138 PROGRESS OF MICROSCOPICAL SCIENCE. 



in the article are constructed — built up, so to speak — in different 

 manners, so distinct from each other that a moderate magnifying 

 power, say 400 diameters, of a decently good instrument, will show at 

 once what they are. Anyone with a very little skill in manipulation 

 can obtain the result. The differences have been described and 

 figured in the books, but there is no need of books. Everyone can 

 obtain genuine fibres of either kind, with almost less trouble than 

 referring to a book, for comparison with those found in the fabric, 

 and the original comparison is of far more value than the authority of 

 a picture. No chemical test is known to distinguish flax from cotton 

 fibre ; but their difference in the microscojie may be seen at a glance. 

 Jute fibre has more resemblance to flax, but can be distinguished with 

 a little more study. The materials of paper may also be ascertained, 

 in part at least, by the microscope : for example, your number dated 

 March 15, is printed on paper containing no cotton or linen ; it is 

 mostly wood fibre, with ' pitted ' and ' scalariform ' ducts, not pecu- 

 liar to any kind of wood, with possibly fibres of manilla, esparto, or 

 ramie, of which 1 have not the means of comparison. But the micro- 

 scope cannot do everything. There is a certain fabric in use purport- 

 ing to be made entirely of cows' hair. The question came up ; Is 

 there any sheep's wool in it? This could not be answered. For, 

 while the bulk of each is easily distinguished, there are some hairs 

 from each animal that cannot be loiown from the other. In this case, 

 so far as is known, chemistry is equally powerless." 



The Phthisis Controversy. — Dr. Joseph Coats thus sums up the 

 results of this serious discussion. In the ' Medical Eecord,' June 4, 

 he says, if we now finally ask, " What is the outcome of this discus- 

 sion ? " the answer may be in some respects difficult. It can at least 

 be said, it was agreed by all the speakers that we have in phthisis 

 pulmonalis, besides the ordinary products of inflammation within the 

 lung-alveoli, also a cellular growth in the walls of the alveoli, which 

 cellular growth is variously called lymphoid, adenoid, and reticular 

 growth. The chief discussion was as to whether this growth is 

 to be called tubercular or not ; whether it is a specific new for- 

 mation of a definite anatomical structure, or whether it is simply 

 the result of chronic inflammation. If the discussion has done no 

 more than state this ground clearly, it may not be entirely without 

 result. 



Histological Characters of Two New British Algce. — The following 

 are given by Mr. E. M. Holmes as the microscopical characters of 

 two new British Algse. The pajjer with full details appears in 

 ' Grevillea,' July, 1873. The first is Callithamnion hormocarjmm ; of this 

 the microscopical characters are : articulations at the base of the 

 stem, coated with branched and jointed filaments ; articulation of the 

 plumules, 6-8 times as long as broad ; those of the pinnae four times, 

 decreasing to twice as long as broad ; flexuose and attenuated towards 

 apex of the ultimate pinnules. Pinnules of the pinnae either simple, 

 once forked, or repeatedly forked, and tufted at the apex ; axils very 

 narrow, so that the less-branched pinnules appear pinnate, and the 



