Scientific American Supplement, Vol. XXI., No. 531, March 6, 1886 by Various
V >>
Various >> Scientific American Supplement, Vol. XXI., No. 531, March 6, 1886
Pages:
1 |
2 |
3 |
4 |
5 | 6 |
7 |
8 |
9 |
10
There are the same obstacles in the use of the written or printed word
as have been mentioned in connection with dactylology, namely, lack of
rapidity in conveying impressions through the medium of the English
sentence.
I have thus hastily reviewed the several means which teachers generally
are employing to impart the use of English to deaf pupils, for the
purpose of showing a common difficulty. The many virtues of each have
been left unnoticed, as of no pertinence to this article.
The device suggested at the beginning of this paper, claiming to be
nothing more than a school room appliance intended to supplement the
existing means for giving a knowledge and practice of English to the
deaf, employs as its interpreter a different sense from the one
universally used. The sense of sight is the sole dependence of the deaf
child. Signs, dactylology, speech reading, and the written and printed
word are all dependent upon the eye for their value as educational
instruments. It is evident that of the two senses, sight and touch, if
but one could be employed, the choice of sight as the one best adapted
for the greatest number of purposes is an intelligent one; but, as the
choice is not limited, the question arises whether, in recognizing the
superior adaptability to our purpose of the one, we do not lose sight of
a possibly important, though secondary, function in the other. If sight
were all-sufficient, there would be no need of a combination. But it
cannot be maintained that such is the case. The plan by which we acquire
our vernacular is of divine, and not of human, origin, and the senses
designed for special purposes are not interchangeable without loss. The
theory that the loss of a certain sense is nearly, if not quite,
compensated for by increased acuteness of the remaining ones has been
exploded. Such a theory accuses, in substance, the Maker of creating
something needless, and is repugnant to the conceptions we have of the
Supreme Being. When one sense is absent, the remaining senses, in order
to equalize the loss, have imposed upon them an unusual amount of
activity, from which arises skill and dexterity, and by which the loss
of the other sense is in some measure alleviated, but not supplied. No
_additional_ power is given to the eye after the loss of the sense of
hearing other than it might have acquired with the same amount of
practice while both faculties were active. The fact, however, that the
senses, in performing their proper functions, are not overtaxed, and are
therefore, in cases of emergency, capable of being extended so as to
perform, in various degrees, additional service, is one of the wise
providences of God, and to this fact is due the possibility of whatever
of success is attained in the work of educating the deaf, as well as the
blind.
In the case of the blind, the sense of touch is called into increased
activity by the absence of the lost sense; while in the case of the
deaf, sight is asked to do this additional service. A blind person's
education is received principally through the _two_ senses of hearing
and touch. Neither of these faculties is so sensible to fatigue by
excessive use as is the sense of sight, and yet the eye has, in every
system of instruction applied to the deaf, been the sole medium. In no
case known to the writer, excepting in the celebrated case of Laura
Bridgman and a few others laboring under the double affliction of
deafness and blindness, has the sense of touch been employed as a means
of instruction.[1]
[Footnote 1: This article was written before Professor Bell had made his
interesting experiments with his "parents' class" of a touch alphabet,
to be used upon the pupil's shoulder in connection with the oral
teaching.--E.A.F.]
Not taking into account the large percentage of myopes among the deaf,
we believe there are other cogent reasons why, if found practicable, the
use of the sense of touch may become an important element in our
eclectic system of teaching. We should reckon it of considerable
importance if it were ascertained that a portion of the same work now
performed by the eye could be accomplished equally as well through
feeling, thereby relieving the eye of some of its onerous duties.
We see no good reason why such accomplishment may not be wrought. If,
perchance, it were discovered that a certain portion could be performed
in a more efficient manner, its value would thus be further enhanced.
In theory and practice, the teacher of language to the deaf, by whatever
method, endeavors to present to the eye of the child as many completed
sentences as are nominally addressed to the ear--having them "caught" by
the eye and reproduced with as frequent recurrence as is ordinarily done
by the child of normal faculties.
In our hasty review of the methods now in use we noted the inability to
approximate this desirable process as a common difficulty. The facility
now ordinarily attained in the manipulation of the type writer, and the
speed said to have been reached by Professor Bell and a private pupil of
his by the Dalgarno touch alphabet, when we consider the possibility of
a less complex mechanism in the one case and a more systematic grouping
of the alphabet in the other, would lead us to expect a more rapid means
of communication than is ordinarily acquired by dactylology, speech (by
the deaf), or writing. Then the ability to receive the communication
rapidly by the sense of feeling will be far greater. No part of the body
except the point of the tongue is as sensible to touch as the tips of
the fingers and the palm of the hand. Tactile discrimination is so acute
as to be able to interpret to the brain significant impressions produced
in very rapid succession. Added to this advantage is the greater one of
the absence of any more serious attendant physical or nervous strain
than is present when the utterances of speech fall upon the tympanum of
the ear. To sum up, then, the advantages of the device we find--
First. A more rapid means of communication with the deaf by syntactic
language, admitting of a greater amount of practice similar to that
received through the ear by normal children.
Second. Ability to receive this rapid communication for a longer
duration and without ocular strain.
Third. Perfect freedom of the eye to watch the expression on the
countenance of the sender.
Fourth. In articulation and speech-reading instruction, the power to
assist a class without distracting the attention of the eye from the
vocal organs of the teacher.
Fifth. Freedom of the right hand of the pupil to make instantaneous
reproduction in writing of the matter being received through the sense
of feeling, thereby opening the way for a valuable class exercise.
Sixth. The possible mental stimulus that accompanies the mastery of a
new language, and the consequent ability to receive known ideas through
a new medium.
Seventh. A fresh variety of class exercises made possible.
The writer firmly believes in the good that exists in all methods that
are, or are to be; in the interdependence rather than the independence
of all methods; and in all school-room appliances tending to supplement
or expedite the labors of the teacher, whether they are made of
materials delved from the earth or snatched from the clouds.
S. TEFFT WALKER,
_Superintendent of the Kansas Institution, Olathe, Kans_.
* * * * *
WATER GAS.
THE RELATIVE VALUE OF WATER GAS AND OTHER GASES AS IRON REDUCING AGENTS.
By B.H. THWAITE.
In order to approximately ascertain the relative reducing action of
water gas, carbon monoxide, and superheated steam on iron ore, the
author decided to have carried out the following experiments, which were
conducted by Mr. Carl J. Sandahl, of Stockholm, who also carried out the
analyses. The ore used was from Bilbao, and known as the Ruby Mine, and
was a good average hematite. The carbonaceous material was the Trimsaran
South Wales anthracite, and contained about 90 per cent. of carbon.
A small experimental furnace was constructed of the form shown by
illustration, about 4 ft. 6 in. high and 2 ft. 3 in. wide at the base,
and gradually swelling to 2 ft. 9 in. at the top, built entirely of
fireclay bricks. Two refractory tubes, 2 in. square internally, and the
height of the furnace, were used for the double purpose of producing the
gas and reducing the ore.
The end of the lower tube rested on a fireclay ladle nozzle, and was
properly jointed with fireclay; through this nozzle the steam or air was
supplied to the inside of the refractory tubes. In each experiment the
ore and fuel were raised to the temperature "of from 1,800 to 2,200 deg.
Fahr." by means of an external fire of anthracite. Great care was taken
to prevent the contact of the solid carbonaceous fuel with the ore. In
each experiment in which steam was used, the latter was supplied at a
temperature equivalent to 35 lb. to the square inch.
The air for producing the carbon monoxide (CO) gas was used at the
temperature of the atmosphere. As near as possible, the same conditions
were obtained in each experiment, and the equivalent weight of air was
sent through the carbon to generate the same weight of CO as that
generated when steam was used for the production of water gas.
[Illustration]
_First Experiment, Steam (per se)_.--Both tubes, A and B, were filled
with ore broken to the size of nuts. The tube, A, was heated to about
2,000 deg. Fahr., the upper one to about 1,500 deg.
NOTE.--In this experiment, part of the steam was dissociated in passing
through the turned-up end of the steam supply pipe, which became very
hot, and the steam would form with the iron the magnetic oxide
(Fe_{3}O_{4}). The reduction would doubtless be due to this
dissociation. The pieces of ore found on lowest end of the tube, A, were
dark colored and semi-fused; part of one of these pieces was crushed
fine, and tested; see column I. The remainder of these black pieces was
mixed with the rest of the ore contained in tube, A, and ground and
tested; see column II. The ore in upper tube was all broken up together
and tested; see column III. When finely crushed, the color of No. I. was
bluish black; No. II., a shade darker red; No. III., a little darker
than the natural color of the ore. The analyses gave:
-----------------------------+---------+---------+---------
| I. | II. | III.
+---------+---------+---------
|per cent.|per cent.|per cent.
Ferric oxide (Fe_{2}O_{3}). | 68.55 | 76.47 | 84.81
Ferrous oxide (FeO). | 16.20 | 9.50 | 1.50
+---------+---------+---------
Total. | 84.75 | 85.97 | 86.31
+---------+---------+---------
Calculated: | | |
Ferric oxide (Fe_{2}O_{3}). | 32.55 | 55.36 | 81.47
Magnetic oxide (Fe_{3}O_{4}).| 52.20 | 30.61 | 4.84
Ferrous oxide (FeO). | | |
+---------+---------+---------
Total. | 84.75 | 85.97 | 86.31
+---------+---------+---------
Percentage of total
oxygen reduced. | 6.93 | 4.02 | 1.07
Metallic iron. | 60.59 | 60.92 | 60.54
-----------------------------+---------+---------+---------
_Second Experiment, Water Gas_.--The tube, A, was filled with small
pieces of anthracite, and heated until all the volatile matter had been
expelled. The tube, B, was then placed in tube, A, the joint being made
with fireclay, and to prevent the steam from carrying small particles of
solid carbon into ore in the upper tube, the anthracite was divided from
the ore by means of a piece of fine wire gauze. The steam at a pressure
of about 35 lb. to the square inch was passed through the anthracite.
The tube, A, was heated to white heat, the tube, B, at its lower end to
bright red, the top to cherry red.
------------------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
Experiment. | 1st. | 2d. | 3d. |
------------------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
Number. | I. | II. | III.| I. | II. | III.| IV. | I. | II. | III.|
------------------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
Total Iron. |60.59|60.92|60.54|65.24|61.71|61.93|57.23|59.73|57.93|55.54|
------------------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
Iron occurring as
------------------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
FeO. |12.60| 7.39| 1.17|46.98|18.59| 4.03| 0.84|29.45| 2.69| 1.12
Fe_{2}O_{3} |47.99|53.33|59.37|18.26|43.12|57.90|56.39|30.28|55.24|54.42
------------------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
Per cent. of Oxides. |
------------------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
FeO. |16.20| 9.50| 1.50|60.40|23.90| 5.18| 1.08|37.86| 3.46| 1.44
Fe_{2}O_{3}. |68.55|76.47|84.81|26.08|61.60|82.71|80.55|43.26|78.91|77.74
Total. |84.75|85.97|86.31|86.48|85.50|87.89|81.63|81.12|82.37|79.18
------------------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
Oxygen in Ore.
------------------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
Before experiment.|25.97|26.10|26.05|27.96|26.45|26.54|24.52|25.60|24.81|23.80
After experiment. |24.16|25.05|25.77|21.24|23.79|25.96|24.40|21.39|24.44|23.64
Difference. | 1.81| 1.05| 0.28| 6.72| 2.66| 0.58| 0.12| 4.21| 0.37| 0.16
------------------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
Per cent. of oxygen reduced.
------------------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
oxygen reduced. | 6.93| 4.02| 1.07|24.03|10.02| 2.18| 0.49|16.44| 1.49| 0.42
------------------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
Degree of Oxidation of the Ore after the Experiment.
------------------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
FeO. | ... | ... | ... |84.66| ... | ... | ... |18.40| ... | ... |
Fe_{3}O_{4}. |52.20|30.61| 4.84|37.82|77.01|28.12| 3.88|62.72|11.14| 4.64|
Fe_{2}O_{3}. |32.55|55.36|81.47| ... | 8.49|59.77|77.75| ... |71.23|74.54|
Total. |84.75|85.97|85.97|85.97|85.97|85.97|85.97|85.97|85.97|85.97|
------------------+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
------------------+-----------------+-----------------------+-----------------+
The ore having | | | |
been exposed to | Steam. | Water gas. | Carbon monoxide.|
------------------+-----------------+-----------------------+-----------------+
_Four Samples were Tested_.--I. The bottom layer, 11/4 in. thick; the
color of ore quite black, with small particles of reduced spongy
metallic iron. II. Layer above I., 41/4 in. thick; the color was also
black, but showed a little purple tint. III. Layer above II., 5 in.
thick; purple red color. IV. Layer above III., ore a red color. The
analyses gave:
-----------------------------+---------+---------+---------+---------
| I. | II. | III. | IV.
+---------+---------+---------+---------
|per cent.|per cent.|per cent.|per cent.
Ferric oxide (Fe_{2}O_{3}). | 26.08 | 61.60 | 82.71 | 80.55
Ferrous oxide (FeO). | 60.40 | 23.90 | 5.18 | 1.08
+---------+---------+---------+---------
Total. | 86.48 | 85.50 | 87.89 | 81.63
+---------+---------+---------+---------
Calculated: | | | |
Ferric oxide (Fe_{2}O_{3}). | ... | 8.49 | 59.77 | 77.75
Magnetic oxide (Fe_{3}O_{4}).| 37.82 | 77.01 | 28.12 | 3.88
Ferrous oxide (FeO). | 48.66 | | |
+---------+---------+---------+---------
Total. | 86.48 | 85.41 | 87.89 | 81.63
+---------+---------+---------+---------
Percentage of total
oxygen reduced. | 24.03 | 10.02 | 2.26 | 0.49
Metallic iron. | 65.24 | 61.71 | 61.93 | 57.23
-----------------------------+---------+---------+---------+---------
NOTE.--All the carbon dioxide (CO_{2}) occurring in the ore as calcic
carbonate was expelled.
_Third Experiment, Carbon monoxide_ (CO).--The tube A was filled with
anthracite in the manner described for the second experiment, and heated
to drive off the volatile matter, before the ore was placed in the upper
tube, B, and the anthracite was divided from the ore by means of a piece
of fine wire gauze. The lower tube, A, was heated to the temperature of
white heat, the upper one, B, to a temperature of bright red. I. Layer,
1 in. thick from the bottom; ore dark brownish colored. II. Layer 4 in.
thick above I.; ore reddish brown. III. Layer 11 in. thick above II.;
ore red color. The analyses gave:
-----------------------------+---------+---------+---------
| I. | II. | III.
+---------+---------+---------
|per cent.|per cent.|per cent.
Ferric oxide (Fe_{2}O_{3}). | 43.26 | 78.91 | 77.74
Ferrous oxide (FeO). | 37.86 | 3.46 | 1.44
+---------+---------+---------
Total. | 81.12 | 82.37 | 79.18
+---------+---------+---------
Calculated: | | |
Ferric oxide (Fe_{2}O_{3}). | ... | 71.23 | 74.54
Magnetic oxide (Fe_{3}O_{4}).| 62.72 | 11.14 | 4.64
Ferrous oxide (FeO). | 18.40 | |
+---------+---------+---------
Total. | 81.12 | 82.37 | 79.18
+---------+---------+---------
Percentage of total
oxygen reduced. | 16.44 | 1.49 | 0.42
Metallic iron. | 59.73 | 57.93 | 55.54
-----------------------------+---------+---------+---------
NOTE.--The carbon monoxide (CO) had failed to remove from the ore the
carbon dioxide existing as calcic carbonate. The summary of experiments
in the following table appears to show that the water gas is a more
powerful reducing agent than CO in proportion to the ratio of as
4.21 x 100
4.21 : 6.72, or ------------ = 52 per cent.
72
Mr. B.D. Healey, Assoc. M. Inst. C.E., and the author are just now
constructing large experimental plant in which water gas will be used as
the reducing agent. This plant would have been at work before this but
for some defects in the valvular arrangements, which will be entirely
removed in the new modifications of the plant.
* * * * *
ANTISEPTIC MOUTH WASH.
Where an antiseptic mouth wash is needed, Mr. Sewill prescribes the use
of perchloride of mercury in the following form: One grain of the
perchloride and 1 grain of chloride of ammonium to be dissolved in 1 oz.
of eau de Cologne or tincture of lemons, and a teaspoonful of the
solution to be mixed with two-thirds of a wineglassful of water, making
a proportion of about 1 of perchloride in 5,000 parts.--_Chemist and
Druggist_.
* * * * *
ANNATTO.
[Footnote: Read at an evening meeting of the North British Branch of the
Pharmaceutical Society, January 21.]
By WILLIAM LAWSON.
The subject which I have the honor to bring shortly before your notice
this evening is one that formed the basis of some instructive remarks by
Dr. Redwood in November, 1855, and also of a paper by Dr. Hassall, read
before the Society in London in January, 1856, which latter gave rise to
an animated discussion. The work detailed below was well in hand when
Mr. MacEwan drew my attention to these and kindly supplied me with the
volume containing reports of them. Unfortunately, they deal principally
with the adulterations, while I was more particularly desirous to learn
the composition in a general way, and especially the percentage of
coloring resin, the important constituent in commercial annatto. Within
the last few years it was one of the articles in considerable demand in
this part of the country; now it is seldom inquired for. This,
certainly, is not because butter coloring has ceased to be employed, and
hence the reason for regretting that the percentage of resin was not
dealt with in the articles referred to, so that a comparison could have
been made between the commercial annatto of that period and that which
exists now. In case some may not be in possession of literature bearing
on it--which, by the way, is very meager--it may not be out of place to
quote some short details as to its source, the processes for obtaining
it, the composition of the raw material, and then the method followed in
the present inquiry will be given, together with the results of the
examination of ten samples; and though the subject doubtless has more
interest for the country than for the town druggist, still, I trust it
will have points of interest for both.
Annatto is the coloring matter derived from the seeds of an evergreen
plant, _Bixa Orellana_, which grows in the East and West Indian Islands
and South America, in the latter of which it is principally prepared.
Two kinds are imported, Spanish annatto, made in Brazil, and flag or
French, made mostly in Cayenne. These differ considerably in characters
and properties, the latter having a disagreeable putrescent odor, while
the Spanish is rather agreeable when fresh and good. It is, however,
inferior to the flag as a coloring or dyeing agent. The seeds from which
the substance is obtained are red on the outside, and two methods are
followed in order to obtain it. One is to rub or wash off the coloring
matter with water, allow it to subside, and to expose it to spontaneous
evaporation till it acquires a pasty consistence. The other is to bruise
the seeds, mix them with water, and allow fermentation to set in, during
which the coloring matter collects at the bottom, from which it is
subsequently removed and brought to the proper consistence by
spontaneous evaporation. These particulars, culled from Dr. Redwood's
remarks, may suffice to show its source and the methods for obtaining
it.
Dr. John gives the following as the composition of the pulp surrounding
the seeds: Coloring resinous matter, 28; vegetable gluten, 26.5;
ligneous fiber, 20; coloring, 20; extractive matter, 4; and a trace of
spicy and acid matter.
It must be understood, however, that commercial annatto, having
undergone processes necessary to fit it for its various uses, as well as
to preserve it, differs considerably from this; and though it may not be
true, as some hint, that manufacturing in this industry is simply a term
synonymous with adulterating, yet results will afterward be given
tending to show that there are articles in the market which have little
real claim to the title. I tried, but failed, to procure a sample of raw
material on which to work, with a view to learn something of its
characters and properties in this state, and thus be able to contrast it
with the manufactured or commercial article. The best thing to do in the
circumstances, I thought, was to operate on the highest priced sample at
disposal, and this was done in all the different ways that suggested
themselves. The extraction of the resin by means of alcohol--the usual
way, I believe--was a more troublesome operation than it appeared to be,
as the following experiment will show: One hundred grains of No. 8 were
taken, dried thoroughly, reduced to fine powder, and introduced into a
flask containing 4 ounces of alcohol in the form of methylated spirit,
boiled for an hour--the flask during the operation being attached to an
inverted condenser--filtered off, and the residue treated with a smaller
amount of the spirit and boiled for ten minutes. This was repeated with
diminishing quantities until in all 14 ounces had been used before the
alcoholic solution ceased to turn blue on the addition to it of strong
sulphuric acid, or failed to give a brownish precipitate with stannous
chloride. As the sample contained a considerable quantity of potassium
carbonate, in which the resin is soluble, it was thought that by
neutralizing this it might render the resin more easy of extraction.
This was found to be so, but it was accompanied by such a mass of
extractive as made it in the long run more troublesome, and hence it was
abandoned. Thinking the spirit employed might be too weak, an experiment
with commercial absolute alcohol was carried out as follows: One hundred
grains of a red sample, No. 4, were thoroughly dried, powdered finely,
and boiled in 2 ounces of the alcohol, filtered, and the residue treated
with half an ounce more. This required to be repeated with fresh half
ounces of the alcohol until in all 71/2 were used; the time occupied from
first to last being almost three hours. This was considered
unsatisfactory, besides being very expensive, and so it, also, was set
aside, and a series of experiments with methylated spirit alone was set
in hand. The results showed that the easiest and most satisfactory way
was to take 100 grains (this amount being preferred, as it reduces error
to the minimum), dry thoroughly, powder finely, and macerate with
frequent agitation for twenty-four hours in a few ounces of spirit, then
to boil in this spirit for a short time, filter, and repeat the boiling
with a fresh ounce or so; this, as a rule, sufficing to completely
exhaust it of its resin. Wynter Blyth says that the red resin, or bixin,
is soluble in 25 parts of hot alcohol. It appears from these experiments
that much more is required to dissolve it out of commercial annatto.
Pages:
1 |
2 |
3 |
4 |
5 | 6 |
7 |
8 |
9 |
10