Dr. lire on Opium and its Tests, Gl 



The distilled liquid was also heated, with a few grains of 

 chlorate of potash, and muriatic acid, in order that the result- 

 ing oxide of chlorine might acidify the sulphur of the sulpho- 

 cyanic acid. This actually happened ; for the liquid now pre- 

 cipitated a sulphate of barytes from the muriate. 



The preceding mode of simple distillation which I adopted, 

 obviates those sources of fallacy in Gmelin's experiments, on 

 which Berzelius comments in his Scientific Annual*, He 

 observes, that in his own researches on the saliva, made some 

 time back, he had tried to produce, with the peroxide salts of 

 iron, the reaction noticed by Treviranus, without success ; but 

 that he had not treated the dried extract of the saliva with 

 alcohol, as Tiedemann and Gmelin did. •' What share," asks he, 

 ** may the boiling with alcohol have on these phenomena ? 

 That sulpho-cyanogen can be formed from sulphuret of 

 carbon, and ammonia, with alcohol, we know from Zeise's 

 investigations. May it not be inferred, that an analogous pro- 

 duct at least, if not the same, may result from the re-action of 

 alcohol on the dried constituents of saliva?" 



When so skilful a chemist as Berzelius doubts of the real 

 presence of sulpho-cyanic acid in the simple saliva, after he 

 had seen Tiedemann and Gmelin' s evidence of the fact, my 

 doubts, in entire ignorance of their work, will not appear un- 

 natural. That a member of that poisonous family of acids, at 

 whose head stands the formidable Prussic acid, should be swal- 

 lowed by man, not merely with impunity but with advantage, 

 every day of his life, is very marvellous. But that it is so, my 

 experiments prove beyond suspicion, since no such re-action 

 as Berzelius alludes to can have place in simple distillation. 



If into a little saliva, contained in a wine-glass, a drop or 

 two of the red muriate of iron be poured, a few rusty-brown 

 spots may be all that appear j but on adding a few drops more 

 of the muriate of iron, and stirring the mixture, a florid blood- 

 red colour will result in the whole liquid. Gmelin has shewn 

 that the sulpho-cyanic acid is associated with potash in the 

 saliva of man ; and with soda, in that of sheep. 



From the similarity of colour between saliva treated with 

 permuriate of iron, and blood diluted with water, it occurred 



* Jahre's Berichte, vol. vii. p. 301, 



