. Optical projection : a treatise on the use of the lantern in exhibition and scientific demonstration. d the otherscrew g also serve to adjust lever and stand on the pillar some experiments requiring great delicacy, it may beadvisable to carefully balance the arm fc, or the somewhatsimilar arms in fig. 121, so that their weight may not inter-fere with the motion. Between the heart and the lever at cis adjusted a small pillar b of elder pith, with a small point ateach end, which communicates the motion, the lower point PHYSIOLOGICAL DEMONSTRATION 237 being sunk in the heart. The motions
. Optical projection : a treatise on the use of the lantern in exhibition and scientific demonstration. d the otherscrew g also serve to adjust lever and stand on the pillar some experiments requiring great delicacy, it may beadvisable to carefully balance the arm fc, or the somewhatsimilar arms in fig. 121, so that their weight may not inter-fere with the motion. Between the heart and the lever at cis adjusted a small pillar b of elder pith, with a small point ateach end, which communicates the motion, the lower point PHYSIOLOGICAL DEMONSTRATION 237 being sunk in the heart. The motions of the heart, which canbe kept beating rhythmically by well-known methods, arethus readily projected, as shown by the disc on a point at/. The same apparatus projects the contractile movements ofpieces of muscle. The plate a is removed, and the arm In,arranged above the lever fc d. To a loop on h is fastened oneend of the muscle, and to a thread attached to fed the otherend; when the contraction of the muscle will affect the leveras before. Czermaks projecting Cardioscope employs the direct optical. Fro. 124.—Action of the Cavdiosoope method of the reflecting mirror. Small slabs of cork are laidon the pulsating body, so as to receive the motion withoutloss or suppression by weight, and resting upon these are thehorizontal arms of very light levers bent at their pivots some-what like an l, which communicate the angular motion tolight thin mirrors. Fig. 123 represents such an apparatuswith two slabs and mirrors, one slab being placed on the 238 OPTICAL PROJECTION ventricle of a heart and the other on the auricle. When theauricle is compressed the slab sinks, and so does the mirror,as shown by the dotted lines; whilst the slab on the ventriclerises and the other mirror is elevated. The optical arrange-ments are as in fig. 124. The foeussed parallel pencils fromtwo small apertures on the lantern b fall on the mirrors ofthe cardioscope c, and are reflected and foeussed on the scre
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Keywords: ., bookauthorwrightle, bookcentury1900, bookdecade1900, bookyear1906
