PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. 491 



5. The drop size depends upon the chemical nature of the solid, from 

 ■which tlie drop falls, and little or nothing upon its density. Of all the 

 solids examined, antimony delivers the smallest, and tin the larg-cst drops. 



6. The drop-size depends upon the temperature generally, the higher the 

 temperature the smaller the drop. With water the effect of a change of 

 temperature of 20^ to 30* centigrade is very small. 



The nature or tension of the gaseous medium has little or no effect upon 

 the drop size. 



The Barberry. 



if. Boutin communicated a note to the Academy of Sciences, Paris, on 

 the advantage to be gained by cultivating the Mahonia Ilicifolia. The 

 juice of the barberry will yield eight per cent of alcohol of agreeable 

 tlavor. The wine made from it is too acid. The seeds when roasted make 

 a drink very like coffee in taste and appearance. 



Photographs of Natural Colors. 



This subject is still under investigation by M. Niepce de St. Victor. He 

 finds that the chlorides which give colored flames reproduce objects of the 

 same color as the flame. Chlorine, chloride of copper and perchloride of 

 iron appear to be the best agents, and by varying the dose of chlorine and 

 chloride he obtains certain colors in a marked manner. They are, however, 

 not permanent. But this gentleman has been completely distanced by M. 

 Chambray, of Mauritius, if the newspaper report be true. The 'portraits 

 made by M. Chambray are incredible resemblances of the originals- life 

 circulates under the skin, and the color is unchangable. These wonders 

 have not yet reached Paris. Americans, who have had some experience in 

 this particular " sensation," are not impatient to hear the particulars re- 

 garding these discoveries. 



Sugar from Palms. 



Dr. De Vey exhibited to the Scientific Congress at Giessen a specimen of 

 sugar made from the juice of certain palms growing in Ceylon and Java, 

 and stated that it was producible in large quantities. 



Electro-Magnetic Locomotive. 



The model of the invention of Messrs. Bellett and De Roavre has been 

 exhibited at Versailles, France. The driving power is attached to a single 

 pair of wheels in the rear. A number of magnets are arranged radially on 

 these wheels, one pole being at the circumference. The Voltaic current is 

 sent from the center of each wheel to all the magnets in succession, and 

 these latter act directly on the rail itself. The inventors propose besides 

 the large locomotive to make a small one for carrying packages at the rate 

 of 120 miles per hour. The great expense of this kind of engine has been 

 fully proved in this country. The only advantage it possesses as a motor 

 for locomotives is that no injurious gas is formed by the products of com- 

 bustion. 



Vaccination. 



The smallpox is rather prevalent in Paris, and it is recommended to fcl- 



