24 
Proceedings of the Royal Irish Academy. 
branchy bits of iron, and a few cotton fibres, which came, no donbt, 
from the artizans' shirts. There were no germs here ; yet the sun- 
beams were full of dancing motes, whose portraits I have given. The 
ray shining on them assumed, in consequence of their hue, a bluish 
colour, similar to that observed when the carbon smoke of a lamp or 
candle is placed in the sunbeam. The magnet attracted the balls and 
carbon, as shown on Plate. 
On entering such an atmosphere the taste of carbon, and indeed 
of iron, may be readily perceived. The dust might serve as a cheap 
stomachic for those who use charcoal biscuits and charcoal and bismuth 
powder. 
I^ffect on Health. — Although a great quantity of this iron, carbon, 
and ash, must daily pass in and out of the lungs, and, besides, although 
a certain percentage must remain, I have rarely found a healthier body 
of men than those who work in such factories. In one case a young 
man, whose lungs were weak, suffered from haemoptysis [blood- spit- 
ting, with cough], which he had contracted in an American brass 
foundry where the heat was excessive. I found him in an air murky 
with these motes, and asked him did it not affect him. He said, no ; 
he found himself well in it ; his cough came on at home on rising and 
lying down. 
Shirt Factory Dust (Plate VIII.). — This is a light-brown dust, in- 
terspersed with visible fibres. It was collected on ledges on a level 
with the breathing of the work girls, observed floating in the air, and 
seen deposited on the heating pipe, about twelve feet high. 
Microscopically examined, the dust itself was found to be com- 
posed of filaments of flax and of cotton, together with minute frag- 
ments of the same of a very great variety of size. There were some 
flat fragments of cotton testa. All the flax and cotton fragments were 
whitish under the microscope, with the exception of a few red-tinc- 
tured particles. There were found in some of the dust, gathered off the 
casements, little eggs, some yj-gth of an inch, and others ^Q^^^th, with 
different sizes between. Some clusters contained large and small eggs, 
thus showing that the same parent may produce different sizes. Some 
were round, others oblong ; they were generally transparent ; a few 
were tawny. As they were found on the window ledges, they can- 
not be regarded as general constituents of the dust. 
The effect of this dust is to make the work girls use snuff. A friend 
told me that, finding a crowd of them clustered round a grocer's shop, 
he observed to the shopkeeper that he presumed they had come for 
their tea. You are mistaken," was the answer, 'tis for their snuff. 
They nearly all take snuff." The reason of this is obvious ; and it is 
fortujiate for them that this fibrous dust is not present in great quan- 
tity. Other workers are less fortunate — cases of embolic phthisis then 
occur. 
Threshing Mill Dust contains fibres and fragments of the grain stalk 
and chaff, together with some smut balls. It would be an injurious 
atmosphere if it were habitually used ; but the season of threshing is 
usually brief. 
