their shops and twenty-five
tons from their warehouses and had them destroyed.
Although potassium carbonate is not used in the making of chocolate,
several cases have been reported of illness caused through eating sweets
in this form.
About the same time a London lady was taken seriously ill after eating
some marzipan sweets which she purchased at a Church bazaar. It appears
she ate about half a dozen of them and became ill shortly afterwards,
the symptoms pointing to arsenical poisoning.
Although powdered glass has been used for criminal purposes from time to
time, it is not generally known that glass itself may be contaminated
with arsenic.
Some time ago it was found on making an analysis of a bottle that the
glass contained both arsenic and lead, insomuch that they probably
contaminated some potassium carbonate that had been kept in the bottle.
The danger in careless packing and handling of arsenic imported to this
country has recently been commented on by the Medical Officer of Health
for the Port of London. He states in a report, that “a ship from Oporto
had aboard about fifty bags of shelled almonds. On the same deck were
twenty-two cases of white arsenic.
“When examined by the inspector two of these cases of arsenic were
standing on end with their heads open, and one was leaking at its bilge
on to the deck.
“Two of the bags of almonds which had become displaced showed arsenic on
their surfaces. Minute quantities of arsenic were found on almonds taken
from one of the bags.”
In another case a ship had landed 160 cases of arsenious acid at the
King George V Dock.
“The cases containing the arsenic were composed of old, dry wood, and
from some of them the poison was leaking on to the floor of the shed.
The possibility that some of it might find its way into any food handled
in the same shed cannot be overlooked.”
That such carelessness might lead to very serious consequences is
obvious.