TRANSACTIONS OF SECTION B. 627 



Nickel yields a pale-green film, which, dehydrated, becomes a brownish-yellow 

 and then a black. Ammonium hydrate turns the solution a fine blue. 



Nickel may be detected in the presence of cobalt. The solution will probably 

 be colourless, unless iron be present, when it will be amethystine. If a drop of 

 the iodine solution be added to the section of the tablet, wetted by the metallic 

 solution, and heated, the centre wiU be black, showing nickel, for in such circum- 

 stances the cobalt tends to leave a white centre, forming a black ring with 

 sometimes a blue ring separating it from the centre, outside that a brownish yellow 

 showing nickel, and farther out a spreading blue showing cobalt. The thio- 

 cyanate heated in the presence of an acid yields a yellow spot, which must be 

 distinguished from the nickel film. The salts experimented with were the nitrates 

 and sulphates, and when cobalt was six times as abundant as the nickel, the reac- 

 tions of the latter were well marked. 



Manganese, vanadium, molybdenum, ruthenium, and osmium also yield solu- 

 tion films. 



Potassium cadmium cyanide has been found to be a reagent which afibrds a 

 very delicate and ready test for sulphur even in the presence of selenium and 

 tellurium. 



Potassium sulphocyanate solution was added to a cadmium solution and 

 dropped on a tablet and heated, and the scarlet of hot cadmium sulphide showed 

 itself. Sixteen drops revealed the presence of cadmium in a ~- normal solution, 

 and this test was not interfered with by the presence of two hundred times as 

 much zinc. 



Zinc in the cobalt test responded with great delicacy, but aluminium gave no 

 very delicate results, on account of the calcium reaction of the tablet itself. 



Another extension of this method is to the compounds of organic chemistry. 



Carbon gives a sooty coating which metaphosphoric and sulphuric acids in- 

 crease. Tars and asphalts give a black tinged with green. 



The phenols with the same reagents yield a black edged with a pinkish red. 

 Picric acid is the only exception found so far. It gives a yellow. The following 

 were among the phenols treated — carbolic acid, pyrogallol, salicylic acid, oils of 

 coniine and wintergreen, Canada balsam, Burgundy pitch, resin, phenol phthalein, 

 hydroquinone, and creolin Many of the phenols when dropped on a tablet pre- 

 viously heated before the blowpipe show very brilliant and characteristic colours. 



The paraflins yield no red, but heavy sooty, films. We have therefore group 

 and individual tests. 



8. Some Experiments with Chlorine. — By R. Ransforp, 



9. Report on the Electrolytic Methods of Quantitative Analysis. 

 See Reports, p. 295. 



10. Report on Isomeric Naphthalene Derivatives. — See Reports, p. 292. 



11. Report on the Direct Formation of Haloids from Pure Materials. 



See Reports, p. 295. 



12. Interim Report on the Bihliograpihy of Spectroscopy. 



[13. Report on the Carbohydrates of the Cereal Straws, 

 See Reports, p. 294. 



