Such are some of the appalling hazards encountered by M. Davy, in his intrepid investigation of the gases. These destructive experiments, during his residence at Bristol, probably, produced those affections of the chest, to which he was subject through life, and which, beyond all question, shortened his days. Nothing at this moment so excites my surprise, as that Mr. D.'s life should have been protracted, with all his unparalleled indifference concerning it, to the vast age, for him, of fifty years.
I cannot here withhold an ungracious piece of information. In the prospect of this establishment, great expectations had been raised, and the afflicted of all descriptions, were taught to expect a speedy cure; so that when the doors were opened, no less than seventy or eighty patients, progressively applied for the gratuitous alleviation of their maladies. But it is too great a tax on human patience, when cures are always promised, but never come. No one recovery, in an obstinate case, had occurred: in consequence of which, many patients became dissatisfied, and remitted their attendance. Independently of which, an idea had become prevalent amongst the crowd of afflicted, that they were merely made the subjects of experiment, which thinned the ranks of the old applicants, and intimidated new. It might be said, that patients after a certain period had so ominously declined, that the very fire was likely to become extinguished for want of fuel. In order that the trials might be deliberately proceeded in, a fortunate thought occurred to Dr. Beddoes; namely, not to bribe, but to reward all persevering patients; for Mr. Davy informed me, that, before the Pneumatic Institution was broken up, they allowed every patient sixpence per diem; so that when all hopes of cure had subsided, it became a mere pecuniary calculation with the sufferers, whether, for a parish allowance of three shillings a week, they should submit or not, to be drenched with these nauseous gases.
This Pneumatic Institution, though long in a declining state, protracted its existence for more than two years, till the departure from Bristol of Mr. D., and then by its failure, it established the useful negative fact, however mortifying, that medical science was not to be improved through the medium of factitious airs.
I happened to be present when Mr. W. Coates casually named to Mr. Davy, then just turned of twenty, that his boy the preceding evening, had accidentally struck one piece of cane against another, in the dark, and which produced light. It was quite impressive to notice the intense earnestness with which Mr. D. heard this fact which, by others, might have been immediately forgotten. Mr. D. on the contrary, without speaking, appeared lost in meditation. He subsequently commenced his experiments on these canes, and thus communicated the results to his friend Mr. Giddy, (now Gilbert).
"My dear friend,
… I have now just room to give you an account of the experiments I have lately been engaged in.
First. One of Mr. Coates's children accidentally discovered that two bonnet-canes rubbed together produced a faint light. The novelty of this experiment induced me to examine it, and I found that the canes, on collision, produced sparks of light, as brilliant as those from flint and steel.
Secondly. On examining the epidermis, I found, when it was taken off, that the canes no longer gave light on collision.
Thirdly. The epidermis, subjected to chemical analysis, had all the properties of silex.
Fourthly, The similar appearance of the epidermis of reeds, corn, and grasses, induced me to suppose that they also contained silex. By burning them carefully and analyzing their ashes, I found that they contained it in rather larger proportions than the canes.