l.S 



TEMPERA. 



TEMPERAMENT. 



lia 



adding water to the solution, part of the oxide b precipitated, and the 

 remainder i* obtained by evaporation to dryness. It U a white 

 granular anhydrous powder, which slowly redden* moist litmus-paper, 

 and i* insoluble in water and acid*. It i* dissolved by a solution of 

 potaab or soda, and by fusing with their carbonate* cry.Ulluable salU 

 are formed : when the** are decomposed by adds, hydrated tellurou* 

 acid U precipitated, which, if washed with very cold water and 

 dried at a temperature not above 58* Fahr., may be preserved without 

 uffrriug change. The hydrate i* soluble in water, acid*, ammonia, 

 and the alkaline carbonate*, which hut it decomposes : the aqueous 

 volution reddens litmus paper : when sine, tin, and some other metal* 

 are left in a solution of this acid, they deoxidise it, and metallic 

 tellurium i* precipitated in the state of a black powder. IU salU are 

 called lelUritet. 



Telluric A cid (TeO ,). This compound U obtained by fusing tellurou* 

 acid with nitrate of potash, which oxidise* it completely, and the result 

 is tellurate of potash. When chloride of barium is added to the hut- 

 named salt, tellurate of baryta i* precipitated, which being decomposed 

 by sulphuric acid, yields a solution of telluric acid, and this solution 

 furnish** hexagonal crystals of the acid. It acU but feebly as an acid, 

 the dilute solution reddening litmui-paper with difficulty, and iU taste 

 ia rather metallic than aour : the crystals contain water, two-thirds of 

 which they lose at about 212' ; the remainder below a red heat 

 becoming a mass of a fine orange colour, which is completely insoluble 

 in water, either cold or boiling, or hot hydrochloric or nitric 

 acids, or solution of potash. It i* decomposed at a high temperature, 

 and converted into a white powder, which is tellurous acid. Its salts 

 are called Irllnralei. 



Hydrogen and Tellurium form tellurctted hydrogen (ToH). -When 

 tellurium U alloyed by fusion with tin or zinc, and the compound is 

 acted upon by hydrochloric acid, the hydrogen of the decomposed 

 acid dissolve* tellurium, and telluretted hydrogen gas is obtained. 

 This gas has a imell resembling that of hydrosulphuric acid : it is 

 soluble in water, forming a colourless solution, which becomes brown 

 by exposure owing to separation of tellurium. As it possesses acid 

 properties, though to a slight extent only, it has been called hydro- 

 It 11 uric acid. It decomposes many metallic salU, yielding an alloy of 

 tellurium with the other metal. Chlorine, nitric acid, and the oxygen 

 of the air, all take the hydrogen from the tellurium. 



Chlorine and Tellurium form two compounds. When a feeble 

 current of chlorine gas is passed over tellurium at a high temperature, 

 the chloride formed passes over as a violet-coloured vapour, which con- 

 dense* at first into a black liquid, and eventually into a solid of the 

 same colour. It is decomposed by the action of water into metallic 

 tellurium, which is precipitated, and bichloride of tellurium, which 

 remains in solution. 



It is composed of one equivalent of chlorine, and one equivalent of 

 tellurium (TeCl). 



The Bichloride of Tellurium (TeCl,) i* obtained, as above stated, by 

 the action of water on the bichloride, but is better procured by 

 pasting a larger quantity of chlorine over tellurium at a lower 

 temperature than in forming the chloride. It is volatile, and any 

 excess of chlorine being separated by agitation with mercury and 

 rectification, it is obtained as a white crystalline solid. 



Sulphur and Tellurium combine in two proportions : the bisulphide 

 (TeS ; ) is obtained when hydrosulphuric acid gas is passed through a 

 solution of tellurous acid, or of a soluble tcllurite. It is of a dark 

 brown colour, and is soluble in a solution of potash. 



Tenulphide of Tellurium (TeS,) is obtained by mixing a solution of 

 persulphide of potassium with one of a salt of telluric acid. It is of a 

 deep yellow colour; but it is a very unstable compound, for it 

 speedily become* black, and is converted into bisulphide. 



TEMPERA (ItaL d tempera), that method of painting in which the 

 vehicle employed is composed of a glutinous material (usually glue, 

 white of egg, or gum), diluted (or " tempered ") with water ; gesso, or 

 plaster of Pan*, being added to the colours to give them greater con- 

 ittency, or, u it is termed, body. This was the method employed by 

 the ancient Egyptians, the Greeks prior to the introduction of wax as 

 a vehicle [E.xcAVSTlc PAIXTISO], and by the early Christian painters. 

 [PAlXTWo.] Distemper-painting, as now practised by scene-painters 

 and decorators, is only a lea* refined form of tempera, from which it 

 ha* indeed derived ^iU designation. [DISTEMPER ; SCESE-PAINTINO 1 



TEMPERAMENT (tcmperamr*tum,K(aaa) is a vague and unsatisfac- 

 tory tenn, but it U one which as Mnyoobwrvet(' Pathology ui' th.> Human 

 Mind ') ha* been long and generally adopted a* a convenient generalisa- 

 tion. The word means literally a tempering, or mixing tvyether, and 

 may b* defined to be a peculiar sUte of the system common to several 

 individuals, which remits from the various proportions in which the 

 elwnenUry parU of the human body are mixed up t.yether, and which 

 gives rise to a tendency to certain phenomena. There i, betides, in 

 rach individual a further peculiarity of combination, which serve* to 

 distinguish hi* temperament from that of any other person, to whom, 

 however, be may in other mpecU bear a great resemblance. 'I 'hi 

 individual temperament Is called an idiotfucroty (that is, a peculiar 

 mixing together), and, a* the two word* are sometime* contour 

 may be useful to point out the distinction between them. AM the 

 different *Tstemi of organ* in tlie human frame are accurately adjusted 

 to each other, to a* to produce one harmonious whole. If the dispro- 



portion be too great, disease ensues ; but there are many gradation*, 

 compatible with health, where yet this disproportion is very observable. 

 The predominance of any particular system of organ* modifies the whole 

 economy, impresses striking differences on the result* of the organisa- 

 tion, and ha* perhap* almost a* great an influence on the moral and intel- 

 lectual a* on the physical faculties. This predominance establishes the 

 temperament : it is the cause of it, and constitute* it* essence. The 

 ancients paid considerable attention to the subject of temperaments, 

 and pointed out various peculiarities in the constitution and action* of 

 the human body, which have been seen *o far to coincide with general 

 observation, that their nomenclature has continued in very general use 

 even to the present day, although the hypothesis on which it wa* 

 founded i universally discarded. They described four temperamenU 

 corresponding to the four qualitie* of Hippocratea hot, cold, moist, 

 and dry. It was supposed that there were four corresponding primary 

 components of the human body, namely, blood (oT/ia), phlegm or pituiu 

 (fAfya), and the two kinds of bile (ai tvo xo\oli, yellow bile ({oi-flfc 

 XoA4), and black bile, or atrabilis (/u'Acura x*''i) ; and th< 

 ance of one or other of these components in different persons produced 

 the different temperaments. These four primary principles of living 

 bodies were supposed to be compounded of the simple elements or 

 qualities of nature thus : hot and moist produce blood ; cold and moist, 

 phlegm or pituita ; hot and dry, yellow bile ; and cold and dry, black 

 bile. Bodies in which blood superabounds are of the sanguine tem- 

 perament; if phlegm is in excess, the phlegmatic temperament is 



1 : if yellow bile, the choleric; and if black bile, the : 

 cholk- or atrabilious temperament. A minute description 

 different temperaments is given by Paulus ..Egincta, ' He l!e Medica,' 

 lib. i. cap. til. The due admixture of the different qualities was 

 supposed to constitute the beat form of temperament or constitution 

 (ftixpcurla), of which the following is Paulus .-Egineta's descrip! 

 " That man is in the best temperament of body when it is in a medium 

 between all extremes, of leanness and obesity, of softness and hardness, 

 of heat and cold, of moisture and dry ness ; and, in a word, who has all 

 the natural and vital energies in a faultless state. His hair also should 

 be neither thick nor thin, neither black nor white. When a b 

 locks should be rather tawny than black, but when an adult, the con- 

 trary wise." (Adam's ' Trans.,' L 60.) 



Further information respecting the opinions of the ancients on the 

 subject of the temperaments may be found in the treatise of Hip 

 pocrates, ' De Natura Hominis,' torn, i., ed. Kiilin ; in Galen's works, 

 De Element!* ex Hippocrato,' torn, i., ' De Temperamcntis,' t 

 ' De Optima Corporis nostri Constitutione,' torn, iv., ' De Sanitate 

 Tuenda,' lib. v., torn. vL, and his 'Ars Medica,' torn. i. ; Oribasius, 

 ' Synopsis,' lib. v., cap. 43, sq. ; Ae'tius, ' Libri Medicinales,' lib. iv., 

 cap. 53, sq. ; Haly Abbas, ' Theor.,' lib. i. ; Averroes, ' Collig.,' lib. vi. ; 

 Alsaharavius, ' Theor.,' tract vi. ; and Avicenna, ' Contica.' 



After the revival of letters, this fourfold division was adopted in it* 

 most essential parts by all the most eminent physiologists. Stahl 

 ingeniously adapted it to the modern doctrines of the humoral patho- 

 logy ; and even Boerhaave, although he increased the number of the 

 temperamenU to eight, and relinquished the erroneous opinions of 

 Hippocrates and Galen respecting the constitution of the blood, yet he 

 still derived the characters of his temperaments from the principles of 

 the humoral pathology, and supposed them to be formed merely by 

 different combinations of the four cardinal qualities. Many late phy- 

 siologists have been inclined to doubt whether the external characters 

 associated with the four temperaments are real and constant signs of 

 diversity in bodily structure, and enable us to distinguish the principal 

 varieties of constitution which exist. Several attempts have a 

 ingly been made to define in a more satisfactory manner the peculiari- 

 ties of organisation and the resulting varieties of predisposition. 

 are chiefly interesting with regard to pathology. Hoffmann and Cullen 

 have, indeed, retained the old division, supposing that tl 

 the ancients, as to the peculiarities of constitution, was founded 

 nally upon fact*, though subsequently combined with an em 

 theory. Haller seems to have been the first who decidedly opposed 

 the ancient doctrine, not only by showing that there was no foun< 

 for the varieties of the temperaments in the peculiar nature 

 fluids, but by substituting in their place the vital actions of the system. 

 Darwin proceeded upon the principle of Haller ; and, in conformity 

 with the hypothesis which he adopted of reducing these actions to the 

 four heads of irritation, sensation, volition, and association, he formed 

 four temperamenU in which these qualitie* were supposed re 

 prevail The only attempt, however, to improve upon the Hi]'] 

 theory and division which has been attended with any <i- _' 

 is that by Dr. Gregory, who, to the four temperamenU of the ancients 

 added a fifth, which he called the ntnoui, and bestowed upon 

 of the others the new appellations of the tonic, .the relaxed, and mi 

 temperament*. Dr. Prichard, however, restricU the number to four, 

 and designates them by their original names ; remarking that only four 

 strongly marked diversities of external character present themselves 

 to observation ; that the nervou* temperament is not so distingu: 

 and that, therefore, as this i* an essential part of the original wlieme 

 for the distribution of temperamenU, the improvement propo.- 

 Dr. Gregory i* lame and defective. These four varieties, then, of ex- 

 ternal character really indicate, more or less cousUntly, well-marked 

 differences of constitution, and, likewise, of morbid predisposition. 



