4'20 On the Effects of Galvanism in Asthma, &^c. 



racks, nor instantaneously either killed or cured, its use has been 

 almost entirely neglected. Perhaps, also, a certain degree of 

 reluctance in patients to bear its action, may have contributed to 

 retard its general application. It must, indeed, be confessed that 

 it requires some patience and resolution to bear the smarting 

 sensations occasioned by the application of the Galvanic wires to 

 the nape of the neck and the chest. A few minutes of the 

 weakest battery and conducting wires armed with silver knobs 

 are generally sufficient to blister the parts to which they are di- » 

 rectly applied. This effect takes place even when the skin is 

 shielded by pieces of tinfoil, and the consequent smarting pain 

 sometimes intimidates debilitated patients. In persons of gross 

 habits, these blisters have been known to remain open for several 

 weeks after they had been galvanized, and have ultimately proved 

 highly salutarv to the general health of the patient ; in others, 

 they healed as rapidly as common blisters. But it does not ap- 

 pear that any effects prejudicial to the constitution have yet 

 followed the administration of galvanism ; and it is certain that 

 in many diseases it has a tendency to exhilarate patients, and 

 might be very advantageously applied to melancholy persons. 

 Out of five asthmatic persons galvanized bv the writer of this, 

 four have experienced very considerable relief; one has passed 

 above nine months without experiencing any painful or even 

 irksome effects in breathing ; three others are attacked only in 

 consequence of exposing themselves to sudden and violent trans- 

 itions of temperature, but now in a much less degree than for- 

 nierlv ; and another seemed to acquire additional energy and 

 spirits, but very little melioration in his breathing. 



In the course of these experiments some curious tacts were 

 observed. It was found that all the patients suffered more from 

 the application of the wires when only half an inch or an inch of 

 the Galvanic trough was covered with the acidulated water, than 

 when the whole trough, consisting of two or of four inch plates, 

 was filled. Very few persons could during the first minute 

 bear more than six two-inch plates when less than half covered 

 with the diluted acid ; but when each plate was moistened to 

 nearly its edge, then they could generally suffer four times the 

 number. This apparently contradictory effect may be easily ex- 

 plained, by considering the necessity of atmospheric air to every 

 Galvanic operation. If a battery composed of fixed plates be 

 entirely covered with acidulated water, it has no Galvanic action ; 

 but whenever the atmosphere is allowed to act on the moistened 

 metal, then its powers develop themselves. In like manner, 

 when only the bottom part of the trough was moistened, aiid 

 the communication made by rapidly pouring in a slender stream 

 the acidulated water along the top of the battery, a greater por- 

 tion 



