Abstract
Schmitt, Olson and Johnson 1 observed that solutions of egg albumin when exposed to supersonic waves became turbid and the albumin precipitated out in fine shreds. Not only is the mechanism of this novel method of coagulation entirely unknown, but it is not even certain whether the coagulation was caused by the mechanical vibration itself or by the heating effect of electric and supersonic waves, since these investigators did not take the precaution to cool the solution during exposure. The present communication extends their observation and examines the mechanism of coagulation by supersonic waves.
The oscillating current was generated by two 75 watt tubes (UX. 852) connected in a modified Hartley circuit. The quartz plate (about 47×50 mm.) lay between 2 brass electrodes the distance between which could be adjusted. The vibrating part was placed in a dielectric liquid, usually benzene. The quartz plate vibrated at the rate of 1.3×106 times per second. On the upper electrode was placed a coil of glass tubing through which cold water circulated.
By adjusting the distance between the 2 electrodes it is easy to produce a mount of several centimeters above the surface of the liquid. We found that the effect of the vibration is greatest at the mount.
About 5 cc. of 1% egg albumin solution was placed in a test tube 15 mm. in diameter. The tube was held so that its bottom was just buried in the mount. A thermometer was placed in the tube. The pH of the solution was about 4.8.
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