26 On the Presence of Muriatic Acid [JttY, 



same tests showed that a much smaller quantity of muriatic acid 

 was carried over than in the former experiments. 



When water was distilled in a similar way over muriate of 

 lime, the distilled water became considerably turbid with nitrate 

 of lead ; in the common temperature of the atmosphere, neither 

 oxalate of ammonia, carbonate of ammonia, carbonate of soda, 

 nor nitrate of silver, produced turbidness ; but when the water 

 was boihng hot, both oxalate of ammonia and nitrate of silver 

 occasioned turbidness. When five grains of carbonate of soda 

 were dissolved in five ounces of the distilled water and evapo- 

 rated to half an ounce, no precipitate was observed. Litmus 

 paper was not at all affected by the distilled water. 



Water distilled over muriate of barytes was rendered very 

 turbid by a solution of nitrate of lead ; a solution of nitrate of 

 silver produced only a turbidness when added to the boiling-hot 

 water. Neither carbonate nor sulphate of soda rendered the 

 water turbid, but when it was boiled with sulphate of soda, tur- 

 bidness appeared on cooling. Litmus paper was not affected 

 by the water. 



In water distilled over muriate of ammonia, both nitrate of 

 lead and of silver immediately occasioned turbidness and pre- 

 cipitation. The same effect took place after the distilled water 

 had again been subjected to distillation. Three ounces of the 

 distilled water when mixed with three drops of a concentrated 

 solution of nitromuriate of platina, and evaporated until only five 

 drops remained, left a reddish yellow precipitate, which was 

 difficultly soluble in water. Litmus paper was not affected. 



Although nitrate of lead might not in all these experiments 

 be a test of muriatic acid, for which it seems M. Kruger had 

 used it, yet nitrate of silver was, with few exceptions, acted 

 upon as if muriatic acid had been present. Any doubts which 

 might remain as to the accuracy of the result have been removed 

 by M. Vogel,^ who boiled an ounce of completely neutral 

 muriate of magnesia in 12 ounces of distilled water with suffi- 

 cient precautions to prevent any of the salt from being carried 

 over mechanically. The vapours were made to pass through a 

 Very dilute solution of nitrate of silver, and rendered it turbid in 

 a quarter of an hour. One part of the solution was kept in a 

 glass covered with black paper, and did not assume any colour ; 

 the other was exposed to the rays of the sun, and became red in 

 a few minutes. In another experiment, the vapours passed 

 through tincture of litmus, which they did not redden, but made 

 the colour rather darker. 



The same result was obtained when a solution of pure muriate 

 of soda was distilled, and sea-water from the Mediterranean 

 which had been kept in a laboratory for nine years, produced 

 similar effects. The precipitate, which in these different expe- 



• Gilbert's Annalen, 1822, No. 11, 



