animals were chemically homologous with the embryonic tissues of the higher ones)." Its quantity as compared with that in the caterpillar and maggot excludes the hypothesis of immature chitin. Nor in the tenia, certainly, can it have a muscular future, though it might be there provided for the use of the ova. The small amount in the generative apparatus at first opposes this view, but the analogy between the ascaris, with its glycogen, and the plant, with its blanched starchstoring tissues, is striking. May not "migration" occur as well in the animal as in the vegetable economy?

(73.) JAFFE has published the results of some examinations of the organs of persons variously diseased, for glycogen.* Only in rare cases was he able to find this substance in the organs of diabetic patients, and then only traces were detected. Once he found it in the brain, once in the spleen, and once in the pia mater; in the latter case the patient had died from suppurative meningitis.

(74.) A paper was sent to the French Academy on the 19th of March, 1866,† by Bizio, in which, after alluding to the discovery of amyloid matter by BERNARD in the liver and the fœtal tissues, he notices particularly McDonnell's research, and states that the large amount of this substance found by him-50 per cent of the dried foetal pulmonary tissue- led him to undertake the examination of this question. In reflecting upon the conditions of animal life at the period when this glycogen is so abundant in the tissues, aided also by other considerations, he concluded that this substance was the more abundant the less the energy with which the force of innervation acted, a view which the facts have subsequently confirmed. Proceeding from this hypothesis, he argued that the glycogen should be as abundant in the classes of adult inferior animals as in the embryonal tissues of superior ones. Certain acephalous mollusks were first examined for glycogen; as, for example, the oyster (Ostrea edulis L.), the Cardium edule L., the Mytilus edulis L., the Solen siliqua L., and the Pecten jacobæus L. They all contained it, some of them in large proportion. To extract it, the finely-divided mollusk is boiled for a long time in water, the water poured off, and the operation repeated twice or thrice. The liquids thus obtained are concentrated, precipitated by alcohol, and the precipitate treated with strong acetic acid. Only a portion dissolves; the supernatant liquid is decanted, and the residue is washed with acetic acid. The acid solution is precipitated again with alcohol, and the precipitate is again dissolved in acetic acid; *Virchow's Archiv., xxxii., 20; Jahresb., 1866, 753. + C. R., lxii. 675.

the process being repeated until the glycogen is freed from inorganic matter, and particularly from magnesia, of which it at first contains a large quantity. Finally, the last precipitate is digested in glacial acetic acid to remove the proteic substances which it still contains, is well washed, first with alcohol, and then with ether, and then dried at 100° C. To compare the weight of the glycogen thus obtained with that of the mollusk, it is necessary to know how much each of the species mentioned loses in weight by desiccation at 100° C., a datum easily obtained. Proceeding as above, Bizio found 14 per cent of glycogen in Cardium edule, and 9 per cent in Ostrea edulis, while Solen siliqua gave a precipitate too small to be determined. These numbers acquire significance when it is remembered that they refer, not to one single organ, but to the whole body. He calls attention to the rapidity with which these mollusks pass into the lactic fermentation, and states that where the glycogen is present in considerable quantity, the lactic acid produced suffices to keep the animal from putrefaction. Hence, from the more or less ready putrefaction of the animal, the quantity of glycogen may be inferred. Experiments show that while the Mytilus edulis and the Cardium edule are thus perfectly preserved, the Solen siliqua and Pecten jacobæus, which contain less glycogen, readily putrefy. Arguing from this analogy up to the tissues of the higher animals, Bizio took a piece of human liver, and a piece of ox liver, and kept them seven days. The acidity of the former

less, and it evolved no odor, while the second gave an unpleasant odor of volatile acids, and gas slowly escaped. In these cases the result is complicated by secondary actions; there is analogy with the mollusks, but not identity.

(75.) A note, by BIZIO, was presented to the Academy, July 22, 1867, on some new researches on glycogen. He had established the identity of the amylaceous substance which he had discovered in the invertebrates, with glycogen. He states that this substance, however prepared, always aggregates into a gummy transparent mass, when, after being precipitated by alcohol, it is allowed to dry slowly in the air at ordinary temperatures; the reason of which is, that, after the evaporation of the alcohol, it absorbs atmospheric moisture. The pulverulent state in which it has generally been obtained, depends on its being rapidly dried. Bizio also remarks that the lactic fermentation which glycogen suffers when in contact with fibrin or casein is exceeding slow. The principal point which he examined, however, was the composition of the glycogen. He finds that this substance, whether dried at 100° C., or at the ordinary *C. R., lxv., 175.

temperature in a vacuum over sulphuric acid, has uniformly the composition 6 H10. A portion was then exposed to humid air till it was perfectly hydrated, and then dried over chlorid of calcium at the ordinary temperature, until it ceased to lose weight. This specimen yielded on analysis the formula €12 H22 →11. A molecule of water remains united in this case to the group 12 H20 10, which is the glycogen formula given above, doubled. This, the author thinks, is the true composition of glycogen, since it agrees perfectly with the experiments and views of Musculus on dextrin, and also with the current views on this class of bodies. Moreover, the lead compound obtained by precipitating a solution of glycogen with basic plumbic acetate is €12H1Pb" 10.

18

(76.) On the 15th of March, 1868, EULENBURG published* the results of some experiments which he had conducted in the laboratory of Professor Städeler, on the sugar-forming power of the liver. He had repeated the experiments of Ritter, following most explicitly his directions; and to his great surprise obtained a distinct sugar-reaction several times. Indeed, if sufficient potassic hydrate was added, and the boiling continued for a long time, the reaction never failed. The liver-extract, therefore, prepared by Ritter's method, contains uniformly a trace of sugar. To settle the question whether this sugar originated in an imperfection of this method, Eulenburg modified the process as follows: the abdomen of a rabbit was opened by a transverse incision just below the sternum, a fragment was torn from the liver, and immediately triturated in a mortar with pounded glass and strong alcohol. Every trace of ferment-action is excluded by the instantaneous action of the alcohol; in a few seconds, the piece taken is bruised to the finest pulp. The alcoholic extract is digested at a gentle heat, filtered, the alcohol evaporated, the residue dissolved in a little water, precipitated by a few drops of plumbic acetate, filtered, the lead removed by sulphydric acid, again filtered, warmed to expel excess of the gas, exactly neutralized with sodic hydrate, and then used for testing. A somewhat more rapid method is to treat the filtrate, after precipitation with plumbic acetate, with sodic hydrate till the turbidity at first produced disappears; the excess of lead left in the solution being without effect on the sugar-reaction. In testing, for sugar, Eulenburg prefers Städeler's mixture. It is raised to boiling, the liquid

* J. pr. Ch., ciii, 108.

The copper solution-which contains 0.1 gram of metal or 0·1252 of oxyd in every 10 c. c.-is prepared by dissolving 10 grams pure copper wire in about 50 c. c. concentrated hydrochloric acid, with some nitric acid, carefully neutralizing the excess of acid, and diluting the cold solution to 1000 c. c. The tartaric acid solution contains 15 grams acid in every 40 c. c. The potassic hydrate solu

to be tested is added, and the ebullition continued for three minutes. If at the end of this time, no reaction takes place, the absence of sugar may be assumed. With six healthy rabbits, experiments conducted in this way gave a negative result throughout; hence not a trace of sugar exists in the livers of these animals during life. With five other rabbits, two parallel series of experiments were made; two pieces of the liver were taken from each animal and examined, the one by the method now given, the other by Ritter's mode. In some instances the latter process was at once applied to the piece first taken. In every case, the piece of liver treated with boiling water gave the reaction for sugar, while the piece prepared by trituration with alcohol, never afforded the slightest trace of sugar. Eulenburg differs also from Ritter on the effect of narcosis on the production of sugar. He shows that the ether-narcosis, at least, when not carried too far, does not cause the appearance of sugar in the liver, by the following experiments: two powerful albino rabbits inhaled pure sulphuric ether for 1 or 1 minutes to complete insensibility to mechanical irritation, when the abdomen was opened, a piece of the liver removed and examined as usual. In both animals, the liver was entirely free from sugar, as also was the urine. After the death of the animals, however, the liver reduced readily the copper-test. A third rabbit was narcotized with carbonic tetrachlorid, until serious disturbances of the respiration, facial breathing and dispnoetic convulsions appeared. At this stage, the animal seemed dead; the abdomen was opened-the heart pulsating regularly-and a piece of the liver removed, and found to contain sugar. The urine was also saccharine. 66 It appears therefore, that only a narcotization by inhalation rising to a fatal, or at any rate to an extraordinarily intense intoxication, can cause the ante-mortem production of sugar in the liver." In conclusion, Eulenburg maintains with Ritter, that "even instantly after death, a fragment of the liver, ever so carefully triturated with alcohol, shows itself distinctly saccharine."

tion contains 150 grams commercial hydrate-which should not contain more than 10 per cent of hygroscopic water-in 1000 c. c. Before each experiment, the three fluids are mixed together-10 c. c. copper solution, 10 c. c. potassic hydrate solution, and 2 c. c. tartaric acid solution, the last being added before the potash solution-diluted with an equal bulk of water and heated to boiling. If no turbidity appears, the solution may be used for testing; if it is troubled, the tartaric acid solution must be prepared anew.-Jahresbericht, 1854, p. 747.

ART. VI.-Aurora at Toronto, Canada; by G. T. KINGSTON.

A VERY grand exhibition of aurora, occupying more or less the whole sky, took place on the night of April 15, and con=tinued with but slight interruption from dusk till daylight on the following morning.

One part of the display deserving notice from its comparative rarity was a dark segment similar to those commonly seen in the north, though not so well defined, which appeared about 9 P. M. in the south, with an altitude of about 25°. But the feature of still more unusual occurrence consisted in a belt of luminous haze from 5° to 10° in width, extending through the zenith from the eastern to the western point of the horizon, the material of which (in appearance) moved like a torrent from east to west with prodigious velocity.

The apparent movement of translation continued from about 13h 10m to 13h 50m, when the matter composing the belt became affected by pulsations, which succeeded each other in the order from east to west, and with a rapidity still greater than that of the previous apparent motion of translation.

About 14h the belt broke up and the pulsations became visible over the whole sky, the order of their succession being from the horizon to the zenith. At 15h the pulsations became intermittent and ceased to maintain any apparent order in their occurrence: they gradually became more feeble and ceased with daybreak.

Throughout the night a generally diffused luminosity prevailed, such as is commonly seen with a full moon and hazy sky. This was evidently not occasioned by the moon, which was scarcely four days old, and was low in the horizon, but was part of the aurora itself, the brilliancy of whose more active features it greatly impaired.

Throughout the day and night a considerable magnetic disturbance was going on.

From a table giving the digressions of the declination, total force, and inclination from their respective standard values the remarks which follow have been derived. The standards employed for the sake of brevity for the declinometer and the horizontal and vertical force magnetometers were the approximate mean normals of those instruments relative to the whole day. The digressions therefore are affected by the diurnal variations proper to the times of observation; but as these are small compared with the actual digressions, the inaccuracy occasioned by using the same standard throughout will not materially disAM. JOUR. SCI.-SECOND SERIES, VOL. XLVIII, No. 142.—JULY, 1869.