APPENDIX. 



Alcohol. The most important of all reagents. It can 

 be purchased, tax-free, by incorporated institutions upon 

 the fulfilment of certain conditions.* As it comes from 

 the distiller it is usually about 95$ alcohol, the rest being 

 water. This is too strong for most purposes, and for the 

 preservation of material it should be reduced to 70$ by the 

 addition of water. 



Specimens for dissection should be kept in 70$ alcohol, 

 but in putting them up a weaker grade (50$) should be 

 used first, and this should be changed every day or two at 

 first. Plenty of alcohol should be used, otherwise the 

 specimens will spoil. 



Instead of alcohol for preservative purposes, other solu- 

 tions are sometimes used with fairly good results. Among 

 these may be mentioned : 



Formol. This is a 40$ solution of formaldehyde, and 

 for use this should be reduced by addition of water to a 

 2$ solution (i.e., 1 part formol to 49 of water), in which 

 specimens may be kept in good condition for some months. 

 The same care must be exercised as with alcohol to 

 change the fluid frequently while hardening the specimens. 

 Formol has the disadvantage of evaporating readily, and 

 so the jars must be tightly sealed. It also has the disad- 

 vantage of freezing. 



* These may be learned by application to tlie Collector of Internal 

 Revenue in any district in the United States. 



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