TRANSACTIONS OF THE SECTIONS. 79 
trated the precipitation is instantaneous, and is almost equal in volume 
to half the solution. When, however, the solution is less concen 
trated, there is at first no precipitation, but as the liquor cools, needles 
appear, and at a certain point a large mass of precipitate is suddenly 
formed. The peculiarity of this process is, that it affords a well cry- 
stallized and fine product of morphia, without requiring the use of 
alcohol. This is owing to the circumstance that the ammonia is not 
added in a free state, but is generated in immediate contact with the 
substance to be acted upon. ‘The morphia is nearly colourless: by 
dissolving it in muriatic acid, and subjecting the solution to crystal- 
lization, we obtain muriate of morphia in perfectly white crystals quite 
pure. The milk of lime, it is to be observed, must not be added to a 
boiling hot solution of the crude opium, otherwise the precipitate 
adheres to the sides of the vessel, and does not afterwards re-dissolve 
perfectly. The liquor containing the morphia should either be coid, 
or only lukewarm when the milk of lime is added to it. If it is boil- 
ing hot, it must be added to the milk of lime, and not vice versd. 
On the Action of Nitrie Acid on the Chlorates, Iodates, and Bromates 
of Potassa and Soda. By Professor Frep. Penny. 
The present communication contains the details and results of some 
experiments undertaken with the view of obtaining additional confirma- 
tion of the correctness of the author's researches on equivalent num- 
bers. In this he has been disappointed, as the action is attended by 
circumstances which render it inapplicable to so delicate a purpose as 
the determination of equivalent numbers. The results, however, that 
he has obtained are new, and he considered them of sufficient interest 
to be worthy the attention of the Section. In order to examine the 
action of nitric acid upon chlorate of potassa, a known weight of the 
salt was mixed in a retort with a measured quantity of the acid, and 
the mixture heated on a sand-bath; as soon as it became warm, chlo- 
rine and oxygen were evolved in a state of mixture and not of combi- 
nation, and the chlorate slowly disappeared. The solution was then 
evaporated to dryness, and the saline residue was found to be a mix- 
ture of hyperchlorate and nitrate of potassa, in the proportion of three 
equivalents of the latter to one of the former. The author expresses 
the reaction that takes place as follows :— 
4(K + Cl+ O,) and 3(N + O,) =(K + Cl+ O,) and 3(K + N + Og) 
and Cl, and O,,;. 
The action of nitric acid on chlorate of potassa differs, then, from 
the action of sulphuric acid on the same salt. With nitric acid the 
salt is decomposed tranquilly, and the chlorine and oxygen are liberated 
uncombined ; whereas with sulphuric acid these gases are evolved in a 
state of combination, forming that dangerous explosive compound, 
chlorous acid. Nitric acid is therefore to be preferred for the prepara- 
tion of hyperchlorate of potassa, as with it the operation may be con- 
ducted without those violent detonations that are so apt to occur with 
sulphuric acid. The action of nitric acid on chlorate of soda is the 
