THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
[July 13, 1872. 
31 
.merits in clauses 4 and 5 that would have the effect of 
making compulsory the appointment of analysts and the 
duties of inspectors in procuring samples of suspected 
articles for analysis. He also proposes to add the follow¬ 
ing definition of adulteration:— 
“ The word ‘ adulteration,’ shall mean,— 
“1. The admixture of any mineral substance (excepting 
the harmless compounds of pctash, soda and ammonia) 
with any article of food or drink. 
“ 2. The admixture of anything with an article of food 
or drink for the purpose of increasing its hulk or alter¬ 
ing its natural strength or flavour, unless such admix¬ 
ture is declared by the dealer or vendor to the purchaser 
.at the time of sale, or unless such admixture is clearly set 
forth in a label upon the article.” 
PAPERS PRESENTED TO PARLIAMENT. 
Report of Sulphur Purification at Beckton Gas¬ 
works by the Gas Referees. 
This Report has been made by the Gas Referees to 
tthe Board of Trade, in consequence of the disappointing 
.failure of the sulphur purification at the magnificent 
.gasworks at Beckton. For a considerable time there 
has been great dissatisfaction in the City of London with 
the gas supplied by the Chartered Company, in conse¬ 
quence of the large quantity of sulphur present in it. 
A correspondence, sufficiently acrimonious in some parts, 
accompanying this report, shows that for the last three 
years this point has been urged upon the attention of 
the responsible parties, and that the time of the com¬ 
pletion of the large gasworks at Beckton has been looked 
iforward to as the time when a satisfactory answer would 
be given to the complaints. But it is mortifying to find 
that, notwithstanding the care, skill and capital that 
Rave been brought to bear towards the solution of the 
problem how best to rid the gas of its impurities before 
its delivery to the consumers, the sulphur detected in 
the gas supplied from the new works when opened was 
more in proportion than in that from the older works. 
Of course, such a result was immediately made the sub¬ 
ject of investigation, and various experiments were tried 
in order to remove this grave defect; but these were 
mostly of special interest only to the gas engineer; and 
we shall confine ourselves to mentioning some general 
conclusions at which the gas referees arrived, and which 
they hope will exercise a beneficial influence on the gas 
manufacture in the future. 
The report relates exclusively to the sulphur in gas 
which exists in other forms than sulphuretted hydrogen. 
•Of sulphuretted hydrogen not a trace has ever been 
found in the gas supplied from the Beckton works, 
.although the test slips are now used for three or four 
•hours continuously, instead of one minute, as prescribed 
•by the Act of 1860. But the other forms of sulphur 
impurity have hitherto baffled the efforts of the ablest 
and most experienced gas engineers and gas chemists to 
eliminate them from the gas, or even to devise any cer¬ 
tain method by which they may be materially reduced 
and efficiently controlled. The “purifiers” at the 
Beckton works are larger in proportion to the make of ga 3 
than at any other gasworks in the country; and it was 
hoped that the hitherto insurmountable difficulty would 
•be at an end; but the result, described by the gas refe¬ 
rees as a “ complete and most startling failure,” shows 
how little the subject is yet understood. 
Opposite opinions have been maintained as to the best 
manner of using lime and oxide of iron in combination 
.as purifying agents ; one opinion being that the oxide 
should be placed before the lime, the other that the lime 
should be placed first. At Beckton, the former plan 
was adopted ; but experiments made by the gas referees 
having convinced them that the gas should pass through 
ithe lime first, in June last the conditions were, at their 
•request, reversed. 
The new mode of purification came into operation in 
the beginning of August. At the outset the result was 
most successful and gratifying, the sulphur for some 
weeks averaging only 10 and 15 (instead of 43) grains 
per 100 feet of gas. 
The superior efficiency of this arrangement over the 
other consists in this, that clean lime has no appreciable 
effect in eliminating the “ sulphur,” i. e. the sulphur 
compounds other than sulphuretted hydrogen; the lime 
has to be fouled by sulphuretted hydrogen (i . e. con¬ 
verted into sulphide of calcium) before it has this effect. 
Now, this “fouling,” or conversion of the lime into sul¬ 
phide, cannot be attained if the oxide of iron is used 
before the lime, for the sulphuretted hydrogen is taken 
out by the oxide; so that the lime, through which in 
this case the gas passes subsequently, is never converted 
into sulphide, and therefore cannot act upon the “ sul¬ 
phur.” But when the gas is passed into the lime before 
passing through the oxide of iron (in other words, while 
the gas is still charged with sulphuretted hydrogen), 
the lime absorbs the sulphuretted hydrogen, thereby be¬ 
coming sulphide of calcium, in which condition it tends 
to absorb the sulphur as it exists in the gas in other 
forms than sulphuretted hydrogen. 
Unfortunately and most unexpectedly, the favourable 
change was only transient; for towards the end of Sep¬ 
tember the sulphur again increased in quantity, and ere 
long became as great as before. 
Another point to which the attention of the referees 
was directed was the temperature under which the gas 
was distilled from the coal. It may be roughly stated 
that a high heat causes tho coal to yield a greater quan¬ 
tity of gas, though of inferior illuminating power. When 
the retorts are over-heated the hydrocarbons are more 
quickly given off, leaving the coke to be roasted, in 
which case a larger amount of “ sulphur ” would be pro¬ 
duced than usual. According to the ordinary estimate, 
about one-half the sulphur originally in the coal remains 
in the residuary coke; but unquestionably the higher 
the heat to which the coke is subjected the larger will 
be the proportion of the sulphur driven off. Moreover, 
the hydrogen, having been already driven off, the sul¬ 
phur vapour from the coke will tend to combine with 
the glowing carbon, forming bisulphide of carbon, i. c. 
the “impurity other than sulphuretted hydrogen.” 
Although it would appear that on the whole the heat 
used at Beckton is lower than at other London gasworks, 
it is thought possible that part of the excess of sulphur 
may result from the overheating of particular retorts. 
Sulphur exists in coal chiefly in combination with 
iron, as pyrites, and also to a small extent in union with 
lime and magnesia, as sulphates ; but as the two latter 
compounds do not readily part with their sulphur, even 
under the high temperature of the retorts, it is only the 
sulphur which exists in the coal as pyrites that is given 
off in the gas, forming sulphuretted hydrogen, bisulphide 
of carbon, and it may be to a small extent other com¬ 
pounds not yet ascertained. It is the accepted belief in 
gasworks that some kinds of coal produce more bi¬ 
sulphide of carbon in the retorts than others; but it 
seems to the referees that it would be more correct to say 
that these kinds of coal only tend to produce more “ sul¬ 
phur” in the gas by yielding more or less of other pro¬ 
ducts (NH 3 C0 2 , etc.), which, as will appear in the sequel, 
considerably affect the action of the purifying processes 
upon the “ sulphur ” impurity. 
This is a point that has never hitherto been noted, but 
in the proper elucidation of which the referees believe 
will be found an explanation of part of the failure. 
The process of cooling and condensing the gas by a long 
series of pipes placed under ground (such as was mainly 
employed at Beckton), although possessing some impor¬ 
tant advantages over the other processes, especially as 
regards the illuminating power ( e . g. 1, by preventing 
any sudden cooling of the gas; 2, by keeping the tar 
for a longer time in contact with the gas; and, 3, by 
