Frankland E

I: Frankland on Mount Blanc

Although his most lasting fame would be for his work in valency and

synthetic organic chemistry, and during his lifetime he was best known for

water analysis and purification, Frankland's work touched many other fields

of scientific research.

EF loved mountaineering: first visit to Alps was in 1856 when he met John

Tyndall in the Tyrolese Alps. They then toured the English Lakes in spring

1859, which was followed by ascension of highest peak of Alps, Mount Blanc

(15,782 ft), on 20 August 1859, and night spent on summit (first to do so).

Mount Blanc first climbed successfully in 1786; Tyndall first ascended MB in

1857, made second ascent following year in order to place a maximum/minimum

thermometer on summit. This prologue to EF's adventure in 1859.

Tyndall had long wanted to obtain scientific data about temperatures in high

altitudes, and had been encouraged by Royal Society and others to conduct

further experiments. Accordingly, he now intended to ascend MB for third

time, to recover thermometer he had left on the summit in 1858, to spend

more time gathering info, and to set up a series of thermometers attached to

stout posts at intervals between the valley and the summit, and asked EF to

join him on expedition.

EF and Tyndall met at Chamonix at foot of mountain, and spent a week

exploring the other side of the valley, waiting for suitable weather an

preparing themselves for major assault. Set out on 20 August with 3 guides

and no less than 26 porters - taking supplies for as much as a week on

mountain. After 7 hrs steady climbing they reached small climbing hut at

Grands Mulets, where 14 of porters left their stuff and returned to

Chamonix. Remainder spent night there (- 2.8 degrees C in tent), and after

sleepless night due to avalanche noise, and set off at first light and

entered the Long Valley of Snow, went via Petit Plateau up to Grand Plateau

(took 3 hrs), an almost level snow platform about 1 and half miles in

diameter, then 2 miles knee-deep in snow up the Corridor, 300 ft climb to

the Mur de la Cote, and then after further hour of stiff climbing they

reached the summit. Seven more porters now dispatched down the mountain,

after depositing supplies.

Although EF totally exhilarated by climb and view from summit, Tyndall was

not so great - had been unwell throughout the climb, suffering from

headaches and fatigue, and within half an hour of reaching the summit rest

of party complained of similar symptoms. This was altitude sickness, and so

tent was erected as matter of urgency. Fortunately EF was relatively

unaffected at first though he too gradually developed symptoms also, but was

better than rest - so was he who had to make the tea. Was then that he

discovered that the guides had brought only enough charcoal fuel to melt an

urnful of snow: but luckily EF had insisted as back-up precaution that the

porters carried a large spirit lamp and a gallon of alcohol - placing

hard-packed snow and some tea in a small copper pan he was abl to provide a

warming drink for everyone, though it took 2 hrs to do it. EF now succumbing

to general torpor but with great difficulty managed to fire a rocket from

summit as a pre-arranged sign to people of Chamonix that all was

(comparatively) wel. Then he and party settled down for night in 7

ft-diameter bell-tent, on rubber ground sheet, with 14 bodies arranged

spokewise towards the centre. V. bad night as to be expected - freezing,

people being sick, crushed, etc etc.

By 8 am, however, most feeling better, including Tyndall who then busied

himself with setting up the first thermometric post and then measuring the

heat of the sun's rays. EF then conducted an experiment of burning stearin

candles for an hour in order to ascertain whether they lost more or less

weight than when burning in Chamonix. Experiment was conducted within the

tent, from which all except himself excluded to minimize moving air

currents.

Was now clear that party needed to leave summit asap, so 22 hrs after their

arrival they began the descent, erecting thermometric posts on the way.

Reached Chamonix an hour after dusk, having completed an expedition that EF

claimed was "the first and only one in which a night has been spent on the

summit of the mountain". Also said that the ascent of Mount Blanc furnished

him with "experimental work extending over nine years". Experiments formed

major scientific spin-off from the expedition, and were all concerned with

combustion phenomena.

I: a) Combustion Experiments - rates and pressure

Started with examination of candles burning on summit: general conclusion EF

reached was that pressure changes have little effect on the rate of

combustion. Each candle allowed to burn for an hour at Chamonix and hour on

mountain top, being weighed before and after each experiment. Differences

not large enough to be significant, esp. as the possibility existed that

temperature - rather than pressure - might be a critical factor, as

temperature on summit was much lower than that in the valley. A controlled

experiment at ground level later confirmed general impression that pressure

was not v. important, only a 15 percent drop in combustion rate being

detected at quite low pressures.

This greatly puzzled EF, esp as had recently read communication by an

artillery officer in India, Quartermaster Mitchell, who had examined the

variation of burning times for shell-fuses at different altitudes and had

found that, unlike EF's candles, his fuses took much longer to burn at high

altitudes than at low levels. EF's response was series of investigations of

time-fuses, acquiring raw materials - six-inch fuses - from F.A. Abel at

Woolwich Arsenal, and constructing an apparatus including a large iron

cylinder with an air-pump at one end and at the other a six-foot long

gas-pipe connected to a mercury pressure-gauge and capable of receiving the

fuse. An iron ball was suspended by a thread at the far end of the fuse so

when combustion eventually reached that end the thread would burn and the

ball would drop on to an iron plate below and make noise. From these exps,

EF concluded that each diminution fo one inch of barometrical pressure

causes a retardation of one second in a six-inch or 30-seconds fuse.

Military implications of this discovery, which closely agreed with that of

Mitchell, were clear, especially in mountainous terrain. Difference between

candles and fuses is their method of burning: candles receive supply of fuel

up wick of high-boiling hydrocarbons, process unlikely to be

pressure-dependent, whereas passage of combustion on a fuse depends on

ignition at any one point being triggered by hot gases from adjacent

material that has just been burnt - if external pressure is reduced, these

gases will be more readily dispersed and "the number of ignited gaseous

particles in contact at any one moment with the still unignited disc of

composition will be diminished".

b) Origins of illuminating power

Remained another puzzle from the Mont Blanc candle observations: whatever

their rate of burning might have been on the summit, there was certainly

considerable reduction in their luminosity. Immediately roused EF's interest

because during past few yrs had performed many exps on illuminating power

for gas producers, manufacturers of candles and others, and so constructed

apparatus and observed combustion of candles in an enclosed space, at varied

pressures. He concluded that within a fairly narrow range of pressures

diminution of illuminating power was proportional to decrease in external

pressure, and established an almost linear relationship for pressures from

atmospheric down to 4.6 inches of mercury (when photometer failed to

respond). If, however, pressure was increased above that of the atmosphere,

a similar relation held true until it was doubled, after which there was a

wide divergence from linearity.

Cause of this behaviour intrigued EF - he concluded that the variations

depend on the relative ease of access of oxygen to the interior of the

flame, and cited well-known effect to be seen on opening the air-hole of a

Bunsen burner - EF argued that at low pressures the increased mobility of

the reacting gases and the increased volume (and therefore surface area) of

the flame render more complete the admixture of oxygen with the burning

gases. At heart of his argument lay the supposition that the light emitted

depended on "the unconsumed amount of carbon separated within the flame",

which plentiful access of oxygen would ensure would be kept to a minimum.

EF communicated results of these 2 sets of exps to the Royal Society in June

1861, but in fact raised more problems than they solved and initiated

another set of experiments. Three lots of work:

i) first some investigations relating combustion to temperature, apparently

occasioned by investigations into gas explosions in London in which EF

observed a differential diffusion of gases as coal-gas escapes from a

confined space. Hence the inflammability of any given sample would depend on

its exact composition which, in turn, would be governed by the relative

rates of diffusion of its components - was therefore important to discover

the ignition temperatures of constituents of coal gas, and EF showed they

rose in the order: CS2 < H2 < CO < C2H4 < CH4. Also concluded that added

carbon disulphide would reduce the ignition points of the other components

but not of ethylene; hydrogen may be ignited by sparks from flint and steel,

so Davy lamps needed to be used with circumspection where (as in coal-gas)

gases other than methane are also present. Thus, by its emphasis on

diffusion of gases, this work is closely related to EF's speculations about

combustion of candles, and thus to the experiments on Mont Blanc.

ii) next, in 1867, EF returned to problem of why some gas flames have high

luminosity but others do not. His first explanation of the Mont Blanc exps

was in terms of Davy's theory that flames owe their brightness to particles

of incandescent carbon resulting from incomplete combustion in the centre of

the flame. However, in 1867, after number of investigations, EF gave a

series of lectures at the Royal Institution on 'Coal Gas': here, where

memory of Humphry Davy sacred, EF proved Davy's theory defective, as EF was

able to show that the black deposit obtained by insertion of a cold surface

into a flame also contains combined hydrogen (removal by chlorine at high

temperature), and cited the brilliant flames obtained by burning arsenic,

phosphorus and carbon disulphide for none of which can incandescent solid

particles be responsible. He therefore concluded that luminosity must be due

to dense but transparent hydrocarbon vapours.

iii) His final paper on subject was read to the Royal Society in 1868 on the

combustion of hydrogen and carbon monoxide under great pressure. Combustions

of the 2 gases in oxygen were conducted in another iron pressure vessel,

furnished with a suitable glass window; pressures of up to 20 atmospheres

used, and as these approached, hydrogen and carbon monoxide each emitted a

brilliant light (whose spectrum was continuous). Similarly, passage of

electric sparks through hydrogen, oxygen, chlorine and sulphur dioxide and

(above all) mercury vapour gave out light whose brilliance increased with

the density of the gas.

II: Protein Experiments

In August 1865, EF sitting in hotel in Geneva watching weather: appeared

hopelessly bad, so telegraphed his brother-in-law Professor of Physiology,

Adolf Eugen Fick (1829-1901) - "Weather too unsettled

for Faulhorn. I return to Zurich".

Pair had arranged, together with Professor Wislicenus to test theory which

assigned the source of muscular power to the oxidation and destruction of

the muscles themselves. Had intended to confine themselves to a

non-nitrogenous diet, and to ascend the Faulhorn, taking strict account of

the greatest possible muscular oxidation by determining the amount of

nitrogen expelled from the body of each person before, during, and after the

ascent of the mountain. Above telegram prevented EF from participating in

what he later regarded as one of most important chemico-physiological

experiments ever made - fortnight later experiment was carried out by Fick,

Prof of Physiology at University of Zurich, and Dr. Johann Wislicenus, Prof

of Chemistry at same university.

By mid-C19th, problem of where energy comes from had been pinned down to

chemical origin, its source being oxidation of organic matter in the body to

(eventually) CO2, water etc. - in which respect was similar to development

of body heat. Had been a growing belief in such ideas from Lavoisier,

through Berzelius and up to Liebig, whose chemical views of life processes

were v. influential. Big question was nature of the chemical fuel consumed

in exercise, and whether it was the same as that used to maintain body

temperature. Liebig had shown that the latter was non-nitrogenous material -

ie what we call carbohydrates and fats - but during the 1860s several

authors had suggested a different fuel for development of muscular power.

Arguing on the basis that muscle is rich in albumen (ie protein), and that

some was probably consumed in violent exertion, they proposed that oxidation

of albuminoid substances must be the source of that energy.

Such a view was, however, opposed by 2 German scientists, Adolf Fick and

Johann Wislicenus, both of whom were relatives of EF by marriage, on three

quite different grounds:

i) Argument by analogy: if albumen/protein is consumed it must effect

structural replacement in muscle tissue - if same idea is applied to

locomotive is ridiculous: machine consists mainly of iron, steel, brass etc

and contains but little coal; therefore its action must consist of burning

iron and steel, not of the burning of coal.

ii) Argument by design: pair point out the oddity of a design (the body)

with two separate fuel systems, "as uneconomical as a manufacturer who

should put up a stove near a steam-engine".

iii) Argument from experience: had been shown several times that muscular

exertion causes a dramatic increase in the expiration of CO2 but not in the

excretion of urea - however, nitrogenous waste-products might leave the

organism in some other form, and the evolution of CO2 might be a mere

side-effect.

Fick & Wislicenus readily accepted that none of these arguments was

conclusive, and that what was needed was a quantitative correlation between

energy expended by muscular action and amounts of nitrogen-excretion, so

proposed to conduct the experiment on themselves. Expenditure of energy

could be determined by ascending a mountain of known height, and chose

Faulhorn in the Bernese Oberland, with ascent of exactly 1956 metres (6417

ft) and with convenient hotel on summit in which to spend the night. This

project EF wished to take part in, but was deterred by weather.

Ascent actually took place on 29 August 1865, with moutaineers on

albumen-free diet: results seemed clear - the energy expended was about 1.75

times that expected on the basis of measured nitrogen excretion. They

therefore concluded that 'since the muscle machine can undoubtedly be heated

by non-nitrogenous fuel, this fuel is in all cases that best suited for it."

However, EF refused to be totally excluded from experiment - studying his

friends' results, he stressed the connection between the 'actual energy'

expended as heat and mechanical motion and the 'potential energy' locked up

in food and released by chemical change in the body.

EF's Experiments: To determine the 'potential energy' of food, EF first

resorted to a series of calorimetric experiments, conducted in a Lewis

Thomson calorimeter - a copper tube containing the sample mixed with

potassium chlorate. A fuse was inserted - consisting of a dry cotton thread,

previously soaked in potassium chlorate solution - and the closed end of the

tube was submerged in water and as soon as the fuse had been lit a bell-jar

was placed over the open end to collect gaseous products. The heat released

by combustion was determined from the difference in water temperatures

before and after the explosion.

EF first measured the energy developed by combustion of one gram of each of

the following: beef-muscle, albumen, beef-fat, hippuric acid, uric acid and

urea. However, an end-product of this experiment 'in vitro' was nitrogen gas

• not as 'in vivo' when almost exactly one third of the nitrogen from

beef-muscle or albumen ends up as urea. On that basis EF was able to show

that Fick and Wislicenus over-estimated the energy derived from nitrogenous

products, and concluded that:

"The combustible food and oxygen coexist in the blood which courses through

the muscle, but when the muscle is at rest, there is no chemical action

between them. A command is sent from the brain to the muscle, the nervous

agent determines oxidation: the potential energy becomes actual energy, one

portion assuming the form of motion, another appearing as heat. Here is the

source of animal heat, here is the source of muscular power! Like the piston

and cylinder of a steam-engine, the muscle itself is only a machine for the

transformation of heat into motion; both are subject to wear and tear, and

require renewal; but neither contributes in any important degree, by its own

oxidation, to the actual production of the mechanical power which it

exerts."

EF then turned to measurements on common constituents of food, determining

the energy released from one gram of each by combustion in oxygen and

oxidation in the body. He showed that ingested fats, though not essential

for diet, nevertheless had a high calorific value - and then made the vital

connection between calorific value and actual cost, showing that fats,

because of their cheapness, were an important item of diet for the poor.

This accorded with his experience in Lancashire, where food of agricultural

labourers contained a high proportion of fat (notably dumplings and egg and

bacon pies), and with memories of childhood, when meals of "navigators

employed in the construction of the Lancaster and Preston railway . . .

consisted of slices of bread surmounted with thick blocks of fat bacon in

which mere streaks of lean were visible. These labourers doubtless found

that from fat bacon they obtained, at the minimum cost, the actual energy

required for their arduous work."

EF reported his calorimetric work to the Royal Institution on 8 June 1866,

and then paper read to the Royal Society in September, where very well

received. A couple of years later, Liebig commented to Wohler on both the

work of Fick and Wislicenus and EF's extension of it, which "sent to the

grave my former theory" - Liebig then tried to accommodate the new work by

supposing the muscular system to be a kind of reservoir of energy that might

be derived from food with or without nitrogen, and would then gradually

release it "like the stretched spring of a clock". Other, less serious

reactions expressed in piece of contemporary doggerel on ascent of Faulhorn

and EF's further work: [could copy out bad poem on request!]. But on the

whole reactions, positive or negative, were muted. Nevertheless, EF's

research was very beginning of measurements of what came to be called

"calorific value" of foodstuffs, an important element in all modern studies

of dietetics. However, omission of his name from even comprehensive

treatises on nutrition indicates that EF is not generally known as the first

to study foods for the quantitative energy values which they yield on

combustion - story of his life apparently.