so harmful as could be desired to the parasites for whose disestablishment it is administered.  One ounce might be contained in about four hundredweight of canned food. 3.  If a possibly harmful quantity of a soluble compound, of tin be placed in a portion of canned food, the latter will be so nasty and so unlike any ordinary nasty flavor, so “metallic,” in fact, that no sane person will eat it. 4.  Respecting the globules of solder (lead and tin) that are occasionally met with in canned food, I believe most persons detect them in the mouth and remove them, as they would shots in game.  But if swallowed, they do no harm.  Pereira says that metallic lead is probably inert, and that nearly a quarter of a pound has been administered to a dog without any obvious effects.  He goes on to say that as it becomes oxidized it occasionally acquires activity, quoting Paulini’s statement that colic was produced in a patient who had swallowed a leaden bullet.  To allay alarm in the minds of those who fear they might swallow pellets of solder, I may add that Pereira cites Proust for the assurance that an alloy of tin and lead is less easily oxidized than pure lead. 5.  Unsoundness in meat does not appear to promote the corrosion or solution of tin.  I have kept salmon in cans till it was putrid, testing it occasionally for tin.  No trace of tin was detected.  Nevertheless, food should not be allowed to remain for a few days, or even hours, in saucepans, metal baking pans, or opened tins or cans, otherwise it may taste metallic. 6.  Unsound food, canned or uncanned, may, of course, injure health, and where canned food really has done harm, the harm has in all probability been due to the food and not to the can. 7.  What has been termed idiosyncrasy must also be borne in mind.  I know a man to whom oatmeal is a poison.  Some people cannot eat lobsters, either fresh or tinned.  Serious results have followed the eating of not only oatmeal or shell fish, but salmon and mutton; hydrate (misreported nitrate) of tin being gratuitously suggested as being contained in the salmon in one case.  Possibly there were cases of idiosyncrasy in the eater, possibly the food was unsound, possibly other causes altogether led to the results, but certainly, to my mind, the tin had nothing whatever to do with the matter.

In my opinion, given after well weighing all evidence hitherto forthcoming, the public have not the faintest cause for alarm respecting the occurrence of tin, lead, or any other metal in canned foods.—­Phar.  Jour, and Trans., March 8, 1884, p. 719.

[In reference to Prof.  Attfield’s statement contained in the closing paragraph, we remark:  It is well known that mercury is an ingredient of the solder used in some canning concerns, as it makes an easier melting and flowing solder.  In THE SCIENTIFIC AMERICAN for May 27, 1876, in a report of the proceedings of the New York Academy of Science, will be seen the statement of Prof.  Falke, who found metallic mercury in a can of preserved corn beef, together with a considerable quantity of albuminate of mercury.—­EDS.  S.A.]