The food value of mangolds and the effects of deficiency of vitamin A on guinea-pigs / by Ellen Boock and John Trevan.

  • Boock, Ellen.
Date:
[1922?]
Catalogue details

Licence: In copyright

Credit: The food value of mangolds and the effects of deficiency of vitamin A on guinea-pigs / by Ellen Boock and John Trevan. Source: Wellcome Collection.

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    the growth, and it will be seen that ont of four guinea-pigs, one died on the first day that the paper was given, but the other three gained in weight as a result, and one of the three continued to gain for over two months before a decline set in. Suggestions are put forward below as to the explanation of this. Post-mortem examinations revealed several abnormalities in the guinea- pigs whilst on the mangold diet. As in Glenny’s experiments, there was constantly some sign of an infection present, either (a) Alkaline stomach contents. (b) Pneumonic consolidation or abscess of the lung. (c) Purulent pericarditis. (d) Enteritis. When the urine was tested during life and post-mortem, it was always found to be strongly acid, and therefore quite free from the normal precipitate of phosphates which renders the urine of the healthy guinea-pig turbid. This observation led to the suggestion that the mangold, bran and oats diet is de¬ ficient in certain basic constituents, and following the indication of McCollum’s feeding experiments on rats [1920] (from which he concludes that roots and seeds, besides other deficiencies, lack the three inorganic elements calcium, sodium and chlorine), it was decided to add a salt mixture to the bran, oats and mangold diet. A mixture of calcium lactate and sodium chloride was made and mixed as thoroughly as possible with the bran and oats, about 1-5 g. of calcium lactate and 1*0 g. of sodium chloride per guinea-pig per diem being given. This resulted in a return of the urine to the normal alkalinity, when examined during life and post-mortem, and improved the growth curves. (First part of Chart V.) In connection with this, we made an examination of the ash, by drying mangold at 100°, and then incinerating in a muffle furnace. Magnesium, sodium, potassium and iron were found to be present, but no qualitative test for calcium could be obtained, and in attempting to estimate calcium by Cahen and Hurtley’s method [1916], no potassium permanganate was used up in the final titration. The beneficial effect of the salt mixture is therefore probably due to its supplying the extra calcium. The packing paper also helps in the same direction, for analyses of the ashed paper showed that there is a certain amount of calcium present: Percentage of ash in paper ... ... 1*7 % 1st determination. ,, ,, ,, ,, ... ... 1*6 % 2nd ,, ,, ,, calcium in paper ... 0*126% 1st ,, „ „ „ „ ... 0*190% 2nd Using Sherman and Gettler’s tables [1912], we have calculated that the calcium supplied by the 5 g. of paper eaten per guinea-pig per diem would
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