408 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. [November 18,1871. 
lowing experiments were made in the laboratory of the 
referees:— 
Three flat-flame burners (Sugg’s No. 7 batwings) 
were fixed two inches apart on a stand, consisting of a 
piece of tubing, in such a manner as to allow the posi¬ 
tions of the flames to be changed without altering the 
consumption of gas, and with the central burner always 
remaining at the same distance from the photometer 
disk. 
The illuminating power was first determined by plac¬ 
ing a stand at a right angle to the point of view (or to 
the photometer bar), and with the flat side of each flame 
exposed to the photometer disk, so as to allow the light 
from each burner to pass to the disk without any ob¬ 
struction. The number thus obtained was taken as 100. 
The stand remaining in the same position as before, the 
burners were turned half round, so as to present the 
edge of the flame to the photometer. The illuminating 
power was again determined, and found to he only 85"5, 
showing a loss of 14-5 per cent. The stand was now 
placed in a line with the photometer bar, the flat side of 
the flames being exposed to the disk. In this position 
the illuminating power was 90-6, showing a loss of 9-4 
per cent. The burners were then turned half round, 
bringing the flames in a line with the photometer-bar 
and edgeways to the disk. In this position the illumi¬ 
nating power was only 71*3, the loss being 28-7 per 
cent. 
The following rough diagram will perhaps show, more 
clearly than a verbal description, the effect of the several 
arrangements of the gas-flames (marked —) upon the 
amount of light received from them on the photometric 
disk, marked *:— 
* 
-=71* 
A similar set of experiments were made, at Mr. Sugg’s 
works, with five fishtail burners (Sugg’s No. 6) placed 
2 ^ inches apart, the consumption of each burner being 
regulated, as in the previous experiment, to a uniform 
quantity by means of a separate governor. The results 
are shown in the following diagram :— 
No. 1. 
| \ 
I 
| =100 
I 
I / 
No. 3. 
— , = 95 
No. 4. 
In this experiment the loss of light from obstruction 
appears less than in the former one, instead of greater, 
as it ought to have been when more burners were used. 
But, owing to the greater length of the stand upon 
which the burners were fixed (10 inches instead of 4), 
the light from the outer burners in the second experi¬ 
ment, when placed in a line at right angles to the photo¬ 
meter-bar, falls only indirectly on the disk ; so that the 
illuminating power in position No. 1 ought to be 
reckoned higher than the actual reading of the photo¬ 
meter as given in the diagram. And in position No. 3 
the illuminating power ought to be reckoned as lower, 
in consequence of the outer burners giving their- light not 
really from the edge of the flames, but partly from their 
sides. Accordingly, although fewer burners were used 
in the first experiment than in the second, the photo¬ 
metric results obtained from the former may be regarded 
as more correct than those given by the latter. 
Erorn both of these experiments, however, it appears- 
conclusively that gas-flames are not perfectly transparent, 
and considerably obstruct the light of other such flames 
placed behind them. Also, the loss of light by such ob¬ 
struction was greatest when the flames were placed edge¬ 
ways to the photometer, in which position the depth of 
flame through which the posterior light had to pass was 
greatest. 
MEDICATED WATERS. 
BY R. ROTHER. 
This apparently unimportant subject has been under 
discussion by many commentators, especially those of 
Europe, and closer scrutiny of it reconciles the opinion 
that further study in its behalf is obviously j ustifiable. 
Most of the medicated waters, particularly the aromatic, 
were formerly directed to be prepared by distillation, 
and at the present day it is the only authorized method 
in most of the states of Continental Europe. The 
United States Dispensatory, in its comments upon the 
subject, sets forth the disadvantages of the method by 
distillation and the resulting products as compared to 
our simple and more expeditious officinal method, and the 
more satisfactory character of its results. 
Yet, notwithstanding the superior elegance of the 
United States’ officinal process, the use of magnesium car¬ 
bonate for this purpose is open to a fatal objection, owing 
to the circumstance that magnesium carbonate is not in¬ 
soluble in water. The Dispensatory states that the alka¬ 
line character of the water thus acquired decomposes the 
salts of morphia, mercury and silver by precipitating 
their insoluble bases, and that eventually a part of the 
magnesium carbonate itself separates. 
By reason of the viscid flakes that separate from some 
medicated waters thus prepared, and the heavy crusts of 
magnesium carbonate which by time deposit from all, it 
is probable that either a portion of the magnesium hy¬ 
drate, of which the officinal magnesium carbonate is 
largely composed, is first dissolved by the water and 
subsequently again precipitated as carbonate by absorp¬ 
tion of carbonic acid, or that by the use of cold water a 
greater amount of magnesium carbonate is dissolved, 
which again deposits as the temperature of the water 
rises, or that the acidity of some oils which are not fresh 
causes the temporary solution of the magnesium com¬ 
pound. The object of the magnesium carbonate is to- 
effect the solution of the volatile oil by presenting it in 
a finely divided condition to the utmost available action 
of the solvent. Other insoluble solids are occasionally 
employed to meet the same end, and the supposition pre¬ 
vails that such a procedure alone, aside from distillation, 
will ensure a saturated solution. The Dispensatory in 
this connection refers to the older method of the Dublin 
Pharmacopoeia as being totally insufficient in compari¬ 
son, since this consisted simply in agitating an alcoholic 
solution of the oil with water, whereby it is thought but 
a very feeble impregnation of the water is effected; and 
furthermore, that the minute quantity of alcohol thus- 
introduced was objectionable per se , aside from the fact 
that it is liable, by the high degree of dilution, to pass 
into the acetous fermentation and render the water sour. 
However, no medicated water of any kind should bn 
kept so long on hand as to become deteriorated by time; 
the simplicity of the modern processes admits of no 
apology for that. 
The most perfect and convenient process by which the 
division of the volatile oil can be secured so as to expose- 
the greatest possible surface to the contact of the solvent, 
is beyond dispute the method of precipitation, and this is. 
