Experimental rickets / by Edward Mellanby.

  • Edward Mellanby
Date:
1921
Catalogue details

Licence: In copyright

Credit: Experimental rickets / by Edward Mellanby. Source: Wellcome Collection.

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    the miik was only skimmed and not separated). The effect of adding the yeast was that the animals appeared to thrive better, but there was quite obviously no anti-rachitic effect, that is to say, the water-soluble factor had no influence in preventing rickets. In other experiments the effect of the anti-scorbutic vitamine was tested. To a diet of milk, bread, yeast, and linseed oil, the juice of a quarter of an orange daily was added. The addition of the orange juice again seemed beneficial for the general health of the animals but once more did not prevent the development of the disease. It was in fact evident that the deficiency of anti-scorbutic and anti- beri-beri factors did not explain the aetiology of rickets. Large numbers of experiments were carried out in the endeavour to determine the part played by other dietetic factors. For instance, to a diet of bread and limited milk, substances like malt extract, cod-liver oil, and other forms of fats such as suet, pea-nut, coco¬ nut oil, and cotton-seed oils, also meat protein, meat extract, casein, were added and their effect on the development of rickets tested. These early experiments were crude, but the results were more or less in keeping with those obtained by the later more refined methods. For instance, cod-liver oil and suet had pronounced anti-rachitic action, meat also had a preventive effect to some extent, and malt extract had an anti-rachitic action when eaten in large quantities. Quantities less than 20 c.c. a day appeared only to have slight inhibitory effect. Some of these earlier results have been published (1). It may be of interest to add that the experimental work had continued for about two years before good evidence of differences in the anti-rachitic action of fats was obtained. IV. THE EFFECT OF DIET ON THE PRODUCTION OF RICKETS (a) The Effect of Various Oils and Fats on the Development of Rickets. We have seen in the foregoing section how the earlier work led step by step to the evolution of a diet which produced rapid and marked rickets in well growing puppies. This diet consisted of: Bread ad lib. Separated milk 175 to 250 c.c. Yeast 5 to 10 grm. Orange juice 5 c.c. Sodium chloride 1 to 2 grm. Linseed oil 10 c.c. I now propose to deal with the effects of other oils, and to describe the experimental work, upon which is based my previously published deduction, that there is great difference in the anti-rachitic effect of the different oils tested. When alluding to this part of the work in previous publications, I have insisted that the classification of fats into a definite order as to the amount of anti-rachitic factor present in each, must be of a tentative nature. This is not because
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