224 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1918. 



mass." An absorbent pad of sphagnum will continue to suck up 

 fluid discharges until it is pretty uniformly saturated throughout, 

 whereas a cotton pad ordinarily ceases to function long before its 

 theoretical capacity has been reached. 



5. When properly made, not only are sphagnum dressings fully 

 as soft as those made of cotton, but, owing to the loose, open struc- 

 ture of the moss, they are cooler and less irritating to the patient. 



6. In times of emergency, sphagnum can be procured more cheaply 

 than cotton. Being a product of nature, all that is necessary is 

 to go and gather it, and with an abundance of volunteer workers 

 available, practically the only expense involved is the cost of trans- 

 portation. 



Now, in ordinary hospital work, as Professor Porter has pointed 

 out, the comparative inferiority of cotton as an absorbent is not of 

 any great consequence. Here, for the most part, the wounds are 

 the result of operations, and they are made by the surgeon himself. 

 They are comparatively slight, and, what is particularly import- 

 ant, they are perfectly sterile. Discharging wounds are exceptional. 

 For ordinary surgical work it is doubtful wdiether sphagnum pos- 

 sesses any special superiority over cotton, if indeed, all things taken 

 into account, it is equal to it ; and it therefore seems improbable that 

 the sphagnum dressings are destined to come into general use, now 

 that the war is over, except, perhaps, for special purposes. In war- 

 hospital practice, however, conditions are very different, for here 

 every wound may be taken as infected ; discharging wounds are the 

 rule, not the exception. Furthermore, " the methods of treatment 

 recently so successfully developed by Carrel, Dakin, Wright, and 

 others deliberately increase these discharges to a very great extent. 

 For such cases, unless absorbent dressings are to be done away with 

 altogether, sphagnum is greatly preferable to any other available 

 material." 



KECOGNITION OF SPHAGNUM IN THE FIELD. 



The genus Sphagnum is classed among the mosses. Unlike the so- 

 called " sea mosses," or seaweeds, and the lichens, which are some- 

 times mistaken for mosses, the true mosses are leafy plants. Com- 

 paratively small, seldom being more than a few inches high, and 

 growing in all sorts of habitats, the mosses are conspicuous chiefly 

 on account of the great masses of vegetation which they commonly 

 form. The sphagnums (pi. 1) include some of our largest and 

 most conspicuous mosses. 



Sphagnum differs from other kinds of moss in a number of im- 

 portant respects. 



First of all, a sphagnum plant seldom exhibits the deep leaf-green 

 color of an ordinary moss. When wet, it commonly is a pale green ; 



