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THE POPULAR SCIENCE MONTHLY, 



The New Eddystone Liglithousc The 



last coping-stone of the new Eddystone 

 Liglithousc was laid on the 1st of June by 

 the Duke of Edinburgh. The foundation- 

 stone was laid by the same prince as Master 

 of the Trinity Board'ion August 19, ISYG. 

 It is expected that the tower will be ready 

 for the exhibition of the light next March. 

 The new tower is double the height of the 

 old one, and is made of uniform granite. 

 The light, instead of being fixed as at pres- 

 ent, will be oscillating, and will consist of 

 a powerful white, double-flashing half-min- 

 ute light, showing two successive flashes 

 of about two and a half seconds' duration, 

 divided by an eclipse of about four seconds, 

 the second flash being followed by an eclipse 

 of about twenty-one seconds. The light 

 will be visible all around the horizon, for 

 seventeen and a half miles, and will over- 

 lap the light of the Lizard, where there are 

 now eight miles of darkness. A subsidiary 

 white light is to be mounted in an upper 

 room, to cover the reef of rocks known as 

 the Hand Deeps, which will be adjusted so 

 as to be seen only within the area of danger 

 occasioned by those rocks. 



Snlphnr Formation in the Soil of Paris. 



M. Daubree has called attention to a for- 

 mation of native sulphur which is now going 

 on in the soil of Paris. The mineral has 

 been found in considerable quantities among 

 the rubbish dug up from the Place de la Pte- 

 publique, presenting a crystalline appear- 

 ance to the naked eye, and showing under 

 the glass the octahedral forms which arc 

 most characteristic of the natural crystals. 

 The origin of this substance, which is found 

 in situations that preclude the supposition 

 of emanations of illuminating gas having 

 anything to do with it, is evidently to be as- 

 cribed to the presence of sulphate of lime, 

 old plaster, and various organic matters 

 which have been brought together during 

 the last two centuries in the filling up of 

 the ditch that formerly encircled the city. 

 The sulphur occurs at a depth of from eight 

 or ten inches to ten feet below the surface, 

 and over an area of one hundred and sixty 

 by fifty or sixty feet, forming in reality a 

 kind of bed or deposit of tlie mineral. Spe- 

 cimens have been obtained from it of work- 

 able sulphur, analogous to that of Sicily and 



other countries, consisting of a breccia of 

 small fragments incrusted with crystals of 

 sulphur, cementing them one to another. 



A Vegetable Digestive Agent. M.Wurtz, 

 in a paper read before the French Academy 

 of Sciences, has drawn general attention to 

 the great chemical and therapeutical value 

 of papaine, a vegetable substance which 

 excites the digestive faculty, as opium pro- 

 duces sleep. Both these substances are ob- 

 tained in the same manner, by cutting into 

 the epidermis of plants whose lactiferous 

 vessels are charged with medical juices. 

 The Carica papaya^ or common papaw-tree, 

 belongs to the family of the Cucurhitacece^ or 

 gourds ; its straight, cylindrical trunk, from 

 ten to sixteen feet high, is terminated at the 

 top by a cluster of large palmate leaves, 

 which give it the appearance of a palm- 

 tree. The fruits, hanging in clusters under 

 the leaves, have the shape of roundish cu- 

 cumbers, and are much esteemed when ripe. 

 The papaw appears to have originated in 

 the Moluccas, but has been acclimated in 

 India, Mauritius, the Island of Reunion, the 

 Antilles, and a considerable part of South 

 America. The milky juice which contains 

 the papaine is white, slightly bitter, and 

 styptic, free from tartness, has an acid re- 

 action, and is so highly charged with albu- 

 men that Vauquelin compared it to blood 

 deprived of its coloring-matter. It flows 

 from incisions made in the bark and the 

 green fruits, and is immediately bottled and 

 sent to market either pure or with the ad- 

 dition of ten or twelve per cent, of alcohol 

 to prevent fermentation. If pure, it comes 

 coagulated ; if mixed with alcohol, it re- 

 mains liquid, and, after standing, separates 

 into a clear liquid and a Avhite precipitate, 

 composed in great part of albumen, tibrine, 

 and a considerable quantity of precipitated 

 papaine. Alcohol precipitates from it crude 

 papaine ; this, after being washed in alcohol 

 and ether, to remove fatty matters, is again 

 dissolved in water. The precipitate from 

 this solution is pure papaine, which, when 

 purified by dyalise, has the composition of 

 an albuminoid substance. Papaine, refined 

 with the sub-acetate of lead, offers several 

 distinctive characteristics, among which are: 

 1. It is very soluble in water, dissolving 

 like a gum ; 2. The solution makes a lather 



