REFLEX ACTIONS. PATHOLOGICAL PHENOMENA. 309 



which have been developed in it; although they will hereafter be passed 

 under a more general review (Section 8). A large part of these were first 

 pointed out by Dr. M. Hall;* and they are receiving continual and important 

 extensions from his own labours and those of other practical inquirers. It 

 may be remarked, in the first place, that the power of the whole Spinal sys- 

 tem is capable of being morbidly diminished or augmented. It may even be 

 for a time almost completely suspended, as in Syncope; which state may be 

 induced by sudden and violent impressions, either of a mental or physical 

 nature, that operate upon the whole nervous system at once, commencing, 

 however, in the brain. It is to be remarked that, in recovering from these, it 

 is the Spinal system of which the activity is first renewed, the respiratory 

 movements recommencing, and the power of swallowing being restored, 

 before any voluntary actions can be performed. A corresponding state may 

 be induced in particular portions of the system by concussion ; as is seen in 

 severe injuries of the Spinal Cord, which are almost invariably followed for 

 a time by the suspension of its functions. Again, the power of the whole 

 Spinal Cord may be diminished by various causes, such as enfeebled circula- 

 tion, pressure, &c. ; and then we have torpidity of the whole muscular sys- 

 tem. If oppression exists in the Brain, the functions of the Medulla oblon- 

 gata will be especially affected; and if it be prolonged and sufficiently severe, 

 Asphyxia will result from the interruption of the respiratory movements which 

 it occasions. 



401. On the other hand, the excitability of the whole Cord, or of particu- 

 lar parts of it, may be morbidly increased. This is especially seen in ordi- 

 nary Tetanus and the artificial Tetanus induced by Strychnine; in which the 

 slightest external stimulus is sufficient to induce reflex actions in their most 

 terrific forms. It is interesting to remark, that in this formidable disease the 

 functions of the muscles controlling the various orifices are those most affected ; 

 and it is by the spasms affecting the organs of respiration or deglutition, that 

 life is commonly terminated. Various remedial agents will probably be found 

 to operate, by occasioning increased excitability in some particular segments 

 of the Cord; so that the usual stimuli applied to the parts connected with 

 these, will occasion increased muscular tension. This seems to be the case, 

 for example, in regard to the influence of aloes on the rectum and uterus, 

 cantharides on the neck of the bladder and adjoining parts, and secale cornu- 

 tum on the uterus. The mode of influence of cantharides is illustrated by a 

 curious case, related by Dr. M. Hall, of a young lady who lost the power of 

 retention of urine, in consequence of a fatty tumour in the spinal canal, which 

 gradually severed the Spinal Cord, and induced paraplegia. The power of 

 retaining the urine was always restored for a time by a dose of tincture 

 of cantharides, which augmented the excitability of the segment of the cord, 

 with which the sphincter vesicae is connected. The researches of Valentin, 

 when grafted (as it were) on the doctrines of Dr. M. Hall, afford the key to 

 the explanation of the numberless sympathetic influences of the organs of 

 nutrition, &c., upon one another; by showing that they are all connected with 

 the Spinal Cord ; and that the muscular structure, with which they are all 

 provided, may be excited to contraction through it. And, lastly, the more 

 recent observations of Dr. M. Hall, in regard to the peculiar excitor power 

 that belongs to the nervous fibres distributed on various serous and fibrous 

 membranes, will probably lead, when they have been fully carried out, to the 

 explanation of the various convulsive actions, that result from pressure or 

 irritation affecting these parts. 



See especially his Treatise on the Diseases and Derangements of the Nervous System. 



