178 ANNUAL OF SCIENTIFIC DISCOVERY. 



must not be admitted so decidedly as Flandin supposes. In the 

 Comptes Rendus for May a case of undoubted metallic colic, occur- 

 ring at one of the Paris hospitals, is described. The patient was a 

 workman in the zinc paint-works, and the attack he experienced was 

 of a very serious nature. By washing' the surface of the body of this 

 person, metallic particles were obtained, which afterwards were 

 proved to be zinc. Workmen engaged in the manufacture and hand- 

 ling of galvanized iron wire (iron wire coated with zinc) have also 

 experienced similar effects, though not so severe in their nature. 

 Suspension of the work always caused a relaxation of the complaint. 

 It does not appear, says Dr. Bouvier, in commenting on these cases, 

 that oxide of zinc is as noxious as lead, but it shows, at least, that 

 some precautions should be taken by those who work in it in order to 

 preserve their health. 



MANUFACTURE OF ZINC PAINTS IN NEW JERSEY. 



IT is well known that extensive operations have been entered into 

 at Sterling, Sussex Co., New Jersey, with a view of manufacturing 

 on a large scale the oxide of zinc from the celebrated red zinc ore 

 which occurs abundantly at that locality. The process by which the 

 oxide of zinc is prepared is exceedingly interesting. The mineral 

 consists of oxide of iron, manganese, and oxide of zinc, or oxide of 

 zinc and Franklinite. The ore is first roasted, and the Franklinite 

 picked out. It is then pulverized and mixed with a small proportion 

 of anthracite or charcoal as a flux ; and about forty pounds is used as 

 a charge for a cylindrical retort made of clay, three and a half feet in 

 length, and eight inches in diameter. The retort is placed in a rever- 

 beratory furnace horizontally, one end being exposed by an opening 

 in the furnace wall : a sheet-iron receiver is attached to the mouth of 

 the retort, having an opening at the neck to admit atmospheric air. 

 The receiver is elongated by flexible tubes that serve as additional re- 

 ceivers, and also to carry off the carbonic oxide. When the proper 

 heat is applied, the zinc is set free from the ore, and conveyed into 

 the receiver as a vapor of zinc, where, meeting the current of atmos- 

 pheric air, from which it takes up the oxygen, it falls at once as a 

 beautiful powder of pearly whiteness. The metallic zinc is made in 

 the same manner, with the exception that in the latter case the air 

 necessary to form the oxide is entirely excluded. 



The demand for the oxide of zinc at present is greater than the sup- 

 ply, and the company are constantly enlarging their works. It is used 

 extensively as a substitute for white-lead in the manufacture of India- 

 rubber goods, but its chief value is as paint. In France it has to a 

 great extent taken the place of lead paints, and is being rapidly intro- 

 duced in the United States. The advantages of zinc as a paint over 

 white lead, in addition to the comparative security of the workmen 

 from disease, are, that the action of gases will not change it, while 

 lead paint is turned black by sulphuretted hydrogen ; it is perfectly 

 and dazzling white. It gives to a wall the lustre of porcelain, and 

 may be washed without risk. It is ground in spirits of turpentine, 



