A Method of Analysing Alcohols and other Liquids or "Liqueflable Bodies, and Apparatus therefor.
Year: 1891

page_text: Date of Application, 318: Aug.. 1891
Complete Specification Left, 81st May, 1892-Accepted, 2nd July, 1892
PROVISIONAL SPECIFICATION.
[Communicated from abroad by EMILE GOSSART, of 70, Rue de Rivoli, Paris,
France.]
A Method of Analysing Alcohols and other Liquids or "Liqueflable
Bodies, and Apparatus therefor.
I, ERNEST DE PASS, of 78 Fleet Street, in the City of London, Fellow of the
Chartered Institute of Patent Agents, do hereby declare the nature of this invention
to be as follows:-
This invention has for its object a method of detecting the impurities or
adulterations existing in spirits of commerce and other spirituous liquids, or
liquefiable bodies, by simply causing drops of liquid to roll over the surface of the
liquid under examination. The apparatus employed for enabling this rolling of
drops to be effected I call a "Homeotrope," and the following method of analysis
which has led to its invention is based upon a molecular physical phenomenon
whose fundamental laws I have established.
In the present description I will describe :-
(1.) The method in general,
(2.) Its special application to alcohols,
(3.) The apparatus employed.
General method for determining the impurities of alcohols by the rolling of
drops.
This method includes the three following principles :-
1st principle. A drop of any liquid may be caused to roll upon the surface of a
liquid by reason of a vapour film which separates it from the surface upon which
it rolls. This rolling may be produced by allowing the drop to fall a distance of
2 to 3 from a pipette or drop tube onto a concave meniscus which rises up
against the walls of the vessel containing the liquid. The drop then rolls along,
like a solid ball upon an inclined plane, before, mingling with the rest of the
liquid.
2nd principle. Given two different liquids, both being pure, the drops of one can
never be made to roll upon the other because the vapour film of the drops is
absorbed by the supporting liquid.
These two principles may be summarized as follows:→
In the conditions above indicated liquids of the same nature appear to repel each
other, while liquids of different natures appear to attract each other.
3rd principle (fundamental). If the supporting liquid contain an impurity or
adulteration whose vapour saturates the supporting liquid, this impurity, used as
the reactive or rolling drop, will roll upon the surface of the supporting liquid
which will offer a certain amount of resistance to the penetration or mingling of
the rolling drop because the liquid being saturated with the impure vapour refuses
to absorb a new quantity of it and does not affect the vapour film which causes
the drop to roll. Thus the drops that roll indicate the presence of an impurity or
adulteration, whereas those which do not roll indicate its absence.
This last principle therefore furnishes a new method of analysis in which the
impure or adulterating liquid is itself taken as the reagent.
This call analysis by "Homeotropy," that is to say the rolling of like
upon like.
The employment of this method for the solution of the problem of the analysis
of spirits may be thus carried out in three stages.

page_text: (1.) DIRECT QUALITATIVE ANALYSIS TO ABOUT THE 20TH8.
Drops from each of the impurities known to exist in bad tasting alcohols, that
is to say badly rectified alcohols, are, causeduto roll upon the suspected liquid.
These impurities are the tail products: Amylic alcohol, butylicu propylic, and the
head products wood spirit, aldehyde, acetone, acetic ether, etc. The rolling of each 5
of these substances will indicate its presence in the supporting liquid at th
mean.
mean.
(2.) INDIRECT QUALITATIVE ANALYSIS TO THE 100THS.
This is effected by means of a suitable rectifying apparatus which concentrates
in the first fifth distilled the head impurities, and in the last fifth not distilled the
tail impurities. A still greater concentration of these two kinds of impurities may
be of course effected, and with more time and more testing material the 1000ths
may be estimated.
(3.) QUANTITATIVE ANALYSIS.
To estimate the number of 20ths, I take for instance 20 centimetres cube of the
liquid to be analysed and, after having ascertained the rolling, dilute it with once,
twice, thrice ete. its bulk of pure ethylic alcohol until the rolling ceases.
The
number of these dilutions indicates the number of 20ths of the, impurity or
adulteration. For the 100th the same operation is performed, ..but after
rectification.
I render the phenomenon of the rolling easier of production and of longer
duration in either of the following ways:(1.) By adding to the liquid to be
tested, and to the reactive drops, a substance which will give viscosity, as, for
instance citric acid; or (2.) By increasing the height and length of the meniscus,
upon which the drop falls and takes its start, by means of a specially constructed
vessel for containing the liquid to be tested. This vessel may be made of any
material which will become wet by contact with the liquid, such as glass, wood,
china, etc., and the form given it is such that the surface of the liquid assumes
a meniscus of greatly enlarged dimensions. This vessel I call the "Homeotrope."
The drops which are to roll upon the surface of the liquid may fall from a
vertically arranged pipette, or drop-tube, situated at a suitable distance above the
meniscus and in such a position relatively thereto,as to obtain, the best rolling
result.
"
21
The specially formed vessel .or "homeotrope" may be furnished with a
reference mark so, as to indicate the best position for the pipette, or drop-tube.
According to another construction of vessel or 66
homeotrope ".for, containing
the liquid to be tested, I form, it of a number of compartments each boing at
higher level than its neighbour so that the liquid is arranged in steps. The
partitions which divide the vessel into compartments are coated on one side with, a
material which will not become wet, while, the other side is left free to become
wet. Thus the liquid in the vessel will have an undulatory, surface caused by the
production of a concave meniscus on one side of the partitions, and a convex
meniscus on the other. Upon this extended surface I can cause the simultaneous
rolling of all the alcoholic impurities at one and the same time which drop from a
number of pipettes, or drop-tubes, arranged at suitable positions above the highest
compartment. This construction is,specially adapted for alcohols.
If necessary the "homeotrope," or the pipette, may be heated in any convenient
manner so as to, prevent the contents from solidifying, and I can thus use the
apparatus for detecting not only, the falsifications, of liquids,, but, also of bodies.
which are capable of being liquefied..
Dated t

page_text: COMPLETE SPECIFICATION..
A Method of Analysing Alcohols and other Liquide or Liqueflable
Bodies, and Apparatus therefor.
J, ERNEST DE PASS, of 78 Fleet Street in the City of London, Fellow of the
Chartered Institute of Patent Agents, do hereby declare the nature of this
invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement, reference being had
to the accompanying drawings and to the letters and figures marked thereon, that
is to say
This invention has for its object a method of detecting the impurities existing
in spirits of commerce, and other spirituous liquids, or liquefiable bodies, by
simply cansing drops of liquid to roll over the surface of the liquid under
examination. The apparatus which I have invented, and which I employ for
enabling this rolling of drops to be effected, I call a Homcotrope," and the
following method of analysis, which has led to its invention, is based upon a
molecular physical phenomenon whose fundamental laws I have established.
I will first describe the method in general, then its special application to alcohols,
and lastly the apparatus employed, and more especially the "homeotrope."
1. General method for determining the impurities of alcohols by a rolling of
drops.
This method utilizes the three following principles :
1st principle. Any liquid may be caused to roll in drops upon itself owing to a
vapour film which separates the drop from the support. This rolling is produced
by allowing the drop to fall a distance of 2 to 3 from a pipette or drop tube
onto the concave meniscus which rises up against the walls of the vessel containing
the liquid. The drop thien rolls liko a solid ball upon an inclined plane before
mingling with 'the rest of the liquid.
2nd principle. Given two different liquids, both being pure, the drops of one can
never be made to roll upon the other, because the vapour film of the drop is
absorbed by the supporting liquid.
These two principles are recapitulated in the general statement:
In the conditions above indicated, liquids of the same nature appear to repel
each other, while liquids of different natures appear to attract each other.
3rd principle (fundamental). If the supporting liquid contains an impurity,
which saturates it with its vapour, this impurity, taken as the reactive drop or
reagent, will roll upon the surface of the supporting liquid, and will offer a certain
amount of resistance to penetrate therein again, because the liquid being saturated
with the impure vapour refuses to absorb a new quantity of it and respects the
vapour film which causes the drop to roll.
This last principle, therefore, furnishes a new method of analysis in which the
impurity to be ascertained is itself taken as the reagent.
This call analysis by "Homeotropy," that is to say by the rolling of like upon
like.
The employment of this method to the solution of the problem of the analysis
of spirits may be thus carried out in three stages.
1. DIRECT QUALITATIVE ANALYSIS TO ABOUT THE TWENTIeth.
Drops from each of the impurities known to exist.in bad tasting alcohols, that
is to say badly rectified alcohols, are caused to roll upon the suspected liquid.
These impurities are the tail products:-Amylic, butylic, and propylic alcohols,
and the head products:-Wood spirit, aldehyde, acetone, acetic ether, etc.
The

page_text: material, the thousandths may be estimated.
III. QUANTITATIVE ANALYSIS.
To estimate the number of twentieths, I take, for instance, twenty, cubic centi-
metres of the liquid to be analysed and after having ascertained the rolling, I
dilute it with once, twice, three times, etc. its bulk of pure ethylic alcohol until
the rolling ceases. The number of dilutions indicates the number of twentieths of
the impurity. For the hundredths, the same operation is performed, but after
rectification. Whatever may be the liquid to be analysed by "homeotropy" I
render the phenomenon of the rolling easier to produce and of longer duration in
either of the following ways: (1) by adding to the liquid to be tested, and to, the
reactive or reagent drops, a substance which will give viscosity, as for instance,
citric acid, (2) by increasing the height and the length of the meniscus upon which
the drop falls and takes its start, by means of a specially constructed vessel' for
containing the liquid to be tested.
I will now explain the importance of this special form of vessel which contains
the liquid to be tested.
Fig. 1 of the annexed drawings shows a rolling drop of alcohol A.B.C.D.E.F.G.
enlarged seven times, thius permitting of the form of its contour being seen.
Fig. 2 shows the natural meniscus formed by a liquid in a wet cylindrical glass.
The curve B' D' F' is exactly the same as the portion B D F, of the drop shown
at Fig. 1, but reversed. It is sufficient to allow a drop of a like liquid to fall
upon this natural meniscus to obtain the rolling.
The height O' B' of the meniscus =0.0025 metre. The best point for the
fall is thus determined: The ordinate A' C'=0 metre 001 mi
10'
The
alscissa A 00 metre 001 The slope or inclination of the tangent at
B=30°.
The pipette or drop tube P contains the liquid to be allowed to fall drop by
drop to cause it to roll upon the meniscus B'D' F'. The point of the pipette
must be in the vertical from the point C for the best fall. m is the drop escaping
from the pipette before rolling upou the meniscus. m is the drop rolling upon
the meniscus. But this natural meniscus produced in the glass by capillarity, has
neither height nor length sufficient to permit a sure and convenient experiment.
It is necessary, by a means or contrivance which constitutes the essential feature
of the invention, to exaggerate these dimensions of the meniscus; for this I have
recourse to Hauksbee's hinged plates between which the meniscus of hyperbolic
section rises so much the more as the dihedral angle of the plates is the more acute.
I have therefore invented and constructed a receptacle in the form of an elongated
boat terminating at its two extremities in two acute dihedral angles with oblique
ends of about 30° to 40°. This boat-shaped receptacle is shown in end elevation
at Fig. 3, in side elevation at Fig. 4, and in plan in Fig. 5. The ends of the
receptacle rise up in points or horns towards the two extremities x, y, and the
point of the pipette must be situated in the horizontal passing through one of these.
extremities, when the receptacle is completely filled. These points therefore serve
as a reference mark for the height of the point of the. pipette above the liquid.
A line or mark drawn upon the edge of the wall determines the position of the

page_text: point of the pipette upon the horizontal, y. The form of the boat-shaped
receptacle to which I give the name of "Homeotrope," is not absolute, and is only
shown by way of example, reserving to myself the use for the analysis of liquids,
of any form of receptacles destined to exaggerate the dimensions of the meniscus
at the place where the drops must fall to facilitate the rolling. This boat-shaped
receptacle can be made in any material capable of being made wet by the liquid,
such as glass, metal, wood, india-rubber, china; etc.
The other apparatus which I employ concurrently with the "homeotrope," are
shown in Fig. 6. I have devised an arrangement of objects of small size, light
and portable, in order that the whole may be placed in a box capable of being
carried by hand.
As shown in Fig. 6 the pipette is held vertically by a rod sliding along a
standard S, upon which this rod may be fixed at any suitable height by means of a
set screw n the standard S being fixed to a cross foot p.
According to a modified arrangement I can employ another form of vessel,
shown in section in Fig. 7 and in plan in Fig. 8, in place of the boat-shaped -
receptacle N This vessel is rectangular and is divided by parallel partitions into
several compartments, A, B, C, D, which I fill with the liquid to be analysed.
The partitions are of decreasing height so that the level of the liquid is arranged
in steps. The partitions are wetted on one side; on the other side they are coated
with a material which prevents them from becoming wet. These liquid steps are
therefore bordered by concave meniscuses on the one side and convex on the other,
as seen in Fig. 7. On these steps I can cause the whole of the alcoholic impurities
to roll simultaneously. I place in the compartments the alcohol to be analysed,
and in the seven pipettes P1, P2, P3, P4, P4, P, P', the seven alcoholic impurities;
these pipettes are arranged above the upper compartment A; the drops which
roll indicate the presence of the impurity, those which do not roll indicate its
absence.
I can therefore make the qualitative analysis of the seven impurities at one
time. It must, of course, be understood that the dimensions of the vessel and the
number of the partitions may be varied. This last arrangement is specially
adapted for alcohols.
"
This invention may serve for other applications for analysis by "homeotropy
for the detection of various falsifications of liquids, such as spirits, oils, acids, etc.
and other liquofiable bodies. I may heat the homeotrope by means of a stove,
or by a bain-marie, in order to prevent theso bodies solidifying by cooling. The
pipette or drop tube may likewise be heated by any suitable means.
Fig. 9 shows a vertical section of the rectifying apparatus employed for indirect
qualitative analysis to the hundredths.
A is a spirit lamp. B is a pan containing 100 cubic centimetres of alcohol to
be examined. C is a dephelgmator; c, c, c, are the return tubes and
d, d,, platinum wire gauze; is a thermometer; g the tube for the escape of
the vapours; the worm; the condenser ; ; a test glass graduated to 100 cubic
centimetres and divided into ten equal parts. K is the main support sorewed to
a-cross foot.
Horizontal roda, capable of being fixed by set screws to the height desired,
support the lamp, the pan, the dephelgmator, and the worm condenser.
Having now particularly described and ascertained the nature of this. inven-
tion and in what manner the same is to be performed, I claim, as communicated
by my foreign correspondent
--
1. The hereindescribed method of analysing alcohols and other liquids or liquefi-
able bodies, by causing drops of the different liquids, whose presence is to be
determined, (either qualitatively or quantitatively) to roll upon the surface of the
liquid to be analysed, and which method I call "Homeotropy."
'
66
2. The apparatus (for use in the above method) to which I give the name of
Homeotrope" consisting in a receptacle terminating at its extremities in acute

page_text: angles, substantially as herein described and shown by Figs. 3, 4, and 5 of the
annexed drawings.
Dated this 31st day of May 1892.
ERNEST DE PASS,
Chartered Patent Agent,
78, Fleet Street, London, and 6, Victoria Street, Nottingham.