Part 7

At a meeting in London the total destruction of “rats” was advocated. Whether it was affirmed at the meeting, or was merely an error of those who wrote and commented on the matter afterwards, I do not know, but it was very generally stated in this connection that the old Black rat (known to naturalists as Mus rattus) is quite extinct in England, and that its place has been taken by the Norwegian, or Grey rat (Mus decumanus), also called the Hanoverian rat, because it became noticeable by its abundance in this country at the time of the accession of the Hanoverian kings. The Black rat is not extinct in England, not even very rare. Mr. Stendall lately sent me specimens caught in his warehouse in the City of London, where they are abundant. In many localities, _e.g._ Great Yarmouth, and in isolated dwelling-places they occur, and even outnumber the Norwegian rat. A most important and remarkable fact is that the rats which infest ships are often all Black rats. The Black rat, or Alexandrine rat (as Mr. Thomas calls it), lives in our houses, in the roof, in recesses of woodwork. It is a house rat, whereas the Grey, or Norwegian rat, lives in the sewers and the banks of ditches, and only comes up into the basement of houses through defective building. The Grey rat has driven out the water-voles from many river banks near towns, just as he has to a great extent taken the place of the Black rat in houses where the kitchen and food stores are close to and in communication with the sewer!

The Black rat cannot be really distinguished by his blackness. That is why some naturalists call him the Alexandrine rat, so as to avoid a misleading implication. He is often of a bright yellowish-brown colour along the back--with longer dark-brown hairs and a good deal of grey elsewhere--quite like the Norwegian or Grey rat in colour. At the same time he is often blackish, and frequently very black. The colour of all these kinds of rats and mice can vary, according to the conditions and colour surroundings in which they live. Black, white, sandy-brown, or a mixture of spots of all three colours, or a uniform “mouse-brown” tint, are (as most boys know) the possibilities revealed by allowing them to breed in captivity. Nature selects accordingly the particular tint which affords protection from observation by enemies in a given locality.

The real distinction between the Black (Alexandrine) rat and the Grey (Norwegian) rat is that the Black rat is smaller, has a tail longer than its body (125 per cent.), and long and wide ears, which stand out from the head. The Grey (Norwegian) rat is a larger, heavy-bodied rat, with a tail shorter than its body (90 per cent.), and short ears. Both these rats are common in India, but there is a third kind, which is the commonest of the three in Calcutta, and is probably the one most concerned in the dissemination of plague. It differs in some definite features from both the Black rat and the Grey rat, although it is very much like the latter in general appearance. It is called Nesokia Bengalensis, or Mole-rat. It is a big rat--its tail is only 70 per cent. the length of its body; the pads on the soles of its feet differ from those of the two other rats; its fur is thin and bristly, and when it is put into a cage it erects its bristles and spits! It is, like the Black rat, a stable and granary rat, and makes burrows in which it stores grain.

The rats of Calcutta have been carefully studied lately by Dr. Hossack, in consequence of their connection with the bubonic plague. In the older native parts of Calcutta, the Mole rat is twice as common as the Norwegian Grey rat, and the Black rat not so abundant as the latter. In the central European part of the town the Grey rat is commoner than the Mole rat--because, apparently, the better-built houses do not afford such facilities for burrowing. The Black rat is here also by a good deal the most uncommon of the three. All these rats suffer from the plague, die from it, and the fleas which lived in their fur leave them as they get cold, and make their way on to human beings, whom they consequently infect with the plague bacillus. This has now been quite conclusively proved by the Indian doctors charged by Government with the study of the causes of the plague. The plague bacillus--a minute, rod-like organism, which grows in the blood and lymph, once it has effected a lodgment, and there produces deadly poison--was discovered some fourteen years ago, but it is only recently that the plague bacillus has been shown to live in the intestine of the flea, which sucks it up with the blood or other fluids of the rat on which it lives. The flea, which readily goes to man, does not suffer from the plague bacilli which it has gorged, but conveys them to man either by its bite or by its excrement.

This being so, it becomes important to know all about the fleas of rats. Quite unexpected facts have been discovered in regard to them. In Europe a very large flea is found on the grey and the black rat. This kind has not, I believe, ever been found on human beings or been known to bite them. But in India, in the Philippines, and in the ports of the Mediterranean, this northern rat-flea is rare, and its place is taken by a smaller and more actively vagrant flea, which Mr. Charles Rothschild (who is the great authority on fleas) found upon several different kinds of small animals in Egypt. He named it “Pulex cheopis.” This is the flea (and not our big northern rat-flea) which acts as the carrier of plague-germs from rats to man in India. It appears from experiments that the common flea of man (Pulex irritans) and the cat-and-dog flea (Pulex felis), as well as the big northern rat-flea (Ceratophyllus fasciatus), can harbour the plague-bacillus if fed on plague-stricken animals, but there are no observations to show (as there are about the “Cheops flea”) that they pass habitually from man to rats and rats to men.

It is happily so long (200 years) since we had a real outbreak of plague in Europe that we are still in doubt as to whether the Grey rat or the Black rat is the more susceptible to the disease--and what flea, if any, acts, or has acted, as the carrier from rat to man in this part of the world. The suggestion has been made that the Grey Norwegian rat takes plague less easily than the Black rat, or than the Indian Mole-rat (Nesokia), and that the multiplication of the Grey rat in England and France and consequent decrease in Black rats, is, therefore, an advantage, so far as plague is concerned. Possibly with the Grey rat has come the big rat-flea, which does not attack man as does the Cheops flea. The disappearance of plague in Western Europe seems to correspond in date with the arrival of the Grey rat. But, on the other hand, an alteration in the character of our houses and their greater “accommodation” for the new rat rather than the old black species may account both for the increase of the latter and for the absence of dirt and vermin in the dwelling-rooms and bed-chambers which formerly enabled the plague-bacillus to flourish amongst us, and to reach the human population--as it does now in India and China. All this shows how necessary it is to have accurate true knowledge of such despised creatures as rats and fleas, if we are to live in great crowded cities closely packed together. And it should also make us try to gain further knowledge as to these creatures, so that we may form a reasonable anticipation of the consequences we are bringing down on our heads when we set about exterminating this or that race of animals. We are not yet sure that the Norwegian Grey rat is not a blessing in disguise.

31. _Ancient Temples and Astronomy_

Janssen, the French astronomer, who died about the same time as Lord Kelvin, acquired celebrity by his discovery of a method for seeing and studying the great flames or prominences which surround the sun. The glare of the great fiery ball is such that the eye is blinded in ordinary circumstances to the light of these prominences. They were only known from their coming into view during the total eclipse of the sun’s disc by the moon. Then they were seen as a great fringe of pointed, tongue-like flames around the darkened disc. But at other times no use of smoked glass or telescope could bring them into view. Janssen went to India in 1868 to study these prominences of the sun during the total eclipse of that year. His purpose was to examine with a spectroscope the light given out by the prominences. The day after the eclipse Janssen found that he could still examine the prominences and make out their shape and the chemical elements present in them by looking at them through the spectroscope, although the sun’s disc was now uncovered, and it was impossible to see the prominences with the unaided eye or with the telescope.

A young English astronomer, hundreds of miles apart from Janssen, on the same day, Aug. 18, 1868, made the same discovery in the same way, independently. The English astronomer was Norman Lockyer, and the French Academy of Sciences caused a medal to be struck in commemoration of this discovery. The medal is before me as I write. It shows the heads of Janssen and of Lockyer side by side, as they were forty years ago.

Each has carried on his researches and discoveries with unabated vigour since that happy conjunction. Sir Norman Lockyer has for many years added to his constant study of the sun, fixed stars, and nebulæ by means of the spectroscope and photographic record of spectra, an inquiry into the evidence afforded by astronomical facts first as to the age of Greek and Egyptian temples, and latterly as to that of the mysterious avenues and circles of stones (such as Stonehenge) scattered about the British Islands, of the history and use of which we have only vague traditions and no actual records. These stone circles and avenues are very numerous in Great Britain. The chief are Stonehenge, Avebury, and Stanton Drew in the middle South of England; the Hurlers, Boscawen-Un, Tregaseal, the Merry Maidens, and the Nine Maidens in Cornwall; Merrivale Avenue and Fernworthy Avenue in Devon; many circles in Aberdeenshire, in Cumberland, Derbyshire, and Oxfordshire, as well as monuments of the same kind in Wales. Sir Norman Lockyer has obtained measurements of most of these and plans showing the relations of the principal lines of their ground plan to the points of the compass, and so to the position occupied by the sun and by certain stars on given days of the year at the rising or setting of those heavenly bodies. It may well be asked what is Sir Norman’s object in doing this?

The explanation is as follows: The builders of Christian churches in Europe have, as a rule, set out the ground plan of the church shaped like a Latin cross, so that the arms of the cross run north and south--the head points to the east, or Orient, and the base to the west. In consequence of this custom the word “orientation” has come into use, to signify the direction purposely given to the main length of a temple or church. Now it appears that many, if not all, ancient temples (including the ancient stone circles and avenues of Britain) were purposely so “oriented” by their builders that a particular star, or the sun itself, should at a fixed day and hour in the year be seen during its movement across the heavens through an opening in the building especially designed for this purpose, so as to allow the light of the star to fall into the most sacred part of the temple, the “Naon,” or Holy of Holies. At the moment of its appearance special ceremonies were performed by the priests and worshippers in the temple. The temple was dedicated to and carefully “oriented to” that particular star. Thus, in ancient Greece, the Pleiades, Sirius (the dog star), Spica, and other stars were thus used; in Egypt, Capella, Canopus, and Alpha Centauri; in Britain, Arcturus, as well as those used by the Greeks.

These temples were really astronomical observatories, and were meant always to remain “oriented” to their special star, which must, if the earth were steady in its position, although spinning like a top, and also circling round the sun, duly appear each year at the expected day and minute in the special “window” or aperture designed so as to allow the star--then, and then only--to shine into the temple. But the astronomers have discovered that the earth is not steady! It “wobbles” very slowly and regularly as a top wobbles. The position of the axis of rotation--corresponding in position to the stem of a top--does not remain one and the same, but is pulled aside by the attraction of the sun and moon, and moves round as one may often see in the spinning of a top. The earth takes about 26,000 years for its poles to complete the cycle of its wobble. Moreover, in addition to this, there is the fact that the earth’s axis (stem of the top) is not nearly upright, but inclined at a considerable angle (23 deg.) to the horizontal or plane of its orbit round the sun, and that this inclination very slowly changes, in addition to the wobbling movement. The amount and rate of these changes in the inclination of the axis of the earth have been definitely ascertained by astronomers.

I mention the nature of these movements because they clearly enough must upset altogether the desired result of the orientation of temples. The last-mentioned slow increase of obliquity affects solar temples chiefly, and the more rapid wobbling affects the star temples--both to such a degree that temples oriented two or three thousand years ago are now quite out of line, and no longer “catch,” so to speak, their particular star or the sun on the appointed day. They no longer point truly, because the “pitch” of the earth has altered since they were set.

The next point is that astronomers are able to calculate with surprising accuracy from other observations how much exactly at this moment the “pointing,” or “alignment,” must be “out” as compared with a thousand, fifteen hundred, two, three, four, or more thousand years ago. Accordingly, if you know the star to which an ancient temple was set or aligned, the day of the solar year which was the festival or critical moment of the appearance of the star in the sacred aperture--and how much the temple is to-day out in its pointing, that is to say, the exact amount of swinging which would bring the temple back into its original relation to the star--you have a means of measuring the age of the temple; you have a measure of the time which has elapsed since it acquired this amount of departure from correct orientation. Astronomy tells you how much it must get out of line in every hundred years.

Mr. F. C. Penrose, F.R.S., investigated this matter in regard to several Greek temples; others besides Sir Norman Lockyer have written on the aberration and calculable age of Egyptian temples. It has, for instance, actually been found that the temple of Ptah was aligned to the sun in the year 5200 B.C. The alignment is no longer correct, and it appears that the Egyptians themselves discovered that some of their most ancient temples had lost correct alignment, and erected new and corrected buildings in connection with them, and re-dedicated them. Now Sir Norman is making a vigorous effort to procure all the possible measurements and indications concerning the prehistoric circles and avenues of Britain before it is too late. They are being more and more rapidly destroyed. Stonehenge has been carefully measured and its present alignment determined by various surveyors. Its age is discussed by Sir Norman Lockyer in an interesting book, but we may soon expect a further discussion of the whole subject of these prehistoric British monuments from his pen. In some cases, as in that of Stonehenge, the relation of the temple to the sun is obvious and confirmed by tradition and existing custom. But in many cases investigation is rendered very difficult by the absence of any immediate indication of what precisely is the heavenly body to which the temple was at its foundation oriented.

In the case of Stonehenge, the conclusion at which Sir Norman Lockyer arrives is that there was an earlier circle of small stones (still represented), but that the temple was rededicated, and the larger trilithons (each consisting of two uprights and a cross-piece) erected, and the main opening of the circle aligned to the midsummer rising sun about 1700 B.C., with a possible error of 200 years, more or less. This is arrived at by measurements showing the exact amount by which the alignment is “out” at the present day. This date is confirmed by the recent discovery of numerous stone hammers when one of the big stones was dug under and restored to the upright position from which it had slipped. The stone age is believed to have given place in Britain to the use of metal before 1700 B.C., and no metal tools were found at Stonehenge.

Stonehenge--the most wonderful, mysterious, and complete of the great astronomical temples of Western Europe--has come down to us from the absolute darkness of prehistoric ages. Its secrets are still buried in the ground around and under its huge monoliths. This prodigious relic of the past is actually the private possession of one happy man, Sir Edmund Antrobus. Only two years ago he earned the gratitude of all men by employing workmen and machinery, at considerable expense, to restore one of the great stones to its upright position. The extraordinary thing is that whatever money is needed for the purpose is not at once offered to enable him to examine and replace with scrupulous care every stone, big and small, every scrap of soil, within an area of many hundred yards, embracing Stonehenge and all around it. I understand that he is willing to sell this great possession to the nation. It surely ought to be acquired as national property, and reverently excavated and preserved, whilst every fragment of significance found in the excavations should be placed in a special museum at Amesbury or Salisbury, under unassailable guardianship. Year by year it has crumbled away. We owe the sincerest thanks to Sir Edmund Antrobus for having placed a light wire fence around the venerated relics, and for putting a guardian in charge so as to arrest, even at this latest moment, the final desecration and destruction of this splendid thing by heedless ruffians. The protection afforded is, nevertheless, insufficient. The delay in examining everything on the spot and in making all that remains absolutely secure is a national disgrace.

32. _Alchemists of To-day and Yesterday_

The claim to have devised a secret process in virtue of which sugar or charcoal placed in an iron crucible and heated to a tremendous temperature is found on subsequent cooling to contain large marketable diamonds has a close similarity to the pretensions of the alchemists. It differs in the fact that very minute diamonds have actually been formed by a scientific chemist (M. Moissan) in such a way, whilst the alchemists’ search was for a substance--the “philosopher’s stone,” as it was called, which was never discovered, but was supposed to have the property, if mixed and heated in a crucible with a base metal, of converting the latter into gold. From time to time those engaged in this search honestly thought that they had succeeded; others were impostors, and others laboured year after year, led on by elusive results and dazzling possibilities.

In England, after the true scientific spirit had been brought to bear on such inquiries by Robert Boyle and the founders of the Royal Society in the later years of the seventeenth century, little was heard of “alchemy,” and the word “chemistry” took its place, signifying a new method of study in which the actual properties of bodies, their combinations and decompositions, were carefully ascertained and recorded without any prepossessions as to either the mythical philosopher’s stone or the elixir of life. But as late as 1783--only a hundred and twenty-five years ago--we come across a strange and tragic history in the records of the Royal Society associated with the name of James Price, who was a gentleman commoner of Magdalen Hall, Oxford. After graduating as M.A., in 1777 he was, at the age of twenty-nine, elected a Fellow of the Royal Society of London. In the following year the University of Oxford conferred on him the degree of M.D. in recognition of his discoveries in natural science, and especially for his chemical labours. Price was born in London in 1752, and his name was originally Higginbotham, but he changed it on receiving a fortune from a relative.

This fortunate young man, whose abilities and character impressed and interested the learned men of the day, provided himself with a laboratory at his country house at Stoke, near Guildford. Here he carried on his researches, and the year after that in which honours were conferred on him by his university and the great scientific society in London, he invited a number of noblemen and gentlemen to his laboratory to witness the performance of seven experiments, similar to those of the alchemists--namely, the transmutation of baser metals into silver and into gold. The Lords Onslow, Palmerston, and King of that date were amongst the company. Price produced a white powder, which he declared to be capable of converting fifty times its own weight of mercury into silver, and a red powder, which, he said, was capable of converting sixty times its own weight of mercury into gold. The preparation of these powders was a secret, and it was the discovery of them for which Price claimed attention. The experiments were made. In seven successive trials the powders were mixed in a crucible with mercury, first four crucibles, with weighed quantities of the white powder, and then three other crucibles with weighed quantities of the red powder. Silver and gold appeared in the crucibles after heating in a furnace, as predicted by Price. The precious metal produced was examined by assayers and pronounced genuine. Specimens of the gold were exhibited to his Majesty King George III., and Price published a pamphlet entitled “An Account of Some Experiments, &c.,” in which he repudiated the doctrine of the philosopher’s stone, but claimed that he had, by laborious experiment, discovered how to prepare these composite powders, which were the practical realisation of that long-sought marvel. He did not, however, reveal the secret of their preparation. The greatest excitement was caused by this publication appearing under the name of James Price, M.D. (Oxon.), F.R.S. It was translated into foreign languages, and caused a tremendous commotion in the scientific world.

Some of the older Fellows of the Royal Society, friends of Price, now urged him privately to make known his mode of preparing the powders, and pointed out the propriety of his bringing his discovery before the society. But this Price refused to do. To one of his friends he wrote that he feared he might have been deceived by the dealers who had sold mercury to him, and that apparently it already contained gold. He was urged by two leading Fellows of the society to repeat his experiments in their presence, and he thereupon wrote that the powders were exhausted, and that the expense of making more was too great for him to bear, whilst the labour involved had already affected his health, and he feared to submit it to a further strain. The Royal Society now interfered, and the president (Sir Joseph Banks) and officers insisted that, “for the honour of the society,” he must repeat the experiments before delegates of the society, and show that his statements were truthful and his experiments without fraud.