Air fo rarify*d as to expand it felf to 5 or 6 times its former and ufual 
dimenfionSjOur Viper was able to live 60 hours, that wc are fureof,and 
perhaps might a pretty while longer. 
ji d'grejfive Experiment Concerning Refpiration upon very hgh Afountainf, 
T O illuftrace what 1 have taken notice of in the Printed Experiments 
-about the unfitnefs for Refpiration obferv'i by the learned Acofid 
in the high mountains of Pariacaca.l fliall here add, what I have had the 
curiofity and occafion to learn from divers Travellers , whom I pur- 
pofely confulted about thefe matters whereof you will „ealily believe 
that not many of them have had opportunity to give Accounts. Meeting 
with an Ecclefiaflical Perfon that had vifited thofc high mountains of 
Artnenia^^on one of which,becaufe of their height, the Tradition of the 
Natives will needs have the Ark^io have reftcd •, ) I ask'd him, whether 
thofe Mountains are really fo high as is given out, and whether at the 
top of that he vifited he found any difficulty of Breathing. To the firfi 
part of which Queftion he anfwer'd That they were really exceeding 
high f which he might well judge of, having been upon fome of the raolk 
famous both in Etir&p-^Afa^2ir6. Africa ) and that he could not come 
to the top,becaufe or the unpafTdble fnows; And to the feconA part he re- 
ply 'd, that whileft he was in the upper part of the Mountain he plainly 
perceiv'd,that he was reduc'd to fetch his breath much oftner than he 
was wont,and than he did before he afcended the Hill, and after he came 
down from it. And upon my inquiring. whether or no that difficulty of 
breathing might not be acciderta',or peculiar to him, he told me that he 
bimfelf having expreft fome wonder to find himfelf fo fhort- winded, the 
people told him that 'twas no more than happened to them when they 
were fo high abovci the plain ^ it being a common obfervation among 
them. And 1 was the more inclin'd both to make inquiry about thefe 
matters-, and to believe what he faid, becaufe what he related of their 
being cover'd with fnow, and of an odd Temperature of Air, I had 
learn'd before from a Travailcr of another Nation than this PerfoDjand 
a ftranger to him. 
The fame Churchman^being askM by me,Whether he had not in fome 
part of Europe made the like obfervation (ot the difficulty of breathing) 
told me, that he had done it upon the Top of a Mountain in theCoun- 
try Seuenes in or near the Province of Languedoc which may fervc 
to confirm what I am about to relate from the mouth of a Learned Tra- 
^vailer,that was upon the Top of one of the Fyt^ncMs thai is not very re- 
mote from the Mountains we fpeak of. 
This Gentleman, who was a perfon Curious and Intelligent, being 
Brother in Law to ene of the chief Lords of thofe parts, was by him in- 
vited, about the beginning of September to v'fit a neighbouring Moun- 
tain, that isat leaft oneof thehigheft of the PyKtf;7tf>r;?j, which is com- 
monly called Fic de 4^idi ^upon whofe Top, (where a Tent wa-^ fpread for 
them) they ftayMmkny hours. His Anfwers to the other Queflionc I 
asked him,are elfewherc related : AH that concerns this place being that 
I 
