304: SCIENCE OF COMMON THINGS. 



Sulphuric, nitric, and muriatic acids. Sulphuretted hydrogen. 



1955 What causes the suffocating odor of a lighted brimstone match ? 



The sulphurous acid generated by the combustion 

 of the sulphur. 



1956 What is sulphuric acid or oil of vitriol r 



It is a compound of sulphur and oxygen, containing 

 one-third more oxygen than sulphurous acid. 



1057 What is sulphuretted hydrogen f 



, A gas formed by the union of sulphur and hydrogen. 

 l lt possesses an offensive odor, and is very poisonous. 



1953 How is sulphuretted hydrogen formed in nature f 



Principally from the decomposition of animal $ub~ 

 stances, as blood, flesh, hair, etc. 



1959 Why does the yolk of an egg tarnish a silver spoon ? 



Because it contains a little sulphur, which, at the 

 temperature of an egg just boiled, will decompose the 

 water or moisture upon the spoon, and produce sul- 

 phuretted hydrogen gas, which will tarnish silver. 



Both the white and the yolk contain sulphur, but the latter the most 

 abundantly. 



1960 What is it that makes an open or foul sewer so destructive of 

 health to any district in which it may be situated ? 



The evolution of sulphuretted hydrogen. When in- 

 haled, it acts directly upon the blood, thickening it, 

 and turning it black. 



1961 Why do surfaces painted with lead paints, in the vicinity of sew- 

 ers, soon turn black, or become discolored f 



Through the action of sulphuretted hydrogen. 



1963 What is nitric acid f 



Nitric acid, or aqua-fortis, is a compound of five 

 parts of oxygen and one of nitrogen. 



It is a liquid ; when pure, colorless, and highly corrosive ; it attacks al- 

 most all dead, unorganized substances, and destroys living tissues. 



1963 What is muriatic, or, more properly, hydrochloric acid? 



A compound of hydrogen and chlorine usually pre- 

 pared from salt. It is an acid much used in the arts. 



1964 What is " lunar caustic ?" 



A compound of nitric acid and oxide of silver. 



1965 Why, when lunar caustic is applied to the flesh, does it burn and 

 destroy it ? 



