486 Mlscellaneom Intelligence, 



into active combustion, and if the cylinder had been again charged 

 and subjected to a temperature capable of producing ignition, there 

 cannot be a doubt, but that a similar inflammation would have taken 

 place. 



However this might be, this quantity of material was now 

 mixed with hydrate of potash to an equal weight with the nitre 

 used ; and the mass subjected to the heat of a sand-bath for some 

 hours, and afterwards submitted to the action of a naked tire for 

 rather more than an hour, and the heat brought up to redness. 

 No considerable action took place, but some particles of the car- 

 bonaceous matter were ejected, and produced brilliant scintillations 

 in the fire, so that we may conclude, notwithstanding the presence 

 of so large a quantity of potash, the properties of the nitre were not 

 destroyed. tt p 



Canal'ttreeU Birmingham, 



III. Natural History. 



1. Squalls of Wind on the African Shores. — The following 

 description is by D. M. Milnegraden, from the relations of his 

 father. " The approach of the squall is generally foreboded by the 

 appearance of jet black clouds over the land, moving in a direction 

 towards the sea, at the same time that a gentle breeze blows 

 towards the shore. In these circumstances, the precaution which 

 my father usually adopted, was to take in immediately all sail, so 

 as to leave the ship under bare poles, and send the whole of the 

 crew below decks. As the tornado approaches nearer, the rain is 

 observed to be gushing down in torrents, and the lightning darting 

 down from the clouds with such profusion, as to resemble con- 

 tinued showers of electric matter. When, however, the squall 

 comes within the distance of about half a mile from the ship, these 

 electric appearances altogether cease ; the rain only continues in the 

 same manner. As the tornado is passing over the ship, a loud crack- 

 ling noise is distinctly heard among the rigging, occasioned by the 

 electric matter streaming down the masts, whose points serve to 

 attract it, and I think that I have been told, that when this pheno- 

 menon takes place at night, a glimmering of light is observed over 

 every part of the rigging. But when the squall has removed to 

 about half a mile beyond the ship, exactly the same appearances 

 return by which the squall was characterised in coming off the 

 shore, and before reaching the same distance from the ship. The 

 lightning is again seen to be descending in continued sheets and in 

 such abundance as even to resemble the torrents of rain themselves 

 which accompany the squall. These squalls take place every day 

 during a certain season of the year called the Harmatan season. 

 The jet black clouds begin to appear moving from the mountains 

 about nine in the morning, and reach the sea about two in the 

 afternooni Another very singular fact attending these tornados is, 

 that, after they have moved out eight or nine leagues to sea, where 



