M 13.1-M 22.1 MOUNTING MEDIA 637 



13.1 Zirkle 1940a 20540b, 15:142 



formula: water 60, acetic acid 50, dextrin 10, sorbitol 10, ferric nitrate 0.5, carmine 0.5 

 preparation: Dissolve dextrin in water. Add other ingredients in order given. Boil, 



cool, and filter. 

 note: See also M 11.1 and 12.1 Zirkle 1940. 



13.1 Zirkle 1940b 20540b, 15:144 



formula: water 55, acetic acid 55, sorbitol 5, pectin gel 10, levulose syrup 10, ferric 



nitrate 0.5, carmine 0.5 

 preparation: Mix all ingredients except pectin. Leave some days. Filter. Incorporate 



pectin. 

 note: The original calls for Certo brand pectin and Karo brand levulose syrup. 



M 20 Mountants Miscible with Alcohol 



Media of this tyjDe, into which objects may l^e mounted directly from alcohol with- 

 out the necessitj^ of clearing, fall into three classes. In the first class (M 21) are the 

 media based on gum mastic; in the second (M 22) are the media based on Venice 

 turpentine. Both these media are regularly used for objects which are considered too 

 delicate to withstand the action of a clearing agent. The third class (M 23), containing 

 the gum sandarac media, comprise those formulas which are usually referred to as 

 neutral mountants. These are widely used both for substances wliich are considered too 

 delicate to preserve in Canada balsam, which involves prior clearing, or for sections 

 which have been stained in mateiial which fades rapidly under the influence of acid 

 balsam. Many are derived from the original euparal of Gilson, the formula for which 

 has never been disclosed and which is a preparatory substance of secret composition. 

 These media have a refractive index much lower than the gum mastic or gum turpentine 

 media so that the}^ cannot satisfactorih- be used for thick objects. It may be pointed 

 out that "dry" Canada balsam is soluble in absolute alcohol and has from time to time 

 been recommended. It is the writer's experience that this solution is not satisfactory, 

 for mounts made with it darken more rapidh' than those made from balsam which has 

 been dissolved in hydrocarbons. 



21 GUM MASTIC MEDIA 



21.1 Formulas 



21.1 Artigas 1935 13461, 10:71 



formula: 95% ale. 100, gum mastic 30, beechwood creosote 100 

 preparation: Dissolve gum in ale. Centrifuge or filter. Add creosote and evaporate till 



no ale. remains. 

 recommended for: nematode worms after clearing in creosote. 



21.1 Hoyer 1921 6630,84:814 



preparation: Suspend mastic in a cloth bag in a considerable volume of 95% ale. 

 Withdraw bag in which remain gross impurities. Shake solution thoroughly, allow to 

 settle, and decant clear solution. Evaporate to required consistency. 



22 VENICE TURPENTINE MEDIA 



22.1 Formulas 



22.1 Langeron 1942 Venice turpentine-alcohol Langeron 1942, 654 



preparation: Dilute crude Venice turpentine with an equal volume of 95% ale. Mix 

 well and allow impurities to settle. Decant and re-evaporate to convenient consistency, 



22.1 Vosseler 1889 23632, 6:292 



formula: 95% ale. 50, Venice turpentine 50 

 preparation: Mix ingredients. Allow to settle. Decant. 



