LECTURE I. 29 



was possible that fluids should undergo 

 those modifications, that are known to take 

 place, from the affections of the vessels in 

 which they are contained. Having convinced 

 himself of these facts, he inferred that Life 

 was a principle, active in all its functions, 

 and that by acting in various modes and 

 degrees it produced the diversified phae- 

 nomena by which it is characterized. 



I shall, on the present occasion, add a few 

 words, to what is contained in my former 

 lectures, to shew the nature and probability 

 of Mr. Hunter's opinions respecting Life, 

 because I am unwilling to leave any excuse 

 for saying, that they are either unintelligi- 

 ble, or inadmissible. 



The progress of science, since Mr. Hun- 

 ter's time, has wonderfully manifested, 

 that the sun-beam when dissected by a 

 prism, is not only separable into seven 

 colorific rays of different refrangibility, 

 producing the iridiscent spectrum ; but also 

 into calorific rays refracted in the greatest 

 degree, or intensity, beyond the red colour, 



