256 APPENDIX. [No. XVI. 



.... Whilst, however, electricity appears to me to be an important agent 

 for the cure of disease, the cases in which it is especially valuable are com- 

 paratively few ; and I myself regard the treatment upon general electro- 

 therapeutic laws as more valuable than the immediate action of electricity 

 itself." Thus much premised, it becomes necessary to describe the battery : 

 the author states that " a central parenchyma, a peripheral parenchyma, 

 connected together, and each supplied with bright arterial blood, are 

 necessary for life. It follows that bleeding causes death ; that the supply 

 of imperfect blood, such as carbonaceous blood, is insufficient for life. 

 Moreover, a destruction of the central parenchyma, by injuring the brain. 

 or of the peripheral, by destroying the body, instantly prevents the 

 manifestations of the functions of animal life. . . . Now a central 

 apparatus, supplied with a peculiar fluid, a peripheral apparatus similarly 

 supplied, the whole connected together to form one universal total, is 

 the apparatus desired: and such an apparatus we have in a double voltaic 

 battery. If we abstract the proper exciting fluid from either end, or sub- 

 stitute any other fluid, or destroy the structure either at one end or 

 the other, or divide the connecting portions or wires, the effects proper to 

 the apparatus will not be manifested, and the battery will be destroyed." 



That animal membranes and fluids may take the place of metallic 

 plates, wires, and acids, is apparent from an experiment suggested by 

 Liebig : a pile was constructed. *' consisting of disks of pasteboard 

 moistened with blood, of muscular substance (flesh \ and of brain. This 

 arrangement caused a very powerful deflection of the needle of the 

 galvanometer, indicating a current in the direction of the blood to the 

 muscle." On this Mr. Smee observes : " In the muscles we have a nitro- 

 genized material which is acid ; in the blood we have a nitrogenized mate- 

 rial which is alkaline; and the connecting part or nervous fibres are 



neutral The periphery or body, therefore, consists of the muscular 



substance, forming one pole : the cutaneous tissues the opposite ; the 

 serous fluid, which lubricates the parts, being the electrolyte. The whole 

 forms a voltaic battery, which I shall hereafter consider in minute detail 

 as the Peripheral Battery. 



" From the peripheral battery two series of connecting media proceed 

 the first, the muscular nerves, or nerves supplied to the flesh ; the second, 

 the nerves distributed to the cutaneous textures. If we examine the nerve- 

 fibres in recently-killed animals, we find that they consist of fine tubes 

 containing a fluid, and lined with a peculiar species of fat, which may be 

 obtained, from their prolongation into the brain, in large quantities, when 

 the part is soaked in alcohol for a long period. In this structure we have 

 all the conditions necessary to insulation namely, a fine membranous 

 tube lined with fat on its inner side, and containing a fluid in the centre : 

 and such a structure, as far as electrical properties are concerned, would 

 be analogous to a glass tube containing liquid. 



" If we follow the course of the nerves, we find that they are prolonged 

 to the brain, and end in the grey matter, where they again come in con- 

 tact with a large quantity of blood-vessels. As the two series of nerves 

 are not immediately connected in the brain, it follows, according to the 

 laws of voltaic action, that another battery exists there, which may be 



termed the central battery For the integrity of the circuit* it is 



essential that the peripheral and central batteries be perfect; that their 



