•4 TxIESENSORIALFUNCTlOM. 



It was formerly the practice to inject various liquids into the nostrils in this way, 

 tor the cure of trlanders. 8ome of them were harmless enough, but others were cruelly 

 acrid. This practice is now, however, abandoned by the scientific practitioner; for 

 it would only be a portion of the cells of the head, and a portion only of the cavity of 

 the nose, and that least likely to be diseased, with which the fluid could be brought 

 into contact. 



As the frontal sinuses are lined by a continuation of the membrane of the nose, 

 they will sympathise with many of the aflections of that cavity; but the membrane 

 of the sinuses is susceptible of an inflammation peculiar to itself.- The disease is 

 rare, and the cause of it has not been fully ascertained. It is oftenest metastasis of 

 inflammation of the brain, — shifting of inflammation from the brain to the mem- 

 brane of the sinus, or communication of inflammation from the brain by proximity of 

 situation. 



The attack is usually sudden — the horse is dull, lethargic, and almost as comatose 

 as in stomach-staggers. The first thing that excites suspicion of the actual character 

 of the disease, is heat in the situation of the frontal sinus, when the hand is placed 

 on the forehead. The lethargy soon passes over, and a state of the highest excitation 

 succeeds. The conjunctiva and the membrane of the nose are injected — the pulse is 

 quick and hard — the horse becomes violent and dangerous ; he kicks, jilunges, and, 

 half conscious and half unconscious, he endeavours to do all the mischief that he can. 

 The disease is now evidently combined with, or is essentially, inflammation of the 

 brain. It is distinguished from madness by this half-consciousness, and also by his 

 being more disposed to bite than he is in pure phrenitis. 



The disease is usually fatal. It rarely lasts more than eight-and-forty hours. 



The post-miirltm appearances are, great inflammation of the brain, with frequent 

 elTusions of blood. The sinuses are sometimes filled with coagulated blood. The 

 brain seems to be affected just in proportion to the violence which the animal has 

 exhibited. 



The treatment should consist of copious bleeding, application of ice to the head, 

 blistering the head, and physic. The trephine is scarcely admissible, from the danger 

 of producing greater irritation. 



Sometimes the disease assumes a more chronic form. There is ulceration of the 

 membrane, but not cerebral aflection. A purulent discharge then appears from the 

 flose, evidently not of a glanderous character, and none of the submaxillary glands 

 are enlarged. In both the acute and chronic form, it is usually confined to one sinus. 

 We are indebted to the late Mr. ,Tohn Field for the ])rincipal knowledge that we have 

 of this disease.* The inner plate of the frontal bone covers a considerable portion of 

 the anterior part of the brain, and it is studded with depressions corresponding with 

 irregularities on the surface of the brain. 



Immediately above the frontal, and extending from the frontal to the poll, are the 

 parietal bones. They are two, united together by a suture when the animal is )'oung, 

 but that suture soon becoming obliterated. They have tlie occipital, g, p. 7'3, above, 

 the frontals, a a, below, and the temporals, d d, on either side. They are of a closer 

 and harder texture than the frontals, because they are more exposed to ihjury, and 

 more concerned in defending the brain. 



A very small portion only of the parietals is naked, and that is composed of bone 

 even harder than the other part, and with an additional layer of bone rising in the 

 form of a crest or ridge externally. Every other part of these bones is covered by a 

 thick mass of nniscle, the temporal muscle, which is principally concerned in chewing 

 the food, hut which likewise, by its yielding resistance, speedily and eflectually 

 breaks the force of the most violent blow. A wool-pack hung over the wall of a for- 

 tress, when the enemy is battering to eflect a breach, renders the heaviest artillery 

 almost harmless. So the yielding resistance of the temporal muscle afiords a sure 

 defence to the brain, however sudden or violent may be the blow which lalls on the 

 parietal. These benevolent provisions will not be disregarded by the reflecting 

 mind. 



On the side of the head, and under the parietals (dd, p. 72) are the temporal bones, 



* The Veterinarian, vol. iv. p. 198. 



