On the Preparation of the Hyaeinthns non/criptus. 103 



adjuftments, obfcrvations may be made fufficiently accurate 

 for anfwerina: the ends of pracSlical artronomy. 



We expe6l foon to have the lunar tables brought to a 

 greater degree of perfection, by applying certain equations 

 that have been lately difcovered, and by which thole pur- 

 pofes will, of courfe, be more fuccefsfully promoted. It is 

 alfo much to be wiflied that the moon's Iranfits were as afli- 

 duouflv obferved bv public and private aftronomers in every 

 country as they are at the royal obfervatory in this, and from 

 time to time communicated to the public at large. 



It fometimes, but not very frequently, happens, that fa- 

 vourable weather will permit one alironomer to obferve four 

 tranfits of the moon over his meridian in the fame number 

 of fucceeding days. If another, or indeed a hundred others, 

 fliould obferve only one or two on any of thofe days, whether 

 at the neare(t or remoteft Nations from the firil meridian ; 

 fuch obfervations are of creat value, and afford the very befl 

 means of finding the difference of longitude with accuracy, 

 becaufe the errors of the lunar tables are thereby completely 

 obviated. 



Paraililc Row, Tflingron, 

 February 14, 1803. 



XIX. On the Vreparatiim of the Hyacinthus non fcr'iptus, or 

 common Blue-Bell, as a SubjHtute for Gum-Arabic. Bj 

 Mr, Thomas Willis, of Lhne- Strut, London*, 



AN the year 1794, whilft collefting plants in a wood for 

 botanical fpecimens, I obferved that the root of the hyacin- 

 thus non fcriptus, the plant commonly called blue-bells,- or 

 hare- bells, was extremely mucilaginous; and, on tafling it, 

 I difcovered only a very flight pungency. I colleAed a pound 

 of the bulbs, and, after flicmg and drying them before a fire, 

 they yielded about four ounces of powder. I thought that, 

 by keeping the powder fome time, the little acridnefs might 

 go off, as it does in the arum-root i)owdcr. I tafled it about 

 fix months after, and found it perfeftly infipid. I concluded 

 it might be rendered ufeful for food or nourifhment, but at 

 that tune purfued the matter no further. 



In the fpring of i<Soo, gum-arabic having been a long 

 time very dear, and likily to continue fo, I thought this 

 mucilaginous root might anfwer fome of its purpofes for ex- 

 Itrna! ufe. I therefore procured fcven pounds and a half of 



* Krom llie 'tra>.f,.ifiioiii of I be Socitly foi ihe F.niomagimi nt 0/ Ayi!,is:>'. . 

 Vol XX,, who voted a lU'cr rr.cd°.il ro the uutlior for hh commuiiicRtion. 



11 4 the 



