33 



No. 14408 B. Wire cloth in use more than live years, from L. R. Rogers : 



Sample a part of the same lot as above. Water extracts a soluble zinc salt. The 

 metal is composed of 84.77 per cent iron and 1.5.23 per cent zinc. One square yard 

 weighs 2.18 pounds and contains 0.33 pound of zinc. 



It is seen that there is a gradual disappearance of the zinc with use, 

 the quantity in one tray droi)ping from about 2 pounds to one-third of 

 a pound in five years. 



PHYSIOLOGICAL ACTION OF ZINC. 



It is probable that the zinc salts contained in evaporated apples exist 

 entirely in the form of organic salts, the most abundant of which is 

 zinc malate. The physiological effects of the organic salts of zinc have 

 not been comprehensively studied, the only one used in medicine being 

 the valerianate. The valerianate of zinc has antispasmodic properties 

 and has also been used as a remedy in neuralgic affections. In gen- 

 eral, however, the physiological effects of the zinc salts, as found in 

 evaporated apples, may be assumed to be similar to those of the inor- 

 ganic .salts of zinc. The sulphate of zinc is the salt which is most 

 generally used for medicinal i)uri:)Oses. It is tonic and astringent and 

 in large doses produces prompt emesis. 



There are a few cases on record of fatal poisoning from large doses 

 of the salt. In one of the fatal cases an ounce and a half of the zinc 

 sulphate was swallowed by mistake for epsom salts. A like quantity 

 of the salt taken at the same time by another patient produced severe 

 toxic symptoms, but did not result fatally. In many cases large doses 

 of the salt have been administered for many days without any symp- 

 toms of toxic effects. In one instance 36 grains of salt were given 

 three times a day for six weeks without the appearance of any symp- 

 toms of poisoning. All writers on toxicology, however, agree that in 

 certain quantities zinc salts exercise a poisonous effect. While the 

 continued administration of zinc salts in small quantities has not 

 been known to produce any very decided disturbance of the ijhysi- 

 ological functions of the body, yet the continued administration of this 

 substance even in minute doses can not be recommended. All author- 

 ities agree that even if zinc be regarded as poisonous it is decidedly 

 less so than lead and copper. A case is recorded (in the Chemisches 

 Central-Blatt, fourth series, Vol. 1, 1894, p. 642) in which from 50 to 100 

 milligrams were administered every day for from two to six months 

 without any disturbance in the health of tlie animals experimented ou. 

 Zinc does not accumulate in the system except in small quantities in 

 the bones. 



Zinc salts have also a certain antiseptic value and have been used 

 to a slight extent for that })urpose. They are also used to a very lim- 

 ited extent for fixing the chlorophyll colors of preserved vegetables, 

 esi)ecially with pease and beans. 

 12956— Xo. 48 3 



