THE POISONS OF THE MANUFACTORY. 665 



a hundred times less. The difference depended on one condition only. 

 The former factory made white-lead in powder or in cakes ; the other 

 prepared and sold it exclusively ground in oil. In the former process 

 much dust, in the latter none, was disengaged. 



Another step in progress may be gained, perhaps, by substituting 

 inoffensive substances for the compounds of lead employed in industry. 

 "White-lead has already a rival in zinc-white, but it is objected to that 

 substance that it has an inferior coloring power. To meet this objec- 

 tion, Mr. Griffith, of England, has prepared a white coloring substance 

 based on sulphuret of zinc, which combines the coloring power of 

 white-lead with the inoffensive qualities of the salts of zinc. 



A pharmacist of Brest, M. Constantin, has received a prize from 

 the French Academy of Sciences for the discovery of substitutes for 

 the use of oxide of lead in the glazing of pottery : glazes based on 

 lime for the uncolored, on oxide of manganese for colored, glazings. 



A number of inoffensive colors deserve mention as substitutes for 

 poisonous colors. Such substances as eosine, fluorescine, and other 

 products derived from aniline, have been fortunately introduced in 

 later years for painting children's toys. 



Nothing need be said of copper. It is as inoffensive as lead is dan- 

 gerous ; and it appears, according to the researches of Dr. Burq, to 

 confer upon workmen who handle it an almost absolute immunity 

 against cholera. 



Mercury is as dangerous as lead. It provokes salivation, destruc- 

 tion and loss of the teeth, tremblings, paralysis, and death. The 

 workmen exposed to injury from it are miners employed in its extrac- 

 tion, gilders, looking-glass makers, and hatters. The personal hygiene 

 is the same as for lead ; but in securing its application we are still 

 opposed by the carelessness and foolhardiness of the workmen. 



The principal means relied upon for preservation against acci- 

 dents from mercury are the employment of ammoniacal sprays in the 

 shops, and of iodide of potassium, as for lead. Both remedies were 

 recommended by M. Meisens after a long series of experiments, and 

 have been used with excellent effect. The division of the labor in its 

 most insalubrious phases and an energetic ventilation are excellent 

 measures. Operations in mercury have been, moreover, much allevi- 

 ated by the introduction of new processes. Gilding with mercury 

 has been replaced by galvanoplasty ; silvering of glass with mercury 

 by a plating process which is performed at half the cost, and is without 

 danger to health. Mercury is used by hatters in a secret process for 

 impregnating the fur of the hare and rabbit, to make it felt, with a 

 mixture of mercury, nitric acid, and water. Efforts have been made 

 to find a substitute for quicksilver, and Dr. Hillairet proposed in 1872 

 to use molasses, but the experiment was not satisfactory. 



Phosphorus is but little used among us except in the manufacture 

 of matches. The troubles which it occasions are cou'h, headaches, 



