No. 2.] CHANGES IN NERVE CELLS. 123 



vent hemorrhage, I always take the muscles up with a double 

 row of ligatures and make the cut between them. Carefully 

 free the plexus from fat for a short distance and, without injury 

 to the nerves or blood-vessels going to them, separate them from 

 the subclavian vessels, and, not including these, slip over the 

 plexus from behind a two-tined platinum electrode.^ Thus the 

 current is made to pass through the nerves obliquely. By in- 

 cluding the whole plexus at this point, four ganglia are stimu- 

 lated. As in the frog experiments, the nerves are not divided, 

 and as the stimulation begins, every muscle of the right leg 

 should contract. This is, in fact, the test of the proper work- 

 ing of the experiment. 



The animal is now to be carefully tended while the stimulation 

 proceeds. The temperature is frequently taken and heat applied 

 or withdrawn as the case demands. Respiration and pulse are 

 watched. Lymph is apt to collect in the axilla about the elec- 

 trodes and should be frequently wiped up with absorbent cotton. 

 With the electrodes in place, the skin is drawn together over 

 the wound and held with a clamp, and the wound is further 

 protected by an ample pad of cotton. In my experiments, 

 strictly antiseptic precautions were not taken. All tools, how- 

 ever, which touched either the wound in the head or axilla were 

 sterilized before each operation ; and, in no case, did any per- 

 ceptible inflammation make its appearance. As before, the mate 

 ganglia of the left side were in all cases used as control. A 

 double control was employed at first, consisting of a pair of 

 thoracic ganglia from the same animal carried through with 

 each pair of test ganglia. This was soon found to be unneces- 

 sary, since the cells of these control ganglia resembled those of 

 the resting ganglion. The results of the first experiment may 

 be read from the following table : — 



1 The electrode first used was the platinum-tipped electrode ordinarily used to 

 stimulate muscle-nerve preparations. Thinking that it would be better to have the 

 platinum tips guarded, I made an electrode by letting heavy copper wires mto deep 

 saw grooves in a strip of gutta-percha. The platinum wires were soldered to these 

 and were made to lie half-exposed in shallow grooves upon the inner side of each 

 of two fork-like prolongations of the gutta-percha. 



