608 GLOSSARY. 8ERALBUMEN STIMULI. 



is made capable of feeling the impression of the needle, and dis- 

 covering the relation in position which itself has to the adjacent 

 parts of the skin. Were a bayonet struck forcibly into the skin 

 instead of a fine needle, the perception of the position of the spot 

 struck would be much less distinct. The indefiniteness of the per- 

 ceptions attendant on violent impressions upon the extremities of 

 sentient nerves, depends on the number of nervous filaments, and 

 their corresponding terminations on the nervous centre, simul- 

 taneously affected, both directly and indirectly that is, by what 

 is called the radiation of sensation, by which sensations arise in 

 parts not in close proximity with that immediately under impres- 

 sion. It is, as it would seem, by a mere extension of the same 

 kind of effect that very intense impressions give a shock to the 

 whole nervous system, and thereby to the whole of the vital organs, 

 so that not only insensibility or fainting, but even death, may 

 occur in a moment. From a sudden blow on the pit of the stom- 

 ach, instant death has been often known to take place in the pugil- 

 istic prize-ring. Opposite to the pit of the stomach, a part that 

 readily yields to sudden force, many nerves congregate. Here, 

 indeed, the trunk is at its shallowest, and the fist of the pugilist 

 may bury itself in his antagonist's body deeper than at any other 

 part where blows in such encounters are dealt. It is within the 

 experience of one of us, that a smart blow on the snout, where the 

 nerves of sense are very numerous, proves instantly fatal to a good- 

 sized pig ; and it is well known that a horse is sometimes instantly 

 killed by a sudden blow on the cantel that is, before the ears 

 with the butt-end of a heavy hunting-whip. 



SERALBUMEN. See Albumen. 



SHEEP-LOUSE. See Parasite. 



SIGMOID VALVES. The same as the semilunar. 



SILICIC ACID. The earth silica. 



SILICON or SILICIUM. One of the most abundant substances in 

 mineral nature ; the basis of flint and of many mineral substances ; 

 in small proportion both in plants and animals. See p. 302. 



SPAYING. See Genital Organs. 



SPECIAL SENSE, is such a sense as that of sight or hearing, as distin- 

 guished from general sensibility of the skin and other tissues. 



SPHINCTER MUSCLES. Muscular fibres, the ordinary state of which is 

 contraction, being designed to guard the orifices of such cavities as 

 the rectum. 



SPIRIT OF WINE. See Alcohol. 



SPORULES. See Parasite. 



STARCH. A non-azotised proximate principle of the vegetable king- 

 dom ; one of the heat and fat giving principles of food ; the same 

 as amylum and fecula. See p. 320. 



STIMULI. The agents in the stimulation, for example, of the muscular 



