Supposed jigency of Galvanism in transferring Colors, 8fc, 317 



purple hue, in consequence of some of the cochineal infusion having 

 found its way through the coats of the bladder, and mixed with the 

 litmus. The same experiment succeeded more slowly without the 

 aid of the galvanic circle ; but it was greatly expedited with it, show- 

 ing I think that the exertion of the agency of galvanism was the cause 

 of all the phenomena of the experiment. 



To satisfy myself more fully, I filled two glasses with the infusion 

 of litmus ; in one I placed a bladder having a small quantity of very 

 dilute sulphuric acid, securely inclosed within it. In the other I pla- 

 ced a bladder containing a weak solution of potassa. I filled a third 

 glass with an infusion of cochineal, and placed in it an infusion of lit- 

 mus. In less than twenty-four hours, I found changes had ensued in 

 every glass. In the first the litmus had become red, while the acid 

 within had assumed a similar color. In the second glass the litmus 

 was green, while the infusion of potassa presented the same color 

 within the bladder. In the third glass the infusion of cochineal be- 

 came more or less purple from the admixture of the litmus, while 

 the infusion of litmus within the bladder had also assimilated its color 

 to that of the fluid without. In each glass there had evidently been 

 established two currents, one passing from without to the fluids with- 

 in the bladders, and the others from the enclosed fluids to the infu- 

 sion without, and continuing to do so probably, till there was a com- 

 plete assimilation of color both without and within the bladder. 



May not some process of this sort take place in the human body ? 

 May not pure water, and the water of melons, reach the kidneys, by 

 a similar electrical percolation ? It appears as probable to me that 

 this operation may ensue in the animal system, as that water of mel- 

 ons when carried to the stomach, is discharged from the bladder in 

 twenty or thirty minutes after being swallowed, although conveyed to 

 it by the very circuitous route of the circulation. Would it not re- 

 quire a longer time for the water to reach the bladder in this case, 

 provided it had first to pass into the duodenum, from thence to the 

 small intestines, there to be converted into chyle, and by the lacteals 

 conveyed to the thoracic duct, and thence conveyed to the subcla- 

 vean vein, and there enter the right auricle by the descending vena 

 cava, and from thence to the right ventricle, and from thence to the 

 lungs, and from them by the pulmonary arteries to the left auricle, 

 and from that to the left ventricle, and from there by the aorta to the 

 venal arteries, and thence to the kidneys, and after being secreted, to 

 be conveyed to the bladder by the uterus ? Can so complicated and 

 circuitous a process take place within twenty or thirty minutes ? It 



