CHEMISTRY. 



113 



Mr. Martin Waldstein. It consists of a wide- 

 mouthed bottle, fitted with a leaden stopper to 

 which a brass rod is soldered, and on this 

 slides a clamp used to hold a thermometer. 

 The stopper has four perforations, one to admit 

 the thermometer, two near this and on oppo- 

 site sides to admit the glass tubes containing 

 the substance to be examined, and a fourth 

 through which one limb of a bent glass tube 

 is passed. This tube is connected at the other 

 end, by means of a perforated cork, with a 

 test-tube. The cork of the test-tube is chan- 

 neled so as to permit the free escape of any 

 gases that do not condense, and thus keep the 

 pressure on the liquid equal to the atmosphere 

 if the boiling-point of the substance under ex- 

 amination is wished to be determined in the 

 same apparatus. The advantages claimed for 

 this contrivance are, that by using a lead stop- 

 per the sulphuric acid employed is not so easily 

 discolored as if common corks are used, and 

 also that two operations can be performed at 

 the same time. 



Valuable improvements in the apparatus for 

 decomposing salt in chemical works, the in- 

 vention of Messrs. Jones & Walsh, of the Mid- 

 dlebro Chemical Works, England, have been 

 brought into use during the year. In place of 

 the common decomposing pan and finishing- 

 furnace, a flat-bottomed circular pan, fourteen 

 feet in diameter, and having a rim about six 

 inches deep, is employed. In this, the process 

 of decomposition by sulphuric acid is begun 

 and finished. The pan is provided with a me- 

 chanical stirrer, and is inclosed in brickwork. 

 The heat is derived from a coke-fire, and passes 

 over the batch, the products of combustion 

 passing on with the evolved hydrochloric acid 

 to the condenser. No heat at all is applied to 

 the bottom of the pan. Forty hundred-weight 

 of common salt and the necessary quantity of 

 sulphuric acid constitute a batch, one of which 

 is finished every six hours. The product is 

 very uniform in quality, and is left in a fine, 

 powdery condition, quite free from lumps. 

 The advantages are, a large reduction in the 

 cost of the furnace, a saving of half in the cost 

 of labor, consumption of less fuel, no " flux- 

 ings," and complete control over the composi- 

 tion of the batch. 



A new apparatus for concentrating sulphuric 

 acid has been devised by Faure & Kessler, in 

 France, which is said to have advantages over 

 the old processes in point of cheapness of first 

 cost and economy of working. The concen- 

 tration is conducted in flat, shallow, dish- 

 shaped vessels, made either of platinum or 

 porcelain. The dishes are covered by a leaden 

 dome, or chamber, which is contrived to con- 

 dense the acid-fumes evolved, and to conduct 

 them into the leaden chamber. It is claimed 

 that the cost of evaporation is lessened by one 

 half. 



^ Dr. Neumayer recently exhibited to the Ber- 

 lin Geographical Society a new form of ther- 

 mometer for the determination of the tempera- 

 VOL. xv. 8 A 



ture, and the direction of the currents at great 

 depths in the ocean. The apparatus consists 

 of an hermetically-sealed copper box, with an 

 external appendage resembling a rudder. In 

 the interior are a mercury-thermometer and a 

 compass, each inclosed in a glass receptacle, in 

 which are admitted traces of nitrogen gas. A 

 small electric battery completes the apparatus. 

 When it is allowed to descend, attached to a 

 sounding-line, the action of the current on the 

 rudder causes the apparatus to take an horizon- 

 tal direction, thus indicating the set of the flow 

 by the relative positions of compass-needle 

 and rudder, while the thermometer indicates 

 the temperature. To fix these indications, a 

 piece of photographic paper is suitably dis- 

 posed near the glass cases containing the in- 

 struments. Then, at the proper time, a cur- 

 rent of electricity is established through the 

 gas in the receptacles, causing an intense vio- 

 let light, capable of acting chemically on the 

 paper for a sufficient length of time to photo- 

 graph the shadows of the compass-needle and 

 the mercury-column. Within three minutes 

 the operation is complete, and then the ap- 

 paratus is hoisted and the paper removed. 



Cotton Gunpowder. This is the name given 

 to a new preparation of gun-cotton, which, by 

 the use of certain chemicals, is rendered per- 

 fectly safe for storage or carriage, though pos- 

 sessing enormous explosive power. The fol- 

 lowing account of some experiments made 

 with it is taken from the Journal of the So- 

 ciety of Arts : 



Cartridges were held in the hand, lit with fuses, 

 and burned with a steady blaze, while, when ignited 

 by detonators, they exploded with a loud report. 

 Ten pounds of the substance was placed on an anvil, 

 and an iron pile-driver weighing one-half ton was 

 allowed to fall fifteen feet upon it, without causing 

 an explosion. Two barrels, each containing forty 

 pounds, were placed in a pile of fagots. Upon these 

 being fired, the powder burned with a steady but 

 intense flame, and without any tendency to explo- 

 sion. A solid block of steel, about one-half ton in 

 weight, was bored to the depth of six inches, and a 

 6-ounce cartridge was inserted in the hole. It was 

 split into two pieces. But the greatest exhibition 

 of force was made in two experiments with steel 

 ingots. In the first experiment, four ingots of eight 

 inches square and three feet long were used. In the 

 centre of these four masses of steel as laid together, 

 two pound cartridges of ^ the powder were placed, 

 and kept in their place with a few handfuls of clay. 

 In the second experiment, the four ingots were each 

 eleven inches square^ and the charge used two and a 

 half pounds. The eight ingots were all broken in 

 halves ; some of these massive pieces of steel were 

 sent flying high in the air, falling thirty, thirty-five, 

 and, in one case, forty-five yards away. At the 

 close of the experiment, a torpedo of fifty pounds 

 of this p^owder, sunk ten feet in the river Swale, but 

 not resting on the bottom, was fired. An immense 

 body of water was projected high in the air, and any 

 vessel which might at the time have been passing 

 over it would have suffered severely. 



Influence of Ammonia on the Colors of Flow- 

 ers. This subject has lately been investigated 

 by Gabba, an Italian chemist. His method 

 was to put a weak ammoniacal solution in a 

 basin, and place over it a receiver containing 



