PREFACE. 
IX 
rity; for though Tournefort and other learned bo- 
tanifts of the laft and prefent age, had labored witli 
great fuccefs in difcovering the characters of the ge- 
nei a ; yet, through an exceflive defire of multiplying 
the number of plants, they eftabliflied new Ipecies 
on too trivial and uncertain diftinclions, to the great 
injury of the fcience; and this error appeared in its 
full magnitude in the ingenious Micheli, who was 
botanifi: to the grand duke of d'ufcany, and died 
in 1737. 
Several members of that celebrated fchool of nar 
tural hiftory, the univerfity of Upfal, have contri- 
buted to the advancement of botany, not only by 
their writings, but by their travels into remote 
countries, with a view to inveftigate the produc- 
tions of nature; as thofe of Kalin into Canada; Haf- 
felquiil: into Egypt and Palelline; Ofbeck into Chi- 
na; Loefling into Spain, and others into other 
parts of the world. 
In 1737, John Burman publifhed at AmRerdam, 
Ins ‘Thefaurus Zeylanicus^ exhibiting the plants of the 
ifland of Ceylon; and the following year he pub- 
lifhed his defcriptions of African plants. In 1739, 
Amman’s defcriptions and figures of the more rare 
plants in the Ruffian empire, were printed at Pe- 
terfburgh. The fame year Grenovius publifhed at 
Leyden, the Flora Virgmica^ treating of the plants 
obferved by John Clayton in Virginia; and in 1755, 
he publifhed the Flora orientalis. In 17^0, Royen 
publifhed his Flora Leydenfts^ in which the charac- 
ters of a great number of foreign plants are given.' 
About the fame time the Herbarium Amhoinenfe of 
Rumphius, in fix folio volumes, was printed at 
Amflerdam. Gmelin, after a hazardous journey 
through Siberia, gave the characters of the plants 
of that country, in the Flora Sibirica^ in four vo- 
lumes, the firfl of which was printed at Peteriburgh 
in X747. The learned Haller has wrote a hiftory of 
b the 
