160 Notes and Memoranda. ' 



Light Organs of Glowworms. — Professor Max. Schultze states that in 

 males of the species Lampyris splendidula numerous trachseal branches in the 

 luminous organs terminate in star-shaped cells. Osmic acid rapidly tinges these 

 cells black, while the cells of the parenchyma remain colourless. It is, therefore, 

 evident that the cells of the trachsea have the property of rapidly abstracting 

 oxygen from the osmic acid, which readily parts with it. — Archives des Sciences. 

 It will be interesting for our readers to try similar experiments with our English 

 glowworm. 



Absorption Bands and Temperature. — M. Feussner finds that chlorides 

 of iron and copper, sulphate of copper, ammoniacal sulphate of copper, bichromate 

 of potash, sesqui nitrate of nickel, proto- chloride of cobalt, and bichloride of platina, 

 have their absorbing powers increased by heat. Chloride of copper in a suitable 

 degree of concentration is completely opaque at its boiling point, and that portion 

 of the spectrum which remains longest visible when the temperature is increased 

 does not coincide exactly with that which is the last to disappear when the thickness 

 of the layer is gradually increased. Chloride of cobalt at ordinary temperatures, 

 and at a convenient degree of concentration, furnishes in the spectroscope two 

 luminous bands, one of which, embracing all the red, all the yellow, and part of 

 the green, is very intense, and the other of little brightness is situated in the vio- 

 let. If heat is applied, the violet band diminishes in intensity, and two new bands, of 

 which no trace previously existed, appear in the red. These bands increase 

 rapidly in breadth, especially that which is the most refrangible, as the tempera- 

 ture augments, and when the boiling point is reached, they completely obscure the 

 luminous band in which they are formed with the exception of a narrow and feeble 

 ray at the extremity of the red. — Archives des Sciences. 



Transparency op the Sea. — Father Secchi communicates to the French 

 Academy the result of experiments made by M. Cialdi, commander of the " Imma- 

 culate Conception" corvette, from six to twelve nauticai miles off Civitta Vecchia, 

 where the sea depths varied from 90 to 300 metres. A great disk 3 m .73, cr rather 

 more than 4 yards in diameter, formed of an iron hoop covered with cloth, pa ; nted 

 white, and provided with apparatus for keeping it horizontal, was sunk on a remark- 

 ably clear day, and ceased to be visible at a depth of 42| metres, or about 140 feet. 

 The sun's height was 60° 17'. Had the sun been vertical, Father Secchi says the 

 disk might have been visible six or eight feet deeper. Smaller disks lost form 

 so much by refraction that they could not be seen at the depths at which the great 

 one remained visible. As the large disk wa3 sunk to different depths its colour 

 became first slightly green, then light blue, after which the blue grew deeper, 

 until it could not be distinguished from the colour of the surrounding water. 

 Thus the disk did not disappear because the light emanating from it was not per- 

 mitted to reach the eye, but because after the sunlight had penetrated to a cer- 

 tain depth in the clear sea, and came back again through the water, it had lost 

 all rays capable of characterizing the disk, and the light reflected from the ' 

 disk could not be distinguished from that coming from the water around it. 

 Yery large objects, such as portions of the sea bottom, Father Secchi thinks 

 might possibly be seen at 50 or 60 metres deep in a sea like the Mediterranean, 

 but he thinks there must be a mistake in the stories of the sea bed having beeu 

 recognized at depths of from 100 to 200 metres. 



Electric Properties op Mineral Waters. — Comptes Bendus contains a 

 note by M. Scoutetten on the electric condition of mineral waters. He states 

 that such waters fresh from their source are in a state of chemical activity which 

 gives rise to an active electrical current, recognizable by a galvanometer. He 

 ascribes their curative properties to this exhibition of electricity. We would sug- 

 gest that, if the electric state be as he describes, it does not follow that the curative 

 action of the mineral water is directly dependent upon it. Yery small quantities 

 of chemical substances in a nascent state may, from the great facility with which 

 they enter into new combinations, produce remarkable physiological effects, and 

 electricity may have nothing to do with the matter excepting so far as is connected 

 with chemical affinity. 



