_B. Diazotans_[1]
At this point, I remember, the long spell of dry weather reached its
end. A heavy series of thunderstorms marked its termination; and for
three days the country was deluged with rain and swept by intermittent
gales. The cracked ground drank up the moisture; but still more showers
fell, until there was mud everywhere.
These meteorological changes in themselves were sufficiently grave
from the farmer’s point of view; but even more serious was the state
of things revealed after the rain had ceased. Whether it was due to
the weather conditions or whether it was a vagary produced by factors
beyond discovery will never be known; but the fact is established that
the spread of the Blight became accentuated during the rainy period.
Wherever it had secured a hold during the hot weather it became more
malignant in its effects; and its extension to fresh fields was so
great that hardly a grain-growing area in the country escaped at this
time. It penetrated as far north as the Border agricultural districts;
and devastated fields were found even in Perthshire.
Since the potato blight in 1845, no such rapid and extensive
destruction of food supplies had been known. The standing crops in
the affected areas withered; and a total failure of the home-grown
cereals seemed to be inevitable. Nor was it only in this section of the
food-supply that the attacks of the Blight became evident. Fruit-trees
seemed arrested in their productivity; vegetables failed to ripen and
began to rot. Everywhere the vegetable kingdom seemed to be falling
into a decline. The great market-gardens and nurseries showed the trace
of the same mysterious agent. Roses withered on their stems; and even
the hot-house plants suffered equally with their open-air fellows. The
only crop which appeared to escape the general disaster was hay.
And now it became clear that the Blight, as it was still called,
was going to produce effects in the most widely-separated fields of
activity. With a total failure of the crops, the financial side of the
question came to the front. Throughout the length and breadth of the
land, small farmers were beginning to realise that it was to be a year
of utter disaster, ending probably in bankruptcy and ruin. The larger
land-owners looked forward to the collapse of tenants and the failure
of rents. Mortgage-holders began to consider the nature of their
security, and when it was agricultural land they were placed in doubt
as to their best course; for no one could foresee whether the Blight
was a temporary epidemic or a permanent factor which would reappear
with the next crops. And all these varying influences had their effects
upon the great financial operations of the City; for even in that
industrial age the land had maintained its value as a basic security
which apparently could not suffer deterioration beyond a definite point.
This, however, was only a minor field of the Blight’s reactions. With
the probable failure of the home crop looming before him, even the man
in the street could not fail to perceive the more obvious results. It
meant a greater dependence upon imported food-stuffs and especially
imported grain. Argentina, Canada, India and the United States must
make up the missing supplies; and since almost half our cereals were
home-grown at that period, the price of food was certain to rise by
leaps and bounds; so that every family in the land would be affected by
the catastrophe.
Then a further factor was brought to light. With the failure of grain
and even of grass, it would be impossible to keep alive the cattle
which furnished part of the nation’s food. The milk supply would be
gravely affected also, from the same cause.
It is difficult for us now to look back and catch again the spirit of
that time. Never before, even during the war, had the food of Britain
been endangered to such a degree. And the steadily rising prices were
sufficient to bring home to the most thoughtless the actual imminence
of the peril. I can recall, however, that at first there was no panic
of any kind. It was assumed by all of us that although we might have
to go short of our usual lavish supplies, yet we should always have
enough food to carry us through to the next harvest. The whole world
was our granary; and if we were prepared to pay the higher prices which
we saw to be inevitable, we had no reason to suppose that we should
lack imported grain. Our attitude was quite comprehensible under the
circumstances, I think. In the past we had always been able to obtain
food; and there seemed no doubt that the same would hold good through
this shortage.
The newspapers were fairly evenly divided in their expressed opinions.
The Government had recently adjourned Parliament, after a session in
which their majority had oscillated dangerously more than once, and
the Opposition Press seized upon the Blight in order to embarrass
the Cabinet, and especially the Prime Minister, as far as possible.
They clamoured that the Government should take steps to secure the
food supply of the country by making immediate purchases of wheat in
the foreign markets. They demanded that a system of rationing should
be established forthwith; and that cases of food-hoarding should be
stringently punished. Day after day they held up to public obloquy the
individual members of the Cabinet, who were then scattered on holiday;
the amusements of each of them were described and coupled with sneering
hopes that they would succeed better in their games than they had done
in the government of the country and the safeguarding of the national
interests. Echoes of the Mazanderan Development Syndicate scandal were
kept alive in the most ingenious manner.
The Government Press, naturally, professed to see in the inactivity of
the Cabinet a proof that they had the matter well in hand. Avoidance of
panic, restriction by voluntary effort of all unnecessary consumption
of food, and the postponement of inquiries likely to interfere with the
wise projects of the Premier: these formed the stock of their leading
articles.
The gutter organ of the Opposition retorted by publishing the complete
menu of the Premier’s dinner on the previous day, which it had
obtained from some waiter in the hotel at which he was staying; and
it accompanied this item of news by interspersed extracts from the
Government organs in which appeals had been made for a less luxurious
form of living.
It must be remembered that this stage of the sequence of events
occupied only a brief period. If I am not wrong, it was within ten days
of the outbreak of the Blight that we got the first American cables
announcing the appearance of the epidemic among the great wheat areas
of the Middle West. Almost immediately after came similar news from
Canada.
The meaning of this was not at first appreciated by the people as a
whole. They still clung to the idea that grain would be forthcoming if
a sufficiently high price were paid for it; but those of us who had
tried to forecast the possibilities of the situation found our worst
fears taking concrete form. Soon even the unthinking were forced to
understand what the American news implied. If the Blight spread over
the wheat-fields of the Western continent, there would be no surplus
grain there for export at all. That source of supply would barely
suffice for the mouths at home.
Then, following each other like hammer-strokes upon metal, each biting
deeper than the last, came the cables from the rest of the world.
Egypt reported the outbreak of the Blight in the Nile valley; British
East Africa became affected. The news from the Argentine fell like a
thunderbolt, for we realised that with it the last great open source
of wheat had failed. The Don and Volga basins followed with the same
tale. Over India, the Blight raged with almost unheard-of virulence.
Then, days after the others, Australia was smitten, and our last hopes
vanished.
* * * * *
During all this period, it must be remembered, we had no idea of the
origin of our calamities. We referred to the thing always as “The
Blight,” though it was made clear at quite an early stage that no
plant parasite was concerned in the matter at all. The most careful
microscopic examination of affected vegetation had been made without
revealing anything in the nature of a fungus or noxious growth.
Yet, on looking backward, I cannot help feeling that we, and especially
I myself, were strangely blind to the obvious in the matter. I have
already mentioned that when I rooted up a clump of grass in Regent’s
Park it came away from the soil without resistance; and that when I
examined the roots I found them almost as free of earthy deposit as
if it had been grown in sand. That, coupled with what I already knew,
should have put me on the track of the explanation; and yet I failed
to draw the simplest deduction from what I observed. To account for
this obtuseness, I can only suggest that already the idea of a “Blight”
had taken root in my mind; and that I was so obsessed with the idea of
a parasite that I never considered the facts from any other point of
view. Since others proved to be equally slow in arriving at the truth,
I can only conclude that they were misled in their mental processes
much as I myself was.
As I have said on a previous page, it was to Johnston, the
bacteriologist, that we owe the discovery. It appears that he had been
growing some bacteria in cultures; and, whether by accident or design,
he had left one of his cultivation media open to the air. On examining
the germs some days later, he had discovered in the culture a type of
bacterium with which he was unfamiliar. He proceeded to isolate it in
the usual way--I believe it is done by dabbing a needle-point into the
culture and using the few micro-organisms which stick to the needle
as the parents of a fresh colony--and he was amazed at its fecundity.
There had never been such a case of bacterial fertility in his
experience.
A paper in the _Lancet_ brought the description of the creature
to the notice of the scientific world. Johnston himself had not
recognised the nature of the organism, as he had never dealt with this
type of bacteria before; but from his description an agricultural
bacteriologist named Vincent was able to identify it as being almost
identical with one of the denitrifying group, from which it differed
only in its immense power of multiplication. It was hurriedly
christened _Bacterium diazotans_, on account of its denitrifying
qualities. Further examination showed that its capacity for breaking
down nitrogenous material far surpassed that of any known denitrifying
agent.
With these discoveries, the mystery of the new blight vanished. An
examination of the soil of stricken areas showed that it swarmed
with colonies of _B. diazotans_--to use the customary medical
contraction--and the whole secret of the destruction was revealed.
It was evident that these new and super-active bacteria attacked the
soil, disintegrated all the nitrogenous compounds within their range
and thus left the plants without nourishment. The death of the plant
followed as a natural result; but the matter did not end there. By
destroying the nitrogenous compounds in the soil, the bacteria altered
the whole texture of the earth in which they grew. All the nitrogenous
organic matter which forms so large a part of the binding material of
some soils was destroyed utterly; with the consequence that the mineral
particles, which previously had been resting in an organic matrix, were
now free to move. Only the clays retained their tenacious character:
all other soils degenerated into sand.
There has, of course, been a great deal of speculation upon the origin
of _B. diazotans_. Hartwell suggested that it came to us from Venus,
propelled by light-pressure across the abysses of space. Inshelwood put
forward the view that in _B. diazotans_ we had an example of bacteria,
originally endemic, changing their habits and spreading into fresh
regions.
Personally, I believe neither hypothesis. I feel sure that I saw the
birth of the first _B. diazotans_ on that night in Wotherspoon’s
laboratory, under the action of the fire-ball; and the evidence is
simple enough.
Every living creature is a wonderfully constructed electrical machine.
Each beat of our hearts, each systole of our lungs, each contraction of
a muscle in our frame produces a tiny electrical current. Our organism
is a mass of colloids and electrolytes which transmit these charges
hither and thither throughout our systems; and were we gifted with an
electrical sense in addition to those which we already have, we should
see each other as complexities of conductors along which currents were
playing with every movement of our body.
This complex electrical system is acutely sensible to external
electrical conditions. Anyone who has held the handles of an induction
coil or who has taken a spark from a Leyden jar knows the physiological
effects which these things produce. The influence of high-tension
currents upon the growth of plants has been proved beyond dispute.
Now it seems to me that in this effect of an external electric charge
upon the internal mechanism of an organism we have a clue to the origin
of these new bacteria. I have already told how the fire-ball, in its
explosion, shattered the denitrifying cultures in Wotherspoon’s room;
and it seems clear that at the moment of the concussion there must have
been a tremendous play of electrical forces about the spot. We know
hardly anything with regard to the nature of the electrical fields
existing in such things as these fire-balls; and it is quite possible
that they may be different from anything of which we have any knowledge
among the more usual displays of electrical energy. I believe, then,
that it is in the action of the fire-ball that we must seek for an
explanation of the change in habit of Wotherspoon’s denitrifying
bacteria.
Again, I have mentioned my observation of the rapid multiplication of
the denitrifying bacteria which I made with Wotherspoon’s microscope
on the following day. That also seems to me to have a bearing upon the
problem; though I admit quite frankly that my evidence is only that of
a layman. It is in every way regrettable that Wotherspoon, having tired
of using his room as an exhibit, should have cleared away every trace
of the wreckage before any expert examination of it could be made; for
in this way the crucial evidence on the point was destroyed.
Further, in support of my views, I would point out that the very first
known occurrence of _B. diazotans_ was that which had Regent’s Park
as its site; and that the first place of attack was in the immediate
neighbourhood of Wotherspoon’s house in Cumberland Terrace. This can
hardly be disregarded, when it is considered in connection with the
other facts which I have mentioned.
At this time of day there can be no question that London formed the
focus from which _B. diazotans_ spread throughout the world. I have
described the ramifications of the great air-services; and it seems
to me obvious that the organisms were carried to and fro upon the
surface of the globe by the agency of the aeroplanes. The order of
attack at various points indicates this very clearly, in my opinion.
First came the American and Egyptian outbreaks; then Uganda and South
America; and finally, long after the others, Australia showed traces
of the devastation. I have checked the possible dates of arrival in
these various places, taking into account the relative swiftnesses of
the aeroplanes on the different routes; and the results can hardly be
gainsaid. Allowing, as one must, a certain latitude for the time of
development of the microbe in various spots, there seems little doubt
that the dates of the outbreaks fell into the same succession as the
times of arrival of the various London air-services.