spikes are mainly instrumental in the production of the new tuber, for how could that new tuber have been healthy and plump, when the old tuber itself was nearly empty? I am aware, of course, that I cannot argue from a particular to a general case, and so I have stated my theory cautiously. I am also aware that this conclusion is opposed to my remark about the old tuber containing a store of food for the new tuber. The fact is this. I am extremely obliged to G. M. for pointing out the discrepancy in my paper, and thus compelling me to observe more carefully, and I hope that he will observe many plants during this season and help me further. The offending remark was written some time before the remainder of the article.

Then, another thing. I have succeeded, in two years, in entirely clearing the leaves of a plant of O. mascula of spots, so that the leaves of the plant are perfectly spotless. If the roots supplied the new tuber directly, why should not one year be sufficient

Malvern Hills, will find themselves in a land rendered classic to geologists by the researches of Murchison, Ramsay, Phillips, Horner, Symonds, Brodie, Salter, Holl, not to mention a host of minor names, and in a district into whose varied features as many interesting geological problems and strata are compressed as into any area of England of similar extent. The fossiliferous Keuper Marl and osseous conglomerate of Pendock and Moorcourt, the splendid sections of the Upper Silurians, West of Worcestershire Beacon, the Mayhill sandstone in its typical locality, the Ludlow Bone bed of Hale end, the noted Permian

to produce this result? Look at the drawing attentively. The roots are exactly opposite the new tuber, but they join the plant, and the new tuber is connected with the leaves. The spike alone appears to descend to the old tuber. O. mascula appears in a critical case. If the roots are damaged by wet, &c., the plant has to feed on the old tuber, and the spike suffers if the embryo starts too soon, or remains too deeply buried, the new tuber suffers. If the spike is broken, the old tuber doesn't suffer, but somehow the flower of the following year is affected.

There were two misprints in my article (vol. xix. p. 52) which have not been noticed. In one place, column was written for collum, and in another, skin for stem. I also made the mistake of calling the embryo the plumule.

Dr. Erasmus Darwin (Botanic Garden, Canto iv. 37) says that the seed of O. mascula only ripens when the tuber is picked off. Then how can this occur in nature, under ordinary circumstances, unless

breccia of Berrow and Bromesberrow, the Hollybush Sandstone and Black Shales with their lavas of Coalhill and Fowlett's Farm, the Old Red Sandstone of Ledbury, and last but not least the physiography of the Woolhope ellipse, are all in the immediate neighbourhood.

But to any geologist above the rank of a mere fossil collector, there is one point of surpassing interest on which he is sure to commence, and to which he is tolerably sure to return. However interested he may be in the inversion on the west of the hills, however fascinating he may find the study of the denudation of Woolhope, and the comparison of the wooded undulating Silurian strata of the west with the fertile Keuper plain that stretches away on the east to the Severn, the question of the age of the rocks constituting the chain of hills is sure to retain most of his attention.

In a series of articles on the Pre-Cambrian Rocks of England and Wales, published in SCIENCEGOSSIP in 1883, by Mr. W. W. Watts, B. A., F.G.S., the author commenced with a brief notice of the Malvern Hills, which he boldly claimed as Archean. I propose in the present article to see what evidence can be adduced in favour of such a conclusion, to

discuss its value, and finally to summarise the arguments which led Murchison to the opinion still retained by the Survey.

First, let us briefly examine the geological structure of the range. The hills consist of a central ridge of Syenite with much syenitic and granitoid gneiss and diorite on each flank are beds of schist which become more and more brittle and contorted as we approach the syenitic nucleus which is exposed at many points, as at Keys End Hill and the valley of the Whiteleaved Oak, and was passed through in the Malvern and Ledbury Tunnel.* Resting very unconformably upon these schists, we find on the west of the Keys End Hill, the Hollybush Sandstone, the basement bed of which contains pebbles of the igneous rocks derived from the hills, the presence of which proves that the sandstone is the more recent formation. From its fossils (Trachyderma antiquissima, Salter, Serpulites fistula, Holl, Obolella Phillipsii, Holl, Lingula squamosa, Scolithus and four undetermined species), Dr. Hicks has correlated it with his Festiniog beds (middle Lingula Flags). This is the oldest fossiliferous bed in the district, and it limits us to two possible theories as to the age of the hills; they may be Archean, or they may be Lower Cambrian.

With the above sketch in, at any rate, its main points, most geologists would agree; but here the two paths diverge, the old school holding that the hills were formed by the metamorphism of Longmynd rocks into gneiss and schist by the intrusion of the underlying syenite; the Archeanists maintaining that the rocks were deposited in some peculiar manner in Pre-Cambrian times.

The latter school found their case mainly on the three following propositions: Ist (which would only be advanced by the more thorough-going members of the school) that as no Post-Archean regional metamorphism is possible, these rocks being metamorphic are consequently Pre-Cambrian; 2nd, that even if we admit the possibility of Post-Archean metamorphism, the period of time between the Longmynd and the Hollybush Sandstone would be insufficient for the deposition of these strata, and their alteration into gneisses; 3rd, that the Malvern rocks are similar to those from other Pre-Cambrian areas.

Let us briefly examine these arguments. The truth of the first proposition most geologists would deny in toto; and while admitting the possibility that many areas now considered metamorphosed Cambrian may prove to be Archean (as has recently been done by Geikie,† with the "Newer Gneiss

of

that its most enthusiastic adherents only claim that it is supported by negative evidence-one cannot but receive such an argument with great caution. Of such instances are the fossiliferous schists of Christiania,* the Liassic Mica schists of St. Gothard,† and the passage in the Pyrenees so well described by Fuchs, of clay slate through Fruchtschiefer chiastolite slate, andalusite schist, and Mica schist into gneiss.

The objection of lack of time cannot be accepted when we remember that during the Lower Cambrian era were deposited over 500 feet of the Menevian, the 6000 feet of the Harlech Grits and the 20,000 feet of the Longmynd: even if the gneiss and schists of Malvern represent the whole of the Longmynd, we have a period represented by the deposition of 6500 feet, and this would certainly seem ample for the elevation of so small a chain of hills, when we bear in mind that the gigantic ranges of the Alps, Andes, and Himalayas were all elevated during the much shorter system of the Miocene.

In replying to the third argument, that from the structure of the rocks, I need not here discuss the possibility of correlating rocks by their mineralogical composition. We need only note the great differences as pointed out by Murchison between the fissile, fine-grained syenitic gneiss of the Malverns, and the thick-bedded coarse gneiss of the Highlands, which differ in every respect save in the abundance of hornblende. Nor do these rocks more resemble the so-called Pre-Cambrian of St. David's. Dr. Callaway, whose fairness and moderation in a controversy that has not been lacking in personalities command our respect, and whose able and lucid series of papers on the Malvern Hills, the Wrekin, Anglesey, and the Highlands, have placed him in the front rank of English Archeanists, says: §"The Malvern Series is almost exclusively gneissic, foliation is well marked, and hornblende abounds. In the St. David's area gneiss is absent." He further points out the absence at the latter place of schists, as the so-called “quartz schists" of Hicks are really granitoids and quartzites. (To be continued.)

tion is not that of a complete preventive of disease, but rather an alteration of its character, a conversion from a malignant horror to a mere outbreak of pimples. Instead of being the most fatal and the most filthy of all diseases, the small-pox, as it appears in vaccinated patients, has become so mild that there are fanatics who actually describe it as a beneficent purifier of the blood. I have heard a lady who is an eminent agitator and a healing medium, but otherwise fairly intelligent, describe a case of chronic life-long suffering as cured by a "refreshing outpour of small-pox." On the other hand, I have witnessed the horrors of malignant small-pox, a whole family-father, mother, and unvaccinated childrenall in one room, and all in a condition of superficial putrescence, a sight and stench too horrible for description. This is what Jenner and his contemporaries familiarly beheld, but which the lady above-named and those who are similarly infatuated have not yet seen, but will see presently in Leicester if the agitation makes much further progress.

66

Pasteur's prophylactic for the cattle plague and rabies appears to act chiefly in effecting an attenuation" of the disease by means of attenuated virus. The demonstration of the efficacy of his attenuation of hydrophobia is difficult on account of the rarity of the disease and the necessary limitation of experimental proof, but when cattle plague settles in a district and threatens an extermination like that which occurred in the Cheshire cheese country twenty years ago, nothing is easier than to vaccinate one half of a given number of cattle, and expose them and the other half to the same conditions of infection, and watch the result. This has been done in India.

In last month's "Journal of the Chemical Society" is printed a paper read at the Society (with the usual omission of the date of reading) by Dr. Peter Griess and Dr. G. H. Harrow, on "The Presence of Choline in Hops." This substance is otherwise named sincaline, neurine, and amanitine. It is called neurine because it is found in the brain. This name and its existence there have promoted fanciful theories concerning its influence, similar to those popularly entertained concerning the mysterious or quasi-spiritual potency of phosphorus as an element of brain

matter.

The writers of this paper find this neurine in hops and beer, and conclude their paper as follows:"Whether the circumstance that choline is present in beer has any physiological significance, is a question which we are not in a position to decide; it is, however, interesting that this neverfailing and peculiar constituent of the brain-substance should also be present in one of our most important articles of diet."

I will not stop to discuss the question whether beer is "an article of diet." I think it better described as a drug, but must protest against the description of this many-named substance, the choline, or neurine,

or sincaline, or amantinine, as a "peculiar constituent of brain substance." The authors of the paper have misused this word "peculiar." It signifies exclusiveness, and thus used implies that the substance only exists in the brain; whereas, as they state in the early part of their paper, it is "a constantly occurring constituent of several parts of the animal body" and "it has also been proved to exist in some plants." Its various names indicate various sources from which it has been derived. Therefore we need not lower the vitality of the mucous membranes of our digestive organs by drinking tonic hop bitters, nor stupefy ourselves with beer, in order to nourish the brain. Cervelli fritti (fried brains) is a standing dish at Italian restaurants. I met a man at the Lepre in Rome who ate that dish there daily in order to strengthen his intellect. The result by no means indicated that even this very direct consumption of neurine was efficacious.

Another paper read by Mr. H. Brereton Baker at the same society is very interesting and important. As Mr. Baker states, his researches were suggested by some recent experiments of Mr. Harold B. Dixon (Philosophical Transactions, 1884, part 2), showing that a highly explosive mixture of carbonic oxide and oxygen is not explosive when dry. We are so accustomed to regard water as antagonistic to combustion that the mere suggestion that ordinary combustion cannot take place without the help of water appears an extravagant paradox. Nevertheless this appears to be the case. The experiments of Mr. Dixon and those of Mr. Baker concur, so far as they go, in showing that there can be no fire without water. The difficulty in making these experiments is that of getting rid of the water. "Water, water, everywhere" expresses a great chemical truth. It holds on with desperate tenacity to the air we breathe, and every gas we produce in our laboratories. I need not here state the particular methods adopted by Mr. Baker to dry the oxygen used in his experiments. They were the best known, and the drying was continued from one to sixteen weeks.

He subjected purified charcoal and phosphorus to the action of the dried gas, and to ordinary oxygen containing its usual supply of aqueous vapour. These placed in comparison tubes were equally heated. The general result was that in the moist oxygen complete combustion of the carbon and the phosphorus occurred, with brilliant outflash of the latter. In the dried oxygen there was no visible combustion, and examination of the residual gas showed that all the moist oxygen had combined, but only a small and varying proportion of the dry oxygen.

There is fair reason to infer that this small amount of oxidation would not have occurred had the gas been perfectly dry, a condition at present unattain

able.

Santini ("Gazetta Chimica Italiana," vol. xiv. p. 274) has already shown that the flame of hydrogen assumes all the colours of the spectrum, and now replies to the objection that this coloration is due to impurities of the gas, as at first prepared, by making it from potassium formate heated with potash. He still observes the same phenomena with this. To show these colours, the hydrogen should be collected in a bell jar about 8 inches long, and 2 inches diameter, which should be then held with its mouth downwards, a light applied and the vessel gradually inclined. A flame pours upwards in which all the prismatic colours may be observed as the jar approaches the horizontal position. Carbonic oxide, sulphuretted hydrogen, methane, and vapours of alcohols, ethers, &c., display similar colours.

1000

In the current volume of "The Proceedings of the Royal Society," W. N. Hartley states that the sensitiveness of the spectrum in detecting magnesia is practically unlimited; that it is possible to obtain a definite magnesium spectrum from a spark carrying only a one thousand millionth part of a milligramme, (a milligramme is a little more than 1% of an ounce). Also that a solution containing one part of magnesia in ten thousand million parts of water displays two of the characteristic lines of magnesia. These quantities are inconceivably small, but still the substance is outspread and continuous; no physical indication of discrete molecules is displayed. Some of my readers may know that I am a heretic in reference to the actual physical existence of any ultimate atoms or molecules, regarding all the speculations concerning the limits of littleness as vain and worthless, quite as vain as discussing the boundaries of space.

A very interesting and important paper was recently read at the French Academy of Sciences, (Comptes Rendus, vol. xcix. p. 1072) by J. Thoulet, describing experiments which justify the conclusion, that an attraction is exerted between a dissolved salt, and an insoluble solid immersed in the solution, and that the amount of this attraction varies with the surface of the solid. Thus when marble, kaolin, quartz, or other solid, is immersed in a solution of barium or sodium chloride in which they are chemically inert and insoluble, they nevertheless disturb the solution, and render it weaker by effecting a deposition upon themselves of some of the dissolved salt.

Important practical consequences follow from this. One of the oft-repeated fallacies of the half-learned, but not of the unlearned, is that of stating that a filter can only remove mechanical impurities from water, that it cannot remove matter which is there dissolved. This statement has been disproved by experiment. By repeated filtrations sea water may be rendered less and less salt, until it becomes nearly if not quite tasteless. This fact has hitherto been rather puzzling, but is now readily explained by the adhesion of some of the salt to the filtering medium.

It should be, however, understood, as a matter of course, that in order to obtain this result, fresh filtering material (sand for instance) must be used at each filtration, since the sand thus used ultimately takes up its utmost attainable supply of salt, and then may rather give some back to fresh water than take any more away from salt water.

As far back as 1878 similar results were obtained by Bayley, but in a different manner. He let fall upon the white blotting-paper used for filtering, drops of various solutions, and observed that generally the salt remained near the centre, and that a ring of water extended round this. By using solutions of metallic salts which became blackened by hydrogen sulphide, he was able, by simply applying this reagent, to obtain a picture of the diffusion, and produced similar pictures by staining the blotting-paper with turmeric or litmus, and then adding allkaline or acid solutions which change the colour of the stain. The greater the dilution, the broader the water ring surrounding the coloured spot and indicating the position of the salt. Concentration of the solution, heat, and looseness of the texture of the paper, increase the mobility of the solution, i.e. the distance to which the dissolved matter may stand before the water leaves it. The mobility of different salts varies, and in mixed solutions they act independently of each other.

These results have been recently confirmed by J. U. Lloyd ("Chemical News," vol. li. p. 51), who modifies the experiments by dipping chips of blotting paper into various solutions, and observing how far the substances in solution climb up the paper before they are left behind by the water. Various solutions were thus tried; in some cases, as with very dilute solutions of ferric sulphate, the salt just creeps up above the surface of the solution, while the pure water travels to the end of the paper (five inches). A concentrated solution of the same travels with the waters, no separation taking place. Such a solution of this salt is like a syrup.

When solutions of ferrous sulphate, copper sulphate and ferric sulphate were mixed, each salt showed a limiting line at the same distance above the solution as when tested separately and of corresponding strength; the ferrous sulphate travelling farthest, the copper sulphate next, and the ferric sulphate lagging behind. Other salts behaved in like manner. Even sulphuric acid is separated from water when the solution is dilute; water quite free from acid passing onwards. By bending the blotting-paper over at a height above the reach of the salt, and allowing the further end to hang below the level of the solution, a perfect filtration of ferric sulphate was effected, drops of water free from iron salt falling from this lower end. Quantitative experiments were made on this and other solutions, showing their relative distances of travelling in solutions of measured strength.

LEAVES FROM MY NOTE-BOOK FOR 1884. By A. KINGSTON.

IN

N transcribing the following extracts from "Leaves from my Note-book for 1884," it is scarcely necessary, perhaps, for me to caution the reader against expecting anything very profound, or anything directed to a special branch of enquiry; still less will he expect them to contain much in the way of novelty. They are the casual observations made, and jotted down as they were made, in leisure moments; and their only merit perhaps will be that they may possibly suggest, here and there, a line of inquiry to others having more ability and leisure to follow it to a profitable issue.

Fig. 89.-Royston Crow.

The opening days of 1884 were well calculated to stimulate observation in many directions. The close of 1883 had left such a legacy of early promise as is rarely witnessed on New Year's Day. In the vegetable kingdom, flowers enjoyed almost a second summer. Many of the yellow-flowered species of the Compositæ among wild flowers, and many annuals in the garden had flourished far beyond their appointed time. Gardens were gay with wallflowers, marigolds, daisies, and pansies, and other favourites. skylark and thrush had vigorously warbled in the new year, and the industrious little honey bee (Apis mellifica) was busy making adventures on its own account at an abnormally early date. evidence, too, was forthcoming on the subject of the hardihood of one or two of our hibernating lepidoptera.

The

Some

The hardiest of all proved to be the common small tortoise-shell butterfly (Vanessa urtica), several specimens of which came under the observation of the writer during the first ten days of January, stimulated by the atmosphere of a warm room, into a vigorous flight. I may add that next to the tortoise-shell in hardiness among the hibernators, comes, apparently, the fine old peacock butterfly (Vanessa Io).

The Royston, or hooded crow (Corvus cornix), as it is seen in its migrations southward, has so distinctly the opposite of the gregarious habit of the rook, that I was somewhat surprised to notice, during January, a little community of half-a-dozen of them together, and showing an unusually sociable disposition. This somewhat remarkable member of a familiar ornithological family having enjoyed its local designation for centuries, has, I suppose, a fair claim to the name by which ornithologists and naturalists have for so long recognised it. It could of course only have derived this local name from the fact of its attachment to the heathy country about Royston, and of its not going much further south in its winter migration. This, however, is not absolutely conclusive evidence of its claim to the title, for in the writer's birds'-nesting days, it was commonly known as the "Dunstable crow," in the neighbourhood of the chalk ridges of the Chiltern Hills, where its peculiar plumage was occasionally recognised. Whether this interesting corvus is likely to preserve its local claims and specific distinction, as it has done in the past, may perhaps be doubtful; for Mr. Henry Seebohm, a great authority on ornithological questions, and well versed in the habits of migratory birds, makes out a strong case against the Royston crow for its disposition to interbreed with the carrion crow and other members of the family. The opinion of so accurate an observer is of course entitled to the highest respect, and yet it is not a little singular that the present representatives of the hooded crow, as they are caught in the neighbourhood of Royston Heath, are as distinctly specific as any of their predecessors, with the same distinct light grey markings as of old, and no perceptible traces of hybridisation. Indeed, I am informed by Mr. Norman, a naturalist, whose business of taxidermy, and that of his father before him, has for a period of sixty years enjoyed a more than local repute, that although many specimens of the local and general rare aves have passed through their hands, yet during the whole of that period only one specimen of the hooded crow has ever come under their notice showing traces of hybridisation. With this there was the uncertain element of its being a young bird; but on being submitted to Mr. Gold, of London, it was pronounced by him to be a hybrid, and the result of interbreeding between the Royston and carrion crows. This specimen is now in the collection of Lord Bray

* Since writing the above, I find that this local name is given to the bird in the Rev. Samuel Ward's "Natural History," 1775; the earliest mention I know of.