ACID A. 131 



Characters. White efflorescent prisms, with a sulphurous 

 taste ; feebly alkaline. Soluble in 4 parts of water. 

 Dose. 5 to 20 gr. 



Sodse Hvposulphia. Hyposulphite of Soda. Na 2 H 2 S 2 4 . 



Source. Made by passing Sulphurous Acid gas into a solu- 

 tion of Carbonate of Soda, with Sulphur. 2Na, 2 C0 3 -f S 2 + 

 2S0 2 + 2H 2 = 2(Na 2 H 2 S 2 4 ) + 2C0 2 . 



Characters. Large colourless transparent crystals, odour- 

 less, with a cool, bitter, sulphurous taste. Soluble in 1^ parts 

 of water. The solution is an officinal test for I and Cl. 



Dose. 10 to 60 gr. 



ACTION AND USES. 

 1. IMMEDIATE LOCAL ACTION AND USES. 



Sulphurous acid is a powerful deoxydising agent. Seizing 

 on oxygen and water, it decomposes organic bodies, and at the 

 same time produces upon them the irritant local effects of 

 sulphuric acid, into which it is converted. It thus destroys 

 low forms of living matter, including the organisms associated 

 with fermentation, decomposition, and certain diseases, 1 part 

 in 666 of water being sufficient for this purpose. Sulphurous 

 acid is therefore applied to ringworms and foul wounds ; and 

 some kinds of sore throat are relieved by a spray of the officinal 

 acid. Morbid fermentation in the stomach attended by the 

 growth of organisms, such as penicillium and sfircina, may be 

 quickly arrested by doses of min. 5 to min. 60 of the officinal 

 acid ; but the non-officinal salts are more convenient forms for 

 internal use, being decomposed by the acids of the stomach. 

 Sulphites given in full doses become converted into sulphates, 

 and act as purgatives. 



Sulphurous anhydride, although not officinal, is very 

 extensively used for fumigating infected rooms and clothing 1 , 

 briii'.: probably the most powerful, certain, and convenient of 

 all disinfectants. Sulphur is burned on a shovel or plate, tho 

 outlets from the room having been carefully closed, excepting 

 the door through which retreat is made. 



2. ACTION ON THE BLOOD, AND SPECIFIC ACTION AND L'SES. 



Sulphites were once supposed to enter the blood an<l \ 

 and to arrest morbid fermentation or fever processes within thnn. 

 The evidence, however, is to the effect that sulphites are not ab- 

 sorbed as such, but as sulphates, and the benefit derived from them 

 in fevers is probably due to the laxative and diuretic effects of the 



