176 



SCIENCE. 



[Vol. I., No. 6. 



Testing for barium or sulphuric acid. — Tlie 

 minimum strength of a solution of barium cliloride in 

 wliich barium can be detected witli certainty, accord- 

 ing to S. Picliering, is 1 part barium in 833,000 parts 

 water; and Ibe re-action is equally delicate with sul- 

 phuric acid or ammonium sulphate. The precipitation 

 was observed against a black background by means 

 of an artificial light placed almost vertically above the 

 test-tube. — (C/iem. neios, xlvi. 223. ) c. p. M. [362 



Estimation of sulphur in iron and steel. — G. 

 Craig meets with good results by passing the gases 

 evolved with hydrochloric acid through an ammoni- 

 acal solution of hydrogen peroxide. — (Cliem. news, 

 xlvi. 199.) c. F. M. [363 



Detection and estimation of titanium. — A. 

 Weller finds that the change in color produced when 

 titanic acid is formed by oxidation of the sulphate 

 with hydrogen peroxide is sufficiently delicate to ren- 

 der the rcraction a stiitable means for the determina- 

 tion of titanium. — {Berickte deutsch. chem. gesellscli., 

 XV. 2.592.) c. F. M. [364 



Estimation of titanic acid in presence of iron. 

 — A method proposed by Pasani for the volumetric 

 analysis of a solution containing titanic acid and iron 

 depended upon his observation that the acid oxide 

 of titanium (TiOo), when reduced to the sesquioxide 

 (TijOj) by nascent hydrogen, could be completely 

 oxidized by potassium permanganate, even in pres- 

 ence of iron in the ferrous condition. According to 

 E. VViegand, this method is incapable of giving con- 

 stant results. Pie finds that ferrous oxide undergoes 

 partial oxidation before oxidation of the titanic ses- 

 quioxide is complete, and therefore infers that ferric 

 oxide and titanium sesquioxide can exist in the same 

 solution. — (Zeitschr. fur anal, chem., 1SS2, .510.) 

 c. F. M. 1^365 



Volumetric analysis of peroxides. — A com- 

 parison of Bunsen's and Mohr's methods for the 

 determination of available oxygen in peroxides by 

 W. Diehl shows that digestion with hydrochloric 

 acid and potassium iodide, recommended by Mohr, 

 gives as exact results as the distillation in Bunsen's 

 method. Digestion with acetic instead of hydro- 

 chloric acid affects as complete decomposition of 

 manganese dioxide, either freshly prepared or in 

 pyrolusite; and at the same time potassium iodide 

 is without action upon ferric acetate. The available 

 oxygen and the percentage of iron in manganese 

 dioxide may therefore be ascertained by two deter- 

 minations, in one of which hydrochloric acid is used, 

 and in the other acetic acid. In lead peroxide the 

 available oxygen may be as accurately determined by 

 digestion with acetic acid and potassium iodide as by 

 Bunsen's method. — {Dingler'n polytechn. journ., 246, 

 196.) c. r. M. [366 



METALLURGY. 



The Siemens direct process. — This consists in 

 heating mixed fine iron-ore and coal in a horizontal, 

 slowly revolving cylinder. The iron forms a sponge 

 ready for rolling, while the silica and earthy impuri- 

 ties form a slag, which removes the hurtful sulphur 

 and phosphoi-us from the iron. Mr. James Davis of 

 Landore, Wales, gives his experience. He makes 

 one ton of wrought iron with one ton of gas-pro- 

 ducer coal, reduces the sulphur to a trace, and the 

 phosphorus to .05 per cent. He finds magnesia 

 bricks to stand the best. In .32 days 21 hours net 

 working time, with 200 heats, using 200 tons of ore 

 and 120 tons hammer scale, he made 217 tons 5 cwt. 

 of blooms. — {Eng. and min. journ., Jan. 6, 1883.) 



R. H. E. [367 



Recovery of precious metals from slags. — A 

 patent has been obtained by Mr. Richard Pearce of 

 Denver, on an improvement in smelting gold and 

 silver ores. Tbe process consists in throwing upon 

 the slags, as soon as the charge is perfectly melted, 

 a fine-powdered oxide of copper or roasted copper 

 matte. The furnace is then closed a short time. A 

 reaction takes place, and a matte descends, thereby 

 robbing the slag of its precious metals. For a 

 charge of 3 tons of ore, 30 lbs. of oxide of copper 

 are needed. — {Min. and sc. press, Dec. 16, 1882.) 



B. H. B. [368 



Basic open-hearth steel process. — Mr. O. T. 



Tellander has described the adaptation of this pro- 

 cess at the Alexandrowsky steel-works, St. Peters- 

 burg, Russia. The steel is made from pig-iron, 

 scrap-iron, spiegel, and ferro-manganese, which are 

 melted in the usual Siemens-Martin furnace. The 

 special feature of the basic process consists in lining 

 the furnace with bricks made of dolomite mixed 

 with IS per cent of coal-tar. The joint between 

 this lining and the outer Dinas briclvs is made by a 

 layer of chrome-iron-ore and coal-tar. A mixture 

 containing .5 per cent of phosphorus yields steel 

 with an average of only .04 per cent. The sulphur is 

 also reduced as much, while the silicon is almost en- 

 tirely removed. — {Eng. and min. journ., Jan. 18, 

 1883.) E. H. E. [369 



AGRICULTURE. 

 Value of sprouted and dried seeds. — Experi- 

 ments by Will led to the following conclusions: — 



1. Mature seeds of common cultivated plants suffer 

 no diminution of the proportion of seeds capable of 

 sprouting, if soaked twelve hours in water, and then 

 dried at ordinary temperatures. Some samples of 

 l^eas constituted exceptions to this rule. Soaking 

 twenty-four hours, and then drying, usually caused a 

 slight decrease in the percentage of seed which ger- 

 minated. 



2. Some seeds even survive an interruption of ger- 

 mination in its first stages. The radicle dies, but is 

 replaced by adventitious roots. The plumule is more 

 enduring : even when the terminal bud is destroyed, 

 lateral buds may develop. 



3. The i^roportion of seeds capable of regermina- 

 tion is, in general, inversely proportional to the extent 

 to which germination has progressed. 



4. The extent to which the first germination may 

 be carried varies in different kinds of seeds. Mono- 

 cotyledonous seeds seem, in general, to withstand this 

 treatment better than di-coty!edonous. 



5. In view of the fact that such seeds germinate 

 only under the most favorable conditions, the use of 

 seed that has once been germinated is not to be 

 recommended in practice. — {Landw. versuchs-stat., 

 xxviii. 51.) H. p. A. [370 



Prevention of potato-disease. — According to 

 Jensen, this disease, which is caused by a fungus 

 (Peronospora infestans, Tul.), attacks first the tops, 

 and is conveyed to the tubers by means of spores 

 washed into tlie soil by rain. He therefore proposes 

 to prevent this by running a plough between the 

 rows, so as to throw up a furrow upon the top of the 

 hills, while at the same time the tops are bent over 

 so as to hang above the neighboring furrow. This 

 should be done at least as soon as the disease shows 

 itself on the tops ; usually by the middle of August. 

 In this way the washing of the spores into the hill is 

 prevented. Furthermore, the potatoes should not be 

 dug for at least two or three weeks after the tops are 

 entirely wilted, to avoid Infection from the latter. 

 Field experiments with this method gave very favora- 



