PHYSIOLOGICAL ACTION OF TIN. 1165 



paratively little of the oxid had been dissolved and absorbed. Death, therefore, 

 had been produced by a far smaller quantity than that administered, and was appar- 

 ently due to the astringent and irritant action of the metal. 



Another somewhat stronger guinea pig took 30 mg of stannic hydrate, also freshly 

 precipitated and moist. As no ill effect seemed produced, a further quantity of 45 

 mg was given on the same day. The feces contained much tin. Next day the ani- 

 mal took two further doses of stannic hydrate of 75 nig each. A few hours after- 

 wards it appeared ill; its abdomen was distended, and the feces were diminishing in 

 size. Next day the pig seemed quite well again, and took, without apparent effect, 

 three doses of 75 mg each. Thus altogether it had in three days 450 mg of tin as 

 stannic hydrate, without much injury, although the astringent effect of the tin had 

 become visible. 



On the following day, when it seemed in perfect health, it took 50 mg of tin in the 

 form of stannous hydrate. It was ill next day and did not take any food until its 

 death, three days afterward. The few excrements passed during that time were very 

 small, much like those observed in the case of pig No. 1. They contained much tin. 

 The stomach was practically empty ; the colon and bowels filled with a semifluid, 

 green, offensive matter, containing much tin. The liver contained a notable quan- 

 tity of tin, and the lungs, heart, and kidneys traces of the metal. 



From these experiments it appears that whilst stannic hydrate, from its compar- 

 ative insolubility in gastric juice, is without much effect in the doses given, stannou- 

 hydrate, very soluble as it is in dilute acids, is a powerful irritant poison. 



In a discussion of this paper before the Society of Analysts, Dr. Wynter Blyth sugs 

 gested that the tin found by Mr. Hehner might not have been in a soluble form, but 

 that minute particles of metallic tin might have been rubbed off by the mere friction 

 of the contents of the can. He had administered 350 mg of finely divided tin at a 

 dose and had seen no deleterious actions arise from it. 



Mr. Wiguer said that he could detect 20 or 30 mg of tin per pound by taste. He 

 had only found one sample of canned fish which was free from tin present ii the 

 fish. This was a can of prawns and they had probably been canned less than a 

 month. He did not think that in the case of fish it was, as Dr. Blyth had suggested, 

 mechanical adherence of the tin. In nearly every case of condensed milk which 

 had been kept more than one month or six weeks, tin and lead were both present. He 

 had lately examined 50 brands of tongues, hams, chicken, corned beef, and roast 

 beef, and had found only one can in which tin was present in any appreciable quan- 

 tity. There was about mg in a pound. He believed that the solder used often 

 contained bismuth. He had also examined more than 300 kinds of canned fruits 

 and only 8 or 10 had turned out bad. 



USE OF TIN CANS FOK PRESERVING. 2 



Niederstadt calls attention to the fact that acid-preserved foods dissolve tin. 

 Green foods (beans, peas, pickles, etc.) contain salts which form double salts with 

 tin compounds. Preservation with SOa should not be allowed on account of the 

 solubility of tin in sulphuric and sulphurous acid. 



POISONOUS ACTION OF TIN. 2 



In conclusion to investigations made by the authors some time since 3 upon tin in 

 canned foods, they have made experiments upon the toxicity of tin combinations. 

 That the tin which is present in these foods in a difficulty soluble form was dissolved 



1 Niederstadt, Apoth. Ztg. 1891, 6, 588; abs. Chem. Centrbl., 1892, 1, 62. 

 2 EmilUngar and Guido Bodliinder, Ztsch. Hyg. ? 1887, 2 ? 241 ; abs. Chem. Centrbl., 

 1887, 644. 

 3 Chem. Centrbl., 1883, 810, 



