l62 



HARDWICKE'S SCIENCE-GOSSIP. 



centimetre, the hundredth part of a metre, and is 

 about a nail-breadth, or 16 fifth metres less than 

 fgths of an inch. The third metret is the millimetre, 

 about the distance across a small pin's head, or as nearly 

 as possible 2 ' 3 th of an inch. The fourth metret is the 

 tenth of this, and is about the thickness of a sheet of 

 P a P er > or ^th of an inch. The fifth metret is inter- 

 mediate in size between the diameters of the red and 

 white disks that float in human blood, about the 23 yh 

 of an inch. The tenth of this, the sixth metret, is the 

 M of the microscopist, about the ^th of an inch. 

 The seventh metret is too small for any microscope to 

 be able to show, and less than the wave lengths of 

 light. The tenth metret is so small that a child 

 during the years of its most vigorous growth is 

 growing at the average rate of between thirty and 

 forty of them every second, and the eleventh metret 

 is the tenth part of this again." 



The Natural History branch of the British Museum 

 in Cromwell Road has just received a most important 

 donation from Lord Walsingham, consisting of a 

 collection of Lepidoptera with their larva?, mainly 

 British butterflies (Rhopalocera) and certain families of 

 moths (Heterocera), including Sphingidse, Bombyces, 

 Pseudo-bombyces, Noctuae, Geometrida?, and Pyra- 

 lidae. There is also a fine series of Indian species, 

 collected and preserved at Dharmsala, in the Punjab, 

 by the Rev. John H. Hocking, and specimens of Exotic 

 silk-producing Bombyces, in various stages of their 

 development, obtained mostly from Mons. Wailly. 

 With very few exceptions, the British lame, which 

 retain a most life-like appearance, and are placed 

 upon models of the plants upon which they feed, 

 have been prepared and mounted by Lord Walsing- 

 ham himself; the process adopted having been 

 inflation of the empty skin of the caterpillar by 

 means of a glass tube and india-rubber spray blower 

 over a spirit lamp guarded by wire gauze. This has 

 been found a simpler and quicker process, and one 

 admitting of more satisfactory manipulation, than the 

 alternative system of baking by means of heated 

 metal plates or ovens. The specimens have mostly 

 retained their natural colour, but in the case of the 

 bright green species it has been found necessary to 

 introduce a little artificial dry pigment. The whole 

 collection consists of 2,540 specimens of larvae, 

 belonging to 776 species, together with a series of the 

 perfect insects of each species. 



Dr. E. M. Crookshanks has been appointed 

 Lecturer on "Bacteriology" at King's College, 

 London. 



The British Association will meet at Manchester 

 on August 31, under the presidency of Professor Sir 

 Henry Roscoe. 



Every geologist in the country will be pleased to 

 hear tha Mr. W. Whitaker, F.G.S., of the Geological 

 Survey, has been elected F.R.S. 



Dr. C. S. Sherrington has been elected Professor 

 of Physiology at St. Thomas's Hospital. 



Professor Studer, the great Swiss geologist, has 

 just died at the ripe age of ninety-three. 



We are sorry to record the death of an old friend 

 and excellent geologist, Mr. Champernowne, F.G.S., 

 of Dartington Hall, Totnes. 



We are pleased to receive Mr. W. P. Collins's last 

 Catalogue of Scientific Books (mostly second-hand). 

 Also No. 81 of Mr. W. Wesley's " Natural History 

 and Scientific Book Circular." 



At the last meeting of the Geologists' Association, 

 Mr. W. J. Abbott read an interesting paper on the 

 " Formation of Agates." 



Dr. C. T. Hudson's interesting paper in the 

 Journal of the Royal Microscopical Society, on 

 " Five New Floscules," has been reprinted. 



We have received a copy of Mr. John Dennant's 

 important paper on "The Post-Tertiary Strata of 

 South-Western Victoria." It is full of valuable 

 original observations and notes. 



We regret having to chronicle the death of M. 

 Boussingault, the distinguished French agricultural 

 chemist, at the age of eighty-five. 



Mr. May all, of New Bond Street, London, is said 

 to have discovered a means of photographing in 

 colours, which may soon make finely-coloured photo- 

 graphs cost only as many shillings as they have 

 hitherto cost pounds when done by the hand process. 

 The new camera does its work in colours almost 

 instantaneously, and what rich and delicate colouring 

 it produces. Every tint appears to be reproduced 

 with a delicacy of shading and accuracy of form that 

 no ordinary brush could effect. Mr. Mayall has 

 taken, by the new process, a photograph of Princess 

 Christian. The colours by the new process are 

 stated to be indestructible, and are as conspicuous in 

 the folds and tints of a lady's dress as in the colour of 

 her eye or the beauty of her face. 



Dr. A. B. Griffiths has just published a 

 communication which is of great importance to 

 horticulturists and agriculturists. He demon- 

 strates that iron sulphate is an antiseptic for most of 

 the most virulent epidemics which attack field and 

 garden crops. These diseases are due to microscopic 

 funguses, whose structures are built up in a somewhat 

 different manner to the corresponding parts in other 

 plants. It appears that the cellulose in these funguses 

 is acted upon by iron sulphate, whereas in the higher 

 plants the cellulose of the cell walls is not influenced. 

 The iron sulphate destroys the cellulose of the 

 funguses, but does not affect that of the attacked 

 plant. It is therefore an antidote and destroyer of 

 such parasitic germs and funguses as the potato 

 disease, wheat mildew, &c. 



