Intelligence and Miscellanies. 367 
ferent occasions, known the phenomena to vary much in ac- 
tivity ; having in some instances seen the phosphorus thrown 
up against the ceiling of my laboratory. It was therefore 
. known to me, and | presume tt is generally known to chem- 
ists, that the reaction of the substances employed in the case 
above mentioned is liable to become explosive. According- 
ly in giving pe ibivaorse for making phosphoric acid by means 
of nitric , the necessity of a very cautious and gradual 
addition of th phosphorus is usually mentioned, but that an 
explosion so violent as that which I have described, could 
arise, under the circumstances in question, I was not led to 
apprehend, either from my reading or experience. 
[ascribe the result to the extraordinary strength of the 
acid employed, probably caused by using in the evolution of 
it from nitre, one half more of sulphuric ‘acid than the equiv- 
alent proportion, with a view of rendering the residuum less 
difficult to remove from the retort. The presence of an ex- 
cess of sulphuric acid, reduces the water in the nitric acid to. 
a minimum, 
REMARKS BY THE EDITOR. 
I am pleased that the above facts and cautions have been 
communicated by Dr. Hare to the public; and it may pert 
haps, add to their effect, if. I state, that I saw a similar 
plosion at a public lecture of Dr. Woodhouse i in Philadel. 
phia, in 1803 or 4, and also at one of Dr. Pearson aaehobaiat, 
in 1805: the burning ehosnless _ thrown en 
the occurrence was unexpected to both h gentlemen, thay 
apologised to their hearers for the yee 
I will here give an oxtings from the MS. of my Chemica! 
Text Book, now in the pres 
“ Phosphorus is oneetel: ‘into phosphoric acid by the ac- 
tion of the nitric acid: if weak, it merely boils, with red fumes 
of nitrous acid ; if very strong ,and especially if warm, it burns 
* This circumstance has happened so often, in my own experience, with ni- 
ws _ distille d from very pure nitre, a anges any water in the receiver, 
I cannot but repeat the caution tha rator should be much on his 
pei With a stick of phosphorus as se as a finger, dropped into two or 
