Scientific American Supplement, No. 441, June 14, 1884. eBook

This eBook from the Gutenberg Project consists of approximately 118 pages of information about Scientific American Supplement, No. 441, June 14, 1884..

A few years ago I had a gentleman under my charge who would attempt to execute any order given him while he was asleep by a person whispering into his ear.  Thus, if told in this way to shout, he shouted as loud as he could; if ordered to get up, he at once jumped from the bed; if directed to repeat certain words, he said them, and so on.

I am not able to give any certain explanation of the phenomena of miryachit or of the “Jumpers,” or of certain of those cases of sleep-drunkenness which seem to be of like character.  But they all appear to be due to the fact a motor impulse is excited by perceptions without the necessary concurrence of the volition of the individual to cause the discharge.  They are, therefore, analogous to reflex actions, and especially to certain epileptic paroxysms due to reflex irritations.  It would seem as though the nerve cells were very much in the condition of a package of dynamite or nitro glycerin, in which a very slight impression is sufficient to effect a discharge of nerve force.  They differ, however, from the epileptic paroxysm in the fact that the discharge is consonant with the perception—­which is in these cases an irritation—­and is hence an apparently logical act, whereas in epilepsy the discharge is more violent, is illogical, and does not cease with the cessation of the irritation.

Certainly the whole subject is of sufficient importance to demand the careful study of competent observers.

* * * * *

THE GUM DISEASE IN TREES.[1]

  [Footnote 1:  Communicated to the Medical Times by Sir James Paget.]

An essay by Dr. Beijerinck, on the contagion of the gum disease in plants, lately published by the Royal Academy of Sciences at Amsterdam, contains some useful facts.  The gum disease (gummosis, gum-flux) is only too well known to all who grow peaches, apricots, plums, cherries, or other stone fruits.  A similar disease produces gum arabic, gum tragacanth, and probably many resins and gum resins.  It shows itself openly in the exudation of thick and sticky or hard and dry lumps of gum, which cling on branches of any of these trees where they have been cracked or wounded through the bark.  Dr. Beijerinck was induced to make experimental inoculations of the gum disease by suspicions that, like some others observed in plants, it was due to bacteria.  He ascertained that it is in a high degree contagious, and can easily be produced by inserting the gum under the edge of a wound through the bark of any of the trees above named.  The observation that heated or long boiled pieces of gum lose their contagious property made it most probable that a living organism was concerned in the contagions; and he then found that only those pieces of the gum conveyed contagion in which, whether with or without bacteria, there were spores of a relatively highly organized fungus,

Copyrights
Project Gutenberg
Scientific American Supplement, No. 441, June 14, 1884. from Project Gutenberg. Public domain.
Follow Us on Facebook