[509] 
tea cup, concreted in a very uncommon manner. In 
the middle of the tea cup it arofe fomething lilce a 
plant, or a fountain, where the water is dilcharged 
from a number of pipes, and fpread from the bot- 
tom of this, fo as to cover both the infide and out- 
fide of the cup, with a iweetiih, white, mealy, fa- 
line crufi, which in many places teemed difpoied 
like the fine fibres of plants, or of the leaves of 
trees. 
2. Asa further proof of the flowers of benzoin 
being an acid of a particular kind, I latu rated tome 
of them with the fal volatile ammoniacum, evapo- 
rated and cryflallifed; and obtained an ammonia- 
cal fait, which had a very Angular appearance. It 
was covered on the top with a very white laline 
pellicle, below which were a number of thin, fiat,, 
white tranfparent cryftals, the greater number ot 
which feemed to be exadt fquares, fome few, oblong, 
parallelograms, fuch as are reprefented in fig. 22. 
The flowers of benzoin generated a considerable 
degree of cold in the time of their faturation with 
the volatile alkali; they funk the quickfilvei in the 
thermometer from 52 to 46. 
Experiments III. and IV . 
With the fait of amber. 
The fait of amber is now generally known to be 
of an acid nature ; but from what Mold. Bourdelin 
has laid of it, in the Memoirs of the French Aca- 
demy of fciences for the year 1742, ac ^ 
„ been 
