342 E A R L E C. GREGG, JR. 



37. Pease, D. C, and L. R. Blinks, /. Phys. Colloid Chem., 51, 556 (1947). 



(cavitation at solid surfaces). 



38. Oster, G., J. Gen. Physiol., 31, 89 (1947) (ultrasonic treatment of tobacco 



mosaic virus). 



COMMERCIAL SOURCES OF ULTRASONIC EQUIPMENT 



39. Eimer and Amend, New York; Fisher Scientific Company, Pittsburgh; 



Televiso Products Company, Chicago, 111.; Piezo Products Com- 

 pany, Framingham, Mass. 



40. Raytheon Manufacturing Company, 178 Atlantic Ave., Boston 9, 



Mass, 



