Henry Faulds e le impronte digitali

Famous people from the past and their discoveries

Cosa sono le impronte digitali?

Le impronte digitali sono le tracce lasciate dai solchi presenti sui polpastrelli e vengono utilizzate per identificare in maniera univoca una persona. Questi disegni sulle dita, composti da linee dritte e curve, hanno due caratteristiche principali: sono pressoché immutabili e uniche per ogni individuo. Le impronte sono antiscivolo migliorando il grip e forniscono migliori sensibilità tattili. Generalmente si possono individuare tre tipi di forme di impronte: ovale allungato, spirale e ad archi.

Le impronte digitali sono formate da:

-zona basale, nella zona fra la seconda falange e il polpastrello;
-zona marginale, linee che contornano il polpastrello nella sua parte superiore e in quella laterale;
-zona centrale che si trova al centro del polpastrello ed è delimitata dalle linee presenti nelle altre zone.

Il pioniere nello studio delle impronte digitali è considerato il chirurgo scozzese Henry Faulds a cui si deve il primo studio completo sull’identificazione delle persone tramite le impronte e un primo sistema per classificarle. Abbiamo avuto modo di “intervistarlo”. Ecco cosa ci ha detto.

Yes, we can.  But now let’s talk about your life and learn how and when you made the discovery, which has made you famous all over the world. You were born in Britain, weren’t you?

“Yes, I was born in Beith, Scotland in 1843”.

You got a degree in medicine at Glascow university and became a missionary too, didn’t you?

“Yes, I did, after a while, I was sent to Japan, Tokyo by the Presbyterian Church to establish a hospital”.

Was it in Japan, then, where you made your discovery?

“Yes, exactly! One day in 1870, I was with my American friend, an archaeologist in an Archaeological dig where I noticed fingerprints on ancient cooking pottery left by craftsmen. I soon was intrigued by these marks”.

So, you started studying fingerprints.

“Yes, I did. I carried out a series of experiments with a scientific approach and found out that fingerprints were unique to each person. I calculated that the chance for two persons to have the same fingerprints was 1 in 64 billion”.

That’s impressing and then you had the opportunity to prove your theory on two occasions.

“Yes, exactly, I convinced the police of the innocence of two suspects accused of burglary in the hospital where I worked and near my house”.

Interesting, how did you do that?

“I compared the fingerprints left at the crime scene to those of the suspects, as they were different, the police released the two innocent men”. 

Then you wrote to “Nature “journal in 1880 and said that fingerprints could be used to identify criminals.

“Correct, that’s what I did. I was so proud at my discovery and decided to report it to Scotland Yard”.

So you went back to Britain, but Scotland Yard didn’t find your work interesting and rejected it.

“Exactly, I was very sad and went back to work as police surgeon in London and then in Wolstanton where I died in 1930, I was 86”.  

We’ve almost reached the end of our interview Doctor Faulds, but there is still a thing we would like you to know, that will make you very proud.

“What might it be, another good news?”.

Yes of course, There have been two plaques acknowledging your work, one near your grave since 2007 and another at your first residence in James Street since 2011; there is also a memorial in your memory in Beith near the house where you were born.

“I am very famous then, therefore from now on I will certainly rest in peace”.

Certainly, you will. Thanks a lot for being with us in our programme Doctor Faulds.

“Thank you for having me here in this surreal programme”.