6 



case was the surface of the tin found to be eroded, and the discolora- 

 tions were due doubtless to the natural effect of the meats upon the 

 tin surface. As is well known, one of the essential constituents of 

 flesh, i. e., proteid matter, contains sulphur in such form that when 

 brought into contact with metal there is a tendency to produce dis- 

 coloration. This is shown familiarly in the action of the white of 

 the egg upon a silver spoon. A careful examination of the discol- 

 orations shown upon the tin of the packages leads us to believe that 

 they are due to the natural action of the proteid matter upon the 

 metal. 



In some countries, notably in Germany, the character of the tin 

 used in making packages for preserved foods is fixed by law; in 

 other words, the maximum content of lead which the tin may have 

 is prescribed. In Germany the content of lead is not allowed to 

 exceed 1 per cent. In some examinations which were made some 

 years ago in this Division of the tins used in the preservation of 

 fruits, it was found that in this country a much larger percentage of 

 lead was often present, in one case over 12 per cent of lead having 

 been found in the tin used in the package. We are now conducting 

 an examination of the tin surfaces in order to determine the content 

 of lead they may contain. The results of this examination will be 

 presented in a supplemental report. 



Particular attention was also paid to the way in which the pack- 

 ages had been soldered. In every instance we found that the rules 

 prescribed by foreign countries, notably Germany, in regard to this 

 matter had been observed. In other words, the solder had been so 

 applied as not in any case to come in contact with the contents of 

 the package. This is a highly important matter, since it is well 

 known that solder contains a very high percentage of lead and there- 

 fore the dropping of solder into the contents of the package or bring- 

 ing the solder in any way into contact therewith is extremely repre- 

 hensible. The method of soldering the cans in all cases examined 

 by us was entirely satisfactory and in no instance did we find any 

 trace of solder in the contents of the can nor did we find the con- 

 tents of the can in contact with the solder in any instance. The 

 care, therefore, which has been exercised in this particular is entirely 

 satisfactory. 



In concluding this preliminary report I again desire to emphasize 

 the fact that preserved foods, especially meats, are not to be preferred 

 to the fresh articles, except in those cases where it is not possible for 

 the articles in a fresh state to be supplied. In the second place, it is 

 highly important that some competent supervising agent be always 

 present to inspect the packages when they are opened in order to 

 detect any failure of complete sterilization in their preparation, or 

 any evidences of incipient or advanced decay in their contents. 



