the ash and protein contents of pneumafil (pn) trash samples collected in a model card room and of the aqueous extracts of these samples are reported. the average ash content of these samples is 12. 5 ( $sigma$ $equals$ 4. 2). the average ash content of the dried aqueous extracts of these samples is much higher than that of the raw samples (mean 36. 9, $sigma$ $equals$ 10. 8). the average protein content of these samples and their dried aqueous extracts are about the same (13. 2 and 14. 9, respectively). trash samples from cotton grown under dry, arid conditions tend to have relatively high inorganic contents. increasing the number of gin lint cleaning stages reduces the dust level in the card room but has little effect on the proximate chemical compostion of the pn samples the fraction of ash in the pn dust tends to increase as the grade of cotton improves. respirable dust collected from an electrostatic precipitator and respirable dust separated from lint trash are shown to have very high inorganic contents (41. 3 and 37. 1, respectively) . 12 refs