v ELECTROMOTIVE ACTION OF EPITHELIAL AND GLAND CELLS 501 



in the same sense as the goblet cells of throat or cloacal mucosa, or 

 the gland cells of the frog's tongue. These being incontestably 

 electrically active, we may affirm with almost positive certainty 

 that granting the glands of the stomach proper to possess 

 electrical action the ingoing mucous current must consist of at 

 least two components. 



In order to decide this question, F. Bohlen (84) carried out 

 under our direction a series of experiments (on the frog in the first 

 instance), the object of which was to demonstrate the influence of 

 the digestive activities of the stomach upon its electromotive 

 properties. If these really depended on the gastric glands, we 

 should expect to find considerable alterations in the fasting state, 

 vs. state of digestion. This proved to be the case, but not, as 

 was expected, in the sense of augmentation of the " current of 

 rest" in the replete animal, but on the contrary of a marked 

 diminution. Only when indigestible substances, such as stones, 

 wood, etc., which excite the mucosa mechanically, were introduced 

 into the stomach, an often considerable increase of the normal, 

 ingoing current became perceptible, together with increase of 

 mucous secretion. This was to a marked degree the case after 

 the introduction of bismuth subnitrate, where the sharp-edged 

 crystals seemed to act as an intense stimulus, and produced a 

 quite specific mucous secretion. When the insoluble salt reaches 

 the cloaca, it causes a marked secretion of mucin, and a corre- 

 sponding augmentation of the electrical current, so that as in 

 the stomach the scale flies beyond the field of vision. For 

 the rest, the E.M.F. of the mucosa of the stomach is con- 

 ditioned, as in other secreting membranes referred to (which 

 secrete mucin only), by a variety of factors : in particular, 

 temperature, dehydration and turgor, anaesthesia, etc. Direct 

 electrical excitation by rapidly alternating shocks from an in- 

 duction coil effects at a small distance of coil a negative variation, 

 usually preceded by a positive swing. The strength of the 

 original current is therefore of essential significance, since the 

 deflection corresponding with the negative variation is, so to 

 speak, in direct ratio with the E.M.F. of the preparation. 



In warm-blooded animals also (rabbit, guinea-pig, rat) Bohlen 

 ascertained the existence of a vigorous ingoing current. After 

 opening the belly, an unpolarisable tube electrode closed with a 

 clay stopper was passed through a hole in the wall of the 



