PATHOLOGY. 



331 



B**, upon to* *ubj* generally, and alao upon "th* Patent Office 

 Muwum and Library," a very valuable article in th* ' Companion to 

 the Britbh Almanac,' for 1MO. 

 PATENT. IPATTXWnj.) 

 PATENT, LETTERS. [LtTTCTa-PATKCT.] 



PATERA, an opan VMM], approaching to th* form of a cup but flatter, 

 u^bTU-fcm^tothefricrin^nwbJdith.yr.e.ivedth.bWl 

 of Ui*>Mtea, MdwtUiwki.ii ***T mad. libations. Sotn* patene hav* 

 The word contain* th* atme root a* palm : " Patera 

 en indioio e*t, pooulum planum ao paten* *f 

 n.'v. SI.) Flat opn ves**l used by the Roman* at 

 a, whence perhaps patera came to be 



On m*dal* the patera i* represented in the hand* of several of the 

 MM** (Raeche, Lexicon UnivenaU* Rei Numariie,' torn, iii., part ii., 

 pp. *J, 87), and frequently in the hands of prince*, to mark the 

 aoctdotal authority a* joined with regal power. The patera was of 

 old, *ilvr, brooM, marble, glass, or earthenware. Such as had served 

 for libation* of win* or any other liquor at a funeral were usually 

 deposited with th ashes of the deceased. Patene were often ornamented 

 with engraved or emboased designs, and sometime* with gem*. They 

 appear to have been called by their prevalent mode of ornamentation, 

 fern and ivy being the most usual, a* patera filicata, patera hederata, 

 The British Museum contain* many fine specimen* of fictile as well as 

 brans* paten*; alao several sculptured marble votive patene, with 

 figure* of Pan, Silenus, Cupid, Ac. Patella (that is, paterula) is the 

 diminutive of patera. 



Th* term putm is applied to a circular flat or concave ornament 

 in claaucal architecture. It is also used for ornaments of a similar 

 form in Italian and Gothic architecture. 



PATERNITY. [BASTARD.] 



PATHOLOGY (from w&ot, ' disease,' and \tyot, ' a discourse ') is 

 the science of diseases, and especially of those which affect men and 

 animals which are the subject* of medical treatment 



For the perfect knowledge of the nature of a disease, the first 

 circumstance to be determined is its cause; and this is commonly 

 regarded as twofold. The predisposing cause or condition (for the 

 term cause cannot fairly be used in this sense) is that state of any 

 individual which renders him peculiarly liable to the attack of any or 

 of some particular disease, of which another person or he himself at 

 another time might be in little danger. Of these predisposing con- 

 ditions the most important is hereditary disposition, by which an 

 individual being constructed with the same peculiarities of internal and 

 of external form and composition, which one or both of his parents 

 possessed, i* liable to the same diseases as they were. Such are the 

 peculiarities of temperament or constitution with which each indivi- 

 dual is born, and by which he is through life disposed to a peculiar 

 character of disease ; and such alao are the special hereditary disposi- 

 tions to scrofula, gout, insanity, some forms of asthma, and probably 

 many more diseases. Other predisposing conditions are the peculiarities 

 of constitution which are acquired in the course of life by particular 

 modes of living. Each individual is adapted by habit and other cir- 

 cumstances to the conditions of climate, Ac. in which he is placed, 

 and is peculiarly liable to be affected by changes of these external 

 conditions. A person of effeminate habits living carefully secluded 

 from all excitant* of diseases, is much more liable to be affected by 

 exposure to any of them than one whose frame by a hardy course of 

 life is rendered comparatively invulnerable to all Any means by 

 which the strength of the body is reduced render it more liable to 

 diseases of .all kinds, and hence our idea of bodily strength is drawn 

 not more from the muscular power of the individual than from his 

 immunity from the effects of those circumstance* which in others 

 excite disease. There are also local peculiarities of individual organs 

 of the body which render them especially liable to disease ; such are 

 th* state bordering upon disease which is brought on by constant 

 over-excitement of any organ ; the condition of an organ which has 

 once been affected with a disease, and which is commonly thenceforward 

 particularly liable to a repetition of it ; the state of the organs which 

 at different period* of life renders one more than another liable to 

 diaeaae, ao that the same excitant will be most likely to produce in the 

 child an affection of the head, in the youth a disease of the chest, and 

 in the adult or old person some disorder of the abdominal organs. 



Any of these predispositions however may exist throughout life 

 without th* occurrence of actual disease ; in order to produce disease, 

 ome more immediate or exciting cause is necessary. This excitant 

 must b* the more powerful the leas the predisposition : but under 

 whatever circumstance* disease i* produced, the predisposing condition 

 of the patient may be expected to confer upon it a corresponding 

 peculiarity of character. The exciting causes of diseases are any 

 change* of a certain extent in the conditions of the external circum- 

 stance* in which man ia placed. For example, a certain range of 

 external temperature, a certain constitution of the atmosphere, a 

 certain supply of pure food and drink, a certain amount of mental and 

 bodily exertion, are circumstance* essential to health, and alterations in 

 any of them may produce diaease, of which the nature and the seat 

 will b* determined in part by the predisposition of each individual, 



and in part by the peculiar mode of action of the excitant. Thus, after 

 the aune exciting cause (for example, exposure to cold and damp), one 

 peraon may have rheumatism, another pleurisy, a third ophthalmia, 

 aad a fourth may escape altogether unharmed. But there are other 

 excitants of di*ease which prevail over all predisposition, and produce 

 a certain character of disease, which the constitution of the patient can 

 only slightly modify; such are the materials of all contagious and 

 epidemic disorders, as influenza, small-pox, measles, ftc., which produce 

 in all whom they attack a similar affection. Many person* however 

 escape from the effect* of these excitants, and by long exposure become 

 inured to them ; hence the disease* of peculiar climates (endemics) 

 affect foreigner* much more than native* ; but even in those person* 

 in whom they do not produce disease, these conditions, which are 

 excitant* of disease in other*, modify the characters of disease* that 

 occur from any other source ; and hence in the course of an epidemic 

 all diseases have a tendency to assume some of the characters of that 

 which is prevalent. Other excitants of disease, still more universal in 

 their influence and more constant in their consequence*, are all things 

 which act immediately on the composition or construction of the body 

 or of the blood, such as mechanical and chemical injuries, including 

 poison* of all kinds. 



The nature of a disease being determined by the condition of the 

 individual and the exciting cause to which he is exposed, the next 

 division of pathology is the study of the symptoms or signs by which 

 the progress of a disease is marked, and by which in practice its nature 

 is to be determined. Of these signs of disease, many are expressive of 

 the altered condition of the part chiefly affected, as pain in a wound, or 

 a local inflammation, coughing in a disease of the lungs, sickness in a 

 disorder of the stomach : but a greater number are the expressions of 

 an affection of other organs, which suffer in association with those 

 primarily diseased ; such are pain in the head when the digestion is 

 disordered, coughing in diseases of the liver, sickness after violent 

 blows on the head. Sometimes these secondary symptoms completely 

 mask those immediately resulting from the primary disease ; as when 

 in a disease of the hip the chief pain is felt in the knee, or in hysteria 

 any organ may appear disordered except that which actually is. These 

 secondary symptoms are ascribed to what is called sympathy, an 

 unsatisfactory expression indicating only the coincidence and pro- 

 bable connection of symptoms of disease in two organs, of which one 

 only is supposed to be materially affected. Entire ignorance mut be 

 confessed of the nature and origin of many of these sympathetic or 

 indirect symptoms of disease ; as, for example, of the fever consequent 

 on local injuries or acute local diseases, and of the hectic fever of many 

 chronic affections ; but it is probable that all sympathies will in time 

 be found to depend either on some communication of excitement from 

 one nerve to another through the medium of the spinal chord or brain, 

 as in the reflex actions [NERVOUS SYSTEM, in NAT. HIST. Div,], or on 

 some change in the blood which affects both organs at once, or which, 

 originating in the disease of one disturbs the functions of the other, or 

 of the whole body. 



Whether directly or indirectly produced, all the symptoms of disease 

 are only the perversions of the natural functions of the part affected, or 

 appreciable changes in its structure ; their value and meaning there- 

 fore can only be determined by a comparison with the same functions 

 and structure in health ; in other words, this, like all other part* of 

 pathology, cannot be rightly studied without a constant reference to 

 physiology. It is believed that an organ may be only functionally 

 deranged ; that is, that its several functions may be performed in a 

 very unhealthy manner, without the existence of any material change 

 in ite structure and composition. These are called functional symptoms, 

 but their number is probably much less than is generally be! 

 and it is most likely that they are limited to the variations to which 

 the organs are subject by the changes in the mode and measure of the 

 influence of the nerves upon them. For all other symptoms we must 

 assume the existence of a substantial change in the part affected, or in 

 the materials on which it has to act, although in many cases these 

 changes are fugacious or inappreciable by our senses. 



For a due performance of all the functions of organic life [VITA- 

 LITY, in NAT. HIST. Div.], a healthy structure of each organ, and a 

 healthy composition of the blood, on which they all act and all de- 

 pend for their own maintenance, are alike necessary; a deviation 

 from health in either will therefore produce the symptoms of disease ; 

 a conclusion in which the long continued disputes of the humoral 

 pathologist*, who ascribed all disease to the blood, and the solidisU, 

 who held all to depend on changes of structure, have at length 

 merged. To these two kinds of alterations, and to perturbations in 

 the distribution of the nervous influence, it is probable that tho 

 signs of all diseases may be referred ; but from the peculiar and 

 complicated nature of the animal body, and the universal connec- 

 tion between all its organs, no one of these changes can long con- 

 tinue without producing the others; and hence in diseases of any 

 degree of seventy the symptoms are commonly a mixture of the dis- 

 orders of all the functions of the body, and the disorder of each is 

 modified by tho changes in all those circumstance* on which its 

 healthy state depended, as the condition of the blood, of the nervous 

 influence, &c. Neither are the symptoms in any case constant pheno- 

 mena; for the influences of all external circumstance* upon a dis- 

 eased body are very different from those which they exert upon the 



