The following experiments were made with that from the yolk of fowls' eggs. Το obtain it, take 200 grammes of viscid matter, introduce into a flask with 500 grammes of alcohol, at 88 per cent., and 50 grammes of hydrochloric or sulphuric acid; leave them several hours in contact, then heat them so as to bring the liquid slowly to the boiling point. After boiling up once or twice remove it from the fire, and pour the liquor into a glass with a foot. electrotype process. He subsequently pur- in obtaining it without decomposing the sued the investigation with the view of latter. In the eggs of the carp as in the forming definite amalgams by a simple yolk of fowls' eggs, it is found in much chemical or mechanical process. When smaller quantity than lecithine. mercury was made negative under a solution of sulphate of copper, an amalgam of copper was formed which, when fully saturated with copper, was found to be represented by the formula Cu+Hg. The author also exhibited a small apparatus whereby amalgams could be made to endure a pressure of sixty tons per square inch of surface. The superfluous mercury was thus expelled through the openings in the sides of the press, leaving an amalgam of definite chemical composition. In this way he had procured the undermentioned compounds: Pt+ 2 Hg Ag + 2 Hg Cu+ Hg I HAVE already stated that I regard the viscid matter of yolk of egg as a soap enveloped by a nitrogenous organic matter which for a long time prevented me from ascertaining its nature. I have likewise said that when the viscid matter is mixed with acids or the mineral alkalis, grey or white pellicles are obtained according as the first or last of these agents are employed. These pellicles form, as I supposed in my first memoir, a nitrogenous organic matter, differing from vitelline, but it does not, as I supposed, contain sulphur. That which I found arose from a small quantity of albuminous substance carried along with it. The pellicles of which I have just spoken constitute the cerebrine: I first proved the presence of this substance by treating the viscid matter with acidulated alcohol; it separates under the form of a white body of a soft consistence, when the oily liquid thus obtained is left to itself. It is found in the yolk of fowls' eggs, and in those of the carp so intimately united with lecithine, that I have hitherto failed *Journal de Pharmacie, August, 1850. In cooling it forms two layers, one oily, the other aqueous; the oily layer occupies at first the inferior portion of the vessel, but as the liquid becomes more dense as it loses the alcohol, it rises to the top of the liquor. After separating it, leave it in a cool place where it will shortly deposit a white substance, of a soft consistence, like caseine. It at the same time deposits cholesterine. Sometimes the cerebric matter is isolated as soon as the liquid is removed from the fire; it must then be collected, the whole thrown on a filter, and the fixed oil and cholesterine that accompany it separated, by placing it in contact with ether, which dissolves these bodies without removing an appreciable quantity of cerebrine. To purify the cerebrine separated from the oily liquid, it must be placed on a filter, spread on blotting paper, so as to remove the fatty body with which it is impreg nated; it is dissolved in boiling alcohol of 88 degrees, the liquor, from which it is deposited almost entirely on cooling, filtered. This treatment is repeated a great number of times, to separate the acid which has been used, and which is most obstinately retained by the cerebrine. Finally the cholesterine which accompanies it is separated by means of ether, and it is dissolved in boiling alcohol. While depositing, it appears under the form of small crystalline grains, but which agglomerate in drying, so as to present no regular form; the cerebrine is likewise often in small plates much resembling white wax in appearance and consistence. When the cerebrine is separated immediately from the alcoholic liquor, it is treated with boiling alcohol, after having, however, separated, by means of ether, the fatty matter and cholesterine; it is then observed that only a very small quantity is dissolved in this liquid, as a very large quantity of alcohol must be employed for dissolving even a very minute quantity of this substance. It dissolves, however, very readily in absolute alcohol; thus obtained, it is under the form of very light, white leaves. Cerebrine, prepared by either means, still retains some phosphate of lime, with which it appears to be very intimately united. To separate it, it must be dissolved several times in absolute alcohol, and the liquor filtered each time: the alcoholic treatments must be repeated until the paper no longer retains any foreign sub stances. The cerebric matter, in separating from the alcoholic liquid, occupies, as we have already stated, a considerable volume; therefore, to collect it, the whole must be thrown on a filter; it is afterwards compressed, and it is removed before it has become quite dry. Without this precaution, it would adhere to the paper, and it might be very difficult to detach it from it. The desiccation is finished, either in the open air, or in a moderately heated oven, for this substance, when it is hydrated, enters into fusion at a rather low temperature. Cerebrine may, therefore, be obtained under several forms; in very light leaves, in small plates, resembling white wax in consistence and appearance, or under the form of small, crystalline grains, when it is dried without pressure. liquor acidulated with nitric acid did not appear at first to be rendered turbid by chloride of barium, but, by repose, a slight deposit of sulphate of baryta was formed. Thus cerebrine is neutral in the yolk of the egg, and the very slight rose coloration which it communicates to litmus is evidently due to its retaining an infinitesimal quantity of the acid with which it has been prepared. Submitted to the action of heat, when it is deprived of all moisture, it fuses between 311° and 320° F.: its point of fusion is therefore higher than that of cholesterine. Above the temperature of 320° F. it soon assumes a brownish tint and decomposes. When it retains water or a little fatty matter, cerebrine enters into fusion at a lower temperature. Heated in a glass tube, it furnishes ammoniacal products; calcined in a platinum capsule, it gives a charcoal which burns difficultly, and which did not appear to me sensibly acid; calcined more powerfully, it always left a slight residue of phosphate of lime. Neither cold nor boiling water dissolve it; but in these liquids, and more particularly in the latter, it swells up like starch and communicates to it the property of frothing like soapy water. Lecithine likewise possesses this latter property; it is this, doubtless, which has contributed to cause these bodies to be regarded as saponaceous compounds. It dissolves in alcohol only when it is boiling, and it separates siderable volume, and under the form of small crystalline grains. Ether exerts no sensible action on it; hydrochloric acid does not color it blue. It does not contain sulphur. It combines with acids and retains them with great obstinacy; that which has undergone the influence of these agents, always contains traces of them. Cerebrine, as I have obtained it, is solid, colorless, inodorous and insipid. Is it an acid or a neutral body? This question it is very important to solve. When we hy-almost entirely on cooling, occupying a condrate cerebrine by heating it with water, that which is separated immediately from the alcoholic liquor, exerts no action on litmus paper; that which is separated from the oily liquid exerts on that vegetable color a very slightly acid reaction. To obtain the rose coloration, the cerebrine must be put in a jelly on light blue litmus paper, and the latter placed in a moderately heated oven. The viscid matter does not exert, as I have said, any action on litmus, and it does not contain any base with which it might be supposed that the bodies of which it is composed could be combined; the very slight acidity which cerebrine presents can, therefore, have been communicated to it only by the treatments which it has been made to undergo, or be due to traces of the acid which has been used for separating it. To ascertain if it retained any of the acid employed, I burned a certain quantity of it with very pure nitrate and carbonate of potassa, and I found in the solution of the product of the calcination traces of chlorine. Cerebrine, prepared by means of sulphuric acid, also retained traces of that acid. The It combines with the metallic oxides, but there is no regularity in the quantities of oxide which cerebrine can retain. I made my experiments with potassa-alcohol, and I ascertained that the quantity of potassa thus removed by the cerebrine varied according to the proportion of cerebric matter employed, according to the temperature at which the operation was performed, and according to the number of washings with alcohol which the precipitates obtained in this manner were made to undergo. brine possesses therefore a certain affinity for bases, but it does not form with these bodies what we call salts, that is to say, compounds in definite proportions. Cere We cannot, however, be surprised at these singular properties to which there is nothing analogous in inorganic chemistry. Substances which have already been studied, such as fibrine, albumen, &c., act, in similar circumstances, like lecithine and cerebrine, which, it appears to me should be ranked among them. I submitted the cerebrine of the yolk of the egg to analysis: the following are the results which I obtained : 0-425 gr. of substance dried at 248° F., furnished 0-414 gr. of water and 1.042 gr. of carbonic acid. 0-410 gr. of cerebrine gave 8 cubic centimetres of nitrogen at 59° F., and 0.764 mm pressure, the humid gas. 0549 gr. of the same substance, burned by means of nitre and carbonate of potassa, furnished 0-17 gr. of phosphate of baryta, which corresponds to 0.43 per cent. of phosphorus. We have, therefore, in hundredths:66.85 10.82 2.29 0.43 Nitrogen... 19.61 100.00 100.0 100.00 Everything tends to show that these two bodies are identical. The foregoing experiments were made, as I have said, with the cerebrine of the yolk of the fowls' egg: I should doubtless have obtained similar results with that of the eggs of the carp, if I had operated on sufficiently large masses to obtain enough for the purpose. that these bodies do not obey all the laws which govern mineral products and the majority of organic compounds. Lecithine and cerebrine are, like albumen, fibrine, cholesterine, &c., &c., elements of our organisation. The substances are modified ad infinitum in the animal economy, and affect very different physical states, but they will always be recognised, the first in the products of decomposition which it gives (oleic, margaric and phosphoglyceric acids); the second, because it swells up in water like starch, and because it contains nitrogen. OLEÏNE AND MARGARINE. When the fatty matter of the eggs of the carp obtained by means of ether is treated with boiling alcohol, there remains attached to the sides of the flask a fatty matter which is almost entirely formed of fixed oil. When a certain quantity of this substance has been collected, it is first washed with boiling alcohol and then dissolved in ether; the liquid filtered and evaporated gives an oil of a reddish color. This fatty matter contains neither sulphur nor phosphorus. I arrived at a knowledge of its nature by analysing the products of its saponification by means of caustic potassa, as I had done for the fixed substance of the fowls' egg. The liquid fatty acid possessed the properties of oleic acid. The melting point of the solid fatty matter was 140° F.; it crystallised in alcohol in the same manner as margaric acid, and it presented all its properties. I obtained too small a quantity of these bodies for analysis. I will make one observation in conclusion. In my researches on the yolk of the egg, I stated that the oil of the egg was formed only of oleïne and margarine, because by saponifying it I obtained only oleïc and margaric acids. Kodweiss has announced that he extracted from it stearic acid.* I have not been able to procure this chemist's memoir, nor, consequently to make myself acquainted with the detail of his Lecithine and cerebrine always retain, experiments: I know not whether he saponotwithstanding a very great number of nified the oil obtained by pressure, or that treatments with alcohol or ether, a certain procured by means of ether and containing quantity of earthy phosphates: they pro-cholesterine, or an oil freed from that subbably aid, as well as the albuminous matter, in putting these salts in circulation in animals, and in dissolving them, so to speak, they disguise their properties. We should not be astonished at these facts, when we consider that albumen with a large proportion of alkali contains a large quantity of phosphate of lime whose presence under the soluble form seems incompatible with that of the alkalis. This is one more proof stance as I have done. It is very well known that cholesterine augments the fusing point of margaric acid and may cause it to be mistaken for stearic; I am enabled to affirm, and I have repeated my experiments with this regard, that by operating on oil of the egg completely deprived of cholesterine by means of boiling alcohol (a long *Revue Scientifique, Jan., 1847. and delicate operation), I have not been able | to prepare an acid fusible above 140° F. Moreover, it is only after treating a very great number of times by alcohol that I have been able to obtain even this point of fusion. ACID OF THE EGGS OF THE CARP. Turmeric paper and reddened litmus paper do not change color when put in contact with the substance contained in the eggs of the carp; blue litmus paper appears to acquire a slight rose tint. The eggs of the carp, like the yolk of the fowls' egg, would, therefore, appear to be neutral or very slightly acid. red coloring principles. When the eggs of the carp are boiled in The fatty matter of the eggs of the carp water, an acid liquor is obtained which presents the reddish-yellow coloration of becomes more acid when reduced to a that of the fowls' egg, and its color is likesmaller bulk, and with the addition of alco-wise due to the reunion of the yellow and hol. The experiments which I have made prove that this acidity is due to an organic acid which appears to me to present the reactions of that which the yolk of the fowls' egg furnishes in the same circumstances. However, I must mention that on putting it in contact with oxide of copper, the filtered liquor did not present that evident blue coloration which, according to M. Pelouze, characterises lactic acid. Although it is probable that the acid furnished by the eggs of the carp is of the same nature as that extracted from the yolk of the fowls' egg, still I cannot, from this experiment, admit that there is any identity between the two bodies. However, I may be permitted to say that if this body is not lactic acid, it greatly resembles it in its properties. Does the organic acid which is found in the liquid resulting from boiling in water the yolk of the fowls' egg or the eggs of the carp exist in these bodies, or is it a product of decomposition? An experiment made on an analogous body made me doubtful in this respect. I obtained the coloring matter of the yolk of the fowls' egg by treating the oil of the egg treated several times with boiling alcohol. I found it impossible to separate that of the eggs of fish by this means, for the fixed oil is, as we have said, in very minute proportion in the latter. I was enabled to isolate it by putting the fatty matter of the eggs of the carp into the same conditions as that of the yolk of the fowls' egg. I agitated it in a flask with oil of bitter almonds, and I threw the whole on a filter; the oily liquid which flowed out had the color of the oil of the egg; it contained no phosphate and yielded to boiling alcohol coloring matter, cholesterine and a small quantity of oleïne. The alcoholic liquor left by evaporation a reddish residue soluble in alcohol, to which it communicated a very powerful red tint. On dissolving and crystallising the cholesterine which separated from the alcoholic liquor, and evaporating the liquid, a new residue in which the yellow tint predominated was obtained. The red coloring matter appears, therefore to be more soluble than the yellow. These coloring principles are, like those of the yolk of egg, in solution in an oily liquid which always retains a little cholesterine; the mixture of these substances is much more soluble in alcohol than oleïne. The soft roe of the carp exerts no action on litmus, and yet, by boiling in water, it furnishes an acid liquor which possesses the properties of that which is obtained with the yolk of the fowls' egg and the eggs of the carp. It cannot be admitted, in this case, that the acid pre-exists, and we are led to believe that it is a product When the alcoholic liquid containing in of decomposition. Is it the same with the solution the red coloring matter is evapoyolk of the fowls' egg and the eggs of fish? rated to dryness, a reddish matter which Does the reddish-yellow coloration of these contains iron remains. Indeed, this residue, substances lead to error? I am not at pre-heated with pure concentrated sulphuric sent in a condition to decide this absolutely. OF THE SALTS CONTAINED IN THE The process which I followed for obtaining the salts of the yolk of the fowls' egg succeeded perfectly for isolating those of the acid, until no more white vapors are disengaged, gives a charcoal which, treated with distilled water, furnishes a liquor which is colored red by sulphocyanide of potassium; the yellow prussiate determines in it a slight blue precipitate. In speaking of the albuminous matter, I have said that, after having been treated by alcohol and ether, it possesses a very decided red tint. To ascertain whether this color was due to the presence of iron, I put this substance in contact with concentrated hydrochloric acid; after twenty-four hours, I decanted and drove off the excess of acid: the residue, diluted with distilled water, took a blood-red color with sulphocyanide of potassium; consequently, it contained iron. ODOROUS PRINCIPLE. During the course of my researches on the eggs of the carp, a peculiar odor, resembling that of fish, was exhaled. I proved by the following experiments that the odorous matter of these eggs does not possess acid properties. I at first submitted to distillation 200 grammes of the eggs of the carp divided in distilled water; the product, which had a very decided fishy odor, exerted no action on litmus paper, and left no residue by evaporation. peculiar substances which I noticed in yolk of the fowls' egg, and which I designate, the first under the name of lecithine, and the second under the name of cerebrine: 8. That the cholesterine is identical, as regards composition and properties, with that of the yolk of egg and biliary calculi : 9. That lecithine is the phosphuretted substance of the yolk of the fowls' egg and of the eggs of the carp; that it constitutes a neutral body which always gave me with the greatest facility, as products of decomposition, in presence of the mineral acids and alkalis, under the influence of water and under that of alcohol, and without the intervention of the oxygen of the air, oleïc, margaric and phosphoglyceric acids: 10. That cerebrine is a neutral body, which contains nitrogen, fuses at a high temperature, and swells in water like starch: 11. That by boiling the eggs of the carp in water, an acid liquid is obtained, which becomes more acid by the addition of alcohol; that this property is due to lactic acid or to an acid which closely resembles it in its properties : 12. That the eggs of the carp contain the salts which I found in yolk of egg, and which exist in the animal economy: chlo I afterwards distilled the same quantity of the eggs which I had previously crushed with great care, and mixed with dilute sulphuric acid. The liquid which distilled over presented the odor which was disen-ride of sodium, chloride of potassium, hygaged during my experiments, but it exerted no action on the vegetable colors, had no perceptible taste, and left no residue by evaporation. CONCLUSIONS. From the foregoing experiments, I think I may conclude: 1. That the eggs of the carp present the greatest analogy, as regards composition, with the yolk of the fowls' egg: 2. That they appear not to contain an alkaline albumen similar to that which envelopes the ordinary yolk of egg: drochlorate of ammonia, sulphate of potassa, and phosphates of potassa, lime and magnesia; that they contain besides a considerable quantity of that indefinite substance to which Berzelius gave the name of extract of meat or alcoholic extract: 13. That the coloring matter of the eggs of the carp appears to be formed, like that of yolk of egg, of two coloring principles, one red, which contains iron, and which is analogous to the coloring matter of the blood, and the other yellow, which may be analogous to the yellow coloring matter of 3. That they contain more than half their the blood or of the bile: weight of water: 4. That the albuminous matter or paravitelline possesses the composition and properties of vitelline: 5. That the fatty substance is formed, like that of yolk of egg, of two distinct parts-of a fixed oil and of a soft, insoluble substance, or viscid matter: 6. That the fixed oil which is found in very small quantity is formed, like that of the yolk of the egg, of oleïne and margarine; that it contains neither sulphur nor phosphorus: 7. That the viscid matter which forms of itself almost the whole of the fatty substance of the eggs of the carp constitutes a complex body, containing phosphorus, from which I extracted cholesterine and two 14. That the average composition of the eggs of the carp is, in 100 parts:Water. Paravitelline.. Oleïne and margarine. Lecithine.. Cerebrine 64.080 14.060 2.574 0.266 3.045 0.205 Hydrochlorate of ammonia.... 0.042 0.447 0-037 0.292 0.389 Membranes and envelopes.... 14:530 |