436 



BARYTES -BASE. 



he \vas elected a member of the American philoso- 

 I'hicai society, and was a luemlx-r of several other 

 learned societies in Europe and Ainrrira. \Ve are 

 indebted to him for the knowledge of many curious 

 and beautiful plants peculiar to North America, ;:ml 

 for the most complete and correct table of American 

 ornithology, before the work of Wilson, who was 

 assisted by him in the commencement of his Ameri- 

 can Ornithology. He wrote an article on the natural 

 history of a plant a few wiimtts before his death, 

 which happened suddenly, by the rupture of a blood- 

 vessel in tiie lungs, July '22, IS^j, in the eighty-fifth 

 year of his age. 



BARYTEK ; the name of one of the earths ; from 

 /3i/f, heavy, on account of the great weight of its 

 acid combinations. It is procured either from tin- 

 native sulphate of barytes, by exposing its powder to 

 a red heat with charcoal, and by forming from the 

 resulting sulphuret a nitrate, which is decomposed 

 by heat ; or from the native carbonate, by dissoh in- 

 it in nitric acid, and, in like manner, subjecting it to 

 heat. Thus obtained, barytes has a specific gravity 

 of 4, is of a grey colour, has a caustic taste, ami 

 slakes on exposure to the air, like lime, falling to 

 powder from the absorption of water. It is soluble 

 in 25 parts at 60", and in the proportion of nearly 

 lialf its weight at 212. The solution, on cooling, 

 affords prismatic crystals. Its watery solution pos- 

 sesses, distinctly, alkaline properties, changing the 

 vegetable blues to green, and acquiring a film upon 

 its surface, when exposed to the air, from the absorp- 

 tion of carbonic acid. It operates as a virulent 

 poison when taken into the stomach. To the flame 

 of alcohol it imparts a yellow colour, which, together 

 with its great solubility in water, serves to distin- 

 guish it from the other earths. It is useful in chemi- 

 cal analysis, in consequence of its property of uniting 

 by fusion with several of the earths and metallic 

 oxydes, and rendering them soluble in acids or water. 



Barytes has been decomposed by the agency of 

 galvanism, and ascertained to be the oxyde of a pe- 

 culiar metal, to which Sir Humphrey Davy lias given 

 the name of barium. It has a white colour, with a 

 metallic lustre, resembling that of silver. Exposed 

 to the air, or thrown into water, it absorbs oxygen, 

 and is converted into barytes. 



Barytes combines with the acids, and forms a 

 variety of salts, two of which, the carbonate and the 

 sulphate, are found abundantly in nature. The first 

 of these is called, in mineralogy, ff^itkerite, from Dr 

 Withering, its discoverer. It is commonly fibrous or 

 bladed in its structure, occasionally including small 

 cavities lined with minute crystals. It is whitish, 

 translucent, and glistening. Specific gravity, 4-3. It 

 is composed of barytes, 78, and carbonic acid, 22. 

 Like all the other salts of barytes (with one excep- 

 tion), the carbonate is a virulent poison. anft> has 

 often proved fatal to domestic fowls and animals who 

 have accidentally swallowed it, about the mines 

 where it occurs. Its principal localities are in the 

 nortn of England, where it is found in lead mines : 

 it also occurs in Stiria, Salzburg, and Siberia. It is 

 used to obtain the pure barytes, and those salts of 

 this earth which are employed as chemical tests, and 

 for the purposes of scientific illustration. 



The sulphate of barytes, called, in mineralogy, 

 heavy spar, is found abundantly in almost every 

 country, usually accompanying galena, or common 

 lead ore, of which it frequently forms the gangue It 

 is often beautifully crystallized under a variety of 

 forms, derived from a right rhombic prism of 101 42, 

 and 78" IS^but is more generally lamellar or compact. 

 It presents numerous colours, of which white is the 

 most frequent It is translucent, and sometimes 

 transparent, capable of being scratched by the knife, | 



and of a specific gravity of 4-7. Like the artificial 

 sulphate of barytes, it is insoluble, and is the only 

 salt of this earth which is not poisonous. It consists 

 of 67 parts of barytes and 33 sulphuric acid. It is 

 employed, though less extensively, for the same pur- 

 poses as the carbonate, and was formerly used by Mr 

 Wedgewood in the manufacture of his beautiful jas- 

 per ware. 



A fibrous variety of heavy spar, allied Ihlogninn 

 stone, and which occurs, bBDHMM in small nodular 

 masses, in a marl near Bologna, has the remarkable 

 property of becoming phosphorescent by calcination. 



The artificial sulphate of barytes, formed by add- 

 ing sulphuric acid to the carbonate of barytes, is em- 

 ployed for the purpose of painting in water-colours, 

 and is the most beautiful white now in use. It is 

 known by the name of permanent white. The sanw 

 substance is much valued for marking bottles in che- 

 mical laboratories, where the acid vapours destroy 

 common ink, and for labeling articles kept in cellars 

 and moist places. In order to be applied, it, is mixed 

 up with spirits of turpentine and linseed oil, to 

 the consistence of common paint, when it is laid on 

 with a brush. If a black marking material is pre- 

 ferred, this may be rendered so by the addition of a 

 little lamp-black. 



The nitrate of barytes is formed by dissolving the 

 native carbonate in diluted nitric acid, and crystal- 

 lizes on evaporation. It is soluble in 10 or 12 parts 

 of water, at 60, and in 3 or 4 parts at 212". 



The muriate of barytes, in like manner, is produced 

 by submitting the carbonate to the action of dilute 

 muriatic acid. It is much more soluble than the ni- 

 trate. Solutions of both these salts are of great im- 

 portance in analytical processes, for the detection of 

 sulphuric acid : the barytes forming, with tlmt acid, 

 an insoluble precipitate, while the nitric or muriatic 

 acid neutralizes the base. The muriate of barytes is 

 employed with advantage as a medicine, in the 

 treatment of scrofulous diseases, though, from its poi- 

 sonous nature, great caution is required in its adminis- 

 tration. 



BASALT. See Trap- Rocks. 



BASE, in architecture, see Architecture ; in chemis 

 try, see Cliemistry. 



Base, or basis ; a term in tactics, first introduced 

 into military language by Henry von Bulow, who la- 

 boured to reduce war to mathematical principles, and 

 to give more certain rules to the commander. By 

 basis, he understands a tract of country well protect- 

 ed by fortresses, and from which the operations of 

 the army proceed. The line on which these opera- 

 tions are executed he calls the line of operation ; the 

 fortresses from which the operations begin, the sub- 

 ject ; the point to be first carried, the object. Thus, 

 in an offensive war of France against the south of Ger- 

 many, supposing Prussia and Switzerland to be neutral, 

 the Rhine, from Basle toCarlesruhe, would be the ba- 

 sis ; Strasburg, the subject ; Ulm or Ratisbon, the ob- 

 ject ; and the road from Strasburg to these places, the 

 line of operation. As Bulow thought magazines indis- 

 pensable, the security of the line of operation against 

 all attacks from the side seemed to him likewise indis- 

 pensable, and he laid down the principle, that both the 

 lines drawn from the ends of the basis to the object, 

 ought to meet there in a right or an obtuse angle, the 

 last being preferable. The novelty and importance ot 

 the subject, and the severity with which Bulow criti- 

 cised his opponents, gave rise to a violent dispute. In 

 1814, the subject was discussed in the Fragmente aut 

 den Grundsazen der Strategic, erlautert durch die Dar- 

 stelluiig des Feldzitgs in Deutschland, 1796 ; a most 

 valuable work, composed by the archduke Charles of 

 Austria. He adopts many of the ideas ol Bulow, 

 and rejects others ; and, oil the whole establishes 





