IODOFORM. 



IPECACUANHA. 



970 



however, when applied to the skin, stains it brown, and even the very 

 email quantity which can be dissolved in water is sufficient to cause 

 rubefaction, and in the form of baths produces decided action both on 

 the surface of the body and the general system. When applied to 

 ulcers or any breach of the skin, it occasions heat and a sense o1 

 pricking and tingling ; it is also absorbed, and may be discovered in 

 the blood and secretions of the patient. Taken internally, even in 

 small doses, it causes a sense of heat in the mouth and throat ; if much 

 diluted by the vehicle in which it is given, and the stomach be healthy 

 it appears to do little more than increase the digestive powers ; but in 

 larger and stronger doses it creates great heat in the region of the 

 stomach, which becomes sensible to pressure, with a feeling of weight 

 heartburn, and often nausea and vomiting. In very large doses it acts 

 as an irritant poison. It is not merely an irritant poison when taken 

 in a large dose, but is a slow or accumulative poison, even when taken 

 in medicinal doses for a length of time, inducing a peculiar state callec 

 Jodirni. It has been generally represented as causing emaciation even 

 to a frightful extent ; but though this has occurred in some instances 

 it does not seem to be frequent, if we except the absorption of certain 

 glands, especially the m.irnnue of females. 



The diseases in which it has been found useful are glandular swell- 

 ings, especially bronchocele or goitre, which rarely resists its action ; 

 in some strumous diseases, in chronic rheumatism, and also as an anti- 

 dote against poisoning with strychnia, brucia, and verataria : but its 

 claims to confidence are not clear in case of such formidable poisons. 

 It is often of use in lessening the injurious effects of mercury and in 

 the treatment of the sequelae of syphilis. (See Lugol, ' On Scrofula.'] 

 A liniment composed of iodide of potass along with strong liquor 

 ammonial and soap liniment, is extensively used in the hospital for 

 consumption at Brompton, as a counter irritant. A mixture of tincture 

 of iodine and tincture of opium, as an external application to the spine, 

 is most useful [SPINAL IRRITATION], its use being suspended every 

 three or four days; or a solution of iodide of potass in compound 

 camphor liniment has the advantage of not discolouring the skin or 

 linen. 



IODOFORM (CjHI,,). This compound, which is analogous to chloro- 

 form in its constitution, is prepared by adding an alcoholic solution of 

 potash to one of iodine, till the colour of the latter is destroyed ; care 

 must be taken to avoid any excess of the alkali ; the alcohol is evapo- 

 rated at a gentle heat, and, as it goes off crystals of iodoform are 

 deposited, which are to be washed with pure water to separate the 

 iodide of potassium. 



The properties of iodoform are : It has the form of yellow brilliant 

 lamime, which have a plight disagreeable odour, somewhat resembling 

 that of saffron ; it is insoluble in water, but very soluble in alcohol, 

 ether, and pyroxylic spirit. It sublimes at 212, and decomposes at 

 248, into carbon, iodine, and hydriodic acid. Its alcoholic solution 

 decomposes very readily. 



IODO-PTROMECONIC ACID. [MKCONIC ACID.] 



IODOQUININE. [CINCHONA, ALKALOIDS OF.] 



IODOSULPHUIUC ACID (SO.C1). An acid said to be formed 

 when sulphurous acid is passed into a solution of iodine in pyroxylic 

 spirit. Its existence is problematical. 



IONIAN SCHOOL, comprises several of the earliest philosophers of 

 Greece, whose speculations were predominantly of a physiological cha- 

 racter, and who, with one or two exceptions, were natives of the Ionian 

 colonies in Asia Minor. From this purely external circumstance the 

 school has derived its name, and its members have been brought into 

 an unbroken connection of masters and disciples by the learned labours 

 of the later Greeks, who strove to give to the first development of 

 philosophy the same orderly transmission of doctrine which prevailed 

 in the later schools. Accordingly Anaximander is made the scholar of 

 Thales and the teacher of Anaximenes, who had two disciples, Diogenes 

 of Apollonia in Crete, and Anaxagoras, whose disciple was Archelaus of 

 Athens, or Miletus, in whom the school closes. Now, not to mention 

 that this purely artificial arrangement omits Heraclitus, the chief of 

 the lonians, it is also open to great difficulties both of doctrine and 

 chronology. As regards the latter, however, we shall only advert to 

 the general difficulty, that between six and seven generations (212 years) 

 are occupied by the lives of Thales, Anaximander, Anaximenes, and 

 Anaxagoras. The incongruity of the received arrangements appears at 

 once on the slightest consideration of the doctrinal systems of the phi- 

 losophers of this school. Agreeing in the hypothesis of a primeval state 

 of things, they differed widely in the mode in which they accounted 

 for the deduction of existing phenomena out of the primal substance. 

 One theory endued the universe with life, and considered the orderly 

 procession of all things to be a spontaneous development of a pre- 

 existent germ of life. A second accounted for all apparent alteration 

 in the form and qualities of natural bodies by certain changes in the 

 outward relations of space, and proceeded on the supposition of certain 

 permanent material elements which change place in obedience to mo- 

 tion, either originally inherent in or extrinsically impressed on the 

 man. The latter is the mechanical, the former the dynamical theory 

 of nature. Of the dynamical theorists, Thales first of all taught that 

 all things are pregnant with life ; that the seed or germ of vitality, 

 which is in all things, is water, because all seed is moist aud humid. 

 Of this potentially living entity Anaximeues advanced a still worthier 

 representation, and taught that the primal substance is infinite and 



sensuously imperceptible. This principle is analogous to the 

 soul, and as the animal soul governs the body, so the universi 



animal 

 ersal soul 



rules and embraces all things. Diogenes made a still farther advance, 

 and maintained that the harmony and design of the mundane fabric 

 suggest the unity and intelligence of its first principle. This principle 

 however he considered as simply physical, and only distinguished from 

 natural phenomena in this, that while it is infinite, as the principle of 

 all, they are finite. Still bolder was the flight of Heraclitus, who 

 taught that the world is an overliving being, a rational fire, whose 

 vitality involves a tendency to contraries, and is ever passing from 

 want to satiety. 



The mechanical theory is first opened by Anaximander, who flou- 

 rished not long after Thales, who conceived the ground both of pro- 

 duction aud motion to be an eternal substance, which he called the 

 infinite, and wherein the immutable elements were indistiuguishably 

 combined. Out of this chaos certain primary contraries, as he con- 

 ceived them, cold and warm, earth and heaven, were first evolved, and 

 in the course of certain separations and combinations alternately pro- 

 ceeding, more perfect forms are spontaneously developed, to be ulti- 

 mately resolved into the homogeneous primary. After a long interval 

 of a century Anaxagoras revived the mechanical physiology, and dis- 

 tinctly advanced the principle on which it rests, that nothing is 

 changeable, but that the nature of every thing is permanent. Seizing 

 the contrariety of the moving and the moved, which the mechanical 

 theory is so well calculated to exhibit, he defined the latter to be 

 extended antitypous bulk, inert body, infinitely multiple both in 

 qualities and parts. The moving principle, ou the contrary, is perfect, 

 simple, and homogeneous soul or spirit, which, as moving the ele- 

 ments into combinations of order and beauty, is endued with the 

 faculty of knowing and surveying whatever was, and is, and shall be. 

 Archelaus rather abandoned than advanced the views of his master 

 Anaxagoras, and in him, as the teacher of Socrates, the Ionian school 

 became extinct before the more extensive development of the Socratic 

 philosophy. 



(Hitter, Gesckichte d. lonitcken Philosophic ; and Brande's Geichichte 

 d. Griech.-HSm Philoa.) 



IONIC DIALECT, the softest of the four written varieties of the 

 Greek language, was spoken in the Ionian colonies of Asia Minor, and 

 in several of the islands of the .lEgean Sea. As the new Ionic, it is 

 distinguished from an older, which was the common origin of itself 

 and the Attic. The old Ionic was widely diffused, and its use was 

 co-extensive with the Ionian settlements in the Peloponnesus and 

 Northern Greece. (Thirlwall, ' History of Greece.') The language of 

 epic poetry arose out of this original tongue, which after the Dorian 

 conquest passed, on the one hand, with the fugitives into Asia Minor, 

 while, on the other, it continued to be spoken, for awhile at least, by 

 the conquered peasantry who remained in Greece Proper. This tradi- 

 tion, which however, like most of the earlier traditions of Greece, is 

 involved in great obscurity, may perhaps serve to explain (what in the 

 common legends of Homer is otherwise inexplicable) the similarity of 

 the language employed by Homer and Hesiod, who, though near to 

 each other in time, were widely separated in the supposed scenes of 

 their poetical labours. This first matured form of the Ionic has been 

 called the epic, aud was faithfully adhered to as the standard of Greek 

 epic and elegiac composition by all subsequent writers of epos or elegy, 

 which also owed its birth to lonians. 



Ou the formation of the new Ionic, or simply the Ionic, great in- 

 fluence was exercised by the commerce of the lonians, and especially 

 by their intercourse with the soft and effeminate Asiatics. Neglecting 

 the combination of strength with softness which gave to the epic dialect 

 its characteristic fulness of tone, the loniaus attended only to mellow- 

 ness and euphony, to attain which they softened the aspirates, accumu- 

 lated vowels, and laid aside every broader and harsher sound. Herod- 

 otus (i. 142) distinguishes four varieties (xapaKrfjpes yktltacrris) of the 

 new Ionic, in one of which he wrote, and, though a Dorian, has left us 

 the best and most complete specimen of it. 



IONIC ORDER. [COLUMN ; GRECIAN ARCHITECTURE.] 

 IPECACUANHA is an emetic substance, the root of several plants 

 growing in South America. All the kinds have nearly the same ingre- 

 dients, but differ in the amount of the active principle which they 

 respectively contain, termed emetina. The best is the annulated, 

 yielded by the C'ephaelis ipecacuanha, a small shrubby plant, native of 

 Brazil and of New Grenada. Of this sort there are three varieties, 

 namely, the brown, red, and gray, or gray-white, called also greater 

 annulated ipecacuau. As this is the only sort sent from Rio Janeiro, 

 t is sometimes called Brazilian or Lisbon ipecacuan. It is sent in 

 , barrels, bags, and serons. The root is in pieces from two to six 

 inches long, and about the thickness of a straw, much bent or twisted, 

 Cither simple or branched, with a remarkably knotty character, owing 

 .o numerous circular depressions or clefts, which give the whole an 

 appearance of a number of rings ; and hence the term annulated. It 

 consists of a central axis called medituUiitm, and an external portion, 

 called the cortical part. One hundred parts of good ipecacuanha con- 

 sists of 80 parts of cortex and 20 of meditullium. Each contains 

 emetina ; but by far the greater portion exists in the cortical. Of the 

 three varieties of 'annulated ipecacuanha the brown contains 16 per 

 cent, of emetina, while the red contains only 14 percent.; the gray 

 >as not been analysed. 



