Chemistry and Physics. 335 



discusses his sub-molecule theory and his independent element 

 theory in regard to them. On the latter theory the spark spec- 

 trum may belong to GS. — Proc. Roy. iSoc, xlii, 111; J. Chem. 

 Soc, li, 1066 (abstr.) Dec, 1887. g. f. b. 



2. On the presence of Chlorine in Oxygen prepared from Potas- 

 sium chlorate. — Bellamy has observed that all of those substances 

 which when mixed with potassium chlorate facilitate the evolu- 

 tion of oxygen give rise also to the production of chlorine, the 

 greater amount being set free at the commencement of the de- 

 composition. He also calls attention to the fact that all these 

 substances which thus favor the decomposition of the chlorate are 

 acidic in character, and by taking up oxygen form acid oxides or 

 anhydrides ; as for example the oxides of manganese, iron, cobalt 

 and nickel. In some cases the activity is due to admixed acidic 

 bodies, as colcothar, which contains generally basic sulphate. 

 The peroxides give oxygen up and take it again alternately. In 

 the formation, even transitorily, of chromates, permanganates, etc., 

 chlorine or its compounds must be set free and the final residue 

 of the operation must have an alkaline reaction. If, however, the 

 chlorate is mixed with a basic oxide such as lime, magnesia or 

 soda, no evolution of chlorine is observable ; but neither is any 

 acceleration of the decomposition of the chlorate produced. The 

 author represents the decomposition in presence of manganese 

 dioxide in three stages. (A) KC10 3 -f-Mn0 2 =KMn0 4 + + Cl. 

 (B) (KMn0 4 ), = K a Mn0 4 +Mn0 a + o . (C) K a Mn0 4 + HoO„ + 

 KC10 3 =(KMn0 4 ) a + KCl + 0.— Per. Perl. Chem.Ges.,xxi, (Ref.) 

 3, Jan., 1888. G. e, b. 



3. On the Interaction of zinc and Sidphvric acid.-^-M.xsiR and 

 Adie have studied the interaction which takes place under vari- 

 ous circumstances between zinc and sulphuric acid. Six different 

 grades of zinc were used, and with acids varying in concentration 

 from H 2 S0 4 to H 2 S0 4 (H 2 O) 100 . About ten grams of zinc and 

 50 cc of the dilute acid were used in each experiment. The reac- 

 tions were effected in small flasks each connected by means of a 

 T tube first with a flask containing an ammoniacal solution of 

 silver nitrate and then with another containing a solution of iodic 

 acid mixed with a little stai'ch paste. The experiments in many 

 cases continued for long periods, sometimes three weeks, the 

 flasks being heated when necessary in a zinc chloride bath. The 

 results, which are given in tabular form, show the interaction to 

 be one of great complexity. While the action is similar for com- 

 mercial and for approximately pure zinc, the quantities of sul- 

 phur dioxide and hydrogen sulphide diminishing as the zinc be- 

 comes purer, pure hydrogen being almost the sole gaseous pro- 

 duct when the acid is diluted with ten or twelve parts of water 

 even at temperatures near the boiling point; yet it is observed 

 that commercial zinc continued to give small quantities of hydro- 

 gen sulphide whatever the strength of the acid and whatever the 

 temperature. When acid of the concentration H 2 S0 4 (H 2 0)„ acts 

 on commercial zinc at 100° scarcely any sulphur dioxide or hydro- 



