Licence: Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)
Credit: The collected papers of Sydney Ringer. Source: Wellcome Collection.
Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.
32/538 (page 14)
![occurred five minutes after tlie immersion hiii ik» otfier movement, and all tlie muscles soon passed into firm rigor.’ ‘ Mere alteration in the percentage amount of salt influeiices the contraction, as the following experiment shows. On April 13 I placed the sartorius in 0’5 per cent, saline solution. For the first three minutes only the faintest contractions occurred. They then for two or three V f/ minutes became moderately .strong and again grew weak. I then added 25 c.c. 2 per cent, solution of salt to 200 c.c. of 0'5 per cent., which much increased the actiyity of the contractions. I then returned to 0 5 per cent, solution and in about a minute the contractions became much weaker. I then added 25 c.c. of 2 per cent, solution to 150 c.c. of 0 5 per cent, solution and the contractions became greatly increased. I added another 25 c.c. of 2 per cent, solution and still further increased the contractions. Again I returned to 150 c.c. of 0*5 per cent, solution and the contractions greatly lessened, occurring in paroxy.sms wdtli quiescent periods of half a minute. I then added 50 c.c. 2 per cent, .solution, and again greatly increased the frequency of the contractions. On returning to 150 c.c. of 0‘5 per cent, solution contractions ceased but returned for a short time on adding 50 c.c. of 2 per cent, solution of sodium chloride. On the other hand, lessening the relatiye amount of NaCl, as by adding distilled water to the saline solution lessens or prevents these muscular contractions. For instance, reducing the 0 6 per cent, to 0'5 per cent. NaCl decidedl}’ lessens the contractions. Here I wdll record one experiment sliowing the ehect of dilution. I first took a trace Avith 200 c.c. 0’6 per cent, saline solution, and obtained acth'e contractions. On adding 50 c.c. distilled Avater, the contractions ceased and failed to return on adding another 50 c.c. and a third 50 c.c. distilled Avater. On returning to 0'6 per cent, saline, slight contractions recommenced, and the further addition of 2 c.c. of 2 ])er cent. BaCL induced actiA’e contractions. I next tested the effect simply of distilled Avater ou the cmitractions. 1 hrst took a trace Avith 0‘6 per cent, saline solution, and tlien replaced this by distilled Avater, Avlien the contractions ceased at once, though in some experiments a feAv single strong contractions occurred at many minutes’ interyal. The distilled water howeyer induced some persisteni contraction, which passed aAvay on tlie addition of saline, proAuded not too long a term had elapsed, before adding the NaCl, i.e., about eight to ten minutes. When these contractions brouglit out by immersion in saline ceast‘](https://iiif.wellcomecollection.org/image/b28036530_0001_0032.jp2/full/800%2C/0/default.jpg)
