Stories of Great Scientists - Charles Gibson

Sir Humphry Davy

A Great Chemist, and the Inventor of the Miner's Safety Lamp

It is always of special interest to hear of a boy of humble origin and destitute condition rising to be a great man. This was my first impression of Sir Humphry Davy, and it must have been shared by many boys who read a very interesting book relating to great men; a copy of this book I possessed when a boy of nine years of age. It pictured Mrs. Davy and her family left "in very distressed circumstances," and being taken care of by a charitably disposed gentleman. Such an impression is not easily removed, and I notice that even the spelling of the word Humphry having been given throughout the story as Humphrey has made it difficult for me to use the correct spelling in later life.

It is true that the origin of Humphry Davy was comparatively humble, in so far that his parents were not wealthy, but he came of a long-established family. His father, although described as a wood-carver, had taken up this profession from the artistic side, and when he came into possession of a small estate, which had belonged to his family for at least two hundred years, he continued to pursue the art of wood-carving as a hobby.

On the family tombstones their ancestors could be traced back to 1588, and it is clear that they were of the middle class, as the descriptions affixed to the names of the deceased were given generally as that of "yeoman," and occasionally "gentleman."

Humphry Davy's grandmother was a member of one of the oldest families in Cornwall. Her dowry was fifteen hundred pounds, which was quite a handsome fortune in those days. It is said that the Davys could trace their ancestry back to a noble family who came over with William the Conqueror.

Humphry's mother was left a widow at the age of thirty-four, our hero being then sixteen years of age. Mrs. Davy was left with an income of one hundred and fifty pounds a year, but with a debt of thirteen hundred pounds, due to some unfortunate mining investments made by her husband. Not only did Mrs. Davy succeed in giving her family a good education, but she determined to pay off the debt which her husband had left. To this end she went into partnership with a French lady who, with her sister, had fled to England from France because of the French Revolution. These ladies established a millinery business, in which Mrs. Davy remained a partner for some years, until she came into possession of a family estate which brought her an income of three hundred pounds per annum, whereupon she retired from business. But what is of special interest is that she succeeded in paying off the whole of her husband's debt.

Humphry Davy was born in 1778, away down in that most southerly point of our Island, Penzance, in which town his paternal ancestors had been settled for a very long time. When his father and family removed to the estate already mentioned, Humphry, who was then nine years of age, remained in Penzance for the sake of his schooling. The estate, however, was only a few miles out of the town, so that Humphry could pay his parents a visit, riding there on his pony "Derby."

He was a clever boy, but not a prodigy. Before he could read he gave evidence of a remarkably retentive memory by reciting a great part of that big volume The Pilgrim's Progress. Other favourite books of his childhood were . Aesop's Fables  and the Arabian Nights. When scarcely five years old he made rhymes, and recited them at Christmas parties, attired in some fanciful dress. We know, on the authority of his brother, that Humphry's disposition as a child was remarkably sweet and affectionate. We may be sure he was a favourite with his schoolmates, for they used to gather around him and listen to him relating wonderful stories. And besides this he was in great demand for writing valentines and love-letters for other boys.

When a child the great Sir Humphry Davy was content to fish with a bent pin and with a bit of bread as bait, a method of angling not yet extinct among little folk. In later years our hero became a keen fisherman.

In a letter written when he was twenty-four years of age, Humphry happened to ask his mother how his younger brother was getting along at school, and he added, "I recollect I was rejoiced when I first went to Truro School, but I was much more rejoiced when I left it for ever."

One is not surprised to learn that young Humphry preferred the society of persons older than himself; he would find most boys of his own age disinclined to talk about such advanced subjects as those in which he began to take an interest. On one occasion when he was discussing some question with a Quaker, who was much older than himself, the Quaker said, "I tell thee what, Humphry, thou art the most quibbly hand at a dispute I ever met with in my life."

Living in a district in which there were copper and tin mines, the boy Humphry became interested in Geology, and would be seen going about with one pocket filled with specimens of rocks, while the other was filled with fishing tackle.

During the time he was residing in Penzance with a family friend—a physician—Davy was in the habit of disappearing to the garret, where he carried out a variety of chemical experiments. Occasional explosions alarmed the household, but although the worthy doctor declared that they would all be blown up into the air some day, that the boy was incorrigible, and was an idle dog, yet the ending of his scoldings usually took the form of some quiet chaff, calling the boy "the philosopher," and playfully nicknaming him "Sir Humphry."

Knowing the boy Humphry's studious disposition, we are apt to picture him as of a soft nature; indeed, the early impression I formed of him was that he was effeminate. I have no doubt that this impression was due to a picture of him in the boy's book to which I have referred already, which picture gave him a decidedly girlish look. But young Davy was something very different; not only in appearance, but in character. His courage was unmistakable; on one occasion he was bitten by a dog that was believed to be rabid, whereupon this thoughtful youth whipped out his pocket-knife and cut out the part which was bitten, and then hastened off to the surgery, where he was at that time an apprentice, and cauterised the wound himself.

Davy had every intention of becoming a doctor, but because he was seen so much at the mines, and among the rocks with a hammer, one looker-on said that "he thought more of the bowels of the earth than of the stomachs of his patients; and that when he should have been bleeding the sick, he was opening veins in the granite. That instead of preparing medicines in the surgery, he was experimenting in the garret." But I do not think that this can possibly be a true picture of young Davy. It should be classed as circumstantial evidence; it was the impression received by one who happened to see Davy only at his play. Although we have no details, it has been stated of Davy that he was most attentive to his patients, and more especially to the poorer ones.

Davy had an impediment in his speech, and although it was nothing so serious as that which worried Joseph Priestley, Davy tried to overcome it by following the example of Demosthenes, in so far that he would go down to the shore and practise speaking aloud. He did overcome the defect to a considerable degree, but the result was apparent in after-years, when he formed a habit of speaking in public with a peculiar intonation which seemed strange to his audiences, and which, unfortunately, was very often mistaken for affectation.

Humphry had no ear for music, and in later life it was a source of amusement to those with whom he worked to hear him trying to hum a tune while absorbed in some experiments. When a lad, his friends had tried to teach him the air of "God save the King," but they gave him up as hopeless. I met with a similar case in my school-days, the boy being quite unable even to distinguish between the air of the National Anthem and any other popular tune. Indeed, I offered him a prize on one occasion if he could name two out of six well-known airs when whistled to him, but he failed to guess even one, and as boys we had no very extensive programme of music.

By the time Humphry Davy was seventeen years of age he had begun to criticise the standard books on Chemistry, and more especially the accepted theory of heat, which was that heat was a material thing. At this time Davy's apparatus consisted chiefly of wine-glasses, tea-cups, tobacco pipes, and earthen crucibles, while his chemicals were those in common use in medicine. Like many another boy interested in Chemistry, Davy made his early experiments in his bedroom, and sometimes in the garret.

By this time Davy was a really enthusiastic chemist, so that he could not help talking of it to any one from whom he might gain information. It so happened that Gregory Watt, a son of the famous James Watt, had gone to Penzance on account of his health, and it chanced to be at the Davys' house that he boarded. This gentleman had come straight from Glasgow University, where he had been studying Science, and we may be sure that he would find an eager questioner in the lad Humphry Davy. Another such friendship which Humphry formed when he was a youth was with Josiah Wedgwood, the famous potter, who had resided also in Penzance for the benefit of his health.

It will be of interest to note Davy's early experiment in connection with the nature of Heat, which was supposed at that time to be a material thing. He caused two blocks of ice to be rubbed together by a clockwork mechanism, all of which he placed under the receiver of an air-pump, and withdrew the surrounding air so that no heat could reach the apparatus or the ice, the whole arrangement resting on a block of ice. He showed that heat was actually produced merely by the friction between the rubbing surfaces of the ice-blocks, and that therefore heat could not be a material thing. Count Rumford, of whom we shall hear later, did original work in this direction. It soon became clear that the temperature of a body is due to the vibratory motion of its particles.

In the earliest form of the experiment referred to Davy had no air-pump, nor had he ever seen such a thing, but he converted a medical syringe into an air-pump. This syringe had been given to him in a case of surgical instruments by the surgeon of a French vessel which was wrecked off Penzance. Davy had been glad to get this case of instruments, not that they would be of use to him in his medical apprenticeship, but because he could turn many of them to use in his chemical experiments.

After four years' apprenticeship to the surgeon-apothecary at Penzance, Davy was offered a post at Bristol, where a Pneumatic Institute had been built. Davy accepted the post of superintendent of this Institute, which was a hospital for the purpose of applying different gases to the patients as cures for diseases. As the work would be largely experimental, Davy would have plenty of opportunities for original work.

On Davy's journey to Bristol he met the mail-coach from London, covered with laurels and ribbons, bringing news of Nelson's stupendous victory over the French fleet in the Battle of the Nile.

Dr. Beddoes, who was one of the principals of the Pneumatic Institute, was very impulsive in his methods, often jumping to a conclusion without giving the problem proper consideration. On one occasion his friend Mr. T—called to consult him upon the case of his wife, and the doctor prescribed a new remedy, but in the course of the day he sent word in haste to say that before Mrs. T—took the medicine, its effect might be tried upon a dog. We are left in the dark as to the fate of Mrs. T—or the dog.

Davy wrote to his mother about this time: "We are going on gloriously, our patients are getting better; and to be a little conceited, I am making discoveries every day."

Dr. Beddoes found Davy a capital worker, and no sooner had the young chemist discovered the properties of nitrous oxide gas, than the doctor immediately jumped to the conclusion that it was a cure for paralysis. Young Davy was to take charge of the experiments upon the patients, of whom, by the way, there were sometimes as many as eighty.

A paralysed man was selected for this new treatment, and it is very evident that the patient had no idea of the kind of treatment he was to undergo, for when Davy placed a pocket thermometer beneath the man's tongue in order to take his temperature, the man mistook this for the treatment, and declared that it gave him a feeling throughout his whole body. Davy pretended to take the matter quite seriously, and after removing the thermometer, he asked the patient to call the following day for a repetition of the treatment. For two weeks this patient called each day and had the thermometer placed beneath his tongue, and at the end of that time he left the Institute a cured man.

Davy had not told Dr. Beddoes what kind of "treatment" he had really given the man, but as the worthy doctor was going to rush off and publish the remarkable proof of the action of nitrous oxide, Davy had to let him into the secret.

This is the gas commonly used by dentists as an anaesthetic. On one occasion while Davy was experimenting with this gas upon himself he was nearly killed, and he resolved never to attempt so rash an experiment again.

Davy was so keen in his work and in his study of Chemistry, that he rose two hours before breakfast in order to get time for writing. But he did not cut himself off from the world; he was a keen angler, and he kept a dog and gun for his shooting expeditions.

One of his friends has left us a description of Davy's fishing clothes. He had a suit made of bright green cloth, and having bought a hat, in a raw state from the manufacturer, he dyed it green with some pigments of his own composition. The idea of this green clothing was to elude the observation of the fish, by appearing as much as possible as part and parcel with the bank of the river. When shooting he put on a bright scarlet cap, but that was to protect himself against any other sportsman mistaking him for prey, or failing to observe his presence.

While at Bristol Davy got an offer to act as Assistant Lecturer at the Royal Institution, London, which had been founded a short time previously. The purpose of this Institution, which, of course, still flourishes, was to diffuse a knowledge of Science and of its applications to the common purposes of life, and to excite a taste for Science amongst people of high rank. Davy accepted this post, and in the succeeding chapter we shall see how he made the Royal Institution famous.