Page:Proceedings of the Royal Society of London Vol 2.djvu/68

Rh inch, then the lamp appeared safe, under all circumstances, in mixtures of coal gas and air.

With a view to explain the non-transmission of inflammation through small apertures, the author considers the nature of flame in general; and since a piece of phosphorus, or even a small taper, will burn in the midst of a large flame made by the combustion of alcohol, he is of opinion that oxygen exists in the centre of all flame, forming an explosive mixture with the vapour, but which burns solely at the exterior surface, because it is there alone sufficiently heated to take fire.

If a piece of wire-gauze be held in the flame of a lamp, or of coal gas, no flame passes through the gauze; for though a portion of the inflammable vapour passes, it loses too much heat in its passage to propagate the flame; but in the case of inflammable mixtures of coal gas entering a lamp, and burning at the interior surface, that which is exterior has not been exposed to any heating cause, and consequently is in no danger of taking fire at the sides of the lamp; and the results of combustion which escape at the top, though heated, are no longer inflammable.

In conclusion the author informs us, that these lamps have now been tried in two of the most dangerous mines near Newcastle with perfect success; and he has great hopes that they will shortly be adopted in many of the collieries in that neighbourhood. 



The fish on which these experiments were made, were generally caught early in the morning, and examined as soon after as possible, but in some instances were kept in buckets of water as long as three days, or more.

They are frequently caught by the seine in Table Bay, to the westward of the Cape, but very rarely in Simon's Bay, which is to the eastward, and never caught by the hook with any kind of bait.

The Torpedo of the Cape differs in no respect from those of the Northern Hemisphere, except in size, which is never more than eight inches long and five in breadth. The columns of their electric organs appeared larger and less numerous than those described by Mr. Hunter. The form of any one singly is cylindric, but in a section of a whole organ the figure is modified by lateral compression. The author found the supply of nerves to these organs, agreeably to former descriptions, to be larger than to any other parts. The greatest shock they give was never felt above the shoulder, and rarely above the elbow joint, the strength of it depending more upon the vivacity of the animal than upon its size. There appeared