177 



BIURET. 



BLACK ASSIZE. 



178 



differ, as stated above, yet as in medical writings the term is restricted 

 to certain forms of these, a slight notice of their uses and modes of 

 action may here be most appropriately introduced. In this limited 

 sense bitumens comprise naphtha, petroleum, and asphaltum, which are 

 all transition states of the same thing, from naphtha the most fluid, to 

 asphaltum the most solid. These appear to be all mixtures in different 

 proportions of naphtha (strictly called naphtha, montana), paraffine, 

 creosote, acetic acid, and of some substance which easily becomes black 

 by the action of the air. The chief constituent principles are carbon 

 and hydrogen. They may be considered mineral empyreumatic oils, 

 and in their action on the human system they are similar to balsams 

 and resins. Their sphere of action does not seem to extend beyond 

 the spinal chord and ganglionic system ; they do not affect the brain 

 or its nerves, except indirectly in case of an overdose, through the 

 vitiated and imperfectly carbonised blood. The functions dependent 

 for their perfection on the nerves of organic life are more powerfully 

 affected by these agents than by any other empyreumatic oil. The 

 secretions of the mucous membranes, of serous membranes, and glan- 

 dular structures, as well as the skin, are promoted by their influence. 

 The process of absorption is also increased, and a more copious secretion 

 of urine takes place. They are better suited for slight and chronic 

 affections of the nerves of organic life, than for acute or violent dis- 

 orders of them. They have been employed in loss of power, cramps, 

 and chronic affections of a nervous but obscure nature ; also in affections 

 of the mucous membranes of the lungs, when balsamic medicines are 

 proper, such as humid catarrh, and some of the forms of asthma arising 

 from nervous debility. Likewise in similar states of the bladder, such 

 as atony of that organ, loss of power of its sphincter muscle, catarrhus 

 vesicse, 4c. They have also been used hi gouty and rheumatic affec- 

 tions, especially when these threaten to terminate in stiffness or loss of 

 power. Lastly, they have been employed as a remedy against worms, 

 especially the tape-worm, in which their efficacy is increased by com- 

 bination with asafcatida. Externally they are used as embrocations 

 in rheumatic and gouty affections, and also to allay cramps and spasms. 

 They are also serviceable as an external application to chilblains, and 

 some other ulcers resulting from an imperfect circulation and low 

 degree of nervous power. 



Their employment would be very improper during any inflammatory 

 state of the system, or increased sensibility of the nerves. An over- 

 dose is decidedly poisonous, causing general excitement, tremblings of 

 the limbs, cramps, convulsions, laborious respiration, a venous state of 

 the blood, great debility, and death : or recovery may take place, if by 

 means of respiration and a copious secretion of bile and urine, the 

 blood can be freed from its excess of carbon. Even after a favourable 

 issue appears likely to occur, death may take place at the end of two 

 or three days. A very large dose may very speedily cause death. 

 [CREASOTE; PARAFFIN; PETROLEUM.] 



BIURET. (C,H 5 N S 4 ,2 Aq.=HO, NH.O,2CyO,2Aq.) When urea 

 fused and exposed for some tune to a temperature of about 230 

 ahr., it evolves a large quantity of ammonia and leaves a pasty 

 residue, which nearly dissolves in a very small quantity of boiling 

 water. This solution must be passed through a filter, and then preci- 

 pitated by Bubacetate of lead. The precipitate must be separated by 

 "iltration and the liquid treated with sulphuretted hydrogen to remove 

 he excess of lead. A final filtration and evaporation yields the biuret 

 a little granular crystals, which may be purified by recrystallisation. 

 Biuret is very soluble in water and in alcohol, and may be detected by 

 n intense red colouration when a few drops of a solution of a salt of 

 opper, followed by a slight excess of potash, are added to its solution. 

 It stands hi the same relation to bicyanate of ammonia, as urea does to 

 cyanate of ammonia. Heated until it fuses, it is converted into cyanuric 

 acid and ammonia. 



KC.H.N.O.) = 2(C.H 3 N 3 OJ + 3NH., 

 Cyanuric Acid. 



BIVOUAC (written also BIHOUAC, BIOUAC), is a term in mili- 

 tary tactics probably derived from the German verb tewachen, or 

 teyieachen, signifying to watch over : it was originally applied to the 

 strong parties of cavalry which were posted beyond the lines of 

 intrenchment in order to watch the motions of the enemy, and pre- 

 vent any attempt to take the army by surprise ; and, because the 

 soldiers thus employed passed the night in the open air, the term was 

 subsequently used to denote the condition of any body of troops when 

 in the field, and not regularly encamped under tents. 



Formerly, no army served during a campaign without being well 

 provided with every material necessary for its protection from the 

 inclemency of the weather ; but, during the wars of the Revolution, the 

 French soldiers, except on a few occasions, dispensed with tents. At the 

 periods in which military operations were suspended, they were quar- 

 tered in towns and villages; and while on active service, they had 

 only the occasional cover afforded by such buildings as happened to be 

 ntuated in the district which they occupied. In all their great expe- 

 ditions they remained an bivouac, as it was called ; and the rapidity of 

 their movements was due, in a great measure, to their freedom from the 

 impedimenta with which armies were formerly encumbered. The im- 

 portant successes which so long attended the armies of Franco were. 



ABTS A.ND sci. nrv. TOL. n. 



no doubt, the cause of their example, in this respect, being followed by 

 their opponents. 



The carriage of an extensive tent equipage is necessarily attended 

 with serious inconvenience on any change of position ; but the removal 

 of this evil must be accomplished, more or less, at the expense of the 

 comfort and health of the soldier. During the summer season, and in 

 the south of Europe, it may be indifferent whether or not the men 

 pass the night under a roof ; and indeed in those climates and in the 

 summer season the open air may be preferred ; but the cold winds and 

 rains which are so frequently experienced in the spring and autumn in 

 northern climates must induce painful and dangerous diseases, which 

 render the men at an early period of their service unfit for the active 

 duties of war. The French troops are now equipped with tentes alms; 

 each tent, which is large enough to afford cover for two men lying 

 down, consists of two pieces of canvas and two small poles, which are 

 carried by the men strapped on to their knapsacks. On camping, these 

 are soon set up, and the men, crawling into them to sleep, are protected 

 from the dew and night-air. 



Generally, in a bivouac, fires are kept up during the night with wood 

 obtained from the neighbouring forests or villages : the arms being 

 piled along the line, the troops place themselves in their rear in 

 groups, each about its proper fire, which is lighted in any convenient 

 situation, the men sitting or lying upon straw if it .can be procured, 

 and endeavouring to shelter themselves from wind or rain by means of 

 boughs planted in the ground, or by boards formed into a roof, accord- 

 ing to circumstances. The bivouac fires of an army often afford a 

 means of arriving at an approximate estimate of its strength, by 

 counting the number of fires, and allowing ten or twelve men to each. 

 The bivouac of an army making a rapid retreat before an enemy is 

 that in which the most disastrous consequences follow, both to the 

 soldier and to the people of the country along the line of march ; a 

 complete disorganisation of the army too often takes place, and lament- 

 able excesses are committed by men suffering the severest distresses 

 from hunger and fatigue. The retreat of the French army from 

 Moscow will be for ever remembered as an example exhibiting every 

 species of misery which can be inflicted and suffered under the con- 

 sequences of a rash and unfortunate expedition. 



When a position is to be occupied for several days, it may happen 

 that the men find means to construct rude huts for then- protection 

 with such materials as are at hand ; and, in an extremely inclement 

 season, they are usually cantoned in such towns or villages as are in their 

 neighbourhood. They then light their fires in the streets, in gardens, 

 or in barns ; certain spots having been previously appointed as alarm 

 posts, about which, on signals being given, the different corps may 

 assemble, in order to form the line of battle, and act immediately as 

 circumstances may require. Permanent cantonments for the winter 

 are of this nature, and they are secured against surprise by outposts 

 constantly maintained at proper distances about them. 



BIXIN. (C 16 H 13 2 ). The red colouring principle of arnotto. It 

 dissolves in alkaline solutions, and is again precipitated by acids as an 

 orange powder. It is sparingly soluble in water, but easily so in 

 alcohol and in ether. [ARNOTTO.] 



BLACK. [LIGHT.] 



BLACK ASH. [SODA ASH.] 



BLACK ASSIZE, the name given to a fatal assize held in 1577 in 

 the old town-hall of Oxford, situated at that time in the yard of the 

 castle. Holinshed, Stow, and Baker make particular mention of it in 

 their ' Chronicles ; ' but the best account of it is in Anthony a Wood's 

 ' History and Antiquities of the University,' published by Gutch, 4to, 

 Oxford, 1796, vol. ii. p. 188; where noticing the trial of one Rowland 

 Jencks, a bookbinder, for sedition, he says : " The assizes therefore 

 being come, which began the 4th of July, and continued two days 

 after in the court-house at the castle-yard, the said Jencks was 

 arraigned and condemned in the presence of a great number of people 

 to lose his ears. Judgment being passed, and the prisoner taken away, 

 there arose such an infectious damp or breath among the people, that 

 many there present, to the apprehensions of most men, were then 

 smothered, and others so deeply infected that they lived not many 

 hours after. The persons that then died," he adds, " and were infected 

 by the said damp, when sentence was passed, were, Sir Robert Bell, 

 baron of the Exchequer ; Sir Nicholas Barham, sergeant-at-law ; Sir 

 Robert d'Oyley, the high sheriff; Hart, his under sheriff; Sir William 

 Babyngton, Robert d'Oyley, Wenman, Danvers, Fetiplace, and Har- 

 court, justices of the peace; Kerle, Greenwood, Nash, and Forster, 

 gentlemen; besides most of the jury, with many others that died 

 within a day or two after. Above 600 sickened in one night, as a phy- 

 sician of Oxford (Georg. Edrycus in ' Hypomnematibus suis in aliquot 

 libros Pauli jEgmetso,' edit. Lond. 1588, lib. 2) attested ; and the day 

 after, the infectious air being carried into the next villages, there 

 sickened 100 more. The 15th, 16th, and 17th days of July sickened 

 also above 300 persons, and within twelve days' space died 1 00 scholars, 

 besides many citizens. The number of persons that died in five 

 weeks' space namely, from the 6th of July to the 12th of August (for 

 no longer did this violent infection continue) were 300 in Oxford, and 

 200 and odd in other places ; so that the whole number that died in 

 that time were 510 persons, of whom many bled till they expired. 

 Some," Wood says, " left their beds, occasioned by the rage of their 

 disease and pain, and would beat their keepers or nurses, and dnve 



N 



