564 General Notes. [September, 
that true wool can be reliably detected by the microscope in mixtures 
where it occurs. The kinds of hairs observed and described by the com- 
mission, may be conveniently arranged in three groups. First, wooly 
hairs. These mostly extend “from half an inch to several inches in 
length, without any medulla, and without perceptible taper. They pre- 
sent (especially in the wool of the sheep), at frequent but irregular in- 
tervals, well-marked, one-sided, more or less spirally arranged thicken- 
ings of the cortical substance, which gives to the wool its curly charac- 
ter. The mean diameter of each hair varies from 5}, to the oyy of am 
inch, or even less; and the scales of the cuticle are so arranged that their 
free edges project somewhat, forming well-marked imbrications, of which 
usually from fifteen to thirty can be counted in the +}, of an inch.” 
Such hairs constitute the wool of commerce, originally limited to the 
sheep but now applied to the goat, camel, and llama, and similar hairs 
have long been known to be mixed with the straight hair of various ani- 
mals, such as the “deer, hare, rabbit, beaver, otter, seal, lion, tiger, cer- 
tain varieties of dog, and some foreign breeds of oxen.” | these hairs 
are so much alike, structurally, that it is believed they should all be des- 
ignated as wool, and it is not claimed that the animal from which they 
were derived can be uniformly and reliably determined by the micro- 
scope. Obviously some of these varieties not now recognized as W00 
might in the future become of sufficient commercial importance to require 
either the legalization of them all as “ wool,” or the discovery of more 
complete methods of discrimination. Second, straight hairs. These are 
often shorter, “ much thicker at their base, and taper rapidly towards the 
point. The medulla occupies a large proportional part of the whole 
hair, and the free edges of the scales of the cuticle, which are so disposed 
as to form from twenty to forty imbrications to the ria of an inch, lie 
quite smoothly upon the surface of the hairs, so that their contours, 4 
seen under the microscope, closely approximate continuous lines. These 
characters are so well marked that the coarser hairs of the cow and calf 
can readily be distinguished from the woolly hairs of any of the wool- 
bearing animals.” Naturally mixed with the wool of the sheep, how 
ever, especially with the inferior grades, and with that of the goat, form- 
ing the “outer coat” of the goat, are coarse, straight hairs, 50 close 
resembling some of the hairs of the cow or calf that their discriminatio? 
presents great difficulties; and such hairs, even when derived from the 
wool-bearing animals, cannot be recognized as wool by the microscop® 
The percentage of “wool,” therefore, as determined in mixed fabrics; by 
a microscopical count of hairs, would probably be underrated in & certain 
proportion of cases. In case all woolly hairs which are “more ue 
crispy, curled, or frizzled ” should be legalized as wool, it would aon 
be convenient to make an exception, admitting as genuine wool sue" 
percentage of straight hairs as is found to be present ina specified sit 
of the sheep’s coat. Third, doubtful hairs. Among the imbricated ha! 
