35 



that it would be dissolved at anj^ greater rate than the zinc of the 

 galvanized iron. The small quantity of alumina which would be intro- 

 duced into the fruit could not possibly be regarded as objectionable. 



It would be useful also to substitute iron wires covered with tin for. 

 the galvanized iron at present in use. Wire netting could be prepared 

 and covered with tin at a much less expense than aluminium could now 

 be furnished. The coating of tin, evidently, for such a purpose should 

 be much heavier than that for ordinary tinware, so that the iron maybe 

 in all points deeply covered, and thus avoid the galvanic action which 

 would ensue on the portion of iron exposed. The tin employed should 

 be pure, and especially free of lead. Pure tin is much more resistant to 

 the action of acids than zinc, and the amount of tin which would be 

 found in evaporated fruits dried on tin trays would probabl}^ be infini- 

 tesimal. 



While it is true that it would cost the manufacturers a considerable 

 sum to throw away the trays which they now have and substitute for 

 them those which would cost a great deal more money, yet the expense 

 seems to be worth incurring. To be able to absolutely guarantee the 

 product free of zinc would result in opening a wide and profitable mar- 

 ket to our evaporated fruits, and in the removal of any justifiable hygi- 

 enic reasons for restricting their sale. 



SUMMARY. 



(1) In many European markets the consumption of American evapo- 

 rated apples is either restricted or prohibited by alleged hygienic 

 reasons resting upon the supposed contamination of the product with 

 zinc. 



(2) In several cases where samples of condemned products have been 

 secured through the agency of our consuls and others, an analysis has 

 disclosed the presence of zinc in some of them and proved its absence 

 in others. In the latter case the prohibition of the sale of the product 

 was evidently discriminating and unjust. 



(3) In samples of American evaporated apples secured from large 

 dealers and directly from the factories, weighable quantities of zinc 

 have been found in nearly every instance in which the drying was 

 accomplished on galvanized iron wire trays. 



(4) The results of the analyses have shown that the slices which 

 were dried in intimate contact with the galvanized iron wire contained 

 a far larger content of zinc than those in which the contact was less 

 intimate. 



(5) An analysis of the galvanized iron wire cloth composing the bot- 

 toms of trays shows tliat in each square yard of the new cloth about li 

 pounds of the zinc are present, and that when these trays have been in 

 use for several seasons the total quantity of zinc is very much dimin- 

 ished, but that still considerable (|uantities are present when the trays 

 are too much worn for further use. 



