24! A FERN BOOK FOR EVERYBODY. 



papers in which specimens are being dried at least four 

 times during the first week ; some persons change them 

 dailj. After the first week, if placed between the folds 

 of a fresh dry sheet of paper once a week, and kept under 

 a moderate pressure for a month, the drying process may 

 be considered complete. JSTo specimen should be tl'ans- 

 ferred to the herbarium in less than a month from the 

 time of its being collected. 



There is one small caution which must not be forgotten. 

 A specimen should never be put under pressure to be dried 

 without being accompanied by a small scrap of paper, on 

 which is written the locality where the specimen was col- 

 lected, and the date of collection. A name can be added 

 at any time, since the specimen itself wiW furnish the data 

 from whence this may be determined ; but it will be impos- 

 sible to furnish localities and dates with any precision at 

 a future occasion, and upon the accuracy of these much 

 of the value of the specimen will depend. 



Before the specimen is permanently transferred to the 

 herbarium, it should be 'poisoned, to prevent its injury or 

 destruction by mites and other predacious little pests. A 

 small quantity of finely powdered corrosive sublimate — 

 about as much as will lay on a fourpenny piece is suffi- 

 cient — should be put into a bottle containing 4 oz. of 

 spirits of wine, and permitted to stand for a day or two, 

 shaking the bottle occasionally in the interim. With a 

 small brush this solution should be brushed all over each 

 specimen on both surfaces, and then, when thoroughly 

 dried, it may take its proper place in the herbarium. 



Opinions may vary as to many of the minor details of 

 a herbarium ; but, at the risk of not pleasing every one, 

 we will present a scheme for the construction and main- 

 tenance of a herbarium of British ferns. 



The paper on which the specimens are to be mounted 

 should not be too thin : a good cartridge paper will answer 

 every purpose. The standard herbarium size is about 18 

 by 11 inches. This is as large as any one could desire. 

 Each species, at least, should have the whole of a sheet 

 devoted to it. The larger ferns will require a separate 



