ARSENIC IN PAPER-HANGINGS. 319 
expressed by me regarding the probable effects of such papers 
on health* 
Allow me to state that I have not adopted the theory that 
arsenious acid is volatilized in the manner supposed by Mr. 
Campbell. In my evidence before the Lords’ Committee 
(Question 1185), when the question was addressed to me 
respecting the effect of gas in bringing out any portion of the 
poison from the paper, I gave the following answers “ It is very 
difficult to say how the material does get diffused in a room, 
whether by currents of air, or in any other way. I asked a 
very distinguished Prussian Chemist (Pettenkoffer), who was 
over here lately, his opinion (for I see these arsenical papers 
are strictly prohibited irt the kingdom of Prussia), and he 
told me that he thought it was from the mechanical diffusion 
of the dust when the powder was put on the paper in a loosb 
manner. He said he had noticed it on a microscope glass 
which had been kept for some time in a room where there 
was a flock paper : that he had sefen particles of flock which 
were not visible to the naked eye, but which were plainly 
visible under the power of the microscopes” 
That Dr. Halley suffered from such symptoms as are pro- 
duced by arsenic in the chronic form of poisoning, I 
entertain no doubti There was headache, with dryneSs 
and constriction of the throat, nausea, loss of appetite* 
irritation of the alimentary canal, followed in fetv weeks by 
great bodily depression, with symptoms of paralysis affecting 
one side* These are not such symptoms as the burning of 
gas in a room would produce. In other cases in which no 
gas was burnt, the symptoms were similar, and the only 
conceivable source of arsenic was the green paper on the 
walls; 
There is a difficulty in suggesting a perfectly satisfactory 
theory to account for these cases; but there is an equal diffi- 
culty in accounting for the mode in which a person has been 
affected with lead-paralysis* by reason of his having slept in 
a room the walls of which had been freshly painted. I have 
myself suffered from a severe attack of lead-colic and other 
unpleasant symptoms, as a result of breathing the vapours of 
fresh paint spread on a large surface of canvas in a small 
room. I do not believe that a chemist would easily detect 
carbonate or oxide of lead in the air of these rooms ; but 
the fact of lead-poisoning by such insidious means is too 
well established to admit of denial. Poisons find their way 
more readily into the blood through the lungs than through 
any other channel ; and in white-lead factories, until the 
practice arose of grinding the mineral in water, the respira- 
