-100 to 150 transactions, 95 per cent. of which are purely unnecessary, untaxed, unrestricted, paying profits, and yielding losses! There is surely something not quite right here!-something that must be harmful in a moral and material sense to all engaged in the business, and to all great trade interests.

The frequent troubles between employers and the employed are doubtless greatly due to the constant disorganisations which unrestricted speculation in paper contracts is now producing. This point and the difficulties merchants and manufacturers suffer could well be enlarged upon, and submitted to actual proof; but the purpose of this article is to draw attention to a growing evil, and not to enter into over-much detail.

In conclusion it may be asked, Is this question without the pale of Government inquiry and restriction, or is business hereafter to be under the control of unrestricted speculation and gambling in paper contracts? That Government should interfere too much in trade matters is not to be advocated; but here is an instance in which large vested interests are thrown into contact with unnatural and unhealthy influences which not every manufacturer or trader has the mental quickness to grapple with, or the cool courage to wait patiently and 'let well alone.' The operations detailed strike far and wide into the very vitals of commerce; and surely, if the morals of a people require legislation, so should the trade of a country be fenced from influences which are morally objectionable, apart from the material damage and disorganisation they cause.

It has been ordained by Parliament that bearing' bank shares is illegal; surely some restriction of the sort is called for in dealings with produce upon which the whole manufacturing industry of this country and of the world is based. It is not needful for commercial purposes that the cotton crop should be turned over twelve times in one year on mere paper contracts, or more hog produce sold than all the hogs in America for several years would yield, or Parisian beetroot sugar warrants dealt in to the extent of several times the annual outturn of the entire Continent.

VOL. X.-No. 56.

NN

WILLIAM B. HALHED.

DISEASE-GERMS.

AMONG the distinguished men who came together at the recent International Medical Congress-a gathering altogether unexampled for its combination of great and varied ability, and worthily representative of almost every country in which medicine is studied— there was no one whose presence was more universally or more cordially welcomed, than a quiet-looking Frenchman, who is neither a great physician, a great surgeon, or even a great physiologist; but who, originally a chemist, has done more for medical science than any savant of his day. And this, not only (probably not so much) through the results already attained by Pasteur himself and by others working on his ideas-great though these results are; but through the entirely new direction he has given to scientific inquiry, the number of new paths of research he has opened out, and of new clues he has afforded to those who will follow them up; and, last but by no means least, by the admirable example he has afforded, in the strictness and severity of his own methods (which have made him almost unerring in his predictions, and have given his conclusions the force of demonstrations), to those who would carry on the same lines of inquiry.

And here I would stop to note, as honourable to the disinterested character of a Profession which has been lately the object of violent abuse for its (alleged) selfish and mercenary spirit, that this unique welcome was given, not to a great physician who had discovered a cure for gout, cancer, or consumption, by the use of which it would be enriched-not to a bold surgeon who had brought into vogue some wonderful operation, the success of which would tend to its renown-but to the scientific investigator of the causes of disease, whose work belongs altogether to the domain of preventive medicine, and thus, so far from being likely to benefit its members pecuniarily, tends only to diminish their remunerative employment. I never felt so proud of belonging to the body which still does me the honour to recognise me as one of its members, as I did when Sir James Paget, the President of the Congress, paused in his opening address, to point out on the platform behind him the greatest living exemplar of the truths he was so admirably enforcing; and when the whole of his vast audience-the like of which had never before been

gathered in St. James's Hall, and perhaps never will be again— enthusiastically cheered, not once only, but again and again, the scientific veteran whose renown has spread from his quiet Parisian laboratory over the whole civilised world.

In order that the last of Pasteur's great achievements-which, with some of the ideas it suggests, it is my object now to bring before the readers of the Nineteenth Century-may be properly appreciated, it will be well for me to sketch out briefly what has been the nature of his lifework, from the time when the singular beauty of some of his Chemico-physical researches (which obtained for him in 1856 the Rumford Medal of the Royal Society) marked him out as one likely to attain further distinction.

It seems to have been by his special interest in the chemistry of Organic substances, that he was early led to examine into the question of fermentation; which had come to present an entirely new aspect through the discovery of Cagniard de la Tour that yeast is really a plant belonging to one of the lowest types of fungi, which grows and reproduces itself in the fermentable fluid, and whose vegetative action is presumably the cause of that fermentation, just as the development of mould in a jam-pot occasions a like change in the upper stratum of the jam, on whose surface, and at whose expense, it lives and reproduces itself. Chemists generally—especially Liebig, who had a fermentation-theory of his own-pooh-poohed this idea altogether; maintaining the presence of the yeast-plant to be a mere concomitant, and refusing to believe that it had any real share in the process. But in 1843, Professor Helmholtz, then a young undistinguished man, devised a method of stopping the passage of organic germs from a fermenting into a fermentable liquid, without checking the passage of fluids; and as no fermentation was then set up, he drew the inference that the particulate' organic germs, not the soluble material of the yeast, furnish the primum mobile of this change, a doctrine which, though now universally accepted, had to fight its way for some time against the whole force of chemical authority.1

A little before Cagniard de la Tour's discovery, a set of investigations had been made by Schulze and Schwann, to determine whether the exclusion of air was absolutely necessary to prevent the appearance of living organisms in decomposing fluids, or whether these fluids. might be kept free from animal or vegetable life, by such means as would presumably destroy any germs which the air admitted to them might bring in from without, such as passing it through a red-hot tube or strong sulphuric acid. These experiments, it should be said, had reference rather to the question of spontaneous generation' or 'abio

1 It was, I remember, in or about that year, that Professor Liebig's visit to England gave me the opportunity of showing him some yeast under a high power of the microscope. He said that he had not before seen its component cells so distinctly.

genesis,' than to the cause of fermentation and decomposition; its object being to determine whether the living things found by the microscope in a decomposing liquid exposed to the air, spring from germs brought by the atmosphere, or are generated de novo in the act of decay-the latter doctrine having then many upholders. But the discovery of the real nature of yeast, and the recognition of the part it plays in alcoholic fermentation, gave an entirely new value to Schulze's and Schwann's results; suggesting that putrefactive and other kinds of decomposition may be really due, not (as formerly supposed) to the action of atmospheric oxygen upon unstable organic compounds, but to a new arrangement of elements brought about by the development of germinal particles deposited from the atmosphere.

It was at this point that Pasteur took up the inquiry; and for its subsequent complete working-out, science is mainly indebted to him for although other investigators-notably Professor Tyndallhave confirmed and extended his conclusions by ingenious variations on his mode of research, they would be the first to acknowledge that all those main positions which have now gained universal acceptance—save on the part of a few obstinate irreconcileables '-have been established by Pasteur's own labours. These positions may be briefly summarized as follows:

:

1. That no organic fluid undergoes spontaneous fermentation or decomposition, even in the presence of atmospheric air; any such action being originated and maintained only by the developmental action of definite organic germs.

2. That different kinds of fermentation (using that term in its large sense) are produced by organic germs of different species. Thus, while torula sets going the alcoholic fermentation in a saccharine wort, other fungoid germs will set up the acetous, and others, again, the putrefactive fermentation, when introduced into fluids of the same kind.

3. That many different kinds of germs-notably those of the bacteria, which induce putrefactive fermentation-are constantly floating in the ordinary atmosphere, so as to be almost certainly selfsown in any organic fluid freely exposed to it.

4. That if these germs be removed by mechanical filtration, or be got rid of by subsidence, or be deprived of their potency by chemical agents which destroy their vitality, the most readily decomposable organic fluid may be subjected to the freest contact with the air from which the germs have been thus eliminated, without undergoing any change.

5. That as there is no such thing as fermentation without the presence of germ-particles, so there is no such thing as the spontaneous origination of such germs; each kind, when sown in the liquid, reproducing itself with the same regularity as in higher plants, and thus continuously maintaining its own type.

6. That such germ-particles, when dried up, can not only maintain their germinal power for unlimited periods, starting into renewed activity so soon as the requisite conditions are supplied; but that, in this state of dormant vitality, they can be subjected to influences which would destroy the life of the growing plants--such as very high or very low temperatures, the action of strong acid or alkaline solutions, and the like.2

The first application of these doctrines to the study of disease in the living animal, was made in a very important investigation, committed to Pasteur by his old master in chemistry (the eminent and eloquent Dumas), into the nature of the pébrine, which was threatening to extinguish the whole silk culture of France and Italy. It had been previously ascertained that the bodies of the animals affected with this disease (whether in the worm, chrysalis, or moth stage) swarm with peculiar minute corpuscles, which even pass into the undeveloped eggs of the female moth; but there was no evidence that these corpuscles were independent, self-developing organisms introduced from without; many regarding their presence as a mere expression or concomitant of the disorder, not as its cause. It would be too long to detail the steps of this most complicated and difficult inquiry; and I must satisfy myself with the mere statement that it not only proved completely successful as to what may be termed its commercial object, but that, though it concerned only a humble worm, it laid the foundation of an entirely new system and method of research into the nature and causes of a large class of diseases in man and the higher animals, of which we are now only beginning to see the important issues.

Among the most immediately productive of its results, may be accounted the antiseptic surgery' of Professor Lister; of which the principle is the careful exclusion of living bacteria and other germs, alike from the natural internal cavities of the body, and from such as are formed by disease, whenever these may be laid open by accident, or may have to be opened surgically. This exclusion is effected by the judicious use of carbolic acid, which kills the germs without doing any mischief to the patient; and the saving of lives, of limbs, and of severe suffering, already brought about by this method, constitutes in itself a glorious triumph alike to the scientific elaborator of the germ-doctrine, and to the scientific surgeon by whom it has been thus applied.

A far wider range of study, however, soon opened itself. The revival by Dr. Farr of the doctrine of zymosis (fermentation),-long ago suggested by the sagacity of Robert Boyle, and practically taken up in the middle of the last century by Sir John Pringle (the most

2 The evidence on which these conclusions rest is fully stated in Professor Tyndal 's recently published treatise on the Floating Matter of the Air.