Did they find documentation (in the form of notes or other material) 
about the process or just "guess" that was the way it was done through a 
chemical analysis of the Shroud?
Randy
On Thu, 19 Oct 1995, OLIVO wrote:
> For the amusement of those interested.
> 
> Friend of mine in the UK saw a program about this, and says that the researchers
> repeated successfully the procedure they claim Leonardo could have followed, 
> using egg, some salt and urine...
> 
> The weakest part of the argument is that they claim Leonardo is also THE SUBJECT
> of the "photo", and they cannot explain why it should be him and not somebody 
> else who discovered this.
> 
> I am amongst the sceptics, though if it can be proved that an Italian produced a
> permanent photograph three centuries before the French, well.... :-)
> 
> Oliv
>