[ 61 3 . 
Thirdly, in fine, I have been informed by ivir. 
SerraOy fecretary of the Neapolitan academy of fci- 
ences, by Father La Torre, and feveral other learned 
men of the country, that in the diffcdtion of animals 
fuffocated in the grotto nothing remarkable was ob- 
ferved, excepting that the lungs were a little too flac- 
cid or collapfe d ; a ftate fimilar enough to that of an 
animal dead purely for want of air. 
However, this teflimony is not to be confounded 
with what the fame M. Serrao relates of the effects 
of certain mof eta's , which were feen for fome time in 
the neighbourhood of Portici, after the eruption of 
Vefuvius in 1737. Altho’ thefe dangerous exhala- 
tions refembled that of the grotto in many refpedts, 
yet they differ’d from it in feveral others : they were 
colder than the air of the atmofphere commonly is 
in fummer ; they turned the flefli of animals livid, 
that were kill’d by them} they gave a bad tafte to 
water. Neverthelefs, by attentively perufing the ex- 
amination * made of them, we find much reafon to 
believe, that if thefe tranfitory or accidental mof eta's 
had any bad quality more than the vapour of the 
grotto ; it was not fo much by that quality that they 
were either mortal or offenfive to animals immerfed 
in them, as by reducing them to an impoflibility of 
breathing their proper element. 
* See chap. 6. of the work above-cited, 
XL 
