I obtained a white substance in flakes and ribbons, which had little consistence, were easily torn, and did not exhibit any fibres in their fracture. This matter having presented the same properties as those of the coagulum of the white portion of chyle No. 2, what I have said of the one will apply to the other. Of the Coagulum formed spontaneously in the White Portion of Chyle, No. 2. This coagulum was white and opake, like boiled white of egg. When washed it stretched under the fingers, and assumed the form of a membrane, possessing a slight degree of elasticity, and its texture presented an appearance slightly fibrous. This matter digested in a hot solution of caustic potash communicated at first a milky aspect to the liquid; but a greasy matter was gradually deposited, and the liquid became clear. This solution had a smell similar to that of the fibrin of blood dissolved in potash. When this solution is decomposed by acids, it exhales a sulphureous odour, which is developed by albumen in similar circumstances. The same matter subjected to the action of acetic acid, assisted by heat, produced a liquor white like an emulsion. The matter which rendered he liquid opake was gradually deposited. It appeared to me to be of the same nature as the fatty matter which I noticed in the liquid part of the chyle. The matter of the coagulum, when dried, and exposed to heat on burning coals, curls up, and exhales ammoniaco-oily fumes. At last it melts, and leaves a bulky coal behind. From the properties which have been enumerated, it is obvious that the coagulum of chyle has a striking analogy with the fibrin of blood: but I must acknowledge that the resemblance is not perfect; there are some differences, both in the physical and chemical characters of these two substances. The coagulum of chyle has not that fibrous texture, nor the strength and elasticity which belong to the fibrin of blood. It is dissolved more readily and completely by caustic potash, and does not, like fibrin, leave a portion insoluble in that alkali. It seems to be albumen which has begun to assume the characters of fibrin, and has been arrested in its passage: : for it unites several properties common to the two substances. If this account be correct, we may conclude that the food taken by animals is converted in the first place into albumen, and afterwards into fibrin. The increasing proportion of fibrin in the chyle as it approaches the place where it mixes with the blood is favourable to this hypothesis. Be this as it may, the rapid change which vegetables experience in the organs of digestion of animals, and their total conversion into animal substances, are truly astonishing. Some houre are suffi cient to make the characters and nature of vegetable substances disappear entirely. The powers which preside over digestion must be very active and very powerful. From this first analysis, it follows, that the chyle of the horse is composed: 1. Of albumen, which constitutes the greatest part of it. 2. Of fibrin, or at least of a substance which resembles it in several respects. 3. Of a fatty substance, which gives to chyle the appearance of milk. 4. Of different salts, such as potash, muriate of potash, and white phosphate of iron; that is, phosphate at a minimum of oxidation. I ought not to neglect to mention here that M. Emmert was occupied before ine with analysing chyle. An extract of his work, by M. Friedlander, is printed in the Annales de Chimie for October, 1811; but as there is some difference between the results which we obtained, I thought it right to publish my experiments. After having written thus far, I received from M. Verrier a new quantity of chyle, the analysis of which furnished nearly the same results. However, as this last portion was not coloured like the preceding, it presented some phenomena which were not perceived before, and which I shall relate in a few words. Chyle from the Sublumbar Branches. It was white, like milk. The bulky coagulum which it contained was red in some parts. Water deprived the coagulum of the greatest portion of this colour. Then it resembled fibrin, but had much less tenacity. The white liquid which surrounded this coagulum being left at rest for 18 hours was found partly covered with drops of a yellowish oil. The same liquid treated with a considerable portion of boiling alcohol let fall a great quantity of albumen. The alcohol assumed a yellowish green colour, and deposited, on cooling, a white oily concrete matter; and yielded, when evaporated, an additional portion of yellowish oil. These phenomena confirm me more and more in the opinion stated above, that the oil of chyle is of the same nature as that which exists in the brain. The chyle deprived of the fatty matter by repeated digestions in boiling alcohol becomes transparent by drying, as happens to the brain. A portion of this chyle coagulated by heat, and then incinerated, furnished carbonate of potash, muriate and sulphate of potash, iron, and phosphate of lime. Among the last portions of chyle sent me by M. Verrier there was one from a horse afflicted with the glanders, which, though taken from the thoracic duct, was colourless, and contained only a small quantity of fibrous matter. This was, no doubt, the reason why it did not coagulate spontaneously, and why it only showed very small traces of that substance by analysis. It was also much less charged with albumen, as was obvious from its greater fluidity, and from its not coagulating when heated. It contained, however, a notable proportion of fatty matter. This difference seems to announce an exception to the general principle which I pointed out above; namely, that the proportion of fibrous matter increases as the chyle approaches more and more to the place where it mixes with the blood; but this difference may depend upon the nature of the aliments, or perhaps upon the diseased state of the digestive organs of the animal. I shall finish this paper by remarking, that if the bile, the gastric juice, &c. contribute to the formation of chyle, as physiologists think, these substances must undergo a complete decomposition, since not the slightest traces of them can be perceived in the animal fluid which constitutes the subject of this paper. I shall observe, likewise, that the comparison which some persons have established between chyle and milk, in consequence of the external appearance of the two fluids, has no real foundation; for chyle contains nothing which agrees exactly with the constituents of milk. ARTICLE X. Astronomical and Magnetical Observations at Hackney Wick. By Col. Beaufoy. Astronomical Observations, August 11, 1813. Beginning of the Lunar Eclipse 13° 41′ 41′′ Apparent Time. Immersion of 1 + Aquarius 11 53 01 Emersion } Mean Time. THESE observations were made under very favourable circumstances; and as no diminution of the star's light took place, the opinion of some of the French astronomers that the moon is surrounded with an atmosphere, seems extremely improbable; or at least, admitting it is so, the air must be exceed ingly attenuate. The thinness of the moon's atmosphere (if there be any) is further corroborated by the great sharpness of the lunar horns in solar eclipses. Magnetical Observations. 82 Latitude 51° 32′ 40" North. Longitude West in Time 6". Ditto 3 8 10 24 15 Aug. 18h 40' 24° 27′ 12′′ 1h 50' 24° 24′ 16′′ 7h 15' 24° 16′ 40′′ Ditto 2 9 47 24 16 33 7 25 24 16 08 36 Ditto 17 835 24 14 15 155 24 23 467 August 1.-The variation is very remarkable. The morning variation of both needles gave within 18 seconds. The noon variation was less than either morning or evening. The weather was calm, no thunder, nor any apparent cause for so singular a circumstance. At noon it was very gloomy, with the appearance of a blight. Greatest height of the thermometer, 68. ERRATA IN THE LAST NUMBER, ARTICLE XII. Line 18, read b=25.07. Line 18, read d = 25.67. Page 139, line 3, for 1st, 2d, 3d, and 4th, read 1st, 2d, 4th, and 5th. ARTICLE XI. ANALYSES OF Books. Philosophical Transactions for 1813. Part I.] This part contains the following papers; of all of which some account has been given in the first volume of the Annals of Philosophy; but we consider it as necessary to give an analysis of them here, in order to correct the mistakes, and supply the deficiencies, of our former accounts. I. On a new detonating Compound. By Sir Humphry Davy, LL.D. F.R.S.] This is the substance of which an analysis by Sir H. Davy is given in our seventh number, under the name of azotane. We now know that the original discoverer of it was a M. Dulong, and that he obtained it by passing a mixture of chlorine and azotic gas through a solution of sal ammoniac. He has lately published a paper on the subject in the Annales de Chimie; but it contains nothing that we did not know before. Azotane has the colour and fluidity of olive oil; its specific gravity is above 1.6. It detonates with a bright light when heated in water, and when brought in contact of oil or phosphorus: it acts slowly on ether and alcohol: with mercury it forms corrosive sublimate: on tin and zinc it has no action: neither does it act on sulphur or resin: it explodes in alcohol and ether, having phosphorus in solution: in muriatic acid it gives off gas rapidly, but does not explode: it has but little action on sulphuric acid. Sir H. Davy conceives it probable, from the properties and formation of this substance, that it is a compound of chlorine and azote; an opinion which he has since verified by a direct analysis. |