I have this data set using R that I named c and I have to take the standard deviation of the first 10 rows, my code I used was sd(c[1:10]) and I keep getting error in is.data.frame(x) : (list) object cannot be coerced to type 'double'

What am I doing wrong? Thanks

crim zn -indus chas nox rm age dis rad tax ptratio black Istat medv 1 0.00632 18.02.31 0.0 7.07 0.0 7.07 0.0 2.18 0.0 2.18 0.0 2.18 7 0.08829 12.57.87 8 0.14455 12.57.87 9 0.21124 12.57.87 10 0.1700412.5 7.87 11 0.22489 12.57.87 12 0.1174712.5 7.87 13 0.09378 12.57.87 0.0 8.14 0 0.5380 6.575 65.2 4.0900 0 0.4690 6.42178.9 4.9671 0 0.4690 7.185 61.1 4.9671 0 0.4580 6.998 45.8 6.0622 0 0.4580 7.14754.2 6.0622 0 0.4580 6.43058.7 6.0622 0 0.5240 6.012 66.6 5.5605 0 0.5240 6.172 96.1 5.9505 0 0.5240 5.631 100.0 6.0821 0 0.5240 6.004 85.9 6.5921 0 0.5240 6.377 94.3 6.3467 0 0.5240 6.009 82.9 6.2267 0 0.5240 5.88939.0 5.4509 0 0.5380 5.949 61.8 4.7075 1 296 15.3 396.90 4.98 24.0 2 242 17.8 396.909.14 21.6 2 242 17.8 392.83 4.03 34.7 3 222 18.7 394.63 2.9433.4 3 222 18.7 396.905.33 36.2 3 222 18.7 394.125.2 28.7 5 311 15.2 395.60 12.43 22.9 5 311 15.2 396.90 19.15 27.1 5 311 15.2 386.63 29.9316.5 5 311 15.2 386.71 17.10 18.9 5 311 15.2 392.52 20.45 15.0 5 311 15.2 396.90 13.2718.9 5 311 15.2 390.50 157 21.7 4 307 21.0 396.908.26 20.4 2 0.02731 3 0.02729 4 0.03237 5 0.06905 6 0.02985 14 0.62976