Dec. 2, 1881.] 



KNOW^LEDGE ♦ 



89 



GERMS OF DISEASE AND DEATH. 



Bv Du. Andkew Wilson, F.R.S.E. 



Paut II. 



rpURNTNG now to the Clun-bon or Sph-nk Fever, we 

 .1 witue.'is another veritable triumph of Pasteur's industry 

 juid research. In 1 850, certain observers noted the interesting 

 fact that minute, rod-like bodies, wliich appeared to be 

 lower forms of plant life, existed in the blood of animals 

 artected with this disease. The " rods," it was observed, 

 originated from jiarticles which might, with ]ierfect 

 accuracy, be called "Germs." And as we watch the 

 '■ rods " in turn, we see that, sooner or later, micro- 

 scopic specks appear in their substance ; these grow 

 to form regular bead-like rows within the " rods ; " and 

 when finally the " rods " themselves break up and fall to 

 pieces, these beads are liberated as the "germs,'' which in 

 time will grow into new rods. Thus countless myriads 

 of rods and germs grow and are reproduced within the body 

 of the animal suffering from splenir fevi'i: The fever, in a 

 word, is the result of the growth and development within 

 the living -soil, of these rod-like plants. But exact demon- 

 stration of the truth of the latter statement can be 

 had. 



If we grow and culti\ate in a proper fluid — such as the 

 aqueous humour of the eye of an ox — the " rods," we may 

 inoculate with our " rods " the Ijody of a healthy animal. 

 We may sow in that animal's body the germs of splenic 

 fever. Thus a drop of a solution containing the " rods " 

 sown within the body of a guinea-pig, produces splenic 

 fever in that animal. And more wonderful still, it has 

 been shown that the dried blood taken from an animal 

 affected with this fever will reproduce the fever, even after 

 an interval of four years, if the dried particles of blood 

 with their " rods " be introduced into the body of a 

 healthy animal. 



Pasteur, armed with knowledge of the kind just detailed, 

 set himself to ascertain the " reason why " splenic fever 

 should suddenly appear in districts which knew it not, and 

 wherein only healthy animals lived. Obviousl}', if the 

 germ theory wci'e true, such sudden and apparently isolated 

 outbreaks must be capable of lieing explained on this 

 liypothesis. The idea of the " spontaneous," or de novo, or 

 ex id/iilo origin of the disease would, if supported by facts, 

 prove fatal to the "germ theory." Here, then, was a 

 typical case for scientific investigation. Let us see how 

 the genius of Pasteur overcame the difficulties of the 

 situation. 



The localities in which splenic fever seemed to burst out 

 suddenly and witliout warning were, as Pasteur learned, 

 former seats of the disease. But the interval between the 

 %'isitation was to be measured by years. How, then, could 

 the new outbreak be accounted for ! It seemed, in truth, 

 as if the one outbreak had little or nothing to do with the 

 other. The infected animals which had died, or had 

 been killed, ^\■hilst suffering ' from the fever, were duly 

 buried, and that very deeply, in the soil. Such a 

 method of interment would seem to ob\iate all risk of 

 infection. But tlie possibilities of nature are illimitalile, 

 and no man knew this better than Pasteur. If the poison 

 had been buried in the soil, wh}- should it not be there 

 still 1 And, further, why should it not be conveyed up- 

 wards to infect the fresh flocks that fed on the graves of 

 their- predecessors'? With a gift of scientific divination, 

 Pasteur sought in the earthworm, the type of the " middle- 

 man" betwixt the living and the dead. He now examines 

 the bodies of the worms which live in the soil wherein the 



bodies of the animals infested with splenic fever, years 

 before, were entombed. By experimental means, he solves 

 his problem. He makes a preparation of the contents of 

 the digestive system of the worms. This he administers in 

 the food of health}- animals, entirely removed from the 

 pastures. And once again a scientific principle dawns 

 in view. The rabbits and guinea-pigs which devoured the 

 matter obtained from tlie worms at once developed splenic 

 fever, whilst in their blooil the rods were seen developing 

 in full force. Once again Pasteur had sown the fever, and 

 had argued thus from the result, backwards to the cause. 

 It has also been proved that even grain may convey the 

 subtle "rods" to healthy animals, and may in this way 

 engender splenic fe\er. Following close upon the heels of 

 the disco^-ery of the germ-origin of this fatal malady comes 

 the gratifying announcement that, as small-pox is modified 

 by vaccination, so splenic fever may be modified by an 

 analogous process. Pasteur has proved that we can 

 inoculate sheep and cattle with a mild form of the fever 

 which protects the animal from a recurrence of the disease ; 

 and this protective influence, as we write, is being practi- 

 cally utilised Ijy the breeders of France. 



Such is a brief recital of a new step towards a perfect 

 knowledge of the nature of the diseases which decimate, 

 not merely animal life, but human existence as well. It 

 may not be inappropriate if, by way of close, we remind 

 our readers of two vei-y noteworthy points in connec- 

 tion with this all-impoi-tant topic, bearing, as it does, in 

 the most intimate manner upon the physical welfare of 

 man. 



The first of tlu; points to \\'hich we refer concerns the 

 apparently trivial origin of an all-ijnportant suliject. It 

 was in the city of Florence, some two hundred or more 

 years ago, that a certain physician, Francesco Redi 

 by name, demonstrated to the Florentme wiseacres 

 that the maggots in meat do not arise fi-om the dead 

 meat by " spontaneous generation," but were produced 

 from the eggs of the flesh-flies. This result he acliieved 

 liy covering over the meat with gauze, so that wliilst 

 the meat-decay proceeded, there was likewise a con- 

 vincing absence of maggots. Childishly simple as was 

 Redi's experiment, it laid the basis and method of all 

 succeeding research ; for from his day down to ours the 

 progress of the " germ theory " — or of that doctiine which 

 holds that all life, however mysteriously generated, must 

 spring from pre-existing life — has b(^en uniform and 

 triumphant. 



But the second point to which attention is worthy of 

 being directed, exists in the statement that the ]iractical 

 and actual benefits which have flowed to human health, and 

 which are likely to flow in the future as well — the saving 

 of life by the prevention and extermination of disease — 

 arise from a simple study in natural history. So-called 

 " practical " minds are often given to loudly express their 

 disapproval of any science which deals with what, to them, 

 seem mere abstractions. Doubtless, to such mmds the 

 study of the development of the " rods " of splenic fever 

 under a watch-glass must seem a piece of scientific dilet- 

 lantism ; just as information respecting the solar system 

 may seem despicable enough, because its results cannot be 

 measui'ed by a profitable currency, or, in plain language, 

 because it "doesn't .seem to pay." The best answer to 

 such foolishness is found in a recital of the results to 

 human and animal life to which natural history study seems 

 likely to lead. Just as two hundred years ago, in Florence, 

 Redi began the good work liy a simple study in zoology, 

 so to-day we are reaping the reward of the earnest work 

 of the botanists and zoologists who toil and labour to spread 

 abroad their saving knowledge. 



