KESULTS OF ANALYSES. 39 



Of the 72 samples examined, 8, or 11 per cent, contain more than 

 .01 grain of arsenic per square yard; 8, or 11 per cent, contain 

 "between 0.004G and 0.01 grain per square yard; 33, or 45.8 per cent, 

 contain less than 0.0046 grain per square yard, and 23, or 32 per 

 cent, contain none. The presence of large amounts of arsenic does 

 not seeni to be confined to any particular class of goods, since those 

 containing the largest amounts include calicos, cashmeres, outing- 

 flannels, ducks, mohairs, and flannelets. It does seem, however, 

 that certain colors are more apt to contain arsenic than others, 

 namely, black, red, and grepn. 



Goods colored with anilin dyes are apt to contain small amounts of 

 arsenic for several reasons : 



(1) In preparing the dyes and substances from which the dyes are 

 made arsenic acid, as well as sulphuric, nitric, and hydrochloric acids, 

 and other compounds apt to contain arsenic, are used. Some of the 

 arsenic will remain in the dye unless it is carefully purified. 



(2) Some dyes are sold in the form of a paste, which is preserved 

 by the use of arsenious oxid. 



(3) Substances used as assistants, fixes, or mordants in the dyeing 

 process may contain arsenic, either as an accidental or as an inten- 

 tional ingredient. 



Sodium phosphate and turkey-red oil are examples of substances 

 which may contain arsenic as an accidental ingredient because of 

 their method of manufacture. In dyeing turkey-red cloth sodium 

 arsenate is often used as one of the constituents of the bath. Natu- 

 rally red-colored goods are extremely apt to contain arsenic, since 

 they are most often colored with magenta (sometimes made by the 

 action of arsenic acid on anilin) or its derivatives. It is more diffi- 

 cult, however, for authors who are not familiar with the details of the 

 various processes used in dyeing to understand why black and green 

 goods should contain more arsenic than those of other colors. On 

 looking over the methods of preparation of a number of the black and 

 green dyes it was found that most of them were prepared either from 

 anilin or from its direct derivatives or by treating certain organic 

 compounds with sulphuric acid. These two facts help to explain the 

 presence of arsenic, since both anilin and sulphuric acid are apt 

 to contain small quantities of arsenic because of their method of 

 manufacture. 



It is difficult to make a comparison of the results given in Table 

 VII with those obtained by Hills in 1891 because of the different 

 methods of expressing the results and carrying out the work, but it 

 can at least be seen that articles of dress .nave improved to a great 

 extent in regard to their arsenic content, since when Hills examined 

 prints and ginghams he found over 20 per cent containing more than 

 0.05 grain per square yard, while now only 11 per cent of all dress 

 goods examined contain more than 0.01 grain per square yard. 



