572 PHILOSOPHICAL TRANSACTIONS. [aNNO 1748. 



the heart; g, g, the kidneys, rather mis-shapen; h, h, the trunks of the large 

 vessels descending to the lower extremities; the vein running before the artery, 

 and sinking behind it again vi^here it divides; i, the right ureter; k, the bladder; 

 and 1, the umbilical arteries, with the urachus turned down, to show m, the 

 uterus, &c. ; n, n, is an artery communicating with, and entering into, the aorta 

 of each, near the going off of the emulgents; o, the heart of the smaller child, 

 much too large in proportion, with the right auricle; p, part of the lungs, which 

 were rendered much too small, in proportion, by the compression of the large 

 heart upon them; q, the aorta and pulmonary artery, as they are connected by 

 r, the canalis arteriosus ; s, t, the descending trunks of the veins ; the latter of 

 which was preternatural, running round the left, and entering into the right au- 

 ricle in its posterior part. 



The other parts were much as those of the former child in general; except 

 the aorta, which was much smaller, as the figure shows. 



On the Preparation and Uses of the various kinds of Potash.* By John Mit 

 chel, M. D. and F. R. S. N° 489, p. 541. 



It is well known, that the ashes of all kinds of vegetables whatever aiford 

 potash in some measure or other; though some are much more fit for that 

 purpose than others, which may be determined from the experiments of Redi in 

 the Philos. Trans. N" 243, Boerhaave, Merret, and others; so that we need not 

 insist on them here. 



Most of the trees and herbs that are common in the American woods are 

 known to be fit for this purpose, as the ashes of them all, burnt promiscuously 

 in their houses, make a very strong lee fit for soap. Of these, the fittest for that 

 purpose is the hiccory, the most common tree in their woods, which makes the 

 purest and whitest ashes, of the sharpest taste, and strongest lee, of any wood. 

 Their stickweed is said to do the same, which is as common a weed. For this 

 reason the ashes of both these plants were used by the Indians there, instead of 

 salt, before they learnt the use of common salt from the Europeans. The ashes 

 of damaged tobacco, or its stalks, stems, and suckers, of which great quantities 

 are thrown away, and rot and perish, are very fit for potash, as they contain a 

 great deal of salts, and are well known to make a strong lie. 



On the other hand, pines, firs, sassafras, liquid amber, or sweet gum, or aU 

 odoriferous woods, and those that abound with a resin or gum, are unfit for pot- 

 ash, as their ashes are well known to make a very weak lie, unfit for soap. 



Besides these, that contain little or no salt, there are some other vegetables 



• See an interesting paper on the same subject by Mr. Kirwan, in the Memoirs of the Roya} 

 Irish Academy. 



