189 



OXYSYLVIC ACID. 



OZONOMETER. 



190 



OXYSYLVIC ACID. A resinous acid which has hitherto been 

 only very imperfectly investigated. 



OXYWATER. A name sometimes applied to binoxide of hydrogen. 

 [HYDROGEN, binoxide of.} 



OYEli AND TERMINER. These words in ancient law French 

 denote a commission forming a court of criminal judicature, the dis- 

 tinguishing character of which is described by them. The substance 

 of the commission, or \crit, as it was anciently called, is an authority 

 given by the crown to certain persons judicially to hear and determine 

 (oyer et terminer) certain specified offences. The commissions of oyer 

 and terminer are the most comprehensive of the several commissions 

 which constitute the authority of the judges of assize on the circuits. 

 On these occasions they are usually directed to the lord chancellor, 

 several high officers of state, two judges of the courts of Westminster, 

 the queen's counsel, the serjeants-at-law, and the associates ; but (ex- 

 cepting on the northern circuit, where all the commissioners but one 

 are of the quorum) the judges, queen's counsel, and Serjeants are always 

 of the quorum, so that the other commissioners cannot act without the 

 presence of one of them. Justices of oyer and terminer have juris- 

 diction to inquire into the truth of all treasons, felonies, and mis- 

 demeanours committed within the several counties and places to which 

 the commission extends, and also to hear and determine the same on 

 certain days to be appointed by themselves. The issue of such a com- 

 mission suspends all others, and hence magistrates cannot proceed 

 under a commission of the peace at the same tune. Besides these 

 ordinary courts of oyer and terminer at the assizes, special commissions 

 of oyer and termiuer are sometimes issued where offences of a 

 dangerous tendency have been committed in particular districts, and 

 the public peace and security require immediate inquiry and punish- 

 ment. So also special commissions have been sometimes issued where 

 from particular circumstances the incompetency of the ordinary 

 tribunals would occasion a failure of justice. A remarkable instance 

 of this kind occurred when Mr. Dunning, afterwards Lurd Ashburton, 

 was recorder of Bristol and sole criminal judge under the charters of 

 the city. A forgery of Mr. Dunning's name to a bill of exchange 

 having been committed in Bristol, he refused to try a case in which he 

 was a party interested, and it was therefore necessary to issue a special 

 commission for the purpose of hearing and determining this single 

 offence. 



The Central Criminal Court is a court of oyer and terminer (and 

 jail delivery) for the jurisdiction assigned to it by statute, comprising 

 the metropolis and portions of the adjoining counties. The jurisdiction 

 of the magistrates in quarter sessions is expressly preserved by the 

 statute, for otherwise they could not hold courts at all. 



oYSTEK TRADE. The management of the oyster fishery presents 

 many peculiar features. The best kind of oysters in this country are 

 the small variety called .Va(iYr / they are found near the mouths of 

 the rivers Colne, BUckwater, and Crouch, in Essex ; the .Swale and the 

 Medway, in Kent ; the Ouse, in Sussex; in Southampton Water; and 

 at other places in all the three kingdoms. These artificial beds are 

 usually supplied with the produce of the coast of Normandy, whence 

 the spat or spawn is gathered. The spawn, when first cast, somewhat 

 resembles in appearance a drop of fat ; it is composed of an immense 

 number of minute oysters, each of which becomes about a quarter of an 

 inch long in three days, as large aa a shilling in three months, as a 

 half crown in six months, and as a crown in twelve months. They 

 are stated to attain their highest degree of perfection when three years 

 old. The oyster is found in the seag of most countries, but never at 

 any great depth, and seldom far from the mouth of a river. The fish- 

 ing for oysters is permitted from the 1st of August to the end of 

 April. 



The fishing, or, to use the more correct term, the dredging, is 

 carried on to a large extent by small sailing- and row-boats they 

 usually dredge in company, as the oysters lie within comparatively 

 small spaces. The dredge is a net on u wooden or iron frame, and is 

 weighted according to the nature of the bed, varying from 12 to 18 

 pounds. It is thrown by one man, while another rows. The beds or 

 banks are found in the British Channel ; off the Isles of Wight and 

 Jersey ; on the coast of Wales ; off the French coast. In Scotland they 

 are found in the Frith of Forth ; in Ireland, in Carlingford Bay, the 

 oysters from which have a high character for excellence. France has 

 also numerous artificial beds, but the fishermen also dredge in the 

 Channel, where frequent disputes arise between them and the English 

 fishermen respecting boundaries. The most esteemed natural beds in 

 France are those off the coast of Brittany, at Dieppe, and Cancalle, near 

 St. Malo. 



Mo far as regards the London supply, the oysters are brought prin- 

 cipally from the Essex coast and rivers ; but the Milton, Fevershaui, 

 and Burnham oysters are most highly esteemed. None are sent from 

 them nil 01 Enghad; but broods arc sent from thence to be fattened 

 in tin; artificial beds. The sale at Billingsgate is enormous. At 

 u.impton there is a wide margin of muddy shore at low water, 

 whk-li oyster-beds are funned. Oysters are brought from 

 the Jersey fishery, laid down on those beds to fatten, turned and 

 ttendcd to every day, taken up when wanted, opened, placed in tin 

 cans, and sent up to London by railway. These oysters are used for 

 pickles and sauces, and not eaten in the ordinary way. 

 The oyster trade in England has been of considerable importance for 



centuries, and now ranks next to the herring- fishery. The dredging, 

 the laying down spawn in the artificial beds, and attending to and 

 gathering the oysters, and the packing for market, give employment to 

 a large number of persons ; while the rapid conveyance afforded by 

 railways enable the inland towns to obtaiu oysters perfectly fresh and 

 in excellent condition ; and at Christmas the quantity transmitted in 

 barrels as presents demands additional accommodation, not only from 

 railways, but from every other means of inland transmission. 



OZONE (from the Greek uw, to smell) is the name given by 

 Professor Schonbein of Basle to an odour evolved during the progress 

 of certain electro-chemical decompositions. It is also produced by 

 common electric sparks, and by the working of an ordinary electrical- 

 machine in the air. This odour attracted no particular notice until 

 M. Schonbein called the attention of the British Association to it in 

 1840, since which time it has undergone much examination, and 

 various theories have been propounded as to its nature and compo- 

 sition. 



Ozone is evolved at the anode, or positive pole of a galvanic battery, 

 at the same time with oxygen, during the electrolisation of any 

 of the following bodies : namely, water, dilute sulphuric acid, solu- 

 tions of phosphoric and nitric acids, potash, and many oxysalts. Of 

 these, dilute sulphuric acid mixed with chromic acid yields it in the 

 greatest quantity. It may also be obtained from atmospheric air, by 

 passing the electrodes through a closely-fitting cork into a jar filled 

 with air, and frequently making and breaking contact. Under the 

 influence of heat ozone disappears, and it cannot be obtained from 

 heated solutions, or solutions of hydracids, chlorides, bromides, or 

 iodides, the presence of which, even in small quantity, prevents its 

 evolution from solutions otherwise yielding it abundantly. It may be 

 developed by electrolisiug a solution of chloride of sodium with 

 platinum electrodes, by placing the gas collected at the anode over 

 ammonia and water to absorb the chlorine. Ozone can be preserved 

 for a length of time with the oxygen collected with it in well-closed 

 bottles. It possesses the property of bleaching litmus-paper and paper 

 coloured with indigo or a solution of that substance. It is readily 

 absorbed by mercury and the oxidisable metals, forming oxides with 

 them ; and when the solutions employed are heated, its affinity for 

 metals is so greatly increased that it oxidises platinum and gold. 

 Water absorbs it. The inspiration of ozone is very injurious, the 

 effects being similar to those resulting from chlorine and bromine. A 

 mouse is killed with it in five minutes ; and M. Schonbein states that 

 he was seriously affected by breathing an atmosphere charged with it. 



The electrodes employed in these experiments have a great influence 

 in respect to the evolution of ozone. With water or acid solutions 

 they must be of platinum or gold ; for when the more oxidisable 

 metals are used it enters immediately into combination with them. 

 It can be obtained from air when the positive electrode is copper, iron, 

 silver, or platinum, and zinc negative, but not when these arrange- 

 ments are reversed, or both electrodes are of zinc. On electrolising a 

 solution of sulphuric acid the following results are obtained : With 

 platinum electrodes the odour is very powerfid ; but it is not produced 

 when copper, zinc, or iron electrodes are employed. With boxwood 

 charcoal, the gas given off from the positive pole has no smell ; but 

 when absorbed by lime-water it turns it milky, proving the gas to be 

 carbonic acid. With gas charcoal, sulphuretted hydrogen is evolved 

 at the negative pole and carbonic acid at the positive, but no odour of 

 ozone is produced. With a solution of chloride of sodium, the odour 

 is not perceptible until the gas obtained from platinum electrodes at 

 the positive pole is placed over ammonia and water to absorb the 

 chlorine. The residual gas emits the peculiar odour. 



There exists much variance in the experimental results with this 

 new substance, and not less in the opinions concerning its nature. 

 Professor Schonbein and Dr. Andrews regard it as oxygen in an 

 allotropic condition, whilst Dr. Williamson and M. Baumert consider 

 it to be a teroxide of hydrogen. The latter chemist has even succeeded 

 in analysing ozone, and thus quantitatively demonstrating its compo- 

 sition ; nevertheless, Dr. Andrews calls in question the accuracy of 

 these experiments, and adduces others in proof of his view of the 

 composition of this substance. 



Teitifur Ozone. Notwithstanding the remarkable characters of this 

 body, no reliable test of its presence in minute quantity (in the air, 

 for instance) is known. Paper imbued with starch and iodide of 

 potassium is rendered blue by ozone, but the same effect is produced 

 by acid gases ; and this test, as used for the detection of ozone in the 

 air, is utterly worthless. Paper soaked in solution of sulphate of 

 manganese, which is turned brown, or impregnated with black sulphide 

 of lead, which is bleached by ozone, are more reliable tests ; but even 

 these are open to so many sources of fallacy as to render their indi- 

 cations of little value. [HYDROGEN, Ttruxitle of.] 



OZONUMETER, an instrument for measuring the quantity of ozone 

 contained in the atmosphere. The only means of ascertaining the 

 presence and quantity of this agent in the atmosphere, is founded upon 

 the known action of ozone in decomposing iodide of potassium. If 

 this salt be exposed to the action of an atmosphere containing ozone, 

 the latter unites with the potassium, forming oxide of potassium or 

 potash, whilst the iodine is set free. In order to render this test 

 obvious, the iodide of potassium is mixed with starch, and the iodine, 

 when it is set free, unites with the starch, the existence of which is 



