580 SCIENCE IN AFRICA 



nutritious cake is made from the compressed bodies of lake flies 

 near the great lakes, and some tribes are fond of locusts. Here 

 again there may be opportunity for expansion. 



Preliminary investigation should be directed to studies of the 

 metabolism of natives, and standard analyses showing the dietetic 

 value of the normal food materials. The former of these subjects 

 is discussed on page 584; some remarks on analyses may be made 

 here. Food analyses are more easily made in the well-equipped 

 laboratories of Europe and America than in Africa itself, but 

 facilities are now developing in Africa, especially in the Union. 

 The analysis of foodstuffs in Africa itself is a less formidable task 

 than it sounds, especially now that most of the important vita- 

 mins can be analysed by chemical and physical methods. In this 

 connection results from the League of Nations Permanent Com- 

 mission on Biological Standardization will be of value, particularly 

 in international co-operation; for instance, the commission has 

 set up official units and standards by means of which the vitamin 

 contents of food and the amounts required for maintaining health 

 can be estimated. In addition, the work done at Washington, 

 D.C., in analysing typical food materials, should be applicable in 

 other parts of the world, but would need to be supplemented by 

 work on African foods. At the Conference of the Co-ordination of 

 General Medical Research in East Africa (Conference, East Africa, 

 1934a) it was decided that all analyses of local foodstuffs should be 

 carried out by the biochemist at the Nairobi laboratory. The 

 studies which have already been completed at Nairobi and else- 

 where in Africa (International Institute of African Languages and 

 Cultures 1937) stress the importance of local variation, so that 

 general standardization of each food material is not sufficient. 

 The nutritive value of different food crops must vary, not only with 

 different strains, but with conditions of soil, climate, use of manure, 

 and irrigation. Some local products can be sent to distant labora- 

 tories for analysis, but this is unsatisfactory, particularly for deter- 

 minations of vitamins A and C, because alteration of these is 

 rapid, consequent on oxidation, storage, etc. The existence of 

 local variations does not, of course, detract from the importance 

 of general standardization. 



When the value of each foodstuff is known, diet charts can be 



