302 
DR. E. DIVERS ON THE UNION OE 
As was stated in the previous section, the temperature above which ammonia nitrate 
and ammonia cease to unite is about 23°-24° ; for on bringing these bodies in contact 
at a temperature belotv 23°, this soon rises to that of 23°-24° (the temperature evidently 
varying with the atmospheric pressure) and remains at this point, even (after some 
liquefaction has taken place) when the ammonia, before it comes in contact with the 
nitrate, is heated several degrees above 23°, the result in this case being, without doubt, 
due to the destruction that then takes place of the liquid already formed. 
The boiling-point of the liquid, when saturated with nitrate at 23°, was found to be 
about 26° ; but as the liquid boils irregularly, it is very probable that the true boiling- 
point lies a few degrees below this. 
6. For the purpose of taking the specific gravities of the products obtained by using 
different proportions of ammonia and nitrate, a flask was employed having a long 
graduated neck. Different quantities of nitrate were weighed in it, and then into each 
quantity ammonia gas Avas passed until the resulting liquid filled it at 15° -5 to some 
point in the neck. The body of the flask was globular, had stout walls, and contained 
nearly 46 cubic centimetres. The neck consisted of a piece of barometer-tube, sur- 
mounted by a larger tube, into Avhich it abruptly expanded. This part of the neck 
served as a funnel, and also to receive any of the liquid carried by the bubbles of 
ammonia above the top of the narrow tube. It was made without everted lip, so as to 
facilitate the scooping up of the nitrate by it. The shoulder it formed with the narrow 
part of the neck served to retain the Avire used to bind down the caoutchouc stopper. 
The narrow, graduated part of the neck Avas about 7 centimetres long, and had an 
internal diameter of about 6^ millimetres. The Aveight of water at 15°-5 held by the 
flask to the level of every twentieth graduation, of Avhich there were sixty-five, Avas 
experimentally determined; intermediate quantities Avere calculated. The delivery- 
tube for the ammonia Avas a slender one, in order that it might leave as much room as 
possible in the neck for the rise of bubbles through the liquid ; but even with this 
arrangement the liquid sometimes rose into the funnel, and did not always satisfactorily 
drain down again. 
The folloAving specific gravities were taken : — 
No. 
Ammonia nitrate. 
Ammonia. 
Specific gravity. 
1. . . 
. 1000 parts. 
495-5 parts. 
1072-5 
o 
jLi. • . 
. 1000 
55 
392-5 
55 
1119-95 
O 
o. 
. 1000 
55 
385 
55 
1126-05 
4. . . 
. 1000 
55 
334 
?5 
1155-9 
5. . . 
. 1000 
55 
316-5 
55 
1167-05 
6. . . 
. 1000 
55 
281-5 
55 
1191-65 
7. . . 
. 1000 
55 
272 
55 
1199 
( L'he liquid No. 7 crystallized when cooled to the standard temperature, so that its 
specific gravity had to be taken at a higher one, and from this its specific gravity at 
