882 Transactions of the American Institute. 



To Prevent the Oxydation of Iron Ship-bottoms. 

 Prof. Calvert lias recently made experiments on iron rust, and 

 expresses the opinion that the oxydation of tliat part of an iron ship 

 exposed to water might be prevented by coating snch surface with 

 an alloy of lead and antimony, and by placing an alkaline compound 

 in the bilge water within the vessel. 



Artificial Light. 

 According to Landsberg, a German chemist, artificial light con- 

 tains ninety per cent of calorific rays, while sunlight contains only 

 fifty. To this predominance of heating power, as compared with 

 illuminating power in artificial light, he attributes the disagreeable 

 sensation produced upon tli^ eyes. Very thin sheets of mica will 

 intercept the calorific ra3's and render the light more agreeable. 



The Effect of Electricity upon Blood. 

 Professor Neumaim, of Ivonigsberg, in studying the action of 

 electricity upon the animal organism, has recently found that, under 

 the influence of powerfully induced currents, the white blood cor- 

 puscles of the frog swell up. Between their walls, which become 

 very smooth, and the interior granular nucleus, a free space is left ; 

 and the granules of the nucleus manifest rapid movements. 



Salt as a Manure. 

 M. ^Yelter having, some time since, published an article " on the 

 utility of common salt to agriculture in consequence of its ulterior 

 transformation into carbonate, and lastly to nitrate of soda," M. Peli- 

 got furnishes a criticism thereon to the Journal de Pharmacie et de 

 Chimie, in which he gives the results of his own researches. He 

 finds that when common salt naturally occurs in an arable soil some 

 plants assimulate this salt, but the greater number do not. 



The Kkfractive Energies of Metals. 

 Dr. J. II. Gladstone read a paper before the British Association, at 

 tke Exeter meeting, on the relation of the refractive energies and the 

 combining proportions of metals, in which he stated that, in most 

 caees, but not all, the less the combining proportion of the metal the 

 greai:er is the refractive energy. The rule seems to prevail among 

 those metals which form definite salts, such as magnesium, iron and 

 zinc, but does not hold at all with non-metallic elements. The coin- 



