Sir Robert Robertson 201 



The workers suffered from a dreadful disease called 

 1 phossy jaw.' It was proved that for making matches 

 red phosphorus was just as good as white, and that it was 

 much less dangerous for the workers. Now one of the 

 tasks of the Government Laboratory is to test imported 

 matches for the presence of white phosphorus. 



Samples of a very large number of foodstuffs are 

 analysed yearly by the staff of the Government Labora- 

 tory, and special attention is paid to butter, margarine, 

 milk, and cream. Frauds to be watched for include the 

 substitution of margarine for butter, and the use in im- 

 ported butter of injurious artificial colouring or preserva- 

 tives. The amount of water which butter may contain 

 is laid down by law; it may not exceed sixteen per 

 cent. 



You may perhaps wonder how the analyst discovers 

 foreign matter in butter. One method involves the use 

 of a specially constructed instrument. Pure butter 

 melted has a definite angle of refraction when a ray of 

 light is passed through it. Since this angle is known any 

 difference from it may be an indication that the butter is 

 not pure. The amount of butter fat in any sample can 

 be determined by distillation of the volatile acids. There 

 are several ways of getting at the truth, and of bringing 

 the adulterator to book. 



It might be expected, after all this, that offences would 

 have been ended, yet the report of the Ministry of Health 

 for the year ending March 31st, 1929, records an increase 

 in the adulteration of the nation's food. Of 129,034 

 samples examined, 7524 were found to be adulterated — 

 that is, nearly six per cent. Some cases were peculiarly 

 scandalous. For instance, paraffin wax was found in 

 three samples of suet, and a sample of flour contained a 

 quantity of fungus. Mustard was mixed with maize 

 flour, and sand was discovered in mixed spice, while 

 samples of cod-liver oil tablets contained no cod-liver oil 



