TEMPERATURE OF LAKES.

AMONG the communications lately made to the

Academy of Munich are some observations by Herr v. Schlagint weit on the temperature in the deeper parts of the Starnberger See and the Chiem See. A few observations on these measurements will not be out of place, as they prove, in an unexpected manner, that the Starnberger See, notwithstanding its having an influx and outflow of water, is sufficiently deep and large to be perfectly cold at the bottom.

In the salt lakes of Thibet (which first gave rise to investigations being made in the above-named Alpine lakes, for the sake of comparison) there is this peculiarity, that except on days when the fall of snow is at a minimum, there is no influx of water. Moreover, while the appearance of the surrounding country makes it evident that these lakes had once an in- and out-let, as well as a much higher level, now the surface lies lower than the ancient outlet: the gradual drying up, too, is plain enough, as is also the relative increase of the saline constituents -a circumstance of course dependent on the lessening of the amount of water, for the continual evaporation is much too great to be replaced by the rainfall.

In the large Atlas of his travels, the author has given five illustrations of the scenery surrounding these salt lakes-a perfect waste, but not without a

certain grandeur. The illustrations are accompanied by the necessary topographical explanations.

His account demonstrates that the maximum or density (differing with the amount of salt contained in them) is reached in lakes which are situated at great heights above the sea, but which are sunk in depressions, in which there is so little difference in the warmth of the ground strata, that the balance of the temperature remains undisturbed. It is well known that water (unlike other fluid bodies) contracts during the process of cooling, until it reaches the freezing-point (distilled water, however, ceases to contract at 4° Cent.), and that it again expands as it gets colder: if it contains salt, this greatest contraction, or maximum of density, commences at a somewhat lower temperature.

Now, what relation has this to the distribution of temperature in the Alpine fresh-water lakes, which, besides, experience a considerable variation in the amount of water, owing to their having both an inlet and a means of escape?

According to Professor Jolly (whose careful observations, made much earlier than those of our author, were confined to the small very deep lakes of the Eastern Bavarian Alps) the temperature at the bottom of the Königs See (742 feet), and of the Walchen See (852 feet), registers 5'3° and 5.2° Cent. Herr v. Schlagintweit chose larger lakes for his experiments. He found that in the Starnberger See, in which the inflow of water is relatively small, the temperature of the bottom (though only 406 feet from the surface) betrayed "the maximum of density," or, in other words, the water is as cold as it can be. The conduction of heat from the ground strata, or in some instances by springs, may in the course of the year tend to modify this force of greatest density (3.5° Cent.), but it could never, it would seem, annul it altogether.

In the Chiem See the result was different, partly on account of the greater change of water, and partly because the depth is very much less-273 feet only, as determined by Von Schlagintweit, more than 130 feet less than that of the Starnberger See. It may be mentioned, en passant, that in Riedell's lake map, the depth is given at 504 feet, which is also the amount in the later map of Statzner,-a difference which can scarcely be accounted for by any change of bottom in the lake basin itself, though Riedell's measurements were made more than half a century ago, in 1810. The temperature of the water in the Chiem See was 71° Cent., a trifle colder than that registered at an equal depth in the Starnberger See, but far from reaching the temperature of maximum density.

These determinations of the temperature at great depths, are not without significance in regard to the conditions under which the fish of fresh-water lakes live. Similar observations made in other still larger lakes would be exceedingly interesting, because the

warning of the vicinity of death in its worst form, brought me to a sense of my situation only just in time, as four more steps must have brought me into contact with the dangerous reptile. My surprise was complete on discovering the glowing coil writhing at my feet, now contracting, now distending, as though about to burst.

What a chaos of fear and passion one might imagine pent up within that tight skin! Its glistening eyes, the nervous vibration of its forked tongue, and above all, the knowledge that it was possessed of a pair of fangs, the slightest scratch of which would be sufficient to cause death, alarmed me not a little, as I was entirely unprotected, having no stick or other weapon wherewith to despatch it.

In this awkward predicament I stood for some seconds, my eyes fixed upon those of the horrid creature before me.

From my feelings at that time I can understand the fear which some of the smaller animals have of Serpents. I felt for the moment rooted to the spot, and, as if suffering from night-mare, could not take the backward step which my reason told me should be made; however it was made at last, and another followed, and another, and yet another; when finding that my enemy did not follow, the blood seemed to flow freely in my veins again, and on placing several yards between myself and the reptile, I had the felicity of seeing it gradually unfold itself and slowly skulk into the adjoining underwood.

Now to return to my argument:-had these animals the natural love of destruction so vividly set forth in the newspapers, it is evident that my life at that auspicious time would not have been worth a year's purchase, for never had snake a better opportunity of making a human victim. You may therefore imagine how I thanked my lucky stars on reading the above-mentioned account that on that adventure with the rattle-snake and other similar occasions, I met not with the same unhappy fate as did the poor horse and Bonassus. I could hardly, however, reconcile the account with my own knowledge of facts founded entirely upon experience, and I am now happy to find the only case in point which could be brought forward against their accuracy removed.

I believe that snakes are, without an exception, most timid and cowardly creatures, infinitely more so than their wonderful power of subduing life and quickness in striking their victim would warrant or lead one to imagine.

In most snakes which it has been my fortune to come across, I have discovered their natural timidity and propensity for skedadling-as the Americans would say on the slightest approach of danger, always provided that they can do so without fear of their tails. Not only are they venomous and swift in flight when it suits them to be so, but, in my opinion, they are not only traditionally cun

ning, but absolutely so; and the reader may laugh if he will, but I believe that when suddenly intruded upon they take all the chances of escape into consideration, and if they feel that they can get off without receiving a crack on the tail in the attempt, they will endeavour to do so; if, on the contrary, the chances of escape appear too slight -like a rat enclosed in a room without means of escape from its enemy, or even a cowardly man with a grain of sense in his head-they will chance the possible but improbable, and endeavour to escape, by first subduing their opponent. Further, I believe that all snakes, as a rule, attack man only in fancied defence of themselves or young, unless it should happen to be a big one-a python, for instance then I allow that they act strictly on the offensive, but only so when hungry. There is none of that tiger-like pleasure of causing pain and death about them which I imagined was the case when I first left England; this I have proved in tempting a newly-caught boa-constrictor by placing live lizards and other small animals in its cage, but unless it was ready for a meal it took no notice of them.

As I am on the subject I may mention, in relation to Brazilian snakes, that many of them are exceedingly beautiful; the Coral Snake (Coluber corallinus, Lin. ?) surpassing in loveliness any animal-birds included that I have ever seen. Its body is beautifully banded with successive belts of brilliant jet black, pure white and coral red, bright and glowing in its beautiful colours almost beyond description. When elive and in motion they are really magnificent, moving in such an elegant curvilineal manner as to appear more like lovely toys than dangerous reptiles; in fact, the little naked children often come to premature graves through playing with them as such. I have one before me now, as I write, preserved in white rum and water, which I found to be the best mixture for their preservation; and although the brilliancy has much deteriorated, it s still a beautiful object.

Its capture was made under rather peculiar circumstances. I was talking and laughing with a company of Mulatto girls, who were sitting on the ground, when one of them suddenly sprang to her feet screaming, as she flung her hands on high, as though terribly alarmed-her companions, in accordance with woman's general character, followed her example, and the uproar was intense. I was quite at a loss to discover the cause of their fright, and this I did on perceiving about a foot of the creature's body hanging from beneath the girl's petticoat, where it had in some way got fixed. As she ran away, however, it fell, and I then put an end to its existence. The creature proved to be a beautiful specimen of its kind, measuring about four feet. Like most other snakes in Brazil, it is poisonous; in fact, the only ones I found to be nonvenomous were a small green variety and a black

amphibian. The latter would sometimes enter the room whilst we were at dinner, creating a fine disturbance with the cat and dog, who—although at all other times antagonistic to each other--on such an occasion would act in unison, one on each side of the reptile, barking and swearing, and the abject fear of the poor snake was laughable to behold; it would wriggle about, tie itself into all sorts of loose knots, and hiss and dart about as if on a plate of hot iron. The natives believe that all snakes are venomous, and fear the black as much as any other.

I have often been checked in my snake-hunting expeditions, by coming across the cast-off skins; and once a skeleton of a boa constrictor that when alive must have been too large in circumference for me to span with both hands-a sight which checked my researches in ophiology a little, for I naturally thought that somewhere in the vicinity it was not improbable that I might come across some of its living relatives, which was anything but desirable; and such an effect had it upon my nerves, that I returned home without having caught a single specimen for my collection-but with the consolatory thought that no snake had caught me.

On killing a snake I generally found it difficult to tell when the creature was really dead, as the vital power remains so long after death, and the bodystill retaining its muscular action-would wriggle about when placed in the bottle of rum as though endowed with fresh life. I also noticed a peculiar fact in the case of a very large snake which, having killed, I left in the garden until not the slightest movement occurred in the body, neither did it show any sign of sensibility in being touched or pushed about with a piece of stick; but, to my surprise, on touching it with my finger, a strong convulsive motion passed through the whole body. This I tried several times, and always with the same result.

Many of the snakes I found to be swift in their movements-one, the whip snake, exceedingly so; one moment it would be before me, perhaps not more than two yards off, and the next I knew not where; all that I could see of the movement was a sort of wave and like a flash of lightning the snake had disappeared. The rattlesnakes, however, from my experience of them, are rather sluggish than otherwise, and, fortunately for man, have not the love of slaughter which the correspondent of the Liverpool Daily Mercury would lead people unac quainted with the habits of snakes to believe.

Upper Kennington Lane.

ALFRED IKIN.

METALLIC MARKINGS OF BEETLES.-The metallic markings on the Cassidæ, which vanish when dry, may be preserved for years by immersing the beetles in spirits whilst fresh, and keeping them moist.W. H. Walcott, in "The Zoologist," p. 5,929.

ZOOLOGY.

RATS.-The black rat becomes every year more scarce in Scandinavia wherever the large brown rat gains a footing. Was once common throughout the whole country. In the days of Linné, the brown rat was unknown in Sweden; about ninety years since the first was seen in Scania. It has now, however, become gradually spread over the land, and is met with in every part to the North Cape. Although at deadly enmity with its smaller brother, it does not interfere with the little mouse. Strange to say, much as this country is overrun with rats, I never saw either a ferret or a rat trap till I got some over from England. I know no country where a good ratcatcher could make a better living than in this. I once saw the rats drummed out of a house here which was full of them. It was a large wooden building. Two regimental drummers were sent for, who began at the very top of the house, and drummed in every room. The rats bolted very fast, and I had some capital shooting outside. It was long before any came back.-Ten Years in Sweden.

THE WHALE (Balena mysticetus).-Nilsson remarks that the weight of the common whale is 100 tons, or 220,000 lb., is equal to 88 elephants, or 440 bears. The whalebone in such a whale may be taken at 3,360 lbs., and the blubber at 140 to 170 tuns. The remains of the fossil whale (Balena prisca) which have been found on the coast of Ystad, in the Baltic, and even far inland in Wangapanse, Westergothland, betoken a whale which, although not more than between 50 and 60 feet long, must at least have had a body 27 times larger and heavier than the common whale.-Ten Years in Sweden.

CURIOUS NEST OF HEDGE SPARROW. - The notice in SCIENCE-GOSSIP of a Chaffinch's nest calls to mind a similar instance which I witnessed a few years since. While searching a hedge row for the larva of the Black-veined butterfly, I discovered a beautifully made nest which had somewhat the appearance of a Linnet's, but as it was composed of such unusual materials, and contained four newlyhatched young, which I could see were not finches (and that was all I could decide upon) I took two, leaving the others in the nest; these I reared, and they turned out to be the Hedge Sparrow. The nest was made in the usual manner, but in the place of moss, &c., it was composed of woollen fibre of various colours, red being the most prominent, evidently a portion of an old carpet; it was lined with a mixture of moss and ends of cotton with a few feathers; all this gave it quite an artificial appearance, but containing the young as it did proved it genuine.-J. B. Waters.

CAT AND KESTREL.-A cat belonging to a neighbour was lying concealed in a drain in a meadow (November, 1865), watching her opportunity to seize a field-mouse, when a kestrel swooped upon a mouse so close to her, that with a sudden spring she caught the bird, and eventually killed it; a termination to her hunt as unlooked for by her, as it was unexpected by the kestrel, who had probably been so intent upon the moving mouse, as to overlook the motionless cat. This was related to me by the owner of the cat, who took the bird from her a few minutes after the event.-Harting's Birds of Middlesex.

A

BLACK REDSTART.-A male specimen of the Redstart (Sylvia tithys) was taken at Gedney, Drove-End, Lincolnshire, on October 25th. Greenshank (Totanus glottis) was taken in a flightnet on the sea-marsh at the same place on October 3rd.-C. E. R.

CLOUDED YELLOW IN IRELAND.-In your number for November, a correspondent mentions having taken a specimen of the Clouded Yellow (Colias edusa) at Kilkee, and asks if it is an uncommon insect in Ireland. I may inform you that it has been taken in considerable numbers during the past summer at Tramore, a bathing place in Co. Waterford, and at other localities in the neighbourhood of Waterford City. Two years ago it was very common, and many were captured. During the same season the Painted Lady (Cynthia cardui) was very abundant, continuing from June till the end of November. One insect I had emerged from the chrysalis on the 11th of December. This year they were again frequently seen, but were not nearly so plentiful, and last year very few were met with. -E. Garnett, Newtown, Waterford.

FANGS OF SPIDERS.-After reading the sceptical remarks of your correspondent, "E. T. S." (page 237, SCIENCE-GOSSIP,) on the structure of the Spiders' Fangs, I determined to examine them carefully for myself. This I have ample opportunity to do, as my cabinet contains no fewer than four specimens of different species, three of which are whole, prepared by myself. The other slide contains the fangs only I had from Mr. Groves Tollington, London. Of these four specimens three show distinctly an aperture opening into the interior of the fang. The sketch by R. Beck, page 201, Vol. II. of SCIENCE-GOSSIP, accurately represents its form and position. There can be no mistake of its actual existence in my specimens. What relation these apertures may sustain to other parts of the insect's structure, or what special or general functional purpose they may have, I know not; nor can I boast of less ignorance respecting the "modus operandi" observed by the constitutional murder in seizing or holding its hapless victim.-B. Taylor.

BUGS.-In a rare and curious old book on insects, written in Latin, and published at London, in 1634, the title of which is "Insectorum sive Minimorum Animalium Theatrum,"I find, amongst other things, a curious account of the common Bug. It states that this insect first occurred in this country at Mortlake, on the Thames, in the year 1563, and that those unhappy people who were first bitten by it, imagined that they had been attacked by a plague, but the writer says, Tandem re coguitâ, ac bestiolis captis, risû timorem omnem excussit.” He then gives a list of preparations which are calculated to destroy these insects, about which he writes, "Contra istos nocturnæ quietis hostes, Deus noster misericors, remedia nobis suggessit." The writer does not seem to have had much opinion about the cleanliness of foreigners, for he says, 'Galli, Germani, et Itali qui munditiem minus curant, pariunt magis hanc pestem; Angli autem munditei et cultus studiosissimi rarius iis laborant." The accounts of the insects in this book are mos curious, and the figures mostly very roughly executed those of some of the Lepidoptera being scarcely recognisable; a great number of our rarer and reputed British insects are figured, doubtless, as British. There is no attempt at arrangement into genera, as neither generic nor specific names were then in use.-Henry C. Lang.

SUBMERGENCE AND EMERGENCE.-In 1772 the greater part of one of the largest volcanic mountain in Java was swallowed up. A luminous cloud enveloped the mountain on the 11th of August, and soon after, the huge mass disappeared with a great noise, carrying with it about 90 square miles of the surrounding country, 40 villages, and 2,957 inhabitants. In 1819 a large tract of country, not far from the eastern mouth of the river Indus in India, underwent considerable change. A tract of probably not less than 750 square miles was raised 10 feet above its former level, and south of this another tract of perhaps 600 square miles became submerged, and occupied by the Lake of Sindree. In 1628, 1720, and 1811, islands have appeared and disappeared in the sea near the Azores. On the last occasion an island rose to the height of 600 feet, and was named "Sabrina." In the following year it disappeared. In 1831 an island appeared to the south west of Sicily, reached an elevation of nearly 200 feet and a diameter of 3 miles. After three months it gradually sank again, until nothing remains but its name of Graham Island." Had the reported submergence of the island of Tortola taken place, it would have surpassed in terrible interest all previous and similar events, and impressed itself on the memory of all men living as the great catastrophe of 1867. Fortunately, however, the "sensation telegram" lacked being true.

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