247 
precipitate produced by potash, or carbonate of potash, is also 
fusible ; but the bead is white and opaque, both in the outer 
and inner flames; it does not bubble, and the flame becomes 
coloured strongly violet. The precipitate caused by soda 
resembles that produced by potash in its behaviour before the 
blow-pipe, with the exception that the colour of the flame is 
the characteristic yellow proper to soda compounds. I think 
there can be very little doubt but that these are double salts. 
“‘ Upon adding the alkalies, or their carbonates, to the acid 
liquid produced by digesting diluted sulphuric acid upon bone 
ashes, exactly similar precipitates are thrown down. These 
are all fusible, and as the beads possess precisely similar cha- 
racters to those I have described, I need not now repeat them. 
Ifthe liquids are mixed cold, after the sediment has been re- 
moved by deposition or filtration, a further precipitation will 
happen upon boiling in the case of alkaline carbonates, but 
this second precipitate behaves before the blow-pipe in a similar 
manner to the first. 
“In conclusion, I submit to the Academy, that the pre- 
cipitate that occurs in the preparation of alkaline phosphates 
is not, as has been hitherto stated, carbonate of lime, or phos- 
phate of lime, but is a double phosphate of lime and of the 
alkali employed.” 
Dr. Anster read a Paper by the Rev. James Wills on the 
subject of Dreams. 
After some general observations on the peculiar difficul- 
ties of the subject, the author proceeded to give a conjectural 
statement respecting the probable origin of dreams, founded 
on the received theory of the nervous system. 
He then entered into some explanations, in which he 
traced the mental operations in dreaming, to the laws.of asso- 
ciation, as stated in his former Papers. 
The author next proceeded to explain two conditions by 
which the peculiar character and direction of these operations 
