444 PHILOSOPHICAL TRANSACTIONS. [aNNO ISQI. 



the top ; and of this plant, it is said, in Barbadoes impregnable fences are 

 made. Others say they may be raised from the seed, or small grains, which 

 are to be found in the proper season in the fruit, which is something like a fig, 

 arising out of certain yellow flowers that grow out at the tops of the uppermost 

 leaves, which fruit is full of a red pulp, that when full ripe stains the hands, 

 like mulberries, with a purple colour, whereon, or on the blossoms, some say 

 the insects feed ; which perhaps may be the occasion of that rich tincture within 

 their bowels. It may be inquired likewise, whether those grains, which are the 

 seed of the fruit, may not produce some tincture, as well as the dried insects ; 

 or whether, whilst they are maggots, or small grubs, being ordered and dried 

 as above, they may not shrivel up like grains, and be as good as when they are 

 become flies with wings. 



Some Experiments and Observations made of the Force of the Pressure of JVater 

 at great Depths, made and communicated to the Royal Society by a person of 

 Rank. N° IQS, p. 504. 



Being off Pantalaria, near Sicily, in a calm, I let down a bottle 70 fa- 

 thoms, stopped with a very good tender cork, well fitted, and bound down ; 

 and the cork came up in the bottle, which was three quarters full of salt water. 

 The bottle was then again fitted with a very good cork, but of a woodiness or 

 hardness as some corks are. This cork continued in its place, but as it were 

 bruised, and the bottle, as before, about three quarters full of salt water. I 

 then took a good ox bladder, and bound it four-fold over the mouth of the 

 bottle, without any cork at all, only I put a piece of leather to keep the glass 

 from cutting the bladder, as it might otherwise do, having rather a sharp 

 mouth ; and so ordered, it was let down as before, but when taken up again, it 

 was without any water, or the least moisture in it. 



Another time being in a dead calm, some leagues distant from the coast of 

 South Spain, off the great hills of Granada, we took a bottle, and spread a lea- 

 ther on the mouth of it, tying over that a single part of a bladder, which was 

 then let down 75 fathoms; but it came up again quite entire. — Whereupon 

 thinking that the leather in great measure had contributed to the resistance the 

 bladder had made, as the same was marked very much by the force of the pres- 

 sure against the mouth of the bottle ; we made a hole in the leather about the 

 size of a large pea, and let the same again down 75 fathoms; but it came up 

 perforated in the vacant place where the leather had the hole in it, and almost 

 full of water. We then bound over another cover of bladder single, and let it 

 down only 30 fathoms, but it came up whole and entire. Whereupon imme- 

 diately we let it down 50 fathoms, and then it came up broken and full of water. 



