Improvements in Apparatus specially suitable for Use in Estimating the Amount of Fat in Milk and other Substances.
Year: 1893

page_text: Date of Application, 30th Nov., 1893
Complete Specification Left, 20th Aug., 1894-Accepted, 22nd Sept., 1894
IMOVISIONAL DE MULTICATION.
Improvements in Apparatus specially suitable for Use in Estimating
the Amount of Fat in Milk and other Substances.
We, RICHARD WILLIAM WOOSNAM, F.I.C. F.C.S. Analyst, of 28 Museum
Street, in the County of London, and THE DAIRY SUPPLY COMPANY LIMITED,
of the same place, do hereby declare the nature of this invention to be as
follows:-
This invention has reference to improvements in apparatus specially suitable for
use in estimating the amount of fat in milk and other substances by mixing the
milk or other substance with an acid solvent such as sulphuric acid or the like and
subsequently subjecting the same to centrifugal force in a suitable whirling
machine, the object being to enable the operation to be conducted by unskilled
persons with greater accuracy and with less liability to injure themselves or their
clothes than is possible with apparatus at present in use.
For this purpose, according to our invention the glass receptacles for containing
the mixtures of milk and acid solvents are each provided with necks or mouths
adapted to receive the ends of suitably calibrated tubes. In order that the said
tubes may fit the necks or mouths of the receptacles tightly, the said necks or
mouths may be made with a taper and internally ground, the ends of the tubes
being correspondingly formed. Each receptacle is formed above the normal level
of its contents with a perforation or pin hole for the purpose hereinafter described.
Since with this construction the necessity of filling the receptacles by pouring the
liquids down the calibrated tubes as has hitherto been done is obviated, the said
tubes can be made of increased length and with a bore of less diameter which
enables the reading to be effected more accurately than usual. In order that the
quantities of acid solvents required to be used in these receptacles may be
accurately measured by persons unskilled in the use of ordinary measuring pipettes
without running the risk of drawing the solvents into their mouths or spilling them
on their hands or clothes, we provide closed vessels for containing the same, each
having in communication with its upper part a compressible air-tight chamber,
preferably a ball of india rubber, and being provided with a tube bent to
approximately U-shape. One arm is in communication with the interior of and
extends downwardly, it may be through the rubber stopper, almost to the bottom
of the vessel, whilst the other arm projects to a certain distance into a burette or
similar vessel that is held in place by any suitable means.
The closed vessel may
be formed with special charging openings having suitable stoppers to enable the
vessels to be filled without displacing the U-tube and its connections.
When the rubber ball is compressed, sufficient solvent will be forced from the
closed vessel, through the U-shaped tube into the burette to cover the open mouth of
the shorter arm thereof. Upon the ball being released a partial vacuum will be
formed in the closed vessel and air, entering through a suitable vent formed in the
stopper of the burette, will force some of the solvent back into the closed vessel, but
immediately the mouth of the short arm of the U-shaped tube is uncovered the flow
of solvent will cease and the air will pass direct to the closed vessel. It will thus be
understood that only the exact quantity of solvent required will remain in the
burette. Instead of the inverted U-tube above described the closed vessel may be
placed in communication with the burette by means of a pipe of approximately
L-shape the horizontal arm of which opens into the bottom of the closed

page_text: vessel whilst the vertical arm opens into the búrette at a certain distance above the
bottom thereof.
The action of this arrangement is similar to that above described.
In estimating the amount of fat contained in milk, for example, a certain quantity
thereof is poured into a glass receptacle of the kind herein before described.
To the milk are added certain quantities of the acid solvents to be employed, the
exact quantities being measured by the means hereinbefore described. After the
calibrated tube has been fitted to the receptacle it is inserted in a vessel containing
hot water, the upper part of said vessel being pivotally connected to the rotary
spindle or the like part of a whirling machine.
Upon the machine being operated the pivoted vessel assumes an approximately
horizontal position and some of the water therein is caused to enter the receptacle
through the pin hole thus completely filling the said receptacle. The fat, which is
maintained in a fluid state by the surrounding hot water, being lighter than the
other portions of the contents of the receptacle is caused to occupy a position nearer
the centre of rotation, that is to say, it is caused to occupy a part of the calibrated
tube where its amount can be easily read off. Some of our improvements may be
employed without others.
Dated this 30th day of November 1893.
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicants.
Improvements in Apparatus specially suitable for Use in Estimating
the Amount of Fat in Milk and other Substances.
We, RICHARD WILLIAM WOOSNAM, F.L.C., F.C.S. Analyst, of 28 Museum
Street, in the County of London, and THE DAIRY SUPPLY COMPANY LIMITED,
of the same place, 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 :-
This invention has reference to improvements in apparatus specially suitable for
use in estimating the amount of fat in milk and other substances by mixing the
milk or other substance with an acid solvent or solvents such as sulphuric acid or
the like, and subsequently subjecting the same to centrifugal force in a suitable
whirling machine, and it has for its object to enable the operation to be
conducted by unskilled persons with greater accuracy and with less liability
to injure themselves, or their clothes, than is possible with apparatus at present
in use.
For this purpose, the glass receptacles for containing the mixtures of milk and
acid solvents are each provided with a neck or mouth adapted to receive the end of
a suitably calibrated tube. In order that the said tubes may fit the necks or
mouths of the receptacles tightly, the said necks or mouths may be made with
a taper and be ground, the ends of the tubes being correspondingly formed. Each
receptacle is formed at a point above the normal level of its contents, with a
perforation or pin hole for a purpose hereinafter described.
In the accompanying drawings,
Fig. 1 shows, in side elevation, a receptacle with calibrated tube according
to this invention, suitable for estimating the percentage of fat in milk and other
substances.
1 is the receptacle for containing the mixture of milk and acid solvents to
be treated, and 2 is a tube having a fine bore calibrated to a scale of degrees
representing say percentages of fat in milk. The receptacle is formed with a
slightly tapered neck 1° which is ground externally to receive in an air tight

page_text: manner the lower enlarged end of the calibrated tube 2 which is correspondingly
formed to fit tightly over the said neck and is ground internally, the arrangement
being such that the tube can be readily secured in an air tight manner to the
receptacle and can be readily detached. Since by this construction the necessity.
of filling the receptacle as heretofore, by pouring the liquids down the calibrated
tube is obviated, the said tubes can be made of increased length and with a bore of
comparatively small diameter, say th of an inch, which enables the readings to
be taken more accurately than usual.
"
3 is a fine perforation or pin hole formed in the upper part of the receptacle 1 at
a point above the normal level of the contents of the said receptacle. The object
of this pin hole is to allow water, contained in the pivoted vessel of a whirling
machine in which the receptacle 1 is placed, after being fitted with the calibrated
tube 2 as hereinafter described, to pass into the interior of the receptacle and so
displace the lighter fat and force it into the calibrated tube. It will therefore be
understood that the pin-hole may be arranged in any other convenient position that
will enable water to enter the receptacle for the purpose mentioned. Thus it may
conveniently be formed in the lower end of the tube 2 at the point 3* and of the
two positions shown i. at 3 and 3*, the latter is considered the inore advantageous
one.
Fig. 2 is a similar view to Fig. 1 showing a modified construction in which the
receptacle is formed with a slightly tapered mouth 12 ground internally, and the
lower end of the calibrated tube 2 is correspondingly formed so as to fit into
the mouth of the receptacle as shown.
The bore of the tube 2 in this case is slightly flared at its lower end as shown, to
facilitate the entry of the fat.
It may be desirable in some cases to secure the calibrated tubes to the receptacles
by means such as a rubber band, a metal clip or the like.
In order that the quantities of acid solvents required to be used in these
receptacles may be accurately measured by persons unskilled in the use of ordinary
measuring pipettes, without running the risk of drawing the solvents into their
months, or spilling them on their hands or clothes, we provide measuring apparatus
of the kind shown in side elevation in Fig. 3. This apparatus comprises a closed
vessel that has in communication with its upper part by a tube 5 extending
through its rubber stopper 6, a compressible air-tight chamber preferably in the
form of a compressible ball or pear 7 of india rubber, and is also provided with a
tube 8-8 bent approximately U-shape. One arm, viz. 8, of this tube is in
communication with the interior of and extends downwardly, it may be through
the said rubber stopper 6, almost to the bottom of the vessel, whilst the other arm 8°
projects to a predetermined distance into a burette 9 or similar measuring vessel,
that is held in place by any suitable means, such as a metal clip 10 that surrounds
the vessel 1 and is provided with a tightening set screw 10". The extent to which
the said arm S projects into the burette is such that the space within the burette
below the mouth of the tube will contain just the amount of acid solvent desired to
be measured off say for example, one cubic centimetre. The burette 9 is provided
with the usual tap 11 and at the top is preferably closed by a stopper 12 provided
with an air tube 12". The vessel 4 inay have a special charging opening 13,
or there may be more than one, normally closed by a stopper 13, to allow of the
ready charging of the vessel 4 with an acid solvent without displacing the stopper 6
with tubes 5 and 8, 8.
With the arrangement described, by compressing the rubber ball 7, sufficient
solvent can be forced from the vessel 4 through the tube 8, 8" into the burette 9,
the tap 11 of which is at this time turned off, to partly fill the burette to a point
above the mouth of the arm 8" of the tube 8, 8. Upon the rubber ball 7 being then
released a partial vacuum will be formed in the closed vessel 4, and air entering
through the vent pipe 12" in the stopper 12 of the burette will force a portion of the
solvent in the burette equal in volume to that above the lower open mouth of the
said arm 8 back through the tube 8, 8" into the vessel 4 but as soon as the mouth of

page_text: the said arm 8" of the tube is thereby uncovered, the flow of solvent will cease and
the air will pass into the vessel 4 until the partial vacuum, produced therein by the
discharge of the solvent is destroyed. Instead of the inverted U-tube 8, 8% above
described, the closed vessel 4 may as shown in Fig. 4 be placed in communication
with the burette 9 by a pipe 8, 8 of approximately L-shape, the horizontal arm 8ª
of which opens into the bottom of the closed vessel, whilst the vertical arm 8 opens
into the burette at the required distance above the bottom thereof, it may be
through a short tube 8b that is in one with the burette and is connected to the
arm 8 by a tubular connection 8°. The action of this arrangement is similar to that
above described with reference to Fig. 3.
It will thus be understood that in each arrangement only the exact quantity of
solvent required, will remain in the burette.
In practice we employ three of these measuring apparatus, one containing a
mixture of 50% amyl-alcohol and 50% hydrochloric acid, adapted to measure one
cubic centimetre another containing strong sulphuric acid adapted to measure
3.2 cubic centimetres and the third containing dilute sulphuric acid adapted to
measure o cubic centimetres.
To estimate the amount of fat in milk, the tap 11 of the burette is turned on and
the measured quantities of solvents, discharged into one of the receptacles 1 into
which a certain quantity of the milk to be tested is poured. The calibrated tube 2
is then fitted to the receptacle and the two inserted into a vessel that is charged
with hot water and then pivotted to the rotary part of a whirling machine.
A suitable construction of whirling machine for this purpose is represented in
Figs. 5 and 6 which are respectively a side elevation and part plan. 14 is the
rotary plate of the machine fixed to a spindle 15 that passes through a pedestal 16
and is driven through bevel wheels or other suitable gear. 17 are cylindrical
vessels to contain hot water and the testing receptacles with calibrated tubes 2.
Each of these vessels 17, which may be made of suitable metal such as tinned iron,
is preferably of such a size that a testing receptacle 1 will fit loosely therein and is
provided with hooks 18 by means of which it can be readily pivoted to supports 14"
on the rotary part 14 so that it can swing radially outward.
Each vessel 17 is of such a length that only the extreme end of the calibrated
tube of a receptacle placed therein will project.
Assuming the charged testing receptacles 1 with tubes 2 to have been placed in
the vessels 17 and these latter to have been charged with hot water, then upon
setting the rotary part 14 in rapid motion each pivoted vessel 17 will, under the
action of centrifugal force, be caused to assume an approximately horizontal position
as shown in dotted lines at the right hand side of Fig. 5, and some of the water
therein will be caused to enter the testing receptacle through the pin hole 3 or 3*
thus completely filling the said receptacle. The fat, which is maintained in a fluid
state by the surrounding hot water, being lighter than the other portions of the
contents of the receptacle will consequently be caused to occupy a position nearer
the centre of rotation, that is to say, it will be caused to occupy a part of the
calibrated tube where its amount can be easily read off when the machine is
stopped.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed we declare that what
we claim is :-
1. For estimating the amount of fat in milk and other substances, an apparatus
comprising a receptacle provided with a neck or mouth through which it can be
readily charged with a mixture of milk or other substance to be tested and a suitable
chemical or chemicals, and a calibrated tube having a small bore, the said
receptacle and tube being adapted to be readily connected together and disconnected
and one of them being provided with a perforation or pin-hole at a point above the
normal level of the mixture, substantially as herein described for the purpose
specified.

page_text: 2. A liquid measuring apparatus comprising a closed vessel provided with a
compressible air-tight chamber in communication therewith, a burette or similar
measuring vessel, and a discharge tube arranged to establish communication between
the said closed vessel and the burette or like vessel at a predetermined height
therein, the arrangement being such that by compressing the said air tight chamber
a quantity of liquid greater than that required can be discharged from said closed
vessel into the burette and upon relieving the pressure on said compressible
chamber, the liquid in excess of the exact amount required will be returned to the
closed vessel by the pressure of the external atmosphere, substantially as herein
described.
3. Apparatus specially suitable for use in estimating the amount of fat in milk
and other substances constructed substantially as herein before described with
reference respectively to and shewn in Fig. 1; in Fig. 2; in Fig. 3 and in Fig. 4
of the drawings annexed
Dated this 20th day of August 1894.
For the Applicants,
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.