Carbolic acid and sulphates combine in the blood to form sulpho-carbolates, which are innocuous.
The symptoms of nerve-poisoning are due to the carbolic acid (or its salts) which circulate in the blood after all the sulphates in the blood have been used up in the formation of sulpho-carbolates (hence, during administration of carbolic acid, the urine should frequently be tested for the presence of free sulphates; as long as these occur in the urine, they are present in the blood and there is no danger).
Insecticides, of which the bisulphide of carbon (CS 2) and the sulpho-carbonate of potassium (KS CS2) remain in use, were injected into the earth to kill the phylloxera on the roots of the vine.
Compounds are known which may be looked upon as derived from ammonia by the replacement of its hydrogen by the sulpho-group (HS0 3); thus potassium ammon-trisulphonate,N(SO 3 K) 3.2H20,is obtained as a crystalline precipitate on the addition of excess of potassium sulphite to a solution of potassium nitrite, KN02+3K2S03+2H20=N(S03K) 3 +4KHO.
This is filtered, washed, and then fused with caustic soda, when the sulpho-group is replaced by a hydroxyl group, and a second hydroxyl group is simultaneously formed; in order to render the formation of this second group easier, a little potassium chlorate or sodium nitrate is added to the reaction mixture.
Amongst the best of these are carbolic acid in doses of one or two grains, creosote in one or two drops, and sulpho-carbolate of soda in doses of ten grains.
The mercaptans may be prepared by the action of the alkyl halides on an alcoholic solution of potassium hydrosulphide; by the reduction of the sulpho-chlorides, e.g.