Pocket Lens Research Articles

Distribution of Hairs on the Phalanges of Hands among Ghanaians

Aim. The study intended to observe the frequency and pattern of distribution of phalangeal hairs on the hands of Ghanaians. Material and Methods. A total of 1040 healthy consenting individuals (529 females and 511 males) aged between 18 and 45 years were randomly selected from the University of Cape Coast Community. Presence or absence of phalangeal hairs was observed with the aid of a pocket lens. Results. Hairs were observed on the proximal phalanges of 98.24% of the males and 96.22% of the females. The most common hair pattern observed on the proximal digits was 2-3-4-5 (65.95% males and 70.32% females). The highest frequency of midphalangeal hairs occurred in the group with hair on the 4th digit alone (3.33% males and 2.27% females) followed by the 3-4-5 group (2.54% males and 1.89% females). Conclusion. Females have lower frequency of phalangeal hairs than males. The outcome of this study may be significant medicolegally and in anthropological racial and gender studies.

Postmortem exsiccation of the fingertips--results of a systematic quantitative and qualitative experimental study

To date there have been no results published on qualitative and quantitative time-related changes with regard to desiccation of human fingertips post mortem. The fingertips of 52 hands from 36 corpses were qualitatively examined soon after death (2-6 h) to 120 h post mortem. The quantitative investigations were confined to the tips of the middle fingers. The width of three adjoining ridges of the skin was measured in four defined areas of the middle fingertips, and photographs were taken at intervals of 2, 3, 4, 5, 6, 7, 8, 12, 20, 26, 32, 44, 50, 60, 72, 84, 96 and 120 h p.m. Concerning the qualitative test results, four time-related stages were classified macroscopically and by a pocket lens (X25). Desiccation stage IV correlates to the period 72 h after death in bodies found in apartments. Besides the rough, wrinkled, and brown or black surface of the fingertips, microwrinkles of the epidermis occur on the skin ridges, which have so far not been described. The quantitative results did not show any changes in the width of the skin ridges, independent of age, sex, right or left hand.

HYBRIDIZATION IN SOME SPECIES OF PTERIS L.

Pteris L. is an almost exclusively tropical genus of ferns of some 280 species (Copeland, 1947), many of which are distinctive and somewhat isolated. Also included in the genus, however, are several complexes containing from a few to many species. These present great taxonomic difficulties and the interrelationships of the components can often only be deduced by experimental methods. One such complex is centered on P. quadriaurita Retz. and the present paper deals with the behavior in Ceylon of three species of this group. Cytotaxonomic studies carried out over the last five years (Walker, 1956; Walker, publication pending) have shown that this complex contains many separate species which are superficially very much alike. Differences nevertheless exist in such fundamental characters as the level of polyploidy, type of breeding system, features of the spores and details of the juvenile plants. These differences, once determined by experimental methods, can then be correlated with relatively small but constant features on dried specimens, enabling species to be recognized in herbaria with, at most, the aid of a pocket lens. At least seven species of the P. quadriaurita complex are to be found growing in Ceylon, including P. quadriaurita Retz. sensu stricto itself. Several are ecologically or genetically isolated from one another and remain distinct in nature, but the three to be discussed below have hybridized freely resulting in the formation of very conspicuous hybrid swarms. Such hybrid swarms may continue to segregate and back-cross or, under certain circumstances, may become stabilized as a result of the sexual breeding system being replaced by apogamy. A complex situation of this nature has led to taxonomic difficulties even greater than those already inherent in the group as a whole.

Improved Pocket Lens Stereoscope: GEOLOGICAL NOTES

Improved Pocket Lens Stereoscope: GEOLOGICAL NOTES

ON THE PRESENCE OF SODIUM CHLORIDE IN CERTAIN GLACIAL CLAYS IN HOLDERNESS

On 26th October 1935 I obtained specimens of the glacial clays exposed in the section described by Bisat1 at the top of the chalk pit at Hesslewood, near Hessle. They were put into new stout paper bags and have been kept in a dry cupboard ever since. On recently taking out the bags I was astonished to find that one of them felt damp; it contained a sample of the chalky boulder clay near the bottom of the section. This and all the other clays mentioned in the paper were examined in the following way: about two and a half ounces (say 70 grammes) of the clay were put in a beaker, covered with distilled water, stirred at intervals until the clay had all disintegrated, and then allowed to settle, the supernatant liquid being then filtered off and evaporated to small bulk; when cold, a small quantity was tested with silver nitrate and the remainder was allowed to evaporate spontaneously. The concentrate from the Chalky Boulder Clay and the Lower and Upper Hessle Clays of the Hesslewood section all yielded crystals of sodium chloride large enough to be visible under a pocket lens and even to the naked eye. The Chalky Clay and the Lower Hessle Clay contained much about the same amount, the Upper Hessle containing slightly less. Gypsum also crystallised out. On the same day in 1935 specimens were also taken of the clays in the section described by Stather2 at Redcliff, North Ferriby. The lower boulder clay ...

Book Reviews

PROF. A. S. EAKLE, of the University of California, published tables in 1904 by which the common minerals could be ‘run down’ by using in a systematic manner the properties of streak and colour, and by the observation of other characters such as hardness, crystal symmetry, cleavage and fracture, the habit or structure of the mineral, the specific gravity, and the chemical composition. Dr. A. Pabst has revised Eaklo's tables, making such additions and changes as were necessary to bring them up to date. About 200 minerals are included. For the application of the tables the only apparatus required is a streak-testing plate of unglazed porcelain, a pocket knife and set of minerals for the scale of hardness, a magnet and a pocket lens. Admittedly tests with this simple equipment do not suffice to identify definitely every mineral, and recourse must frequently be had to determination of specific gravities and to optical and chemical tests, but the application of the physical tests in a systematic way is good training for the student who will need to identify minerals in the field.

Optical Utilities

MESSRS. W. WATSON AND SONS, LTD., 313 High Hol-born, London, W. C. I, have issued a booklet entitled “Optical Utilities”, containing a catalogue of small optical instruments for aiding vision. These include magnifiers mounted as spectacles, the “Speera” for dissecting or viewing minute objects, and the “Spect-opera” for viewing distant scenes, a magnifying glass with electric bulb in the handle for examining maps, prints, etc., a “Strip” magnifier for reading small print, a pocket lens compass, the needle of which is mounted between two lenses so that it can be used as a pocket magnifier, and other useful devices.

The teschenite of Point Garry, North Berwick

Point Garry is the name of a locality on the shore, about one half mile west of North Berwick Harbour. At this place, at about high-water mark, there is a very considerable intrusion of teschenite (see Map, Fig. 1). A large part of the rock is fairly fresh in appearance, but is nevertheless somewhat decomposed. The remarkable thing about the intrusion is that fully one half of the mass of the rock which is visible is so much altered as to appear of a light greenish colour, resembling fine ash in appearance, even with the aid of a pocket lens. It is clear the teschenite has been much modified along the line of contact with the rocks outside. It in fact approaches in nature to a white trap. It may be observed that there is a moderate quantity of a very white and very soft white trap associated with this particular intrusion. ( Trans. Edin. Geol. Soc., vol. xii. pt. 2, p. 191.) The structure of the igneous rock varies a good deal, from columnar to platy and massive (Plate XLVIII., Figs. 1 and 2). The rocks which are invaded by the teschenite are composed of bedded, sandy volcanic ash, of a dark chocolate brown colour, on the eastern half of the section, with a fairly regular dip of 30° N.E. The ash on the western side is green in colour, with irregular shallow dips. The ash, all along the section, which was in contact with the teschenite, has been almost

FURTHER STUDIES OF PORCELAIN GLAZES MATURING AT HIGH TEMPERATURES1

The investigation covers three fields of glazes: Series A contains 21 glazes with variations in composition as shown in the formula . Series B contains 10 glazes, each having the formula but having their clay content varying triaxially between Florida kaolin, North Carolina kaolin, and Kentucky ball clay No. 4. Series C contains 20 glazes with variations in composition as shown in the formula . The method of experimentation consists of grinding the corner glazes of each series wet, for 18 hours, cross blending the corner glazes to produce the intermediate glazes, applying the glazes by dipping to green porcelain discs, and firing them in commercial periodic and tunnel kilns to temperatures between cone 16½ and cone 19 flat. The glazes were examined with the naked eye and a 10 X pocket lens. The triaxial replacement of CaO by MgO and BaO, as tested, makes practically no change in the appearance of the glazes. With the pocket lens the bubbles in the glazes appear smaller and more numerous, near the BaO apex. When fired in the periodic kilns for 42 hours the transparency of all the glazes in- creases with the temperature. The glazes fired in the tunnel kiln to cone 19 flat in 31 hours are more opaque and smoother than in the periodic kiln at three cones lower temperature. The triaxial replacement of the Florida kaolin, by North Carolina kaolin and Kentucky ball clay No. 4 produces relatively little change in the fired appearance. The glazes containing all ball clay or a mixture of ball clay and North Carolina kaolin overfire at a lower temperature than do those containing all kaolin or a mixture of Florida kaolin and ball clay. The best glazes with 0.2 K2O and 0.8 CaO have approximately an alumina: silica ratio of 1:9 and 1:11 for the field covered. These glazes are generally more trans- parent than the glazes with 0.3 K2O; otherwise the results are similar. The conclusions are: (1) that the nature of the firing conditions are of the utmost importance in the development of a glaze, and (2) that an intelligent choice between glazes of equally desirable appearance requires a resort to petrographic method and mechanical tests.

Green and Colourless Hydra

IN NATURE of April 7 a short account is given of the interesting experiments made by Goetsch on the conversion of the green Hydra into a pale Hydra. Some years ago I observed what may be called a natural experiment of the same kind. At the south end of the tunnel that conducts the water supply of Manchester from Lake Thirlmere under Dunmail Raise to the Grasmere valley there is a small settling tank, and on the walls of this tank I found a very large assembly of milk-white Hydras. An examination with a pocket lens led me to the conclusion that they were only a white variety of the common Hydra viridis, and were probably the offspring of parents living in the tunnel. These white Hydras were evidently enjoying the full vigour of life.

Notes on the Identification of Anophelinae and their Larvae in the Zanzibar Protectorate

Medical Officers and others interested in tropical sanitation often find great difficulty in rapidly identifying adult mosquitos. Four Anophelines have been found in the Zanzibar Protectorate, two of these being well-known malaria carriers. The identification of the two latter with the aid of a pocket lens is quite simple.

The effect of gravity upon the movements and aggregation of euglena viridis, ehrb., and other micro-organisms

In the course some experiments on the effect of various physical forces upon the movements of Euglena viridis , it was found that, when placed in the dark in shallow vessels or narrow tubes, a peculiar aggregation of these organisms takes place into network-like patterns or more or less well-defined circular groups. The aggregation is only visible when the Euglenæ are abundant, and is more regular and pronounced in a shallow vessel than in a deep one, especially if it is completely filled with the liquid containing the organisms, and sealed up so that the upper surface is not in contact with the air. If a narrow tube filled with water containing sufficient Euglenæ to give it a pronounced green colour is placed horizontally in the dark or in a weak light, the aggregation takes the form of a series of nearly equally spaced groups, like green bands, crossing the tube from one side to the other, and extending along its whole length. Each group shows clearly two distinct regions, a central denser one consisting of cells moving downwards, and a lighter peripheral area consisting of cells moving more or less regularly upwards. There is, in fact, a constant cyclic movement downwards and upwards, which is kept up so long as the aggregation persists. Examination with a pocket lens shows that, as the organisms reach the bottom of the stream, they gradually separate from one another, and begin to move upwards. As they reach the upper surface, they are seen to be drawn towards the central denser region of the group, and again enter the downward stream.

Ooze and Irrigation

AGES have passed since the cultivator first realised the value of rivers as agents in fertilising the soil. The Nile is the classical illustration, and everyone has learned in early life to think of Egypt as being dependent on the life-giving waters for its fertility. But have the reasons for that ever been sufficiently investigated? Probably the majority of people would say that the waters of the Nile bring down vast quantities of soil and disintegrated rock from the heart of Africa, and this earthy matter, held in suspension or carried down by the river in spate, contains the chemical elements which are essential to the growth of plants. I believe that is the usually accepted theory; but does it go to the root of things? Others find the secret in the action of bacteria. I grant the point, but do not think it fully accounts for the facts. I have for some years been engaged in the study of our fresh-water annelids and their place in the economy of nature. I had occasion a few days ago to bring home from the banks of one of our Midland rivers some of the ooze from its banks. When I collected it I found some half-dozen specimens of a common fresh-water worm wriggling about in the slimy mass; but when I came to examine it at leisure, with pocket lens and microscope, I found it to be teeming with life. Vast numbers of tiny annelids (Tubifex templetoni, Southern, or an allied species), minute larvæ, and other living things were to be seen, and at once the question arose, Would the ooze, detritus, alluvium, or disintegrated rock of itself be so special a fertiliser if this teeming life were absent? The ooze is enriched both by the passing of the matter through the bodies of the animals and by the nitrogen from their corpses.

XXVII. Detached Microliths from the Pitchstone Sill at Corriegills, Arran

The Great Pitchstone Sill at Corriegills has often been examined and described. Bryce in his “Geology of Arran” (3rd ed. 1865, p. 70), says, “There is no remarkable change [produced by the pitchstone] on the sandstone—a slight induration merely—but the lower portion of the pitchstone is changed into a blue-coloured, porous, slag-like matter, like a pumiceous lava; this, however, is probably the mere result of decomposition.” That the pitchstone has been decomposed by percolating water finding its way between it and the sandstone—and which still oozes from that quarter—I think there can be no doubt, but I can see no resemblance in the decomposed part to the so-called “slag-like matter.” The following is my measurement of the bottom part of the pitchstone sill here, at a part of the cliff where it is easily accessible, its total thickness, according to Bryce, being 13 feet 5½ inches:— 1. Red Sandstone. 2. Pitchstone, laminar and columnar. 3. Pitchstone decomposed, but laminar, 5 inches. 4. Pitchstone decomposed, laminae not visible, joints still seen, 7 inches. 5. Pitchstone decomposed into yellow clay, neither joints nor laminae, 5 inches. 6. Red Sandstone. No. 3 can be dug out in thin layers which contain many irregular cavities caused by decomposition. When dry it is greenish in colour, and many white microliths can be seen in it with a pocket lens. Its surfaces are covered with minute circular patches which, where they run together, form figures like those seen on the polished surfaces of some jaspers. The intermediate spaces This 250-word extract was created in the absence of an abstract

Beginselen der Scheikunde

THIS is an elementary text-book on qualitative analysis, which aims also at imparting some of the fundamental principles of chemistry. A short introduction explaining the difference between physical and chemical change is followed by a list of the more important elements (iron is omitted) with their symbols. From this we pass on to a brief account of some fourteen elements, which are to furnish material for experimental investigation. The author then selects the unfortunate case of copper and sulphur to illustrate the difference between a mixture and a compound. It is needless to say that a more illogical and false illustration could scarcely be conceived. 6.3 grams of copper powder and 3.2 grams of sulphur are mixed together. The student must puzzle out for himself why these precise quantities are taken. Having satisfied himself by the help of a pocket lens that both substances are still present when they are shaken up, the mixture is heated. The blue-black mass which results is now, we are told, a chemical compound consisting of 63.12 parts of copper and 31.83 parts of sulphur, when the author must be fully aware that it is a non-homogeneous mixture of cuprous and cupric sulphide and free sulphur. One is tempted to suggest another example of the same order. Take 1 lb. of sugar and 1/4 lb. of butter, and mix them together. The butter and sugar may still be observed with a lens. Proceed to heat them until the required consistency is obtained. The substance is no longer sugar and butter. Consequently, the resulting toffy is not a mixture, but a compound made up of the original ingredients in the proportions taken.

Protobasidiomyceten Untersuchungen aus Brasilien

THE present work forms the eighth part of Dr. Schimper's “Botanischen Mittheilungen aus den Tropen.” The author is well known for his mycological researches, having previously contributed two parts to the above-named communications—“The Fungus-Gardens of some South American Ants,” and “Brazilian Fungus-Flowers.” To Elias Fries is due the credit of having first reduced the previous chaotic condition of mycology to an intelligent and scientific standpoint; even much beyond what could have been expected, considering that naked eye characters, or at most when aided by a pocket lens, were only available. Berkeley and Tulasne followed, and, aided by the microscope, added greatly to our knowledge of the minute structure and affinities of the various groups of fungi, a knowledge which has been in some instances more readily utilised than acknowledged by their successors. Later, De Bary's classical work indicated clearly what could be done, by means of pure cultures, towards the elucidation of the life-history of species, and a knowledge of true affinities; a method which is being developed at the present day by Brefeld, to the extent that the last-named author has presented us with his idea of the gradual evolution of the fungi, from their algal ancestors to the highly differentiated, asexual condition, represented by the members of the Basidiomycetes. As usual in classifications based on progressive morphological development, connecting links between groups that the evidence at hand suggest as forming a natural sequence, are not always forthcoming. The purport of the work under consideration is to make known a series of such connecting links or primitive types of the great group of fungi known as the Basidiomycetes; and if the author's conclusions prove to be well founded, the neighbourhood of Blumenau, in the province of Santa Catharinea, Brazil, where the material was collected, must be looked upon as a veritable garden of prototypes of the higher fungi. Protobasidiomyceten. Untersuchungen ans Brasilien. Von Alfred Möller. Pp. xiv + 179. (Jena: Fischer, 1895.)

The Vitreous State of Water

TO-DAY, between 2 and 3 p.m., with the barometer standing at 29 inches, the thermometer a little below 0° C., and the wind north-east, we had for the space of about twenty minutes an interesting fall of hail in this neighbourhood. The stones varied in size from that of a mustard-seed to that of a hemp-seed or thereabouts. Some rain accompanied them, and this became frozen in part on cold exposed surfaces. The stone sill of my study window, which faces nearly north-west, was soon covered in this way with a thin pellicle of ice, which served as a convenient resting-place for the hailstones at a low temperature. I was struck at once with their glassy appearance, and examined a number of them with a pocket lens as they lay on the cold surface of the stone, not having at hand any refrigerating arrangement adjustable to the stage of a microscope. Nor was the latter necessary. The lens showed most distinctly the clear transparency of the glass of which these hailstones consisted, and the vitreous fracture of some which had been broken by impact. Watching them as they lay, one saw minute nests of crystals form, in some cases in a peripheral zone, extending gradually inwards; but in the majority of instances the crystallization began in the centre of the ice, and gradually extended in a beautiful crystal growth more or less through the mass.

Chipped Flints

A FEW days ago a man who had been cutting turf in this neighbourhood came to tell me that he found a quantity of small flints at the bottom of the “bog-hole,” and he brought some of them for my inspection. Seeing that they all bore very obvious marks of handicraft, while a few were more or less rudely shaped like arrow-heads, I immediately went to the place, accompanied by the man, and succeeded in getting a number of specimens, of which some fifty or sixty show pretty plainly the design of the workman. Among them are a few white flints, evidently from the Chalk, and indeed with some chalk attached to them. This is worthy of remark, as there is no chalk nearer than the North of Ireland, nor are there any chalk flints among the boulders here, where the drift was unmistakably derived from the limestone, Silurian, mica slate, and syenite rocks of the west and south-west. The other flints are black, like the chert, which occurs plentifully enough in the carboniferous lower limestone formation of the district. Several pieces of charcoal were mixed with the flints, showing probably that fire was used in breaking them up in the first instance. The final operation of chipping seems to have been done with a very delicately-pointed instrument, not thicker than a large sewing-needle. Its marks, both where it struck off the chip and where it failed to do so, are as plain and fresh-looking as if they were made quite recently. It must have been used as a punch and worked with a hammer, and there must have been some contrivance like a vice to hold the flint during the operation. It is really hard to think that the instrument with a point at once so minute and powerful could be other than metallic; but then, if there was metal available, why have recourse to flint? Perhaps these flints might be referred to a time late in the neolithic period, during the transition from stone to metal, when the latter, being scarce, was used only for tools. At one time I fancied that I made a capital discovery of metallic particles struck off and lodged in the stone, but with a pocket lens they were found to be only specks of pyrites. A small sandstone slab, quite smooth on one side, lay among the flints, but it was either taken away or thrown into one of the turf holes filled with water before I came to the place, and I failed to find it. By its impression in the turf which remained untouched it appeared that one surface was quite polished. The other was described as rough. Whether it was used in the manufacture of the arrow-heads or not I cannot surmise. The shape of a large sandstone pebble that I found might suggest its use as a hammer, but it showed no signs of abrasion. At one time there must have been at least twelve feet of turf over the flints. They lay immediately above the roots of a pine close to a short piece of the stem that remained. The tree was most probably growing when the flints were worked, and it may be of some interest to note that the craftsman selected the shade or solitude of a wood for his atelier.

ON A MITE PREYING ON THE ORANGE SCALE INSECT

About the last of March my friend, Mr. Allen Curtiss, a botanist, brought me some Orange twigs infested with the Orange Scale Insect (Aspidiotus Gloverii). On examining them with my pocket lens, I was surprised to see numerous small black mites running in and out of the scales, and which no doubt prey upon the eggs of the Scale Insect, and probably prevents their increase.

ON A MITE PREYING ON THE ORANGE SCALE INSECT

About the last of March my friend, Mr. Allen Curtiss, a botanist, brought me some Orange twigs infested with the Orange Scale Insect (Aspidiotus Gloverii). On examining them with my pocket lens, I was surprised to see numerons smail black mites running in and out of the scales, and which no doubt prey upon the eggs of the Scale Insect, and probably prevents their increase. Since then I have been enabled to examine them with a more powerful microscope,and I think they are entirely new to science.