December 23,1871.] THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
519 
the only question open to dispute is whether the process 
fairly indicated its amount. 
[The reduction process furnishes a ready means for assay¬ 
ing precipitates of morphia obtained by the usual methods. 
These precipitates should always be washed with chloroform, 
and their solutions shaken with carbon disulphide before 
being submitted to the test.] 
Mr. Groves said “ he should be surprised if such a compli¬ 
cated process could be got through in two hours and a half.” 
I can assure him, however, that the work is quite easy of 
execution, and may be completed (not, of course, including 
the drying) in the time mentioned. 
It appears Dr. Tilden would question the accuracy of any 
volumetric process for morphia until the reactions of the 
“ twenty-five different alkaloids described as having been de¬ 
rived from opium ” have been ascertained. From this point 
of view the prospect is dismal enough, and the case for the 
present, at all events, quite hopeless. 
After all, let me repeat that I do not put forward my 
method as being accurate in the strict scientific sense, but as 
affording “nearer approximations to the truth” than are 
obtainable by the inexact processes in common use. This 
notion may be erroneous, but if so the proof will consist, not 
of opinions, but of facts. 
Sheffield, December, 1871. John T. Milleb. 
Peofessob Tyndall’s Theoey of the Blue Coloue 
of the Sky. 
Sir,—Utterly unwarranted by any connection whatever, 
-except from the fact of being a subscriber to your valuable 
periodical, I take the liberty of addressing you on a subject 
which has for me peculiar attractions. 
In the eleventh Conversazione of the Liverpool Chemical 
Association, held February 3rd (Phakm. Jouen., February 
18th, 1871, p. 671), Mr. Albert EC. Samuel states, “The long 
red waves have also a much greater amplitude or depth than 
the short blue waves, and are thereby enabled to roll over or 
pass by small obstacles -which would interrupt and throw 
back the short and shallow blue waves,” . . . and “ the long 
deep red waves roll over or pass by these small particles, but 
the short shallow blue waves are stopped by them and thrown 
hack or scattered into space, to which they communicate the 
blue appearance -which we call sky.” 
1. I desire to ask if, on spectral analysis, any sunbeam 
has yet been found without the blue ray ? 
2. If the blue rays or waves are stopped and the red ones 
come on to the retina, how is it that a red wave produces a 
blue impression ? 
3. If the blue is always present in all solar rays, what 
reason is there for saying that it is stopped in ethereal 
space ? 
4. I have always read that on the highest mountains and 
in balloons the sky has an inky hue. Has any one ever ana¬ 
lysed sunbeams at such altitudes, and, if so, is the blue there 
more intense than at the ocean level P 
5. Upon what basis rests the supposition that our atmo¬ 
sphere is “ filled with countless millions of excessively minute 
particles” ? Has Professor Tyndall ever had opportunity to 
experiment with the air of the highest altitudes accessible 
to man ? 
I can understand Professor Tyndall’s theory of the sea in 
regard to its colour, but it appears to me that this is inappli¬ 
cable to the explanation of the blue colour of the sky; for in 
the case of the sea we are above it, and of all the rays the blue 
is the last to be absorbed, and, for that reason, the sea is blue; 
but in the case of the air or sky we are inside, looking up 
through the sea of ether. Professor Tyndall says, “That 
when a beam of light entered the sea, the heat-rays were ab¬ 
sorbed by the surface, the red rays by a very superficial layer 
of water, the green rays next, and ultimately the blue;” be¬ 
cause of this, the air, to the eyes of a fish, would have various 
colours, according to the depth, and finally it would be blue, 
because this is the ultimate ray which advances beyond its 
associates—the rest were stopped. Apply this theoretical ex¬ 
planation to the air or sky, it should be red. And, finally, 
how is it that the short vibrations of the blue waves have so 
much more locomotive power in water than in air ? To me 
this appears a bad rule that will not work both ways. 
“ On bringing the powerful light of a magnesium light to 
bear upon the particles, the water assumes the characteristic 
•appearance of the sky” (vide id.). This appears to sustain 
the theory of the colour of the sea, and disprove that of the 
air or sky. On the supposition that the bottle was between 
the light and the retina, the blue ray reached it because the 
others could not get through the bottle—were stopped. Ac¬ 
cording to the ethereal theory, the blue stopped in the bottle 
and the other rays went on; therefore, with the light in this 
position, the colour of the. bottle would be a compound of the 
prismatic colours minus the blue. The sky is, with regard to 
our retina, in the same position as the contents of the bottle, 
ergo, the sky ought to be of the same colour. 
How is it that this ethereal theory can be applied to what 
Thomson says ?— 
“ ’Tis distance that lends enchantment to the view, 
And robes the distant mountain in its azure hue.” 
If you should have time to give me a word in your Journal, 
I will be much obliged. I am in this benighted land without 
light, except as it comes through the magnesium light of 
your periodical and others which I receive. I am so deep in 
the sea of ignorance here, that everything is blue to me, ex¬ 
cept when your red light comes from across the sea. 
Trusting that you will make due allowance for this letter, 
I remain, 
Geoege S. Baensley, M.D. 
Barra 3Iansa, Province of Bio de Janeiro, 
Brazil, S. A., 8th September, 1S71. 
The Substitution of Peopoetional foe Specified 
Weights and Measuees. 
Sir,—Whilst reading the very able paper by Dr. Redwood 
in the last Journal, it struck me that all the difficulty which 
the writer appeared to encounter, would be easily removed by 
the adoption of a new unit of weight (the decern of 10 grains), 
and another unit of measure (the septigallon, of 10,000 grains), 
and strike out all other denominations of weights or measures, 
so far as the Pharmacopoeia is concerned. The advantages 
that I see in this are that we still keep the grain weight, 
which I hold it is not advisable to do away with at present, and 
we get a system of weights and measures strictly decimal, 
and the numbers can be read as proportional parts, or as 
grams in the metrical system, or by the system of decerns 
in English grains. The terms are all quite convertible, and 
equivalent one to another. I think every formula could 
easily be expressed in decimal proportions, with only slight 
alterations, on this principle, and it would be a virtual adop¬ 
tion of the metrical system. My engagements will not per¬ 
mit me going into the subject at any length, but I have 
thought it worth while to point this out for the considera¬ 
tion of those who are interested in the subject. 
Bradford, Dec. 12th, 1871. F. M. Rihmington. 
Shall the Phaemaceutical Society cease to be an 
Educating Body? 
Sir,—I perceive from Mr. Hustwick’s letter that my mean¬ 
ing in an important portion of my communication of Nov. 
18th is capable of being misunderstood. I think if that gen¬ 
tleman will do me the favour to read the passage once more, 
he will see he has somewhat misrepresented me. The fault, 
however, is doubtless my own. I ought to have made my 
meaning so clear as to be incapable of misapprehension, and 
I hasten to supply the defect. 
My scheme pretends to suggest no change whatever in that 
portion of the Society’s duties which concerns the Pass Ex¬ 
aminations. It is only its educational processes that I pre¬ 
sume to discuss ; and the Annual Simultaneous Examination, 
with its attendant rewards, is suggested simply as a just and 
equitable method by which the Society could aid all systematic 
efforts, whether provincial or metropolitan, in the cause of 
scientific pharmaceutical education. 
Clifton, December 1 6th, 1871. G. F. Schacht. 
Difficulties in Dispensing. 
Sir,—I again trouble you with a few lines, since the re¬ 
marks of Mr. Wilkinson in the Journal of to-day seem to 
give me a sufficient reason for doing ^o. 
In his first paragraph, Mr. W. alludes to a remark of 
mine in the Journal of the 25th, upon the bad tendency of 
part of his otherwise admirable paper read at Manchester a 
few weeks ago. Not having used the words without some 
thought, I state the reasons I had for my belief. They are 
these two. Firstly, Mr. W. did not throughout the whole 
course of his paper assert the principle that in all cases. 
