1040 FOODS AND FOOD ADULTERANTS. 



work on the part of the canners is responsible for the fact that many 

 cans contain fragments of solder of varying sizes. Above a certain 

 limit these particles can be hand picked and below this point in the 

 method of grinding the samples used in the analyses of canned vegeta- 

 bles, much of the solder was flattened sufficiently to be picked out dur- 

 ing sifting. Metallic lead is probably also present in another form in 

 these goods. The food dissolves out more or less of the metal from the 

 solder, and this is again precipitated in a finely divided state by the tin 

 of the walls of the cans. This of course can not be mechanically sepa- 

 rated. It is probable, however, that this latter metal, by reason of its 

 state of aggregation, from a hygienic standpoint is about as dangerous 

 as if it were oxidized. This is of course not true in the case of lead 

 existing as solder. Solder, or metallic lead in any shape, present in 

 food is bad, but in point of danger it is not comparable with lead exist- 

 ing as salts. 



For the reasons adduced above, the quantities of lead found in the 

 various samples of canned foods must be understood to represent merely 

 the sum of the metal present in a finely divided condition and that in 

 an oxidized condition. Were it otherwise, and did these figures repre- 

 sent altogether dissolved lead, canned goods would be a source of 

 great danger to health. Of course, in the case of samples put up in 

 bottles, solder is not present and the lead found was probably all in 

 an oxidized condition. 



Lead is a dangerous metal, and the canners are very free with it. 

 The solder used seldom contains less than 50 per cent and it is found 

 on the inside of the can in liberal quantities, not considering that pres- 

 ent as detached particles. Besides this, the tin plate often carries lead 

 to large extents. Were it not for the reaction cited in speaking of tin- 

 ning alloys, that metallic tin precipitates lead from its solutions when 

 present in large excess, careless canning would be much more danger- 

 ous than it is. Unluckily, because tin, although not innocuous by any 

 means, is not so dangerous as lead, this reaction is not absolute. After 

 a certain quantity of tin is dissolved lead begins to go into solution to 

 some extent. The relative quantities of the two metals in solution will 

 depend partly upon the nature of the food and partly upon the relative 

 quantities of metallic lead and tin exposed to the action of the food. 

 Some lead is frequently found dissolved, though not often where the 

 canning lias been conducted with proper care and good materials li.ivc 

 been used. 



Little need be said in regard to the poisonous nature of lead com 

 pounds. This is so well known that its repetition here is almost unnec- 

 essary. 



The most unpleasant characteristic of lead is its propertj^ of accumu- 

 lating in the system and then suddenly manifesting a strong poisonous 

 action. "Wrist drop," "printer's palsy," "painter's palsy," and "lead 

 colic" are common names for maladies produced by its action. The 



