136 ANNUAL OF SCIENTIFIC DISCOVERY. 



I have experimented with no other. It would perhaps be proper to cleanse 

 the iron of its skin and grit before using. I, however, used no such precau- 

 tion. A fair trial of this battery will not fail, we think, to establish for it a 

 place among the best of those now in use." 



Avcry's Improvements in the Galvanic Battery. Mr. T. C. Avcry, for many 

 years electrician at West Point, has invented and patented several important' 

 improvements upon the Grove Battery used in the working of telegraph 

 lines. The new instrument has been in use upon the lines of the American 

 Telegraph Company for several months. Mr. Avery's improvement con- 

 sists: 1. In insulating the outside of the zincs, thereby reducing the sur- 

 face of metal brought in contact with the sulphuric acid, and preventing the 

 local action, which interferes seriously, at times, with the successful work- 

 ing of the telegraph. 2. The use of double the surface of platinum this 

 increases the positive current, and equalizes it with the negative, thus pre- 

 venting, to a great extent, as he alleges, the escape of the current in damp 

 or stormy weather. 3. The insulation, at the top and bottom of the porous 

 cups, preventing the nitric acid from destroying the zincs, and creating 

 local action on the inside, which is equally as injurious as the action of the 

 sulphuric acid on the outside. 



Mr. Avcry claims, in point of economy, the saving of at least two-thirds of 

 the zinc, one-half of the sulphuric acid, one-eighth of the nitric acid, and 

 three-quarters of the mercury or quicksilver, now used. 



OX THE ELECTROLYSIS OF SULPHURIC ACID. BY DR. NORTON 



GENTHER. 



The following experiments were undertaken for the purpose of deciding 

 the question, whether an electrolyte of different constitution than the simple 

 binary relation of atom for atom of each clement, is capable of decomposi- 

 tion by the current. Previous experiments with chromic acid, chloride of 

 iron, and chromate of potash, had well-nigh decided the question in the 

 affirmative; but the attempt to decompose sulphuric acid, made with eight 

 cells of Bunscn's battery, by Magnus, failed to confirm this view of it. 

 This failure Dr. Genther attributed to the limited force of the current, and 

 accordingly renewed the experiment, with fourteen of Bunsen's cells. The 

 anhydrous acid still resisted, and even when the platina poles were ap- 

 proached so close as to insure the direct transmission of the current, it only 

 gave signs of a rapid bubbling movement. The anhydrous acid was next 

 mixed with different quantities of acid of the constitution S0?5 + HO, and 

 the mixture exposed to the action of the same battery in a U-form tube. 

 The proportions first tried were four of the anhydrous to one part of the 

 other acid. This mixture yields a solution crystallizing at C8 D Fall. It is 

 therefore necessary to apply a higher temperature, which is invariably ob- 

 tained by the continued action of the current. The conducting power of 

 this solution is so low as only to allow a very small distance to intervene 

 between the poles. Soon after the action commences, oxygen is liberated 

 at the positive pole, while not a gas-bubble appears at the negative. The 

 solution, however, being of a brownish-yellow cast, becomes colorless in 

 the arm of the tube containing the positive electrode, the color being entirely 

 confined to the other arm. The action being allowed to continue, blue 

 streaks slowly make their appearance at the surface of the liquid at the 



