Chapter 7

We had thus to find a cheap method of eliminating these two gases from the producer gas, and converting them at the same time into their equivalent of hydrogen. The processes hitherto known for this purpose, viz., passing a mixture of such gases with steam over lime (which I mentioned some time ago) or over oxide of iron or manganese, require high temperatures, which render them expensive, and the latter do not effect the reaction to a sufficient extent for our purpose.

We have succeeded in attaining our object at a temperature below that at which the gases leave my producers, viz., at 350° C. to 450° C., by passing the producer gases, still containing a considerable excess of steam, over metallic nickel or cobalt. These metals have the extraordinary property of decomposing almost completely, even at the low temperature named, carbonic oxide into carbon and carbonic acid and hydrocarbons into carbon and hydrogen.

In order to carry the process out with small quantities of nickel and cobalt, we impregnate pumice stone or similar material with a salt of nickel or cobalt, and reduce this by means of hydrogen or producer gas. These pieces of pumice stone are filled into a retort or chamber and the hot gases passed through them. As the reaction produces heat, it is not necessary to heat the chambers or retorts from the outside when the necessary temperature has once been attained. This process has not yet been carried out on a large scale, but the laboratory experiments have been so satisfactory that we have no doubt as to its complete success. It will enable us to obtain gases containing 36 per cent. to 40 per cent. of hydrogen and practically free from carbonic oxide and hydrocarbons from producer gas at a very small cost, and thus to make the latter suitable for the production of electricity by our gas battery. We obtain, as stated before, 50 per cent. of the energy in the hydrogen absorbed in the battery in the form of electricity, while, if the same gas was consumed under steam boilers to make steam, which, as I have shown before, could in this way be raised cheaper than by burning fuel direct, and if this steam was turned into motive power by first-rate steam engines, and the motive power converted into electricity by a dynamo, the yield of electricity would in the most favorable case not exceed 8 per cent. of the energy in the gas. I hope that this kind of battery will one day enable us to perform chemical operations by electricity on the largest scale, and to press this potent power into the service of the chemical industries.

The statement is frequently made that "Necessity is the mother of invention." If this has been the case in the past, I think it is no longer so in our days, since science has made us acquainted with the correlation of forces, teaching us what amount of energy we utilize and how much we waste in our various methods for attaining certain objects, and indicating to us where and in what direction and how far improvement is possible; and since the increase in our knowledge of the properties of matter enables us to form an opinion beforehand as to the substances we have available for obtaining a desired result.

We can now foresee, in most cases, in what direction progress in technology will move, and in consequence the inventor is now frequently in advance of the wants of his time. He may even create new wants, to my mind a distinct step in the development of human culture. It can then no longer be stated that "Necessity is the mother of invention;" but I think it may truly be said that the steady, methodical investigation of natural phenomena is the father of industrial progress.

Sir Lowthian Bell, Bart., F.R.S., in moving a vote of thanks, said that the meeting had had the privilege of listening to a description of results obtained by a man of exceptional intelligence and learning, supplemented by that devotion of mind which qualified him to pursue his work with great energy and perseverance. The importance of the president's address could not possibly be overrated. At various periods different substances had been put forward as indications of the civilization of the people. He remembered hearing from Dr. Ure that he considered the consumption of sulphuric acid to be the most accurate measure of the civilization of the people.

In course of time sulphuric acid gave way to soap, the consumption of which was probably still regarded as the great exponent of civilization by such of his fellow citizens as had thereby made their name. From what he had heard that morning, however, he should be inclined to make soap yield to ammonia, as sulphuric acid had in its time succumbed to soap. For not only was ammonia of great importance to us as a manufacturing nation, but it almost appeared to be a condition of our existence. England had a large population concentrated on an area so small as to make it almost a matter of apprehension whether the surface could maintain the people upon it.

We were now importing almost as much food as we consumed, and were thus more and more dependent on the foreigner. Under certain conditions this would become a very serious matter, and thus any one who showed how to produce plenty of ammonia at a cheap rate was a benefactor to his country. Mr. Mond's process seemed to come nearer to success than any which had preceded it, and it needed no words from him to induce the meeting to accord a hearty vote of thanks to the president for his admirable paper.

Mr. J. C. Stevenson, M.P., in seconding the motion, said that no paper could be more interesting and valuable to the society than that delivered by the president. It opened out a future for the advancement of chemical industry which almost overcame one by the greatness of its possibilities. Mr. Mond had performed an invaluable service by investigating the various methods proposed for the manufacture of ammonia, and clearing the decks of those processes supposed by their inventors to be valuable, but proved by him to be delusive. It gave him hearty pleasure therefore to second the vote of thanks proposed by Sir Lowthian Bell.

The vote having been put and carried by acclamation, after a brief reply from the president:

The secretary read the report of the scrutators, which showed that 158 ballot papers had been sent in, 154 voting for the proposed list intact, and four substituting other names. The gentlemen nominated in the list issued by the Council were therefore declared elected.

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In his brief report for the year ending May 1, 1889, the director of the Pasteur Institute, Paris, announces the treatment of 1,673 subjects, of whom 6 were seized with rabies during and 4 within a fortnight after the process. But 3 only succumbed after the treatment had been completely carried out, making 1 death in 554, or, including all cases, 1 in 128.

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ALKALI MANUFACTORIES.

When the alkali, etc., Works Regulation Act was passed in 1881, it was supposed that the result would be that the atmosphere in the districts where such works are situated would be considerably improved, and, consequently, that vegetation would have a better chance in the struggle for existence, and the sanitary conditions of human dwellings would be advanced. In all these respects the act has been a success. But perhaps the most notable result is the effect which the act and those which have preceded it have had upon the manufactures which they control.

This was not anticipated by manufacturers, but now one of the principal of them (Mr. A. M. Chance) has stated that "Government inspection has not only led to material improvement in the general management of chemical works, but it has also been in reality a distinct benefit to, rather than a tax upon, the owners of such works."

This expression of opinion is substantiated by the chief inspector under the act, whose report for last year has recently been laid before the local government board.

There are 1,057 works in the United Kingdom which are visited by the inspectors, and in only two of these during 1888 did the neglect to carry out the inspectors' warnings become so flagrant as to call for legal interference; viz., in the case of Thomas Farmer & Co. (limited), Victoria Docks, E., who were fined 20l. and costs for failing to use the "best practicable means" for preventing the escape of acid gas from manure plant; and in the case of Joseph Fison & Co., Bramford, who were fined 50l. and costs for excessive escape of acid gas from sulphuric acid plant. There were seven other cases, but these were simply for failure to register under the act.

It is very evident, therefore, that from a public point of view the act is splendidly successful, and from the practical or scientific side it is no less satisfactory.

Of the total number of chemical works (1,057) 866 are registered in England, 131 in Scotland, and 44 in Ireland--a decrease in the case of Scotland of 8, and in Ireland of 2 from the previous year, while England has increased by 1. This must not, however, be taken as a sign of diminished production, because there is a tendency for the larger works to increase in size and for the smaller ones to close their operations. The principal nuisances which the inspectors have to prevent are the escape of hydrochloric acid gas from alkali works and of sulphurous gas from vitriol and manure works.

The alkali act forbids the manufacturer to allow the escape of more than 5 per cent. of the hydrochloric acid which he produces, or that that acid must not exist to a greater extent than 0.2 grain in 1 cubic foot of air, steam, or chimney gas which accompanies. The inspectors' figures for last year show that the percentage of the acid which escaped amounted to only 1.96 of the total produced, which is equal to 0.089 grain per cubic foot, and much below the figures for previous years. The figures in regard to sulphurous gas are equally satisfactory. The act allows 4 grains of sulphuric anhydride (SO3) per cubic foot to escape into the air, and last year's average was only 0.737 grain, or less than a fifth of the limit.

Of course it is now the aim of the Leblanc alkali manufacturers to reduce the escape of hydrochloric acid to the lowest possible amount, as their profits depend solely upon the sale of chlorine products, soda products being sold at a loss. In this connection it is interesting to note that the amount of common salt manufactured in the United Kingdom in 1888 was 2,039,867 tons, and of this nearly 600,000 tons were taken by Leblanc soda makers, and over 200,000 tons by the ammonia-soda makers. The figures are very largely in excess of previous years, and indicate a gratifying growth in trade.

The salt used in the Leblanc process yields the hydrochloric acid, and that in the ammonia-soda method none, so that we may put down the theoretical production of acid as 380,000 tons, 7,600 tons of which was allowed to escape.

What was a mere trace in the chimney gases amounts, therefore, to a good round figure at the end of a year, and if it were converted into bleaching powder it would be worth nearly 150,000l. These figures are, it should be understood, based on theory, but they serve to show to what importance a gas has now reached which twenty-five years ago was a perfect incubus to the manufacturers, and wrought desolation in the country sides miles and miles around the producing works. There has long been an expectation that the ammonia-soda makers would add the manufacture of bleaching powder to their process, but they appear to be as far as ever from that result, and meanwhile the Leblanc makers are honestly striving to utilize every atom of the valuable material which they handle. Hence the eagerness to recover the sulphur from tank waste by one or other of the few workable processes which have been proposed.

This waste contains from 11 to 15 per cent. of sulphur, and when it is stated that the total amount of tank waste produced yearly is about 750,000 tons, containing about 100,000 tons of sulphur, it will be seen how large is the reward held out to the successful manipulator. Moreover, the value of the sulphur that might possibly be saved is not the only prize held out to those who can successfully deal with the waste, for this material is not only thrown away as useless, but much expense is incurred in the throwing.

In Lancashire and in other inland districts land must be found on which to deposit it, and the act of depositing is costly, for unless it is beaten together so as to exclude the air, an intolerable nuisance arises from it. The cost of haulage and deposit on land varies, according to the district, from 1s. to 1s. 6d. a ton. In Widnes it is about 1s.

In the Newcastle district the practice is to carry this material out to sea at a cost of about 4d. a ton.

Mr. Chance's process for the recovery of sulphur from the waste signalizes the centenary of the Leblanc process; Parnell and Simpson are following in his wake, and lately Mr. F. Gossage, of Widnes, has been working on a process for the production of alkali, which enables him to save the sulphur of the sulphuric acid. In his process a mixture of 70 parts Leblanc salt cake (sulphate of soda) and 30 parts common salt is mixed with coal and heated in a furnace, and so reduced to sulphide of sodium. The resulting "ash" is then dissolved in water and exposed to the action of carbonic acid, when sulphureted hydrogen is given off, to be dealt with as in Mr. Chance's sulphur process, while bicarbonate of soda is formed and separates by precipitation from the solution of undecomposed common salt.

Ere long it is expected this new method will be in active operation in some Leblanc works, the plant of which will, in all probability, be utilized. It has these great advantages: The absence of lime, the recovery of the sulphur used in the first instance and the consequent absence of the objectionable tank waste. Thus a bright promise is held out that the days of alkali waste are numbered, and that the air in certain parts of Lancashire will be more balmy than it has been in the memory of the oldest inhabitant.--_Chemist and Druggist._

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THE FUELS OF THE FUTURE.

It is undeniable that in this country, at least, we are accustomed to regard coal as the chief, and, indeed, the only substance which falls to be considered under the name of fuel. In other countries, however, the case is different. Various materials, ranging from wood to oil, come within the category of material for the production of heat. The question of fuel, it may be remarked, has a social, an antiquarian, and a chemical interest. In the first place, the inquiry whether or not our supplies of coal will hold out for say the next hundred thousand years, or for a much more limited period only, has been very often discussed by sociologists and by geological authorities.

Again, it is clear that as man advances in the practice of civilized arts, his dependence upon fuel becomes of more and more intimate character. He not merely demands fire wherewith to cook his food, and to raise his own temperature or that of his dwelling, but requires fuel for the thousand and one manufacturing operations in which he is perpetually engaged. It is obvious that without fuel civilized life would practically come to an end. We cannot take the shortest journey by rail or steamboat without a tacit dependence upon a fuel supply; and the failure of this supply would therefore mean and imply the extinction of all the comforts and conveniences on which we are accustomed to rely as aids to easy living in these latter days. Again, socially regarded, man is the only animal that practices the fire-making habit. Even the highest apes, who will sit round the fire which a traveler has just left, and enjoy the heat, do not appear to have developed any sense or idea of keeping up the fire by casting fresh fuel upon it. It seems fairly certain, then, that we may define man as being a "fuel-employing animal," and in so doing be within the bounds of certitude. He may be, and often is, approached by other animals in respect of many of his arts and practices. Birds weave nest materials, ants make--and maul--slaves, beavers build dams, and other animals show the germs and beginnings of human contrivances for aiding the processes of life, but as yet no animal save man lights and maintains a fire. That the fire-making habit must have dawned very early in human history appears to be proved by the finding of ashes and other evidences of the presence of fire among the remains and traces of primitive man.

All we know, also, concerning the history of savage tribes teaches us that humanity is skillful, even in very rude stages of its progress, in the making of fire. The contrivances for obtaining fire are many and curious in savage life, while, once attained, this art seems to have not only formed a constant accompaniment but probably also a determining cause in the evolution of civilization. Wood, the fat of animals, and even the oils expressed from plants, probably all became known to man as convenient sources of fuel in prehistoric times. From the incineration of wood to the use of peat and coal would prove an easy stage in the advance toward present day practices, and with the attainment of coal as a fuel the first great era in man's fire-making habits may be said to end.

Beyond the coal stage, however, lies the more or less distinctively modern one of the utilization of gas and oil for fuel. The existence of great natural centers, or underground stores, of gas and oil is probably no new fact. We read in the histories of classic chroniclers of the blazing gases which were wont to issue from the earth, and to inspire feelings of superstitious awe in the minds of beholders. Only within a few years, however, have geologists been able to tell us much or anything regarding these reservoirs of natural fuel which have become famous in America and in the Russian province of Baku.

For example, it is now known that three products--gas, oil, and salt or brine--lie within natural receptacles formed by the rock strata in the order of their weight. This law, as has well been said, forms the foundation of all successful boring experiments, and the search for natural fuel, therefore, becomes as easy and as reliable a duty as that for artesian water or for coal. The great oil fever of the West was attended at first, as Professor M'Gee tells us, with much waste of the product. Wells were sunk everywhere, and the oil overflowed the land, tainting the rivers, poisoning the air, and often driving out the prospectors from the field of discovery. In Baku accidents and catastrophes have, similarly, been of frequent occurrence. We read of petroleum flowing from the ground in jets 200 feet high, and as thick as a man's body; we learn how it swept away the huge cranes and other machinery, and how, as it flowed away from the orifices, its course was marked by the formation of rivers of oil many miles in length.

In America the pressure of rock gas has burst open stills weighing over a ton, and has rushed through huge iron tanks and split open the pipes wherewith it was sought to control its progress. The roar of this great stream of natural gas was heard for miles around as it escaped from the outlet, and when it was ignited the pillar of flame illumined the surrounding country over a radius extending in some cases to forty miles. It is clear that man having tapped the earth's stores of natural fuel, stood in danger of having unloosed a monster whose power he seemed unable to control. Yet, as the sequel will show, science has been able to tackle with success the problems of mastering the force and of utilizing the energy which are thus locked up within the crust of the globe.

As regards the chemistry of rock gas, we may remark in the first place that this natural product ranks usually as light carbureted hydrogen gas. In this respect it is not unlike the marsh gas with which everyone is familiar, which is found bubbling up from swamps and morasses, and which constitutes the "will o' the wisp" of romance. In rock gas, marsh gas itself is actually found in the proportion of about 93 per cent. The composition of marsh gas is very simple. It consists of the two elements carbon and hydrogen united in certain proportions, indicated chemically by the symbol CH4. We find, in fact, that rock gas possesses a close relationship, chemically speaking, with many familiar carbon compounds, and of these latter, petroleum itself, asphaltum, coal, jet, graphite or plumbago, and even the diamond itself--which is only crystallized carbon after all--are excellent examples.

The differences between these substances really consist in the degree of fixing of the carbon or solid portion of the product, as it were, which exists. Thus in coal and jet the carbon is of stable character, such as we might expect to result from the slow decomposition of vegetable matter, and the products of this action are not volatile or liable to be suddenly dissociated or broken up. On the other hand, when we deal with the _hydrocarbons_ as they are called, in the shape of rock gas, naphtha, petroleum, tar, asphaltum, and similar substances, we see how the carbon has become subordinated to the hydrogen part of the compounds, with the result of rendering them more or less unstable in their character. As Professor M'Gee has shown us, there is in truth a graduated series leading us from the marsh gas and rock gas as the lightest members of this class of compounds onward through the semi-gaseous naphtha to the fluid petroleum, the semi-fluid tar, the solid asphaltum, and the rigid and brittle substance known as albertite, with other and allied products. Having said so much regarding the chemistry of the fuels of the future, we may now pass to consider their geological record. A somewhat curious distribution awaits the man of science in this latter respect. Most readers are aware that the geologists are accustomed to classify rocks, according to their relative age, into three great groups, known respectively as the primary, secondary, and tertiary periods. In the secondary period we do not appear to meet with the fuels of the future, but as far back as the Devonian or old Red Sandstone period, and in the still older Silurian rocks, stores of gas and petroleum abound. In the latest or tertiary period, again, we come upon nearly all the forms of fuels we have already specified.