ground illumination with medium powers, was introduced by Col. Horsley of the East Kent Natural History Society. He uses light reflected from the inside of a broad, short, silver-plated tube beneath the object. The tube may be silvered, not very permanently, by rubbing it with a solution of nitrate of silver and hyposulphite of soda. Such a tube, placed in the stage opening, would give a more oblique illumination than could easily be obtained otherwise in instruments having a thick stage.

GLYCERINE IN MICROSCOPY.-- Dr. W. M. Ord, of St. Thomas Hospital, London, questions the safety of glycerine as a medium for studying and mounting microscopic objects. Its solvent power over carbonate of lime is well known, and he had found it ruinous to crystals of murexide, oxalate of lime, and triple phosphate. Might it not produce unsuspected molecular changes in other objects? Portions of tissue preserved unaltered in it for years, might have been affected in molecular constitution by it at the first penetration and before the first observation. light is wanted on this subject.

More

PRACTICAL HISTOLOGY.- Dr. Wm. Rutherford gives, in the Quarterly Journal of Microscopical Science for January 1872, a synopsis of his course of instruction in Histology. The paper is too long to reprint and too dense for abstract, but it is full of suggestions that will be useful to many others besides medical students. The author has a dashing and not unattractive manner of expressing his dissent from the opinions of most microscopists in England and this country in regard to apparatus, etc.

VARIATIONS IN SIZE OF RED BLOOD-CORPUSCLES.― Manassein ("Centralblatt" No. 44, October 28th, 1871) gives the result of more than forty thousand measurements on one hundred and seventy-four different animals, intended to show the effect of various physiological and morbid influences on the size of the red corpuscles. In general, influences which raise the temperature of the body were found to diminish the size of the corpuscles, such as very high temperature of the external medium, or septic poisoning. Excess of carbonic acid in the air also acts in the same way. Oxygen, on the other hand, increases the dimensions of the corpuscles, and so do, in general, all substances which depress the animal temperature, as external cold, quinine, hydrocyanic acid, and intoxicating doses of alcohol. Morphia is an exception, since,

though it generally reduces animal temperature, the corpuscles become larger under its influence. Finally, acute anæmia (produced by arterial hemorrhage) increases the dimensions of the corpuscles. Quarterly Journal of Microscopical Science.

COMPARATIVE SIZE OF RED BLOOD-CORPUSCLES.- Mr. George Gulliver states in the same Journal, that recent measurements confirm his conviction that the size of these corpuscles, in families of fishes and reptiles, bears little relation to the size of the species; while in many families of birds and mammals, there is such relation, the largest corpuscles occurring in the largest species and the smallest corpuscles in the smallest species.

VITALITY OF ORGANIC GERMS AT HIGH TEMPERATURE.— This standard question of the experimenters in spontaneous generation, is attracting increased attention from its relation to the more fashionable question of disinfection. It is discussed in several numbers of the "Chemical News." Mr. G. E. Davis calls attention to the fact that the ovens, in which fabrics are baked for purposes of disinfection, are often irregularly heated and may vary fifty degrees from the thermometer's indication. Hence, making allowance for this uncertainty, the highest temperature desired cannot be safely attempted, and the temperature attempted may not be gained. He believes that the heat employed has little action upon the disease germs, and rather tends to encourage their growth. He advises that a vessel of carbolic acid diluted with an equal volume of water be placed near the clothing, in order to gain the combined effect o' the heat and the phenol vapor.

Mr. Richard Weaver states that 350° Fahr. is the highest temperature available for disinfecting clothing: and Mr. H. B. Yardley queries whether germs might not be destroyed at intermediate temperatures although they would live at certain lower and higher degrees; thus, might not life be destroyed at 330°, which would continue to exist at 200°, 300° and 400°?

OBJECT TEACHING" IN MICROSCOPY.-It is customary at the regular fortnightly meetings of the East Kent Natural History Society at Canterbury, England, to make dissections of plants and animals, and microscopical demonstrations of the same. The three following items are derived from the Proceedings of this society.

SIZE OF BLOOD-DISCS.- Mr. George Gulliver predicted that

these corpuscles would soon be recognized as of importance in systematic zoology, and demonstrated the relation of their size to the respiratory function. The blood-dises of Amphiuma are the largest now known, supplanting, in this respect, those of the familiar Proteus.

RAPHIDES AND PLANT-CRYSTALS.- Mr. Fullager gave demonstrations of the crystal-prisms of Quillaia bark, and noticed their size, prismatic and angular outline and polarizing properties, as points of distinction from true raphides which are acicular and occur in bundles. The order Iridaceæ abounds in crystal-prisms. Mr. Gulliver showed the great importance of plant-crystals, especially raphides, in systematic botany; the raphidian character being so eminently natural, and so much more fundamental and general than other single diagnostics. "The shortest and sharpest diagnosis of the Onagracea would be Calycifloral Exogens abounding in raphides; of Galiacere, Corollifloral Exogens abounding in raphides; of Orchidacea, Gynandrous Endogens abounding in raphides; of Hydrocharidaceae, Hydral Endogens destitute of raphides." Similar examples occur extensively in Mr. Gulliver's Memoirs in the Pop. Sci. Rev., Oct. 1865; Ann. Nat. Hist., 1861-1865; Quart. Jour. Mic. Sci., 1864, 1865, 1866, 1869; Seeman's Jour. Bot., 1864, 1866, 1867 and 1869. The crystalprisms of Quillaia bark, shown by Mr. Fullager, and of Guaiacum, demonstrated by Col. Horsley, test the genuineness of the officinal barks; for though crystal-prisms abound in many British Endogens and in exotic Exogens they have not yet been observed in native Dicotyledons and while true raphides are not uncommon in foreign shrubs and trees, they have not yet been demonstrated in any British trees. Sphæraphides were shown by Col. Horsley in the prickly pear (Opuntia) and by Mr. Gulliver in the Carophyllace. The raphidian character of the British species of Lemna was constrasted with the exraphidian Wolffia. Of the British Euphorbiaceæ, Mercurialis alone abounds in sphæraphides; and the curious starch-sticks are equally characteristic of Euphorbia. By the raphidian diagnosis, the minutest portion of a plant may often be located in its own order as distinguished from all other orders of the same alliance.

RESPIRATION IN ABRANCHIATE WORMS.- Mr. Gulliver exhibited and described a worm, about a quarter of an inch long, of the

Naid family which abounds in pools near Canterbury. The vivid action of the vibratile cilia within the intestines, causing a rapid current of water, was seen in the pellucid segments of the thin, flat body, and was regarded as a true respiration. The same may be seen in Sanuris variegata.

DEVELOPMENT OF HYDRODICTYON.- Mr. Keit, of the Dublin Microscopical Club, obtained, by cultivation, two forms of this plant, an irregular network of large cells, and the ordinary nets which “appeared" to be produced from the irregular form. Further study is promised.

THE MALTWOOD FINDER.-This little accessory, used by almost every microscopist, is used under two disadvantages, the want of exact correspondence in position of the scales on different plates, and the size of the squares, in one of which, under a high power, an object may still be lost. Mr. W. K. Bridgman offers, in the "Monthly Microscopical Journal," a means of correcting these difficulties.

Each person using the finder in exchanges, is advised to prepare a common slide with a label in the centre and a dot on this, indicating the position of the centre of the central square of his own Finder. This "test slide," properly named, may be sent to any correspondent as a key to the correction if any, to be made in using his Finder.

The position of an object in a square must be recorded, or much of the usefulness of the Finder is lost. Mr. Bridgman indicates this position by a dot having the same relation to the figures. Thus would indicate that the object was situated in the centre of the square, or 23. that it was far to the right of the centre. The writer (R. H. W.) has always been accustomed to record the position in the square by decimals; as, in the cases above, and 3. This plan, which is convenient, and not liable to mistakes, has been mentioned to many persons, and doubtless used independently by many more, but is not recollected to have been published before. It is accurate to within one-tenth of the diameter of a square, which is quite sufficient in practice; but two places of decimals may be used, if deemed necessary, to indicate positions very near a line, as

25.5

25.01 25.5

or

25.99
25.5.

NOTES.

PHILADELPHIA.— ÂMERICAN PHILOSOPHICAL SOCIETY, December 15th. A sum of money was appropriated for the planting and preservation of a grove of oaks in Fairmount Park, to be called the Michaux Grove, in accordance with the will of the botanist Michaux.

Prof. E. D. Cope read a paper "On the Pythonomorpha of the cretaceous strata of Kansas." This embraced a synopsis of the species of the order known from all parts of the world, by which it appeared that America was its home, only four species having been described from Europe. He said that the Danubiosaurus of Bunzel had no relationship to the group. The American species were forty-two, distributed as follows: New Jersey green-sand, 15; rotten limestone of Alabama, 7; chalk of Kansas, 17; other localities, 3. The Kansas species were referred to Clidastes 3 sp., Edestosaurus 4 sp., Holeodus 4 sp., Liodon 6 sp. Of these Edestosaurus tortor and E. stenops, Holeodus coryphaeus and H. tectulus; and Liodon curtirostris, L. latispines, L. glandiferus, and L. crassartus were described as new.

January 5, 1872.—Hon. Eli K. Price read a paper "On some Phases of Modern Philosophy," in which he combatted the views of the Heterogenists and of the Evolutionists. In the latter part of the subject he opposed the views of Darwin, asserting that the variations seen among domesticated animals had no parallel among those in a state of nature, and the fact of their ready hybridization is indication of their specific unity. He quoted Professor Wyville Thompson, to the effect that no transition from species to species had ever been observed in palæontological history; and asserted that the variations observed among animals on which the developmentalists relied in evidence of their theory, were few and abnormal, and entirely insuflicient for the use made of them. That the origin of man from apes was not supported by evidence. Lastly, that the theories of evolution are highly injurious to faith and morals, and thus to Christian civilization.

January 19th.-Benj. Smith Lyman read a paper "On the Oil Bearing Region of the Punjaub," accompanied by a topographical map. He pointed out the Tertiary age of the oil-bearing beds.