An X-ray vision

In December 1863 a New York physician, Samuel Ward Francis, sat down to write a letter to The Medical and Surgical Reporter. The medical achievements of Dr Francis – whatever they may have been – are forgotten today, but his work as an indefatigable amateur inventor lives on in the records of the US Patent Office.  I’ve collected several of the highlights in an earlier post (they included a combined spoon and fork and a self-opening coffin).

His letter was prompted by a lecture he had attended a few days earlier. It was given by John Draper, professor of chemistry at New York University, an imaginative scientist who did important work on the nature of gas exchange in the lungs. In his talk, entitled ‘The historical influence of the medical profession’, Draper made an observation that particularly interested Francis:

It is the astonishing fact, that no action, of violence or benignity, committed in the forum or amid sequestered shades, is lost to view, should proper methods be adopted to bring out the all-important photograph. Professor Draper went so far as to say that if the hidden tombs of any of the Pharaohs, which have been concealed for several thousand years, were opened, the portraits of those who attended the sad obsequies could be successfully obtained.

Draper was one of many scientists of the time who believed that it would one day be possible to use the methods of photography to recover the past: his thesis was that surfaces retained some invisible trace of every ray of light that had ever hit them. This would, in theory, make it possible to reconstruct scenes that had occurred years, or even centuries, earlier. One version of this doctrine – alluded to in his lecture – was known as ‘optography‘, the retrieval of images from the eye. This raised the idea that the retinas of murder victims would retain a spectral image of the last thing they saw for some hours after death: if this image could somehow be ‘developed’, detectives would be able to obtain a photograph of the murderer and thus solve the crime.

Francis was fascinated by this idea of capturing the transient sensations of the past; indeed, he had already been working on a similar idea:

Some six years since I studied carefully the anatomical arrangements of the human ear, made preparations and worked silently for three long years on the invention of what I termed an “Aurographer”, a collector of sounds which, by a system of machinery, was to record the words emitted from the mouth of man.

A phonograph, in other words.

It is not necessary to explain in detail how it was to be accomplished. I applied to a first-class mind to make what I proposed, and, for an answer, received the ridicule of unbelief; nevertheless, I worked and studied, when, to my astonishment, bewildered fancy, and unalleviated disappointment, after laboring for three years on the invention, I read in a newspaper that a Frenchman in Paris had exhibited a series of diagrams displaying the results of a similar instrument.

This was the phonautograph, invented by Édouard-Léon Scott de Martinville and patented by him in 1857. It converted sounds into a graphical image, a two-dimensional waveform, though was not able to reproduce sounds thus recorded. It was not until 1877, when Edison invented the phonograph, that it would be possible to record and replay sounds.

Here’s where Dr Francis’s letter gets really interesting. He concludes with an impressive piece of medical prophecy:

It is to the following effect, that ere long so great improvement will be made in the microscope that, on stripping the body of any person, and by artificially illuminating him internally by electro-magnetism or otherwise, and by looking through the countless multiplied lenses of the improved microscope, the workings of his organs may at once be studied, the complex localities of the nervous system effectually understood, and a practical chart of normal and abnormal differences easily procured. For instance, by aid of a powerful glass, we may now follow, for a short space, the circulation of a frog’s foot. In a few years a thicker membrane than the web will be as readily pierced, and, eventually “seeing through a mill-stone” will not be so extravagant an idea as at present we are led to suppose.

Francis had something of a reputation as a wild visionary, and many of his readers must have dismissed this fanciful idea as the ravings of a crackpot. But thirty years later the German physicist Wilhelm Röntgen discovered the astonishing properties of X-rays, taking the first X-ray photograph of the human body, an image of his wife’s hand – a picture that announced the advent of the most impressive diagnostic tool of modern medicine.

Not content with making one outrageous prediction, Dr Francis concludes with another:

A fit climax for the previous assertion is, that subsequently, by a careful adjustment, the workings of the brain may be distinguished, and, as a reward for labors past, the scientific student will be at length permitted to “See Thought.”

I suspect that even the enthusiastic author thought this one was just wishful thinking. But in the early 1990s a revolutionary new technique, functional magnetic resonance imaging (fMRI), made it possible to see the workings of the living brain. By detecting blood flow and how it varies over time, fMRI creates an image which shows how areas of the organ respond to different stimuli – indeed, it allows researchers to ‘see thought’.

Dr Francis may have been a bit of an eccentric – but for once, at least, he hit the mark.