380 PHYTO<;KAIMIY. 



rosive sublimate as it will take up. thon add a trifle more of alcohol, 

 so as to keep the solution just In-low tin- point of saturation. 

 The stronger the solution tin- better, except that, at lull satura- 

 tion and where copiou>ly used, an etllorcseence may soinetinies be 

 Id'l on the surface of the poisoned specimens upon the evapora- 

 tion of the alcohol. Some add to the solution some carbolic 

 acid, at the rate of a fluid ounce to each quart of alcohol. The 

 solution may be applied with a soft brush (one with no metal in 

 its fastening), or by a dropping bottle, or even the specimens 

 may be dipped in the solution placed in a flat porcelain dish. 

 The brush (using a pretty large and soft one) is the most con- 

 venient and ellicient. The moistened specimens should be placed 

 betwc-.cn driers and in shallow piles until the alcohol evaporates. 



805. Thoroughly poison all specimens before admitting them 

 to the herbarium. Jt is well to poison all specimens whatever. 

 as soon as they are made or at the close of the botanizing sea- 

 son, as well those intended for exchanges as for the collector's 

 own herbarium. 



806. Keep all specimens between sheets of paper, or within 

 folded sheets, not too crowded or overlaid, away from dust, and 

 in a perfectly dry place, so as to avoid mould. When attacked 

 by mould, the corrosive-sublimate solution should be applied. 

 A properlv dried specimen, duly cared for, should be as lasting 

 as the paper which holds it. 



807. The Herbarium, called by the earlier botanists ffortus 

 Siccns, is a collection of dried specimens, named and systemat- 

 ically arranged. It is indispensable to the working systematic 

 botanist, and every devotee of botany should possess, or have 

 access to an herbarium containing representatives of the plants 

 of the immediate vicinity or district, if not of the whole country. 

 Or an herbarium may be restricted to a particular family of 

 plants, made the object of special study. A general herbarium 

 should contain specimens representing all the natural orders and 

 as many of their genera and species as possible. 



sos. The form of the herbarium as to the size of its sheet- is 

 considerably variable. That of Linna-us is of the si/e of fool-cap 

 paper: this would now be universally regarded as much too 

 small. The principal liritish herbaria adopt the size of 16 by 

 in. 1 , indies, which is rather too narrow, rarely permitting two 

 specimens of the same species of any considerable size to be 

 placed side by side on the same sheet. In the United States, 

 16i inches in length by 1 1 - 4 ! in width is adopted ; that is. for the 

 genus-covers, the species-paper being a quarter of an inch nar- 

 rower. 



