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V. Observations on the Foramina Thebesii of the Heart. By 
Mr* John Abernethy, F. R. S. Communicated by Everard 
Home, Esq. F. R. S. 
Read February 1, 1798, 
A s the investigation of the resources of nature in the animal 
oeconomy, for the maintenance of health, and the prevention of 
disease, cannot but be interesting to the philosopher as well 
as to the physician, I therefore am induced to submit to the 
Society the following observations. 
There is a remarkable contrivance in the blood vessels which 
supply the heart, not to be met with in any other part of the 
body, and which is of great use in the healthy functions of 
that organ, but which is particularly serviceable in preventing 
disease of a part so essential to life. 
A distended state of the blood vessels must always impede 
their functions, and consequently be very detrimental to the 
health of the part which they supply ; but, as the cavities of the 
heart are naturally receptacles of blood, a singular opportunity 
is afforded to its nutrient vessels, to relieve themselves when sur- 
charged, by pouring a part of their contents into those cavities. 
Such appears to be the use of the foramina by which injec- 
tions, thrown into the blood vessels of the heart, escape into 
the cavities of that organ ; and which were first noticed by 
Vieussens, but, being more expressly described by Thebesius* 
generally bear the name of the latter author. 
