576 TROPICAL HYGIENE, SANITATION, ETC. 



The most common chemical preservatives are : — 



Formaldehyde and Borax to milk. 



Salicylic acid to fruit juices. 



Sodium henzoate to ketchup, jams and sauces. 



Sulphites to dried fruits, gelatin and chopped meat. 



Fluorides to beer. 



Some of these, such as salicylic acid, borax, benzoic acids, and 

 fluorides are normally present in certain products, hence their mere 

 presence cannot always mean that such have been added. 



Minute amounts of preservatives of a certain specified kind are 

 essential in most cases but there is not the slightest doubt that the 

 opportunity to add preservatives by unscrupulous manufacturers is a 

 constant temptation to put on the market food unsuitable, and partly 

 decomposed. When preservatives are added to arrest decomposition 

 the quantity must be sufficient to interfere with the normal digestion 

 of the consumer. 



The following notes may be of interest. 



The nutritive value of meat after refrigeration is unaltered. 



Salt in butter causes mycelial fungi to disappear and reduces the 

 vigorous multiplication of micro-organisms. 



Formaldehyde in small quantities is apt to cause headache; nausea, 

 vomiting and intestinal cramps. 



Boric acid rubbed on hams penetrates the substance deeply and its 

 consumption mav derange the digestive tract. 



Boric acid, 20 grains to the pound, was found in certain sausages. 



This inhibits putrefaction but does not appreciably inhibit the 

 growth of ihe Coli group of organisms, hence stale meat can be used 

 for sausages (Bernstein). 



Certain preserved tinned lobsters contained from o"8o to 4*47 grains 

 per pound of dissolved metal in their contents. More than i to 8 

 grains has caused poisoning. As much as 13 grains per pound has 

 been found (Wiley). 



Copper sulphate, added to make vegetables a nice green colour, 'S 

 unnecessarv, unwholesome and unadvisable. 



The black spots sometimes seen on chilled beef are due to a 

 mycelium, Oidium carnis, and though unsightly are harmless. 



The following organisms have been found in preserved fish, sar- 

 dines, &c., B. enteritidis (Gaertner), B. prodigiosus, B. botulinus, 

 Penicillium glaucum, Aspergillus glaucus and others. 

 Davies proposes : — 



All preservatives in milk should be forbidden. 



Borax preservative in hams, bacon and sausages should be allowed. 

 Salicylic acid in wines and jams to be allowed. 



