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AN EFFICIENT AND ECONOMICAL 

 HERBARIUM PASTE 



E. D. Merrii-l 



Generally speaking, ordinary types of fish glue have been 

 found to be very unsatisfactory for mounting botanical speci- 

 mens, because, when dry, there is a great tendency for thick 

 leaves, branchlets, etc., to "snap off" as the sheets are handled. 

 This entails considerable loss of valuable material and much 

 extra repair work in any large herbarium; yet curiously, little 

 attention seems to have been given to the matter of selecting 

 adhesives better adapted to the purpose. Aqueous solutions 

 of gum arabic (the best form for use is powdered acacia), or a 

 mixture of gum arabic and gum tragacanth protected against 

 fermentation by the addition of a small amount of carbolic acid, 

 are, generally speaking, more satisfactory than ordinary types 

 of glue. The chief objection to the use of gum arabic or of 

 gum tragacanth is the fact that a certain degree of viscosity is 

 essential to insure the best results, and proper viscosity can be 

 determined only through actual experience. 



About two years ago my attention was called to Special A 

 Tin Paste, manufactured by the Russia Cement Company, 

 Gloucester, Mass. This product was developed primarily for 

 attaching labels to tin cans. A wide experience with this 

 paste, involving the actual mounting of over 30,000 sheets of 

 herbarium material, has demonstrated that it is in general 

 eminently satisfactory for the purposes indicated and is far 

 superior to the ordinary types of glue now generally used. 



The product is one of the inverted starch pastes much thinner 

 than the ordinary library pastes of the same general class. It 

 is low in price, flows readily, has a pleasant odor, and comes 

 in a form entirely satisfactory for immediate use, requiring no 

 thinning, heating, or other treatment. Furthermore, it is 

 durable, does not become brittle, nor weaken, crack, or loosen 

 with age, as do the ordinary types of fish glue such as are cur- 

 rently used in mounting botanical materials. It is available in 

 one-gallon cans, six cans to the case, in five and ten-gallon kegs, 

 and in half-barrels and barrels. It keeps indefinitely. 



