498 MATER i A MEDIC A AND THERAPEUTICS. 



metabolism, are also means of preserving or increasing 

 muscular nutrition and activity. 



b. Motor depressants are a parallel series of agents. The 

 motor convolutions are disturbed, depressed, and finally com- 

 pletely " paralysed : ' by large doses of Alcohol, Chloroform, and 

 Ether, which completely arrest all voluntary movements. The 

 motor functions of the medulla are so powerfully depressed by 

 Opium, Chloral, Aconite, Conium, Physostigma and large doses 

 of Alcohol and Chloroform, that death from poisoning by these 

 substances occurs in this way. The anterior cornua of the cord 

 are depressed by Physostigma and many less powerful drugs, 

 which cause paralysis of the limbs through this channel. The 

 same effect is produced by Conium and other substances, through 

 depression of the motor nerves, not of the cord. The motor 

 nerve-endings are remarkably under the influence of Belladonna ; 

 more, however, those of the involuntary muscles, with which 

 we are not at present concerned. Galvanism is the most 

 powerful local depressant of muscular activity, and is our ordi- 

 nary means of producing this effect directly. 



c. The co-ordination of movement is peculiarly interfered with 

 by certain drugs, at any rate by Alcohol, which in considerable 

 doses produces staggering gait, disturbance of the ocular mus- 

 cles with double vision, thickness of speech, and awkwardness 

 of the manual movements. 



3. Consciousness. From the very exalted position which it 

 occupies in the system, consciousness is peculiarly amenable to 

 a variety of influences at our command. 



a. It can be roused by powerful, especially by painful impres- 

 sions : for instance, the cold bath or douche ; heat, or hot appli- 

 cations such as mustard to the surface ; loud sounds, or powerful 

 odours. Besides these, many drugs directly excite the brain, 

 the cerebral stimulants and deliriants, such as Caffein, Cam- 

 phor, Alcohol and Chloroform in the first stage; Opium, 

 Chloral, and Cannabis Indica, in some individuals ; Belladonna 

 and its allies ; Camphor, Salicylic Acid ; laughing gas, etc. 



The mental faculties are readily disordered by many of the 

 same measures which increase consciousness, leading to 

 laughing, crying, brilliancy of the imagination, increase of the 

 appetites, confusion of the intellect, loss of control of the will, 

 delirium in its many forms, and even convulsions. Alcohol, 

 Opium, Cannabis Indica, Chloral, Chloroform, Camphor, and 

 Belladonna, are specially active in producing these effects, which 

 are seldom or never desired by the therapeutist for their own 

 sake. 



b. Equally valuable are our means of reducing conscious- 

 ness, or removing it, and thus producing general anaesthesia, 



