194 SODIUM SULPHITES 



injected into the circulation. Like other saline purgatives, 

 it has a low diffusive power, for the S0 4 ion is absorbed to a 

 very slight extent ; it impedes absorption of fluids present in 

 the intestines, draws out fluid from the blood, increases 

 peristalsis, and thus augments the quantity and fluidity of 

 the dejections. Bile poured into the intestine is hurried 

 along and excreted, its reabsorption being prevented, and 

 the same occurs with sodium phosphate. While large doses 

 of Glauber salts are removed by the bowels, small doses, freely 

 diluted, pass off, in great part unchanged, by the kidneys. 

 Although little used for horses, it is still prescribed for cattle 

 and sheep, for the same purposes as Epsom salt, with which 

 it is sometimes conjoined. Catharsis is seldom, however, 

 produced within twenty-four hours. It is an antidote in 

 poisoning by carbolic acid and barium chloride. In dogs it 

 acts both as an emetic and purgative. 



DOSES, etc. As a purgative cattle take Ib. j. to Ib. jss. ; 

 sheep, ij. to iv., given with ginger and treacle, and suc- 

 ceeded by liberal supplies of chilled water. As a febrifuge 

 for horses ^ij. to jv. may be given. 



SODIUM SULPHITE. Normal sulphite. Sodii Sulphis. Na 2 

 S0 3 .7Aq. 



SODIUM HYPOSULPHITE. Hyposulphite of Soda. Sodium 

 Thiosulphate. Sodii Hyposulphis. Na 2 S 2 3 .5Aq. 



Sodium sulphite may be obtained by the interaction of 

 sulphurous acid and sodium carbonate. In colourless 

 crystals, efflorescent, inodorous, with a saline taste. 



Sodium hyposulphite may be prepared by dissolving 

 sulphur in a boiling solution of sodium sulphite and crystal- 

 lising. The hyposulphite is very soluble in water, and fusible. 

 It is more permanent than the sulphite. 



ACTIONS AND USES. The sulphite and hyposulphite are 

 antiseptics, deodorisers, and insecticides. In the presence 

 of acids, without and also within the body, they give off 

 sulphurous acid, which they therefore resemble. They 

 destroy ferments and bacteria, and remove offensive smells 

 by abstracting oxygen from organic matter to become 

 themselves converted into sulphates. These bactericidal 



