i 877 *] Technology. 143 
until all the iodine is precipitated as iodide of lead, which is then separated 
by filtration and treated for the production of iodine or iodides. After filtration 
the liquid is boiled, nitrate of soda is added to convert the chloride of potassium 
present into nitrate of potash. The latter is separated by crystallisation. 
There remains a solution of common salt containing traces of ammonia from 
the previous soda operation and a trace of chloride of potassium. This solu- 
tion is again treated by the ordinary ammonia-soda process for the production 
of bicarbonate of soda and white alkali. 
Under the title of “ Country Laboratory Apparatus,” Mr. Edward T. Hard- 
man, F.C.S., of H.M. Geological Survey, Ireland, describes a substitute for 
crucible jackets, useful to those who have occasion to shift their quarters 
often, and are obliged to work with a necessarily limited laboratory accommo- 
dation. The ordinary crucible jacket being made of sheet-iron has in reality 
but one use — to protect the flame from currents of air. An ordinary earthen- 
ware flower-pot answers the purpose in every respect. It is the proper shape, 
and being made of anon-conducting material it in a great measure prevents 
loss of heat from the burner. The bottom of the flower-pot has a circular 
hole : this serves for the introduction of the Bunsen burner. As the supply of 
air would be otherwise insufficient, it will be necessary to enlarge the opening 
This can be easily done by cutting the aperture nearly in the form of a cross, 
and not too large. A current of air is then obtained which not only steadies 
the flame, but acts in some degree as a blast. The flower-pot may be sup- 
ported in the ring of a retort-stand in the usual way. The chimney is a 
second flower-pot inverted. To support it the handiest way will be to make 
three S hooks of stout wire, and having passed the narrow end of the pot 
upward through the ring, fix the rim within the hooks caught on the ring, as 
in Fig. 1. The apparatus acts admirably as a small gas furnace for crucible 
operations, such as the fusion of silicates with carbonate of soda — as in the 
analyses of rocks ; while for simple ignition of precipitates it renders the flame 
of a common glass spirit-lamp most eiiective. The size of the flower-pot 
required will, of course, depend on that of the crucible and of the burner used. 
The support for the crucible may be either a triangle of wire covered with 
