THE PREPARATION OF ALKYL-SULPHINE, SELENINE, AND PHOSPHONIUM SALTS. 47 
that a considerable risk is run of losing one’s time and labour and material by 
violent explosions. Letts, indeed, found that it was impossible to avoid losing the 
large majority of his tubes; and, though we have not found this to be the case 
when all precautions are taken, we agree with him in considering this objection as 
a serious one. 
It is obvious that a general method of preparing such compounds as the iodides 
of triethyl-sulphine, triethyl-selenine, and tetraethyl-phosphonium, which gives good 
yields, which does not involve the use of any poisonous or troublesome compounds 
of sulphur, selenium, or phosphorous, and which avoids loss of material by explosions, 
is one that should be acceptable to chemists. 
We have found the following method work well. Its most important features 
are the use of the elements themselves (sulphur, selenium, or phosphorus), the 
conversion of these direct into polyiodides by heating with ethyl iodide, and the 
decomposition of these polyiodides by means of water and hydrogen sulphide. The 
following equations illustrate the formation of sulphine salts by this method :— 
(1) § +36¢,H,1=S (GH, 1 
(2) § (C,H,),1,+ H,S=8 (CH,),1+2H1+S8 
(1) Powdered roll sulphur and ethyi iodide are mixed in the proportions 
indicated in the equation, and are heated in sealed tubes for 24 hours at 180°C. 
There is but slight pressure developed (due to the formation of a combustible gas by 
a secondary reaction), and no special precautions are necessary in making the tubes. 
When cold they are seen to contain a quantity of a semi-liquid black substance, 
easily recognised as a polyiodide by anyone accustomed to work with such bodies. 
The sulphur is seen to have entirely disappeared. 
(2) The tarry polyiodide is washed into a tall cylinder, and covered with water 
to the depth of a few inches; and a current of hydrogen sulphide is then passed 
in until all the polyiodide has disappeared, leaving a deposit of sulphur and a 
clear acid solution. 
(3) This solution, decanted from the sulphur, cannot be evaporated direct, as 
the free hydriodic acid present reacts with the triethyl-sulphine iodide. It may be 
treated with excess of moist silver oxide, so as to precipitate all the iodine as silver 
iodide, and leave a solution containing only the free base, S (C,H;); OH; and from 
this any desired salt may of course be obtained by neutralisation with the proper 
acid. 
It is necessary to use excess of silver oxide, z.c., more than enough to react with 
all the hydriodie acid and all the sulphine iodide present in the solution. In our 
