162 Notes and Memoranda. 



analyses of Mr. Baldock, who found various specimens to contain lead, the purest 

 having rather more than 34 per cent, of that metal, and the worst 86 per cent. 



Carbolic Acid. — Dr. Crace Calvert calls this substance the most powerful 

 preventive of putrefaction with which he is acquainted. By its aid he succeeds 

 in preserving gelatine solutions, and preparations of starch, flour, etc. It pre- 

 vents the conversion of tannin into carbonic acid and sugar, and arrests lactic 

 fermentation. Diluted with from two to seven parts of water, it is found useful 

 in putrid ulcers and sloughing wounds. The non-chemical reader may be re- 

 minded that carbolic acid is very similar to creosote, and obtained from coal-tar. 



Divisibility op Matter. — A writer in the Chemical News proposes, as an 

 illustration of the mechanical subdivision of matter, that a film of gold leaf reduced 

 by Faraday's plan, through the action of cyanide of potassium, so as to be quite 

 transparent, and about l-3,000,000th of an inch in thickness, should be divided 

 by cross-lines l-80,000th of an inch apart, like those in Nbrbert's test-plates, 

 belonging to the highest series which the microscope will revolve. By this means 

 squares of gold might be obtained so small, that three billion eight hundred 

 and forty million of them would occupy no more than a single square inch ; and 

 yet each one would be distinctly visible under the best objectives of modern 

 microscopes. 



The Comet oe 1861. — The Comptes Rendus of the 13th of January contains 

 an elaborate paper by M. Faye on " the Figure of the Great Comet of 1861," 

 in which he first comments upon what he terms the " eyathiform," or "nucleated 

 cup-shaped anterior emission." He alleges various reasons for considering this 

 emission to have the shape of a cup, with reversed edges. He remarks that in 

 attempting to compare theoretical figures with the forms naturally observed, it is 

 necessary to remember that the former represent geometrical surfaces without 

 thickness, while the latter exhibit considerable thickness, and are not homo- 

 geneous in substance. He further compares the cometary emission forms to the . 

 conical or spherical sheets of water in wide-spread fountain jets, which after a 

 certain limit lose their regular shape, and are resolved into torn and divided 

 streams (lambeaux) and drops. M. Faye states that these details may be con- 

 veniently studied by causing the flame of a spirit-lamp to be deflected by an 

 obstacle held in a horizontal plane. He also describes "a posterior conoidal 

 emission," which he finds prolonged far into the tail, following its curvature, and 

 gradually enlarging itself until it presents the perspective appearance of two 

 distinct branches. 



Intra-Mercttrial Planets. — The same number of the Comptes Rendus 

 contains an extract from the Annales de V Observatoire on the theory of Mercury, 

 detailing various objections to the hypothesis of a large planet comparable with 

 Mercury in size, and circulating within its orbit, and suggesting the belief in a 

 series of asteroids, whose joint action might produce the disturbance which has 

 to be accounted for. The writer urges the importance of noticing every regular 

 spot that may appear on the disk of the sun, in order to ascertain whether it 

 possesses the character of an asteroid. 



Telocity oe Bolides. — M. Petit estimates the velocity with which the bolide 

 of the 9th of December, 1858, passed over the communes of Muret, Longage, etc., 

 at 5200 metres per second, and its height above the earth during the explosions at 

 5000 metres. A previous meteor (13th September, 1858) had an elevation of 

 220 kilometres, and a velocity cf 29 kilometres. The metre is 39 - 37100 English 

 inches, and the kilometre 4 furlongs 213 yards 1 foot 10'2 implies. M. P< tit 

 observes that the last-named meteor exhibited a brilliant light, far beyond the 

 limits usually assigned to our atmosphere. 



PnoTOOKAPiiy and Ethnology. — The Russians have taken photographic 

 portraits of the various inhabitants of the Steppes of the Oural, with a view to 

 ethnological studies. One view gives a profile, and another a lull lace ; and the 

 subjects of the operation were shaved, so as to exhibit the true form and dimen- 

 sions of the skull. 



A New Volcano has appeared in the Planeito de los Vaqueros, Chili, in a 



