[ 62 ] 
ftrongly diftending the Lungs. In this Action I never 
could difcern that the Heart began the Motion, but 
the Auricles always contracted firft, and then the 
Heart immediately afterwards,- though, at laft, I 
favv feveral Contrattions of the Auricles, which 
were not fucceeded by any Motion of the Heart. 
CXL1V. 
I muft not forget to mention, that in another 
Dog I faw feveral Syfloles and ‘Diafloles of the 
Heart after I had purpofely cut afunder both the 
Vena. Cava's ; and could plainly perceive the Ven- 
tricles to relax and open themfelves, when very lit- 
tle or no Blood could pollibiy flow into them. 
This however is much more eafily feen in the Heart 
of a Viper, when taken out of the Body, which 
will continue its Syftole and Diajiole. for a long 
time; and if it ceafes to beat ever fo often, and 
you renew its Motion again and again, by breath- 
ing upon it, &c. You may obfervc that the Auri- 
cle always contradts before the Ventricle, and that 
the T)iaftole is the laft Motion, though thefe is no 
Blood to diftend the Heart. 
CXLV. 
The Capacity of the right Ventricle of the Dog’s 
Heart, in the above Experiment, as it open’d of its 
own accord, was fomething more than a cubic Inch, 
as I found, by pouring in melted Wax from a 
Ladle, without any Treflure from a perpendicular' 
Height, 
