OHElflSTBY. 



95 





distillatory apparatus some sulphur remains, 

 \\liicli i-; removed ami again applied. It ap- 

 ili.it tliis industry has become vor;> 

 I and is carried cm with great success in 



. 



Furnace for Chemical Operations. Mr. 

 rh.-irle-; (irilliu, in the Journal of the Chemical 

 ':/, describes a new gas-furnace for chom- 

 i.-.d "i"Tutions at a white heat which does not 

 require a blowing-machine. The gas is sup- 

 plied to this furnace through a bundle of six- 

 Hunsen's burners, the upper ends of 

 which nro surrounded by a metal jacket fitting 

 into a perforated clay plate supported on a tri- 

 pod. When largo crucibles nro to be employed, 

 a plumbago cylinder, open at both ends and 

 pierced with holes, is placed on the clay plate, 

 the conical crucible being supported by the 

 upper end of the cylinder. The crucible and 

 plumbago cylinder are surrounded by a fire- 

 clay cylinder resting on three bronze pence 

 placed on the lower plate. The cylinder is 

 closed at the top by a clay plate, through 

 which a flue is so made that the current of 

 spent gases is bent twice at right angles before 

 escaping into the sheet-iron chimney; the ob- 

 ject of this flue is to check the stream of gas, 

 which would otherwise be so great as to cool 

 the furnace very considerably. When small 

 crucibles have to be heated, they must be sup- 

 ported on a grate consisting of a clay plate 

 with a cusped aperture. By means of this fur- 

 nace, ingots of cast-iron 4 Ibs. in weight have 

 been fused in 2 hours, starting with a cold 

 furnace ; when the furnace is hot, 5 Ibs. could 

 be fused in the same time ; the quantity of gas 

 used is 33 cubic feet per hour. The cylindri- 

 cal body of the furnace may be replaced by 

 one of an oval shape, and containing a muffle 

 in which many operations may be performed, 

 the temperature inside the muffle being suffi- 

 ciently elevated to fuse silver, gold, and copper. 

 Composition of Iron-Rust. Dr. Grace Cal- 

 vert, in a communication to the Chemical So- 

 ciety on this subject, says that he had lately 

 analyzed samples of rust from two different 

 places, and found both specimens to be com- 

 posed as follows : 



Sesqnloxide of iron 92.001 



Protoxide of iron 6.177 



Carbonate of iron o!fH7 



Carbonate of lime 2<ij 



Silica o!oil 



Ammonia traces 



100.000 



This result induced the author to inquire to 

 which of the constituents of the atmosphere 

 the formation of rust is chiefly due. To this 

 end, clean blades of steel and iron were put 

 into tubes filled respectively with oxygen, ox- 

 ygen and a little carbonic acid, oxygen and 

 moisture, etc. The blades were introduced 

 into the tubes, which then were filled, over 

 mercury, with oxygen. But this proved an 

 unsatisfactory method, inasmuch as always 

 some globules of mercury remained adhering 

 to the iron, whereby a galvanic action was pro- 



duced, which, of course, induced a rapid oxida- 

 tion. To avoid this, tho tubes w.-re filled sim- 

 idy by displacement of the atmospheric uir. 

 The. blades were then left exposed to tho ac- 

 tion of tho different agents for a period of four 

 months. Tho results wero as folio \ 



Blades in dry oxygen. No oxidation. 



Blades in moist oxygen. Out of three ex- 

 periments, only in one a slight oxidation. 



Blades in dry carbonic acid. No oxidation. 



Blades in moist carbonic acid. Slight in- 

 crustation of a white color. Out of six experi- 

 ments, two did not give this result. 



Blades in dry carbonic acid and oxygen. 

 No oxidation. 



Blades in moist carbonic acid and oxygen. 

 Most rapid oxidation. 



Blades in dry oxygen and ammonia. Xo 

 oxidation. 



Blades in moist oxygen and ammonia. No 

 oxidation. 



These facts led the author to assume that it 

 is tho presence of carbonic acid in the atmos- 

 phere, and not oxygen or water vapor, which 

 determines the oxidation of iron. 



The author next investigated tho behavior 

 of iron in water into which, successively, oxy- 

 gen, carbonic acid, a mixture of the two gases, 

 etc., were conducted. The results were analo- 

 gous to those above mentioned, inasmuch as 

 the most effective oxidation took place when a 

 mixture of oxygen and carbonic acid was in- 

 troduced into the water. The action com- 

 menced immediately, and, in a short time, a 

 dark precipitate covered the bottom of the ves- 

 sel. The oxidation, in these cases, was not 

 due to the fixation of the oxygen dissolved in 

 the water, but to oxygen liberated from the 

 water by galvanic action ; the occurrence of 

 hydrogen collected above the liquid in the bot- 

 tles proved this sufficiently. 



Analysis of Ooze or Chalk-Mud. Mr. James 

 Mahony, of Glasgow, has analyzed a sample of 

 ooze, or fine white mud, procured from the 

 comparatively level plateau between Ireland 

 and America, at a depth of 2,435 fathoms. 

 Part of the sample was air-dried and a small 

 portion put, when fresh, into methylated spirit. 

 The analysis is as follows: 



Silica 26.60 



Peroxide of iron and phosphates 3.80 



Protoxide of iron 0.03 



Carbonate of lime 68.80 



Carbonate of magnesia 1.76 



Sulphate of lime .trace 



Soluble salts 4.20 



Organic matter \ ,\ 2.80 



Water 2.50 



100.04 



The silica was found under tho microscope to con- 

 sist chiefly of minute structureless fragments, some 

 of them being crystalline. A small number of dia- 

 toms wore also found. The calcic carbonate consisted 

 of larger organisms (class Foraminifera), some still 

 containing the small particle of jelly-like matter t con- 

 stituting tho animal substance of these organisms, 

 and called sarcode by Dujardin. These doubtTbss 

 yielded tho organic matter noted in the analysis. 

 The soluble salts were ncsounted for by the evapora- 



