C 175- ) 
in this our Cafe, the Pulfe is quicker, and there is no 
Puife, but wheo the Heart is cootraded ; and the Hea|rt 
being a Mufcle aod contraded ac every PoMe : The 
Heart is either the chief or only Cau(e that determines 
this Liquor, that diileods and ftrerches the fides of Ar- 
teries aod makes a Pulfe or a very extraordinary oiea* 
fure of fuch detentions : But as I faid it has the grea* 
teft fhare in propelling the Blood round the whole Body, 
in refped: of the help of the Arteries, which they are 
fuppofed to give by the^r reftitution, after their extra- 
ordinary Diftention. Be it how it will, both their afti- 
ons are by Gontracftion (tbo' afterwards I take no no- 
tice of that of the Arteriesj and no Concradion in Muf- 
cles was ever fuppofed by any fober Man to be per- 
form'd, but by an Influx of Spirits into the Fibres of 
the Mufcles fo contracted. So that now our queftioo 
changes thus , Horn wounding ly Cantharides makes the 
Contra II ion of our Heart weaker. 
The Contradion of Mafdes, and Confequently of 
the Heart , being by the Spirits that flow into them, 
as r have faid before. Therefore whatfoever weakens 
the Contradion of any Mufcle ; fuppoft the Heart, 
muft either be fuch a thing'lt^c can hinder the Sepa- 
ration of thefe Spirits ; or imercept them in their 
Channel of Conveyance to that Mufcle ; after they are 
feparated. 
The Spirits are known, by Anatomical Experiments, 
to be feparated from the Blood in the Brain : now^ what- 
foever hinders the feparation of the Spirits from the Blood 
muft either hinder that Rarefafticn of the Blood , that 
comes by befng broke down into fmall parts, and makes 
them Spirits in their proper place, or the Biood of that 
finenefs, that is neceflary for it to be perfpired, h, e, a 
Body that affeSs the Blood fo, as not to fep^rate Spirits, 
muft be of a Nature to make its Parts more compad 
in 
