Scientific American Supplement, No. 415, December 15, 1883 eBook

This eBook from the Gutenberg Project consists of approximately 102 pages of information about Scientific American Supplement, No. 415, December 15, 1883.

The bruised leaves applied directly usually prove sufficient for the purpose; as to whether it will prove sufficiently valuable to add to our list of pharmaceutical preparations will require longer and more extended experiment.—­New Remedies.

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DANGER FROM FLIES.

Dr. Grassi is said (British Medical Journal) to have made an important, and by no means pleasant, discovery in regard to flies.  It was always recognized that these insects might carry the germs of infection on their wings or feet, but it was not known that they are capable of taking in at the mouth such objects as the ova of various worms, and of discharging them again unchanged in their faeces.  This point has now been established, and several striking experiments illustrate it.  Dr. Grassi exposed in his laboratory a plate containing a great number of the eggs of a human parasite, the Tricocephalus dispar.  Some sheets of white paper were placed in the kitchen, which stands about ten meters from the laboratory.  After some hours, the usual little spots produced by the faeces of flies were found on the paper.  These spots, when examined by the microscope, were found to contain some of the eggs of the tricocephalus.  Some of the flies themselves were then caught, and their intestines presented large numbers of the ova.  Similar experiments with the ova of the Oxyuris vermicularis and of the Toenia solium afforded corresponding results.  Shortly after the flies had some mouldy cream, the Oidium lactis was found in their faeces.  Dr. Grassi mentions an innocuous and yet conclusive experiment that every one can try.  Sprinkle a little lycopodium on sweetened water, and afterward examine the faeces and intestines of the flies; numerous spores will be found.  As flies are by no means particular in choosing either a place to feed or a place to defecate, often selecting meat or food for the purpose, a somewhat alarming vision of possible consequences is raised.

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THE ZOOLOGICAL SOCIETY’S GARDENS.

The erection of the new house for the accommodation of the serpents, alligators, and other reptiles, which is shown in our illustration, must be commended as a valuable improvement of the Zoological Society’s establishment in Regent’s Park.  This building, which has a rather stately aspect and is of imposing dimensions, constructed of brick and terracotta, with a roof of glass and iron, stands close to the south gate of the Gardens, entered from the Broad Walk of the Park.  The visitor, on entering by that gate, should turn immediately to the left hand, along the narrow path beside the aviary of the Chinese golden pheasants, and will presently come to the Reptile House, which is too much concealed from view by some of the sheds for the deer.  The spacious interior, represented

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Scientific American Supplement, No. 415, December 15, 1883 from Project Gutenberg. Public domain.
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