[ 5 6 ] 
The effedt was the fame, when I poured off this 
fame fyrup into another glafs, upon fome of the earth 
frefh taken from the fame fpot. 
I foaked a linen cloth in very ftrong vinegar, and 
having tied it to the end of my cane, I put it into the 
vapour of the grotto ; but tho’ I held' it there above 
three minutes, I faw no fign of fermentation. 
It came into my mind to try, if the fmell of vinegar 
might not be capable of fecuring an animal againft the 
ill effects of the vapour. I wrapped the fame piece 
of linen round the mouth of the dog, which had 
ferved for the former experiment, and feemed now 
not to feel any of its effects j I wrapped it, I fay, fo 
as that he might breathe freely ; and while his ma- 
iler kept him lying down in the grotto, I held a 
fponge imbibed with vinegar to his nofe. But all this 
did not prevent his having the fame fymptoms, and 
in the lame fpace of time, as in the former trial. 
And he recover’d in the fame manner, when he was 
removed into the open air. 
As we had paffed part of the day in the S r ljCitara> 
our fhoe-buckles, which were of ( tombac ) yellow 
metal, had conhderably changed their colour. I was 
forry, that I had not fome pieces of the fame me- 
tal poliflied, to throw into the vapour of the grotto, 
in order to fee, if we might not difeover fome arfeni- 
cal quality in it : but Father La Torre, to whom I 
intimated my concern, told me, that that was one of 
the experiments made by M. Tailbout j and that the 
metal, after a confiderable fpace of time, ftill appeared 
of the fame colour as before. 
A moment afterwards I found on the ground a bit 
of leaf-brafs, which I had made ufe of above two hours 
before, 
