162 An Inquiry concerning the 
avail, and this cannot be added in fufficient quantity without 
caufing it to fink into, and fpread upon the paper; fo that, 
sideeui its ufe is altogether interdiéted. The beft plan which 
{ have Hitherto found as a preventive to the vegetative pro- 
cefs I here allude to, is, to add the ingredients of which the 
ink is compofed to the cold decoétion 5 if recourfe be had to 
boiling, ALL together, it is found very rapidlv to promote the 
itt aise h's ; and were ebullition totally avoided, it would 
on that account be better, but then we could not obtain the 
ink of fo deep a colour; yet I know of no inftance in which 
mouldinefs wiil not appear in time, and that in no inconfider- 
able degree. In fine, I am ignorant of any fubftance, or me- 
-thod, that has been hitherto ufed as a fpecific to remedy the 
 defe&t. If there is any that can be fuggefted, I fhould be 
happy to put it to the teft of experiment. 
Iam, Sir, yours, &c. 
L. DESORMEAUX jun, 
No. 8, Vine Court, Spitalfields. : 
. 
IX. An Inguiry concerning the Weight afcribed to Heat. | By 
BensaAmMin Count Rumrorp, F.R.S.M.R.LA. &e, 
Read before the Royal Sogiety May 2, 1799. 
"Tue various experiments which have hitherto been 
made with a yiew to determine the queftion fo long agi- 
tated, relative to the weight which has been fuppofed to be 
gained, or to be loft, by bodies upon their being heated, 
are of a nature fo very delicate, and are liable to fo many © 
errors, not only on account of the imperfections of the in- 
framents made ufe of, but alfo of thofe, much more difficult 
to appreciate, arifing from the vertical currents in the atmo- 
fphere, eaufed by the hot or the cold body which is placed 
in the balance, that it is not at all furprifing that opinions 
have been fo much divided relative to a faét fo very difficult 
to afcertain. 
Yt is'a confiderable time fince I firft began to rexeaipine on 
this fubje&, and I have made many experiments with a view 
so its inveftigation; and in thefe experiments | have taken 
all 
