644 PHILOSOPHICAL TRANSACTIONS. [aNNO 1755, 



the force of the bellows. But at 18 inches depth the air could freely be blown up 

 in showers, through the water ; therefore when it is requisite to blow up through 

 great depths of water, the bellows may be worked with a lever, as smiths' bellows. 



As it is foimd by experience, that the milk and butter of cows, which drink 

 stinking water, has a very bad taste, this plainly shows that the water retains its 

 putrid quality when mixed with the blood. Whence it is much to be suspected, 

 that the stinking water, which is drank in ships, by retaining its putrid quality, 

 even when mixed with the blood, may thereby promote that putrid distemper the 

 scurvy, as well as some other distempers. And much more does the putrid close 

 air in ships, which is mixed with the blood from the lungs, promote putrid and 

 other disorders. By the same means also pestilential infections are taken in : for 

 as the salutary properties of good air are conveyed by the lungs, so are also the 

 malignant qualities of bad air. Thus also the putrid water in marshy aguish coun- 

 tries, may be a cause of agues, as well as the putrid air, which they breathe ; 

 which, as well as the putrid water, may probably carry some of its putrid quality 

 into the blood through the lungs. This method therefore of sweetening stinking 

 water, by blowing showers of air up through the stinking water of some aguish 

 places, may be beneficial.* 



Live fish may well be carried several miles, by blowing now and then fresh 

 air up through the water, without the trouble of changing the water: for this 

 ventilation will not only keep the water sweet, but also enrich it with air, which 

 is necessary for the life of fishes ; with which air they supply their blood, by 

 breathing the water, thin spread, between their gills; but stinking water will 

 kill fish. He also found that much of the heating oil may be got out of tar-water, 

 by blowing showers of air up through it when scalding hot, for 15 or 30 minutes, 

 the longer the better ; the less volatile and more salutary acid remaining. 



Explanation of the Figures. — PI. 15, fig. 8, (oopr) a tin or copper air-box, 6 

 inches diameter, and an inch and a half deep from (o to p). 



The lid of the box full of holes, one 20th inch diameter, and about a quarter 

 of an inch distant from each other, (gikl) a nozel soldered to the lid of the air- 

 box, into which the tin pipe (agikl) is fixed so as to take in and out ; this pipe 

 to be 2 feet long, and -^V inch diameter, (ab) a bend in the pipe 5 inches long, 

 to which is fastened the leathern pipe (ccdt) 6 inches long ; to which the nose of 

 the bellows is fixed at (df) . 



Fig. 9, (giklooxx) the lid of the box, whose rim (oxox), is a quarter of an inch 

 deeper than the box (op fig. 8), that the air-holes (o) may be pierced in its upper 

 part ; and the lower part is scolloped with wide scollops, for the air to pass 

 through the holes (pp fig. 8.) 



• It has been shown of late years by Mr. Lowitz of Petersburgh, that putrid water may be rendered 

 gweet and wholesome by filtration through pulverized charcoal. 



