Concerning the action of salts of potash, soda, and ammonia on the frog's heart / by Sydney Ringer.

  • Ringer, Sydney, 1835-1910.
Date:
1882
Catalogue details

Licence: Public Domain Mark

Credit: Concerning the action of salts of potash, soda, and ammonia on the frog's heart / by Sydney Ringer. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    employed, the cannula on which the heart was tied served as the one electrode, the other electrode pressed against the outer surface of the ventricle, care being taken that contact persisted throughout faradisation. The excitations were very frequent, the hammer of the induction apparatus vibrating rapidly. The results obtained were in accordance with the previous statements from Marey, and it became clear that fusion, complete or incomplete, i.e. tetanus, complete or incomplete, could be produced in the following ways, viz.: 1. By lessening the refractory period. Increase of the strength of the current will effect this. Raising the temperatnre will do the same. Further, certain drugs will do the same. Even in the cool months of October and November we met with hearts whose irritability was such that they exhibited this fusion from the onset. It was especially to this form of fusion that Luciani drew attention. 2. By prolonging the duration of each contraction. It is obvious that, other things remaining the same, increase in the duration of the beat must favour fusion. Some drugs, e.g. soda, ammonia, and its salts, probably act in part in this way. 3. Yet another way is to be noted. Certain drugs, e.g. soda, ammonia, potash, antiarin, digitalin, strophanthus, induce a persistent spasm of the ventricle, not, however, means of a fusion of beats, for these may occur so infrequently as to exclude this mode; in such cases, even when the intervals between the beats are a minute or more, the persistent spasm may last during the whole period of the intervals. This persistent spasm will, ccet. 'par., tend to fuse together neighbouring beats. It has been suggested (f Journal of Physiology/ Decem- ber,1 1881) that this spasm may be an increase of the tonus of the heart and allied to contracture. 1 “ Regarding the action of Hydrate of soda, ammonia and potash on the Frog’s Ventricle.”—Sydney Ringer, M.D.