The Faber Book of Science

by John Carey

  Lady Mary was as good as her word. She had her own son and daughter inoculated and, on her return to England, did all in her power to encourage the practice. When a smallpox epidemic hit London in 1721, she urged Princess Caroline to inoculate the royal children. As a preliminary safeguard, six condemned criminals in Newgate were allowed to volunteer for the operation, with freedom as their reward should they survive it – as they did. The operation was then performed on the pauper children of St James’s parish, again successfully. Persuaded by these experiments, the Princess had two of her daughters inoculated, and the practice instantly became fashionable, though opposed by some clergymen who denounced it as a defiance of God’s will.

  Lady Mary’s estimate of its safety was, however, over-hopeful. Roughly 1 in 50 died of inoculation, and inoculated patients tended to spread the disease. Salvation came via an obscure country doctor Edward Jenner (1749–1823), working in the Cotswolds. He was familiar with old wives’ tales to the effect that the unsightly but harmless disease of cow pox, which milkmaids caught from cows’ udders, gave protection against smallpox, and he hit on the idea that cow pox might be artificially induced. The human guinea pigs he used were a young dairymaid, Sarah Neimes, with a fresh cow pox lesion on her finger, and a boy, James Phipps, a labourer’s son. Jenner announced the results in his epoch-making paper An Inquiry into the Causes and Effects of the Variolae Vaccinae, Known by the Name of Cow-Pox (1798).

  The more accurately to observe the progress of the infection I selected a healthy boy, about eight years old, for the purpose of inoculating for the cow-pox. The matter was taken from a sore on the hand of a Dairymaid, who was infected by her master’s cows, and it was inserted on the 14th day of May, 1796, into the arm of the boy by means of two superficial incisions, barely penetrating the cutis [skin], each about an inch long.

  On the seventh day he complained of uneasiness in the axilla [armpit] and on the ninth he became a little chilly, lost his appetite, and had a slight headache. During the whole of this day he was perceptibly indisposed, and spent the night with some degree of restlessness, but on the day following he was perfectly well…

  In order to ascertain whether the boy, after feeling so slight an affection of the system from the cow-pox virus, was secure from the contagion of the smallpox, he was inoculated the 1st of July following with variolous [smallpox] matter, immediately taken from a pustule. Several slight punctures and incisions were made on both his arms, and the matter was carefully inserted, but no disease followed. The same appearances were observable on the arms as we commonly see when a patient has had variolous matter applied, after having either the cow-pox or smallpox. Several months afterwards he was again inoculated with variolous matter, but no sensible effect was produced on the constitution.

  Jenner had invented the Latin name Variolae vaccinae (meaning ‘smallpox of the cow’) for cow pox. The English word ‘vaccination’ was not invented until 1803, by Jenner’s disciple Richard Denning. Following the publication of his paper, vaccination swiftly spread through Europe and America, earning him worldwide fame. He became, in his own lifetime, the acclaimed saviour of thousands of Germans, Spaniards, Italians and Russians. Ironically, the English were slow to follow suit. Whereas early nineteenth-century Vienna, where an intelligent vaccination programme was enforced, became virtually smallpox-free, in London ‘the speckled monster’ (as Jenner called it) still claimed 1,700 lives each year.

  Sources: Edward Jenner, Inquiry (1798) and The Complete Letters of Lady Mary Wortley Montagu, ed. Robert Halsband, Oxford, Clarendon Press, 1965–7, volume I, pp 338–9.

  The Menace of Population

  Thomas Malthus (1766–1834), mathematician and clergyman, published his Essay on the Principle of Population in 1798, arousing a storm of abuse and controversy. By applying scientific thought to the question of population, which no one had done before, he contrived to show that it was impossible – despite the dreams of Utopian philosophers – for the whole of mankind to live in happiness and plenty. Idealists and reformers were enraged by Malthus’s demonstration that social welfare, if it consisted of cash handouts to the poor, did more harm than good. Co-founder of Communism, Friedrich Engels denounced ‘this vile, infamous theory, this revolting blasphemy against nature and mankind’.

  Malthus’s case – that food supply increases only arithmetically (1, 2, 3, 4, 5, etc.), whereas population increases geometrically (1, 2, 4, 8,16, 32, etc.) – has been modified by developments in agricultural technology. Also, his contention that ‘misery’ (war, disease, starvation, etc.) and ‘vice’ (abortion, prostitution, etc.) are the only possible checks to population fails to take account of contraception, which was not publicly advocated in England until the 1820s. But despite its flaws Malthus’s theory did not exaggerate the prodigious effects of unchecked population increase. In 1956 Professor W. A. Lewis calculated that if the world population were to double every 25 years (a rate of increase currently observable in some parts of Africa and Asia), it would reach 173,500 thousand million by the year 2330, ‘at which time there would be standing room only, since this is the number of square yards on the land surface of the earth’.

  Population, when unchecked, increases in a geometrical ratio. Subsistence increases only in an arithmetical ratio. A slight acquaintance with numbers will shew the immensity of the first power in comparison of the second.

  By that law of our nature which makes food necessary to the life of man, the effects of these two unequal powers must be kept equal.

  This implies a strong and constantly operating check on population from the difficulty of subsistence. This difficulty must fall somewhere and must necessarily be severely felt by a large portion of mankind.

  Through the animal and vegetable kingdoms, nature has scattered the seeds of life abroad with the most profuse and liberal hand. She has been comparatively sparing in the room and the nourishment necessary to rear them. The germs of existence contained in this spot of earth, with ample food, and ample room to expand in, would fill millions of worlds in the course of a few thousand years. Necessity, that imperious all pervading law of nature, restrains them within the prescribed bounds. The race of plants and the race of animals shrink under this great restrictive law. And the race of man cannot, by any efforts of reason, escape from it. Among plants and animals its effects are waste of seed, sickness, and premature death. Among mankind, misery and vice. The former, misery, is an absolutely necessary consequence of it. Vice is a highly probable consequence, and we therefore see it abundantly prevail, but it ought not, perhaps, to be called an absolutely necessary consequence. The ordeal of virtue is to resist all temptation to evil.

  This natural inequality of the two powers of population and of production in the earth, and that great law of our nature which must constantly keep their effects equal, form the great difficulty that to me appears insurmountable in the way to the perfectibility of society. All other arguments are of slight and subordinate consideration in comparison of this. I see no way by which man can escape from the weight of this law which pervades all animated nature. No fancied equality, no agrarian regulations in their utmost extent, could remove the pressure of it even for a single century. And it appears, therefore, to be decisive against the possible existence of a society, all the members of which should live in ease, happiness, and comparative leisure; and feel no anxiety about providing the means of subsistence for themselves and families.

  Consequently, if the premises are just, the argument is conclusive against the perfectibility of the mass of mankind … The poor laws of England tend to depress the general condition of the poor in two ways. Their first obvious tendency is to increase population without increasing the food for its support. A poor man may marry with little or no prospect of being able to support a family in independence. They may be said therefore in some measure to create the poor which they maintain, and as the provisions of the country must, in consequence of the increased population, be distributed to every man in smaller prop
ortions, it is evident that the labour of those who are not supported by parish assistance will purchase a smaller quantity of provisions than before and consequently more of them must be driven to ask for support.

  Secondly, the quantity of provisions consumed in workhouses upon a part of the society that cannot in general be considered as the most valuable part diminishes the shares that would otherwise belong to more industrious and more worthy members, and thus in the same manner forces more to become dependent. If the poor in the workhouses were to live better than they now do, this new distribution of the money of the society would tend more conspicuously to depress the condition of those out of the workhouses by occasioning a rise in the price of provisions.

  Fortunately for England, a spirit of independence still remains among the peasantry. The poor laws are strongly calculated to eradicate this spirit. They have succeeded in part, but had they succeeded as completely as might have been expected their pernicious tendency would not have been so long concealed.

  Hard as it may appear in individual instances, dependent poverty ought to be held disgraceful. Such a stimulus seems to be absolutely necessary to promote the happiness of the great mass of mankind, and every general attempt to weaken this stimulus, however benevolent its apparent intention, will always defeat its own purpose. If men are induced to marry from a prospect of parish provision, with little or no chance of maintaining their families in independence, they are not only unjustly tempted to bring unhappiness and dependence upon themselves and children, but they are tempted, without knowing it, to injure all in the same class with themselves. A labourer who marries without being able to support a family may in some respects be considered as an enemy to all his fellow-labourers …

  The evil is perhaps gone too far to be remedied, but I feel little doubt in my own mind that if the poor laws had never existed, though there might have been a few more instances of very severe distress, yet that the aggregate mass of happiness among the common people would have been much greater than it is at present.

  Malthus’s work triggered the theory of evolution. Alfred Russel Wallace recalls in My Life: A Record of Events and Opinions (1905) that in January 1858 he had just arrived at Ternate in the Moluccas to collect butterflies and beetles:

  I was suffering from a sharp attack of intermittent fever‚ and every day during the cold and succeeding hot fits had to lie down for several hours, during which time I had nothing to do but to think over any subject then particularly interesting to me. One day something brought to my recollection Malthus’s ‘Principles of Population’, which I had read twelve years before. I thought of his clear exposition of ‘the positive checks to increase’ – disease, accidents, war and famine – which keep down the population of savage races to so much lower an average than that of more civilized peoples. It then occurred to me that these causes or their equivalents are continually acting in the case of animals also; and as animals usually breed much more rapidly than does mankind, the destruction every year from these causes must be enormous in order to keep down the numbers of each species … as otherwise the world would have been densely crowded with those that breed more quickly … Why do some die and some live? And the answer was clearly, that on the whole the best fitted live. From the effects of disease the most healthy escaped; from enemies, the strongest, the swiftest or the most cunning; from famine, the best hunters or those with the best digestion; and so on. Then it suddenly flashed upon me that this self-acting process would necessarily improve the race, because in every generation the inferior would inevitably be killed off and the superior would remain – that is, the fittest would survive … I awaited anxiously for the termination of my fit so that I might at once make notes for a paper on the subject.

  He wrote the paper during the following two evenings and sent it to Darwin by the next post. Alarmed to find that a rival had reached the same conclusions as himself, Darwin was spurred to publish the Origin of Species, in which he states that ‘The struggle for existence is the doctrine of Malthus applied with manifold force to the whole animal and vegetable kingdom’.

  Sources: Thomas Malthus, Essay on the Principle of Population, 1798; Alfred Russel Wallace, My Life, London, Chapman & Hall, 1905.

  How the Giraffe Got its Neck

  Jean-Baptiste Lamarck (1744–1829), who invented the word ‘biology’, did not intend to be a biologist. His father destined him for the Church, but he quit the seminary at Amiens at the age of 16 and joined the French army on the eve of the Battle of Fissingshausen. By the end of the next day all the officers in his company had been killed, and he was commissioned for his gallantry. When he was 22, however, he hurt his neck during some horseplay and had to leave the army. His scientific interests were stimulated by Jean-Jacques Rousseau, with whom he went on botanical excursions. His three-volume work on French flora (1778) brought him fame and the job of keeper of the herbarium at the Paris Jardin du Roi (renamed the Jardin des Plantes at the Revolution). Appointed professor of ‘insects and worms’ at the Museum of Natural History, he reformed the study of invertebrates. His Zoological Philosophy (1809) propounded a theory of evolution half a century before Darwin’s Origin of Species. It argues that animals, birds and fishes exercise willpower to adapt themselves to their living conditions. They strengthen some organs by use, and weaken others by under-use, and pass on these acquired characteristics to the offspring.

  The bird which is drawn to the water by its need of finding there the prey on which it lives, separates the digits of its feet in trying to strike the water and move about on the surface. The skin which unites these digits at their base acquires the habit of being stretched by these continually repeated separations of the digits; thus in course of time there are formed large webs which unite the digits of ducks, geese, etc., as we actually find them. In the same way efforts to swim, that is to push against the water so as to move about in it, have stretched the membranes between the digits of frogs, sea-tortoises, the otter, beaver, etc.

  On the other hand, a bird which is accustomed to perch on trees and which springs from individuals all of whom had acquired this habit, necessarily has longer digits on its feet and differently shaped from those of the aquatic animals that I have just named. Its claws in time become lengthened, sharpened and curved into hooks, to clasp the branches on which the animal so often rests.

  We find in the same way that the bird of the water-side which does not like swimming and yet is in need of going to the water’s edge to secure its prey, is continually liable to sink in the mud. Now this bird tries to act in such a way that its body should not be immersed in the liquid, and hence makes its best efforts to stretch and lengthen its legs. The long-established habit acquired by this bird and all its race of continually stretching and lengthening its legs, results in the individuals of this race becoming raised as though on stilts, and gradually obtaining long, bare legs, denuded of feathers up to the thighs and often higher still.

  We note again that this same bird wants to fish without wetting its body, and is thus obliged to make continual efforts to lengthen its neck. Now these habitual efforts in this individual and its race must have resulted in course of time in a remarkable lengthening, as indeed we actually find in the long necks of all water-side birds …

  It is interesting to observe the result of habit in the peculiar shape and size of the giraffe (Camelo-pardalis): this animal, the largest of the mammals, is known to live in the interior of Africa in places where the soil is nearly always arid and barren, so that it is obliged to browse on the leaves of trees and to make constant efforts to reach them. From this habit long maintained in all its race, it has resulted that the animal’s fore-legs have become longer than its hind legs, and that its neck is lengthened to such a degree that the giraffe, without standing up on its hind legs, attains a height of six metres (nearly 20 feet).

  After Lamarck came Darwin (see p. 114), who attributed evolution not to the inheritance of acquired characteristics, but to ‘Natural Selection’, i.e.
random genetic mutation plus the survival of those mutations that were better fitted to their environment than others.

  Lamarckism has been discredited by most twentieth-century geneticists, but it has great attractions for progressives and social reformers, who wish to believe in the perfectibility of mankind. Promoted by the agriculturalist Trofim Lysenko (1898–1976), it remained official Soviet scientific doctrine until the 1960s.

  It appealed, too, to George Bernard Shaw. Brainpower and energy, such as his own, could, he believed, bring about a New Jerusalem through ‘Creative Evolution’. As a Neo-Lamarckian he denounced Darwin and ‘Circumstantial’ (i.e. Natural) Selection in the Preface to Back to Methuselah (1921). They were both ‘ghastly and damnable’, he declared, because they emptied the universe of ‘beauty and intelligence, of strength and purpose, of honour and aspiration’ and reduced it to a ‘universal struggle for hogwash’. Shaw knew nothing of science, and his Preface is a good example of how the combined powers of ignorance, rhetoric and common sense approach a scientific problem.