88 CHLORINE AND SULPHUR. < 



other matter, as importing a direct trace by which they may he 

 defined. Thus, we may suppose chlorine to be a compound of 

 nitrogen (yellow ray) in excess, carbon (as a compound consti- 

 tuent), and hydrogen. fa ataibdnirni 



One reason to ground such a conclusion is its greenish color, 

 and that carbon will not combine with it. 4 ifii 



Chlorine destroys the color of indigo, in the same manner as 

 nitric acid ; and the yellow ray imparted by the Voltaic circle, 

 which is an instance of their analogy. 



Sulphur affords in its character circumstances favourable to 

 the opinion of its compound nature. 1st. From its color, 

 which is a greenish-yellow, it indicates that nitrogen and 

 hydrogen, with carbon, are constituents ; as well from the 

 color of its flame a bright violet in which oxyen, as a com- 

 ponent part of carbon, must contribute the reddish tinge, 

 forming, with blue (hydrogen), the violet color. 



2nd. That it crystallizes at 220 of Fahrenheit. 



3rd. Melted in an open vessel, and poured into a basin of 

 water, it assumes a red colour, is as soft as wax ; but when 

 exposed to the atmosphere, it recovers its brittleness, but re- 

 tains its red color. 



4th. As lac sulphuris, in combination with a small quantity 

 of water, it is white. 



5th. That it combines with hydrogen, carbon, chlorine, 

 oxygen, and phosphorus ; therefore, the simple and compound 

 constituents of which it is formed are numerous, and not in 

 such excess of proportion as to exclude combination with a 

 further minute quantity of any of them. 



Sulphuretted hydrogen burns with a purplish flame. 



The color of arterial blood is florid red ; while that of 

 venous is a dark reddisli-purple. The oxygen absorbed in the 

 act of respiration forms carbonic-acid gas, which is evolved ; 

 and the alternate changes from arterial to venous blood, and the 

 reverse, while kept up during the life of the animal, are still 

 indicated by the color, evincing the predominancy of oxygen in 



