L, 230 ] 
verfely near the finciput, and faw with 
furprife, that when the dog madd an in- 
ipiration, the blood flowed flowly from 
it as happens in open veins, and when he 
expired, it efcaped in jets as from a 
wounded artery. 
On counting the jets from the moment 
of the beginning of an expiration to the 
commencement of a new infpiration, he 
found them to be conftantly three, but 
when the animal was dying they became 
fo frequent, that his eye could no longer 
follow them. 
The finus was divided into two por¬ 
tions, one towards the forehead, and the 
other towards the occiput, but the blood 
only flowed with force from the occipital 
part, which fhewed it was thrown back to 
the finus by the fuperior vena cava and ju¬ 
gular veins. 
The dodtor farther obferved, that the 
jets of blood correfponded with the fyftole 
of 
