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SCIENCE-GOSSIP. 



CONDUCTED BY J. H. COOKE, F.L.S., F.G.S. 



To whom Notes, Articles and material relating to Microscopy, 



and intended for Science-Gossip, are, in the first instance, to 



be sent, addressed "J. H. Cooke, Thomdale, Lincoln." 



Microbiology. — M. Duclaux, the Director of 

 the Pasteur Institute, has just issued a new work 

 in three volumes on "General Microbiology." 

 Vol. i. contains forty chapters, and includes a 

 history of the action of ferments and of the different 

 interpretations that have been put upon these from 

 time immemorial. Pasteur's work is treated in 

 great detail, and at the end of each chapter there 

 is a notice of the published works that have 

 reference to the subjects treated. Vol. ii. consists 

 of a study of diatases, poisonous substances and 

 viruses ; while the third volume treats especially of 

 alcoholic and other fermentations. 



Manchester Microscopical Society. — The 

 work that has been done by this Society during the 

 past month has been of exceptional interest. On 

 March 3rd Mr. W. H. Pepworth gave an illustrated 

 lecture on the slime fungi, " Myxomycetes," after 

 which Mr. A. H. Tabor exhibited a specimen 

 showing an apparent malformation of one of the 

 joints in antenna of a crane-fly. On February 

 17th the Mounting Section met, and Mr. W. Moss 

 gave a demonstration on the dissection, prepara- 

 tion and mounting of the radula? of various 

 species of British Hyalinia, and Mr. E. Ward 

 described the best methods for mounting in glyce- 

 rine jelly. 



Our Invisible Friends and Foes. — The 

 bacteria known now number 560 species, according 

 to a London Institution lecture by Professor 

 W. B. Bottomley, and practically our entire know- 

 ledge of these has been worked out since 1830 

 through the influence of Pasteur. Of the harmiul 

 species there are only about forty. Bacteria are 

 found everywhere in the air and in our homes. They 

 are so minute that 250,000,000 could be accommo- 

 dated on a penny postage stamp, and they multiply 

 with incredible rapidity. It is estimated that a 

 human being takes in by respiration 30,000 germs 

 each day, or 100 millions a year. Not only are most 

 of them harmless, but they give flavour to butter, 

 cheese, game, etc., and they are the scavengers 

 of nature. They are absolutely necessary for the 

 "round of life." 



Stereum hirsutum. — Professor H. Ward has 

 cultivated the mycelium of Stereum hirsutum, Ft., 

 obtained from spores on sterilized wood, and after 

 several months the cultures developed yellow 

 bosses, which proved to be the hymenophores 

 bearing the basidia. He points out in the " Pro- 

 ceedings of the Royal Society," p. 286, that this 

 fungus has not hitherto been made to produce 

 spores in cultures, and that Basidiomycetes 

 generally have rarely been made to do so. The 

 actions of the mycelium on the wood of /Esculus, 

 Finns, Quercus and Salix have also been examined 

 for the first time, it is believed, with pure cultures. 

 Anatomical and histological details with figures are 

 given in the complete paper. 



A New Micro-Objective, — The most powerful 

 microscopic objective yet made is a one-tenth-inch 

 mono-bromide of naphthalene immersion lens, made 

 by Zeiss. Its numerical aperture is i'6o, and it 

 has resolved, or made visible, a detail only goo 1 ooo t h. 

 of an inch in width. 



Composition of Peat. — Peat owes its origin 

 almost always to that particular kind of moss 

 which is commonly used for packing plants, and is 

 known as sphagnum moss, although its formation 

 may be afterwards carried on by heather, lichen 

 and other plants. The explanation of this is seen 

 when one examines the minute structure of this 

 moss. Its leaves are folded in such a way as to 

 give it a great capacity for holding water. If one 

 goes, further and examines a section of the leaf with 

 the microscope, one again finds an adaptation for 

 taking up water in the spongy nature of the dead 

 cells lying between the living tissues of the leaf, 

 the internal cavities being connected by canals 

 with the exterior. No water is so full of animal 

 life as that of a Sphagnum bog, great numbers of 

 desmids, diatoms, protozoids, and other varieties 

 being found. It is remarkable that the same 

 species are everywhere associated with this moss, 

 the Sphagnum of even Spitzbergen offering no 

 exception. 



Preparation of Crystals. — The determination 

 of the geometrical and physical constants of 

 crystals affords many opportunities for delicacy of 

 manipulation, and for exactitude in observations. 

 M. Tassin, in the course of a review of the various 

 methods for preparing crystals for microscopic 

 examination, groups them under the three heads — 

 solution, sublimation and fusion. In the first 

 class, crystals of a substance are prepared from 

 its solution in a liquid by evaporating and cool- 

 ing, by the reaction of soluble compounds, or 

 by chemical changes in general. To secure 

 crystals by fusion, either with or without pressure, 

 it is necessary to prepare a solution of the sub- 

 stance in a molten magma, or to slowly cool a 

 homogeneous magma. To obtain the crystals by 

 the former method, crystallization must proceed as 

 slowly as possible, and the removal of the crystals 

 should preferably be effected when the solution 

 is at its minimum temperature. Crystals desired 

 for measurement must be quickly and completely 

 dried in order to prevent corrosion or etch figures 

 forming. 



Mechanism of Protoplasm. — From " Natural 

 Science" we learn that Professor A. L. Herrera 

 has experimented with the object of explaining by 

 mechanical principles some of the phenomena 

 observed by Dr. Fol in the fertilization of the 

 eggs of echinoderms. A thin layer of olive oil was 

 allowed to float on the surface of water contained 

 in a plate and a little yolk of egg then dropped into 

 the middle glided easily upon the oil. On the 

 approach of any pointed body the yolk rose into a 

 bubble, resembling the cone of attraction observed 

 by Fol before the penetration of the spermatozoid 

 into the vitellus. The emission of pseudopodia, 

 which fell back into the yolk as soon as the 

 attractive force was removed, was noted in some 

 cases, and with albumin the phenomenon was still 

 more remarkable, a coin brought near the drop 

 causing it to become slowly distorted as it was 

 attracted by the metal, while subsequently it 

 became pear-shaped. The analogy with the natural 

 phenomena is described as being complete, the oil 

 or less dense liquid representing the albumin, while 

 the drop of yolk serves for the vitelline sphere. 



