300 The Mecroscope. 



of the laws of crystalloo^raphy, as were seen by the faint lines form- 

 ing a lace work of tiny triangles on the faces when the stone is placed 

 in a proper light. Professor Hanks concluded with the remark that 

 it would be an act of vandalism to cut the beautiful crystal, which is 

 a gem in two senses, and he protested against it ever being defiled 

 by contact with the lapidary's wheel. 



The diamond was placed under the microscope and arranged by 

 Professor Hanks to demonstrate the points of his very accurate 

 description. It was a beautiful object and was admired by all present. 



Dr. Riehl, of Alameda, gave a demonstration of discovering 

 tubercule bacilli in the sputum of consumptives. He proceeded 

 with the operation of staining, decolorizing, etc., and finally showed 

 the minute germs clearly under the lens. Dr. Riehl made no claim 

 to originality in the method employed, but showed how he handled 

 the material so as to disclose the bacilli quickly for purposes of diag- 

 nosis. Discussion ensued as to the value of different methods, Dr. 

 Ferrar and Dr. Mouser maintaining the value of the careful and 

 exact methods of procedure laid down by the German investigators 

 for purposes of exact determination. Dr. Mouser showed a very 

 handsome piece of apparatus called "Schlessing's Thermo Regular," 

 which he had just received from Germany. It is to be attached to 

 the incubator used in cultures of bacilli, etc., in such a way that the 

 water of the incubator comes in contact with the rubber plate of the 

 regulator and expands it. This expansion of the rabber presses upon 

 the other parts in contact with it and partly closes the pipe,- admit- 

 ting gas to the jets which heat the incubator. The appliance is so 

 delicate that an elevation of one-tenth of a degree in the heat vrill act 

 upon the gas flame and reduce it. 



President Wickson exhibited a specimen of sonorous sand sent 

 to Professor Hilgard by W. G. Thompson, of Pescadero, and referred 

 to him for examination. Mr. Thompson's letter explained that the 

 sand when driven over or walked on or even disturbed with a stick 

 or the hand, gives out a distinct musical sound. Perhaps the strang- 

 est thing about it is that the persons longest in the vicinity of Pesca- 

 dero seem not to know of the existence of such a place. It is away 

 from the usual places of resort. The much-talked of "singing beach" 

 of Manchester, Mass., is only one-fifth of a mile long, while Mr. 

 Thompson has traced this sand at Pescadero along the beach for over 

 a mile and a half. Mr. Wickson i-emarked that the subject of sono- 

 rous sand had been before the society some years ago in connection 



