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conceived to be one mode in which tho blister, as a general 

 remedy, proves beneficial. 



But whatever be their mode of operation, tho fact is cer- 

 tain that blisters often prove more extensively beneficial 

 than could have been anticipated from t lie limited surface 

 on which they act, and from tho \ery slight discharge they 

 induce. Though, as already stated, they are most bene- 

 ficial when the inflammation is seated in a particular organ 

 or in part of an organ, yet they are by no means without 

 advantage in cases in which tho system is generally and 

 deeply involved; but then benefit eau only be obtained 

 from them after bleeding, purging, and other evacuants 

 have lessened or subdued the general action of the system. 

 In this case they often complete and render permanent the 

 benefit derived from the preceding remedies. 



For tho reason already assigned, they are most commonly 

 employed (after remedies that act powerfully on the general 

 system) in pneumonia (inflammation of the lung) ; in gas- 

 tritis (inflammation of the stomach) ; in hepatitis (inflam- 

 mation of the liver); in phrenitis (inflammation of the 

 brain), and so on : but there are diseases of tho nervous 

 system in which they are decidedly useful, as in spasmodic 

 affections attended with pain but without inflammation ; in 

 the paroxysms of angina pectohs and of spasmodic asthma ; 

 in epilepsy, catalepsy, hysteria, paralysis, &c. 



Benefit is sometimes derived from tho application of blis- 

 ters through their immediate and direct action as stimulants, 

 chiefly in full habits, in which languor is the consequence 

 of over-distention. In these cases they excite the wliole 

 system, and produce an exhilarating effect. A gentleman 

 once highly distinguished at the bar, and of brilliant con- 

 vivial powers, always applied a blister when he wished to 

 shine in either sphere, and the effect was produced as soon 

 as the warmth in the part began. Many persons, even 

 though they feel acutely the pain produced by blisters, de- 

 clare that the relief from the previous languor counter- 

 balances all their sufferings. 



The application of a blister is sometimes successfully 

 employed as a means of directly lessening pain. The ex- 

 citement of one pain diminishes another : hence the relief 

 afforded in tooth-ache and other painful affections. Al- 

 though in general blisters relieve more pain than they give, 

 yet in some irritable skins and in some irritable states of 

 the system, they produce occasionally extreme excitement 

 and suffering. By the previous employment of the appro- 

 priate remedies for soothing the irritable state of the system, 

 the beneficial effect of blisters may be obtained even in 

 constitutions thus predisposed to irritation from the operation 

 of this remedy, which constantly produces good or bad 

 effects just as its application is well or ill timed. One pain- 

 ful affection occasionally induced (strangury) is effectually 

 relieved by an anodyne injection thrown into tho rectum, 

 consisting of four or six ounces of thin tepid gruel, with 

 thirty or forty drops of laudanum. 



BLISTER-BEETLE. [See CANTHARIS.] 



BLOCK (German, Bttcke; Dutch, Blohhen; Swedish, 

 Skeppt-block ; French, Poulie ; Italian, Bozelli; Spanish, 

 Motones; Portuguese, Moutoes ; Russ, BloM), an instru- 

 ment generally made of wood, but sometimes of iron. It is 

 chiefly employed in the rigging of ships to give facility to 

 the raising or lowering of the masts, yards, and sails, and 

 for such other purposes as require and admit of the applica- 

 tion of the pulley a block, as used on board of ships, being 

 simply a pulley in the greater part of its modifications. 

 One description of blocks, to which the name of dead-eyes 

 has been given, is not a pulley, being unprovided with 

 heaves. These dead-eyes are used for setting up and 

 fastening tho shrouds and other standing rigging of the 

 ship, while sheaved blocks are used for the running rigging. 

 The more usual form of blocks of both descriptions is that 

 of an oval spheroid, flattened at opposite sides. Dead-eyes 

 are made out of one piece of wood, pierced with the requisite 

 number of holes, through which the standing rigging is 

 passed; and single-sheaved blocks are made up of three 

 distinct parts, viz., tho shell, tho sheave, and the pin which 

 ervcs at an axis round which the sheave revolves. Some 

 block* are made with two, and others with three, and even 

 four sheaves, which all revolve on tho same pin or axis, and 

 consequently parallel to each other, in separate chambers 

 formed for that purpose in the shell of tho block. 



The construction of blocks would seem to bo a very simple 

 operation, such an any man accustomed to work in wood 

 could perform with facility and accuracy ; but this in practice 



s not found to be the case, as the parts must be fashioned 

 and fitted together with the greatest possible accuracy, iri 

 order to insure their easy working when put together a 

 circumstance of considerable importance in the management 

 of a ship. For this reason, block-making has long formed 

 a substantive branch of manufacture, and it carried on cither 

 by itself, or in conjunction only with ma&t-maki: 



The vast number of blocks constantly required for the 

 use of the English navy and the merrantilu marine of this 

 country may be understood from the fact, that upwards of 

 1400 blocks of all sorts are needed for fitting one ship <>f 71 

 guns, while for smalli lihmigh the sires maybe 



different, the number will not materially vary from what is 

 here stated. It was therefore long a matter of considerable 

 moment to devise means for simplifying the mode of manu- 

 facture, and thus diminishing the cost. In the year 1781 a 

 large manufactory was established on the river Itchen at 

 Southampton by Mr. Taylor, who had secured a patent for 

 an improved method of making shearcs, and who further 

 adapted machinery for cutting the timber and shaping tho 

 shells of the blocks. Mr. Taylor so far succeeded, that he 

 was enabled for some time to supply all the blocks required 

 for the use of the navy. A few years after the expiration of 

 his patent, machinery was introduced into the dock-yard at 

 Portsmouth, and the government undertook the manufacture 

 for the navy, with the double object of economy as to the 

 cost, and of being independent of any individual forthe supply 

 of an article of first necessity for the equipment of ships. 



About this time (1801) Mr. Brunei succeeded in com- 

 pleting a perfect working model for constructing both the 

 shells and sheaves of blocks. This model being submitted 

 to the inspection of the Lords of the Admiralty, the inven- 

 tion was at once adopted by government, and Mr. Brunei 

 was engaged to superintend the construction of the requisite 

 machinery upon a scale sufficiently large for making blocks 

 to supply the whole naval service of the country. The 

 completion of this machinery occupied nearly six years, and 

 was not brought into full operation until September, 1808, 

 since which time it has been found to work without re- 

 quiring any alteration, and is attended only by workmen 

 of the ordinary description. 



The machinery in the Portsmouth Dock-yard is put in 

 motion by a steam-engine of thirty-two horse power, tho 

 work performed by which consists of various laborious pro- 

 cesses in addition to moving tho block-machinery. By 

 means of this latter, the shells and sheaves of blocks are 

 cut of all the requisite sizes, and finished with a degree 

 of precision which is found in itself to be of great ad- 

 vantage, since the shell or the sheave of anyone block, of a 

 given size, will fit, and may be at once adapted to any other 

 sheave or shell, of the same size, without requiring any ad- 

 justment. It is found that with this machinery ten men 

 can perform the work that previously required one hundred 

 and ten men for its completion, and can easily finish, within 

 the year, 140,000 blocks of various sorts and sizes, the value 

 of the work performed being not less than 50,0(Hi/. 



As a reward for his ingenuity, and for his services during 

 six years in superintending the construction of the ma- 

 chinery, Mr. Brunei received from government 20,00u/., a 

 sum exceedingly moderate when it is considered that tin- 

 annual saving to the public by means of his invention 

 amounted every year, during the continuance of the war, to 

 a sum at least equal to the whole compensation. 



The great importance, in a national point of view, of this 

 invention, Js such, that, in order to guard against the con- 

 sequences of any accident happening to the machinery at 

 Portsmouth, during a time when the fitting of a fleet might bn 

 in progress, duplicate machinery has been constructed in the 

 Dock-yard at Chatham, and is kept in constant readiness 

 for action, although hitherto it has not been wanted. 



BLOCKADE, LAW OF. Whenever a war takes place, 

 it affects in various ways all states which have any con- 

 nexion with the belligerent powers. A principal part ac- 

 cordingly of the science of international law is that which 

 respects the righto of such neutral states. For obvious 

 reasons this is also the most intricate part of the subject. 

 There a here a general rule, namely, that the neutral ought 

 not to be at all interfered with, conflicting with a great 

 variety of exceptions, derived from what is conceived to bo 

 the right of each of the belligerents to prosecute the ob- 

 ject of annoying its enemy, even though (within certain 

 limits) it inflicts injury upon a third party. In the first 

 there 13 to be settled the question, of what these limits 



