220 



A DICTIONARY. 



and unvarying hue ; it will not enlarge and 

 diminish as in a healthy horse, when re- 

 moved farther from, or nearer to, the light ; 

 for the retina, ceasing to be influenced by 

 the luminous ray, no longer controls the 

 movements of the iris. It is, therefore, from 

 the peculiarities in the manner of the horse, 

 the invariable size of the pupil, and a green- 

 ish glassy cast in such eyes, that these cases 

 may be distinguished. As it has hitherto 

 proved incurable, we shall waste no time on 

 its treatment. 



Ammonia. — This is a volatile alkali ; is 

 rapidly absorbed by water ; and, by union 

 with acids, forms several salts. The com- 

 pounds of ammonia employed medicinally 

 are: hydrochlorate of ammonia, sesqui-car- 

 bonate, and solution of the acetate of 

 ammonia. The aromatic spirit of ammonia 

 is a valuable stimulant and anti-spasmodic 

 in colic or hoven. For the preparation of 

 the latter, I\Ir. Morton gives the following 

 formula : 



Talic of spirit of ammonia, 8 fluid ounces ; volatile 

 oil of lemons, 1 fluid drachm ; volatile oil of rosemary, 

 1^ fluid drachm. Dissolve the oil in the sjm-it by 

 agitation. 



Anasarca. — That form of dropsy that 

 affects the whole, or nearly the whole sys- 

 tem, or, in other words, an effusion of serum 

 into the meshes of the cellular tissue. 



Anasarca, CEdema,and Water Farcy.* 

 — "We need make no distinction between 

 these terms, particularly the two fii'st. As 

 generally accepted, oedema carries probably 

 rather a more local definition with it ; thus, 

 we say an cedematous swelling : but ana- 

 sarca is more frequently used to designate 

 an extensive dropsy of tlie cellular mem- 

 brane. Both, however, have the same 

 origin, and are accompanied by the same 

 symptoms. It differs from ascites princi- 

 pally in its external seat, which is some- 

 times partial and sometimes general. It 

 also appears under different forms, as it has 

 different origins ; and its terminations are 

 also under the influence of these ckcum- 

 stances. A debility of the absorbent system 



* Blaine. 



is usually observed in the spring and au- 

 tumn. There is, however, some general 

 atony of the whole system, and the oedema 

 disappears as the constitution establishes 

 itself. At other times anasarca and oedema 

 appear as accompaniments or sequelae to 

 acute diseases that have disturbed the func- 

 tions generally, in the which case the 

 absorbents become irritated ; or to the 

 oedema is added tumefied lymphatics. 



ANiESTHETics. — Agcuts which produce 

 insensibility to external impressions and to 

 pain. The author uses, for inhalation, three 

 parts of sulphuric ether to one of chloroform. 

 In allusion to the use of anaesthetics, 

 Mr. Morton wi-ites : " Anaesthetics are less 

 used in surgical and other painful operations 

 in the lower animals than in man, on account 

 of the larger quantities required, the diffi- 

 culty of administration, and the undue pro- 

 longation of the preliminary stage of 

 excitement. They have been used in par- 

 turition, and afford, as in the human subject, 

 immunity from pain, but without apparent 

 interference with the force or frequency of 

 the involuntary contractions of the uterus. 

 They have fiuther been used for relieving 

 the irritability and pain of such diseases as 

 peritonitis, pleurisy, and pneumonia ; for 

 removing the spasms of tetanus, colic, and 

 asthma ; and for alleviating, by local appli- 

 cation, the irritability of severe wounds. 

 For all such purposes their use might, with 

 advantage, be much extended." 



Anastomosis. — The communication of 

 blood-vessels with each other, or their open- 

 ing one into the other, by which means, 

 when the passage of blood through an 

 artery or vein is prevented by ligatm*e, com- 

 pression, or any other cause, the circulation 

 is still kept up by means of the anastom- 

 osing vessels. 



Anatomy. — The science that teaches 

 the structure of the animal economy. 



Analysis. — The resolution of compound 

 bodies into their original or constituent prin- 

 ciples. 



Anchylosis. — The loss of motion in a 

 joint. There are two kinds, caUed com- 



