A lecture on muscular motion, read at the Royal Society, the 13th and 20th of November, 1788 ... / [Sir Gilbert Blane].

  • Blane, Gilbert, Sir, 1749-1834
Date:
1788]
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Licence: Public Domain Mark

Credit: A lecture on muscular motion, read at the Royal Society, the 13th and 20th of November, 1788 ... / [Sir Gilbert Blane]. Source: Wellcome Collection.

    17/68 (page 11)
    cafe of tenfion, which is the only cafe bearing analogy to Mufcular Motion, I made the following experiment : I took a piece of the —elaftic gum, or kahoutchouck, three inches fquare, and about the eighth of an inch in thicknefs; I procured a piece of fheet-tin, three inches broad, and fix inches long, cut into fharp teeth at each end. The gum was firft weighed in air, and found to be 380.25 grains. It was then weighed in water, along with the tin, to which it was loofely attached, and the weight of both was then 758,75 grains. The gum was then ftretched upon the tin, by means of the teeth at each end, to a furface of about five inches {quare, the tin being bent fo as to leave a free, {pace between it and the gum, in order that when immerfed in the water, no air bub- bles might be entangled. ‘In this fituation, the weight of both in water was found to be 74657 5 gtains. Here wasa difference of twelve grains, which could be owing only to a diminution of {pecific gravi- ty ; and in order to be fure that there was no fallacy nor inaccuracy in the experiment, the gum was immediately afterwards difengaged from one end of the tin, fo as to allow it to fhrink, and being again weighed in this ftate in the water, it was found to have recovered exactly its former weight. This, as well as the fubfequent ftatical experiments, was performed by means of the exquifite balance lately invented and conftruéted by Mr. Ramfden, and belonging to Sir Jofeph Banks, who politely allowed me the ufe of it. I was alfo aflifted by Mr. Gilpin, clerk of this fociety, who is extremely accurate and expert in all operations of this kind. Now, does the ftate of relaxation and contra@ion make in like manner a temporary difference in the denfity of mufcles ? When the circumftance of decurtation only is confidered, we fhould be tempted to think that there muft be an approximation of the particles of the C2 fibre ; . sy I IE Experiment. Experiments to determine ~ whether the denfity of a Mutcle is af- fected by cone traction.