856 



TASTE. 



that the nervous system takes part in the pro- 

 duction of such phenomena, which ought ra- 

 ther to be ascribed, in the one case, to the 

 continuity of blood-vessels, and, in the other, 

 to contamination either by effused fluids or 

 by morbid blood. (-R. B. Todd.*) 



SYNOVIA is that fluid which exists within 

 the membrane lining joints, to assist motion 

 by lubrication ; as also in the bursse. The 

 membranes generally, which line the various 

 cavities of the body, are lubricated by fluid. 

 This varies in character according to circum- 

 stances ; and among these perhaps none more 

 tend to the requirement of especial conditions 

 than that of active and frequent motion, in- 

 volving friction of the surfaces so lubricated. 



Thus we find that the fluid of the peri- 

 cardium differs essentially from that of the 

 ventricles of the brain ; while again the synovia, 

 supplying moisture to the joints, varies greatly 

 from the fluid of the pericardium, probably in 

 order to assist the opposed surfaces in bearing 

 friction in an exaggerated degree. The word 

 attrition appears, indeed, the most appropriate 

 to the conditions relieved by the presence of 

 synovia, placed as it is between surfaces oc- 

 casionally s.trongly approximated either by 

 superincumbent weight or muscular contrac- 

 tion. 



Synovia was chemically examined by Mar- 

 gueron.* The specimen he analysed was 

 viscid, and became gelatinous soon after it 

 was obtained. It then deposited a fibrous 

 matter, and became clear above. Though the 

 analysis of Margueron was not conducted on 

 the more exact principles characterising those 

 of the present day, it still serves to show that 

 the specimen was peculiar as an animal fluid, 

 and differed in one respect from the fluids 

 generally, which lubricate surfaces. Thus it 

 appears that as much as 1T86 per cent, was 

 composed of fibrinous matter (fibrin), which 

 coagulated, as stated before, soon after the 

 fluid was obtained. 



Margueron's analysis is as follows : 



Fibrin - 

 Albumen - 

 Chloride of Sodium - 

 Soda - 



Phosphate of Lime .- 

 Water - 



-- 11-86 



.- 4-52 



- 1-75 

 -- 071 

 .- 0-70 



- 80-46 



100- 



Synovia has of late years been examined by 

 John.-f- It is described as a viscid transparent 

 yellowish or reddish fluid, resembling in its 

 odour the serum of the blood. The analysis 

 is stated as follows : 



Water - - - 92-80 



Albumen - 6'40 



Extractive Matter, Chloride of 

 Sodium, and Carbonate .of 



Soda - - 0-60 



Phosphate of Lime - 0'J5 



* Ann. de Chimie, xiv. 



f Simon's Animal Chemistry. Trans. Sydenham 

 Society. 



It will be seen that these two analyses vary 

 greatly they were not made, it must be 

 recollected, at the same date; and the methods 

 of animal analysis are greatly improved since 

 Margueron published. There is, however, an 

 important point in which both analyses agree, 

 viz. in stating phosphate of lime among the 

 constituents of the fluid. John makes no 

 mention of the existence of a coagulable fibrin- 

 ous matter ; a fact of much importance, which 

 it appears desirable carefully to inquire into, 

 insomuch as it is very possible the analyst may 

 have extracted the synovia after coagulation 

 had occurred within the membrane, and so 

 obtained the clear fluid only ; while Mar- 

 gueron may have been fortunate enough to 

 secure it before such change had taken place, 

 and in its natural condition. 



With regard to this subject, on which our 

 knowledge is but scanty, it appears still of 

 importance to reflect on the material before 

 us ; and it is matter of no small interest to 

 .consider how far the results of peculiar me- 

 chanical conditions are modified by variations 

 in the character of lubricating fluids, know- 

 ing, as we do, that, while the ventricles of the 

 brain, subject to agitation only, contain no 

 albumen in their lubricating fluid, the liquor 

 of the pericardium contains that principle in 

 abundance ; and that in the synovial fluid 

 adapted to the lubrication of the joints, we 

 have, in addition to albumen, not only a con- 

 siderable proportion of phosphate of lime, but 

 probably fibrin also, as a necessary consti- 

 tuent. (G. Owen Rccs.) 



TASTE. The sense by which we distin- 

 guish the sapid properties of bodies. The term, 

 as commonly understood, includes much more 

 than this ; being usually employed to desig- 

 nate the whole of that knowledge of the 

 qualities of a body (except such as is purely 

 tactile), which we derive through the sensory 

 apparatus situated within the mouth. But it 

 will be hereafter shown tnat a considerable 

 part of this is dependent upon the assist- 

 ance of the olfactive sense ; which is affected, 

 through the posterior nares, by the odorous 

 emanations of all such bodies as are capable 

 of giving them off; and the indications of 

 which are so combined with those of the true 

 gustative sense, as to make an apparently 

 single impression upon the sensorium. More- 

 over, there are certain sensorial impressions 

 received through the organ of taste, which are 

 so nearly allied in their character to those of 

 touch, as to render it difficult to specify any 

 fundamental difference between them : such 

 are the pungent sensations produced by mus- 

 tard, pepper, the essential oils, &c. ; all of 

 which substances produce a sensation when 

 applied for a sufficient length of time to any 

 part of the cutaneous surface, which can 

 scarcely be distinguished from that excited 

 through the organ of taste, in any other way 

 than by its inferior intensity, and by the ab- 

 sence of the concurrent odorous emanations. 

 The taste of such substances might, perhaps, 

 be considered, therefore, as the composite re- 



