186 



GLOSSARY. 



be proved by a chain of reason- 

 ing, the conclusion being stated ; 

 in arithmetic and algebra, some- 

 times used to denote a rule. 



Theoretical (The'ory). Pertaining to, 

 or depending on, theory or specula- 

 tion ; not practical. 



The'orize (The'ory). To form a 

 theory ; to speculate. 



The'ory (Gr. flewpew, theoreo, I see). 

 A doctrine or scheme of things 

 which terminates in speculation 

 without a view to practice. An 

 exposition of the general prin- 

 ciples of a science, and the rules 

 derived therefrom, as distinguished 

 from an art : as the theory and 

 practice of medicine : as distin- 

 guished from hypothesis, it means 

 an explanation of phenomena 

 founded on principles established 

 on independent evidence, while an 

 hypothesis is a proposition assumed 

 to account for certain phenomena, 

 and having no other evidence of 

 truth than in giving a satisfactory 

 explanation of the phenomena. 



Therapeu'tic ((Jr. eepairevw, thera- 

 peu'o, I heal). Healing ; pertain- 

 ing to the art of healing. 



Therapeu'tics (Gr. Bfpairevw, thera- 

 peu'o, I heal). The part of medical 

 science which describes the proper- 

 ties of medicines and their modes of 

 administration. 



Thermal (Gr. deppos, thermos, warm). 

 Belonging to heat ; warm ; applied 

 to springs of which the temperature 

 is above 60 Fahr. 



Thermo - electricity (Gr. Oep^, 

 therme, heat ; electricity). Elec- 

 tricity developed by heat. 



Ther'mo-electrom'eter. An instru- 

 ment for ascertaining the defla- 

 grating or heating power of an 

 electric current. 



Thermom'eter (Gr. BepM, therme, 

 heat ; /j.erpoi>, metfron, a measure). 

 An instrument for measuring the 

 heat or temperature of bodies, by 

 the regular expansion of mercury 

 or some other substance. The 

 thermometers usually employed are 

 Fahrenheit's, the Centigrade, and 

 Reaumur's. In Fahrenheit's ther- 



mometer, the space between the 

 freezing and boiling points of water 

 is divided into 180 degrees, the 

 freezing point being marked as 32 

 degrees, and the boiling as 212. 

 In the Centigrade thermometer the 

 space is divided into 100 degrees ; 

 and in Reaumur's into 80. Hence 

 5 degrees of the Centigrade, or 

 4 of Reaumur's thermometer, are 

 equal to 9 of Fahrenheit. 



Thermomet'ric (Thermometer). Be- 

 longing to the thermometer. 



Ther'mo-murtiplier. A thermo-elec- 

 tric pile, used for detecting changes 

 of temperature. 



Ther'mophoiie (Gr. 0eftU7j, therme, 

 heat ; (fxavij, phone, sound). An 

 apparatus for producing sound from 

 heated bodies. 



Ther'moscope (Gr. 6epnvi, therme, 

 heat ; ovcoTrea,', skop'ed, I view). 

 An instrument for measuring mi- 

 nute differences of heat and cold. 



Ther'mostat (Gr. Oepw, therme, 

 heat ; Iffrrifu, histemi, I make to 



. stand). An apparatus for regu- 

 Jating temperature in distilleries, 

 baths, furnaces, &c. 



Thermot'ics (Gr. eepw, therme, heat ; 

 The science of heat. 



The'sis (Gr. nQ-t]^ tithe mi, I place). 

 A proposition to be maintained by 

 argument. 



Thoracic (Thorax). Belonging to 

 or contained in the chest. 



Thoracic Duct. The vessel which 

 conveys the chyle into the subcla- 

 vian vein. 



Thorax (Gr. 0pa, thorax, a breast- 

 plate). The chest, or the part of the 

 body between the neck and the ab- 

 domen ; in entomology, the second 

 segment of insects, or the part be- 

 tween the head and the abdomen. 



Thrombus (Gr. Opo^oy, throm'bos, 

 a clot of blood). A small tumour 

 of clotted blood that has escaped 

 under the skin. 



Thymus. A temporary organ, which 

 exists at the lower part of the neck 

 in children, disappearing gradually 

 after the second year. 



Thy'ro- orThy'reo-(Gr. Ovpeos, thu'reos, 

 a shield). In anatomy, a prefix in 



