ON DUST AND DISEASE. 181 



large towns, where iron vessels are enamelled by coating 

 them with a mineral powder, and subjecting them to 

 a heat sufficient to fuse the powder. The organisation 

 of the establishment was excellent, and one thing only 

 was needed to make it faultless. In a large room a 

 number of women were engaged covering the vessels. 

 The air was laden with the fine dust, and their faces 

 appeared as white and bloodless as the powder with 

 which they worked. By the use of cotton-wool respi- 

 rators these women might be caused to breathe air as 

 free from suspended matter as that of the open street. 

 Over a year ago a Lancashire seedsman wrote to me, 

 stating that during the seed season his men suffered 

 horribly from irritation and fever, so that many of 

 them left his service. He asked for help, and I gave 

 him my advice. At the conclusion of the season, this 

 year, he wrote to inform me that he had folded a little 

 cotton-wool in muslin, and tied it in front of the 

 mouth ; and that with this simple defence he had 

 passed through the season in comfort, and without a 

 single complaint from his men. 



Against the use of such a respirator the obvious 

 objection arises, that it becomes wet and heated by the 

 breath. While casting about for a remedy for this, 

 a friend forwarded to me from Newcastle a form of 

 respirator invented by Mr. Carrick, a hotel-keeper at 

 Glasgow, which, by a slight modification, may be 

 caused to meet the case perfectly. The respirator, 

 with its back in part removed, is shown in fig. 4. 

 Under the partition of wire-gauze q r, is a space in- 

 tended by Mr. Carrick for ' medicated substances,' and 

 which may be filled with cotton-wool. The mouth is 

 placed against the aperture o, which fits closely round 

 the lips, and the filtered air enters the mouth through 

 a light valve v, which is lifted by the act of inhalation. 



