XXIV.—Creatine a constituent of the flesh of the cetacea
作者:
David S. Price,
期刊:
Quarterly Journal of the Chemical Society of London
(RSC Available online 1851)
卷期:
Volume 3,
issue 3
页码: 229-231
ISSN:1743-6893
年代: 1851
DOI:10.1039/QJ8510300229
出版商: RSC
数据来源: RSC
摘要:
ON CAPICOIC AND CENANTHYLIC ACID. XXIV.-Creutine a constituent of the Flesh of the Cetacea BYDAVIDS. PRICE,Ph. I). A fine specimen of the Rorqual Whale (Bala?nopteramusculiis) having been brought into Rlargate in February last I availed myself of the opportunity afforded of ascertaining whether creatine which has been found to be a constituent of the rnuscIes of various mani- rnals birds and fishes was likewise contained in those of the cetacea. It has been shown by Liebig that the muscles of fat animals yicld a much smaller quantity of this substance than those of lean oiies; and as the whale may be ranked pre-eminently among the former it was deemed necessary in ordcr to ensure a decided result that a large quantity of the flesh should be employed.For this purpose about 40 lbs. the freest from fat that could be selected were treated in the manner described by TAiebig in his research into the constituents of the juices of the flesh; 10 lbs. of the flesh were cut into small pieces and well kneaded with an equal weight of cold water. The DR PRICE ON CREATINE IN THE flesh was then removed to another vesrel holding the same amount of water and after being again well pressed was put in linen bags into a strong screw-press and as much of the liquor obtained as possible; the second water served as the first receptacle for another 10 lbs. of flesh which were treated in like manner &c. In this way the extract from the 40 lbs. was eventually obtained. The large quantity of fat which collected on the surface of the fluid had to be removed prior to the liquid being strained through flannel bags for the purpose of separating any muscular fibre and fatty matter that might be suspended in it.The filtered liquid which was of a blood colour and exhibited an acid reaction was heated in large evaporating pans over a water bath whereby the albumen was coagulated taking with it nearly the whole of the colouring matter the liquid on being strained through linen bags retaining only a very faint colour. The odour and flavour of this filtrate was not distinguishable from that of the extract of beef. In order to separate the last traces of albumen the liquid extract was rapidly heated to ebullition over a strong fire in a tinned copper vessel.After being filtered the solution was mixed with concentrated baryta-water till a precipitate ceased to be formed a point which was reached long after the acid reaction had disappeared. The almost colourless filtrate when evaporated in the water bath acquired a dark brown eolour and became gradually gelatinous emitting an odour very similar to that of glue. The concentrated liquor was now placed in a cool situation in several shallow vessels when after the lapse of forty-eight hours numerous minute glittering crystals were deposited which owing to their great specific gravity could be easily separated by decantation of the supernatant liquid. When dried in this minute state these crystals presented a beautiful appearance refracting light with remarkable intensity.After three or four crystallizations they may be obtained quite pure. If their aqueous solution be allowed to crystallize slowly crystals one quarter of an inch in length are formed presenting a silky lustre and frequently arranged in groups. These crystals are insoluble in alcohol but very soluble in boiling water; when warmed on platinum foil they lose their lustre becoming opaque and white; when heated more strongly they carbonize emitting the odour of burning nitrogenous substances ; on the application of a still stronger heat the carbon is entirely consumed no ash remaining behind. 0.30537 grms. of this substance when kept for some time in a water bath at a temperature of 212* F, lost 0.0378 grms. FLESH OF THE CETACEA 231 corresponding to 12.2 per cent of water the amount found by Liebig in creatine prepared from different sources. I must not forget to state that I obtained this substance (a specimen of which I have the honour to lay before the Society) in very small quantity. There can be no doubt as to the identity of this body with that described by Chevreul Liebig Schlossberger and Gregory; and we may safely conclude that it is a constituent in greater or less amount of the fluids Iof the flesh of all the higher class of animals.
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