Analogy between Vegetables and Animals, 507 



plant of the Basella rubra, and on some other plant whose name I have 

 forgotten. In the green-houses at Cambridge, a very vigorously growing 

 perennial species of dodder (of the twelve species grown in English collec- 

 tions, five are said to be perennial), if I rightly remember, from China, 

 luxuriates on plants of the common and broad-leaved ivy, and on the 

 succulent shoots of the kinds of pelargonium known by the name of the 

 horse-shoe-leaved. 



Qornu Amvibnm in Somersetshire. — On this subject, see additional remarks 

 in p. 538. — J. D. 



Art. II. An Essay on the Analog}/ bettueen the Structure and 

 Functions of Vegetables and Animals. By William Cjordon, 

 Esq., Surgeon, Welton, near Hull. Read before the Hull Lite- 

 rary and Philosophical Society, Nov. 19. 1830. Communicated 

 by Mr. Gordon. 



{Continued from p. 412.) 



The next function which we have to consider is respiration. 

 The blood which flows from the right cavity of the heart to 

 the lungs is of a dark hue. It possesses many deleterious pro- 

 perties, and is unfit for nutrition, or any of the other functions. 

 During its circulation through the lungs, it acquires a florid 

 red colour, it is deprived of its noxious ingredients, and be- 

 comes adapted for all the purposes of life. Now, it has been 

 ascertained that these changes, which take place in the nature 

 of the blood, are effected by the agency of the atmospheric 

 air, to which it is freely exposed as it proceeds through the 

 lungs. The air of the atmosphere is composed of oxygen 

 and azote. When an animal is confined in a certain quantity 

 of it, a part of the oxygen disappears, and nearly an equiva- 

 lent proportion of carbonic acid is produced in its stead. These 

 results are caused by all animals, whether they possess a 

 respiratory apparatus or not : oxygen is consumed, and car- 

 bonic acid is generated. Carbon, then, appears to be the 

 material which deteriorates the blood ; while oxygen is the 

 element which purifies it. The ultimate object of respiration, 

 then, is to bring a quantity of oxygen into contact with the 

 venous blood, in order that it may combine with and abs- 

 tract its carbon, and thus convert it into a pure and nutritious 

 fluid. Oxygen, then, appears to be perfectly essential to life. 

 There is no animal in the whole scale of created existence 

 but would, if deprived of it, languish and die. Besides the 

 evolution of carbonic acid, and the consumption of oxygen 

 during respiration, a quantity of vapour is exhaled from the 

 lungs, and a portion of azote is absorbed. The apparatus by 

 ^hich the function of respiration is carried on, is diflferently 



