112 



iriitant for all mucous membranes, care has to be taken in its 



use. 



c. Salt. — Should other fluids fail, a concentrated solution of 

 salt makes a fair substitute. If fairly concentrated it answers 

 Avell for succulent fruits or stems and similar objects, jjrovided 

 care be taken that they are completely immersed in it. 



Unless the collector enjoys special facilities for trausport, con- 

 siderations of space and weight will be very imjoortant and the 

 receptacles will have to be selected so that they pack well. Tubes 

 of two lengths (in the proportion of 1:2) and diameters from | to 

 5 in. and jars from 2 to 5 in. wide will generally be found to 

 answer in most cases. The tubes should be provided with well- 

 fitting cork stoppers, the jars with such patent lids as are 

 used for liquid preserves. Spirit and formaldehyde may be 

 carried in glass, earthenware or metal vessels, but salt and water 

 can only be used in glass or earthenware receptacles. 



The specimens should always be wrap])ed first loosely in soft 

 paper and tied round with thread, with a label placed inside. 

 Otherwise they will get mixed up and injured in transport. The 

 fuller the vessel the better, as the little parcels will thus be kept 

 in position, but it will be advisable to distribute the speciniens, 

 so ^ that light specimens are not placed together with heavy 

 objects. Large succulent fruits or stems need, as a rule, only 

 be immersed for a few days in spirit or formaldehyde, and can 

 then be packed up in sawdust, moistened with the same fluid in a 

 well-closing box or tin, and posted home at the first opportunity. 



Schweinfurth's method.— The method invented by the famous 



traveller and collector, Dr. G. Schweinfurth, consists of the 

 combination of preservation in spirit or spirit vapours and sub- 

 sequent drying. The plants are laid into folded sheets of paper 

 or on single sheets of paper as if they were intended for imme- 

 diate drying, the sheets being ])iled up'without "dryers " between 

 them, and then tied fairly tightly into bundles 2 to 3 ins. thick. 

 The bundles are then put into a tin and saturated with spirit, 

 after which the tin is soldered up. The vapours forming in the 

 hermetically sealed tin are quite sufiicient to preserve the speci- 

 mens for a long time. When the tin finally reaches home the 

 speciniens are dried in the ordinary way. It is obvious that this 

 process has great advantages, but on the other hand it is more 

 ex])ensive and adds to the difficulty of transport. During a 

 prolonged rainy season when no fires are available for drying, 

 or in cases where the collector has not the time to attend to 

 the sometimes laborious process of drying, or when he travels 

 in boats where there is no accommodation for drying his papers, 

 and hi other similar circumstances, -this method may be the only 

 possible w-ay of preserving specimens. The tins should be about 

 1 in. wider and about l in. longer than the paper, whilst the 

 depth may vary from 6 to 8 in. If they are much deeper they 

 will get too heavy, or bv the time they have to be closed and 

 soldered up there may not be enough material to fill them. The 

 tins must be open at one end, which should be provided with flaps 

 prepared for the soldering. These flaps should project about 1 in. 



