404 Notes and Memoranda. 



if the nickel is melted and the antimony reduced. The last portion of tin is then 

 made to pass through the charcoal, and the mixture well agitated. 



The New Eotifee. — Professor Williamson, in calling the attention of the 

 Manchester Literary and Philosophical Society to the Cephalosiphon Limnias, 

 described in the Intellectual Observer for February, noticed its possessing only one 

 calcar, whereas the floscularia, when furnished with them, have two, and he sug- 

 gested the importance of ascertaining whether two existed in the primary condi- 

 tion, and one was suppressed in the process of development. 



Crystallizations eor Polaris cope. — Mr. Davies read a paper to the above 

 Society, showing how beautiful arborescent forms could be obtained by taking a 

 salt like the double sulphate of copper and magnesia, drying a portion on a glass 

 slide, fusing it in its water of crystallization, then allowing it to cool slowly. 

 Starting points for groups of crystals could be obtained by touching the film with 

 a fine needle. 



The Brighton Well. — After digging to the great depth of 1285 feet, water 

 was obtained on the 16th of March. It burst up suddenly with great violence, 

 and a loud report, through the lower green sand, which had been reached in the 

 excavation, and rose more than 800 feet in thirty-six hours. 



• Sib John Herschel on Meteorology. — In a letter to the Manchester 

 Literary and Philosophical Society, Sir J. Herschel denies that he has abandoned 

 the Hadleian theory of winds. He is disposed to attribute the extraordinary 

 climatic features of the last two years to the great outbreak of solar spots in Sep- 

 tember 1859, which was associated with unprecedented magnetic disturbances. 

 This occurred as the sun was passing southwards across the equator, and Australia 

 experienced a summer of unusual heat. The quantity of vapour then thrown 

 into the atmosphere from the southern ocean does not appear to have been yet 

 got rid of. 



Homoeopathic Medicines and the Spectroscope. — Dr. Ch. Ozanam states 

 in the British Journal of Homoeopathy that a spectroscope by Steinheil enabled 

 him to recognize lithium in the fifth dilution of its chloruret, a drop containing 

 5 billionths of a milligramme. The milligramme is one thousandth of one 

 gramme, which is a minute fraction less than 15 j grains. He detected sodium in a 

 drop of the 6th dilution of its chloruret, which weighed 3 centigrammes, and con- 

 tained three hundred billionths of a milligramme. 



Markings on Diatoms. — Professor O. K Eoad, TJ. S., has published in 

 Silliman's Journal (Jan. 1862) some fresh investigations on the much-disputed 

 question of diatom markings. He brings the microscope to a horizontal position, 

 removes the mirror, and places a lamp or candle in the axis of the instrument, 

 and not more than three inches from the stage. If a small sphere of glass is 

 then placed in the focus of the objective the inverted image of the lamp or can- 

 dle which it forms is seen in an erect position, and if a rod one-tenth of an 

 inch in diameter is moved up and down between the sphere of glass and the light, 

 its image is distinctly seen. " Upon replacing the sphere by a minute concave 

 lens, as an air-bubble in water, the reverse takes place ; to gain distinct vision of 

 the flame, it becomes necessary to move the compound body within the focus : 

 the image of the flame appears inverted, and the motion of the rod seems reversed." 

 Having thus noticed the different action of concave and convex lenses, he experi- 

 mented with the markings on Coscinodiscus, Triceralium, etc. When these objects 

 were mounted in water, which possesses a much smaller index of refraction than 

 the silica of which they are composed, and viewed with a power of 600 or 800 

 diameters, " each hexagon was found to contain a minute distinct image of the flame, 

 the motion of the rod showed that the images were inverted, and consequently 

 formed by concave lenses. When mounted in Canada balsam, which has a higher 

 index of refraction than silica, the influence of the balsam predominates, and the 

 action of the lens is reversed, so that the markings behavo like convex glasses. 

 Balsam of Tolu, with a still higher index of refraction, gives the same results. 



