PUPIL AND SCHOOLROOM EQUIPMENT 465 



and 15 grams of zinc chloride. These are mixed together 

 until thoroughly dissolved. Open preparations well before 

 placing them in the liquid and use about twenty times the 

 volume of the object to be preserved. 



To keep fresh dissections. — For materials which are 

 dissected fresh and must be kept over for several days in 

 a fresh condition add a few drops of carbolic acid to the 

 water which covers them. Carbolized water (2 per cent 

 in water) will preserve a great many tissues for a long time. 

 Hearts will remain for years in a supple condition in this 

 solution. 



Obtaining marine animals, microscopic preparations, 

 etc. — For schools not on the seashore the marine animals 

 such as starfishes, etc., which are to be dissected or examined 

 as examples of the branches to which they belong must be 

 obtained as preserved specimens from dealers in such supplies. 

 Among such dealers on the Atlantic coast are the Marine 

 Biological Laboratory, Woods Holl, Mass.; F. W. Walm- 

 sley, Academy of Natural Sciences, Philadelphia, Pa.; and 

 and C. S. Brimley, Raleigh, N. C; on the Pacific coast, 

 the Supply Department, Hopkins Seaside Laboratory, Stan- 

 ford University, California. Ward's Natural Science Estab- 

 lishment, Rochester, N. Y., and the Kny-Scheerer Co., 

 New York City, supply almost any biological specimens 

 asked for. These establishments furnish ready made 

 dissections and sets illustrating Hfe-history and meta- 

 morphosis. The few permanent microscopic preparations 

 which are mentioned in the book as desirable to have 

 can be made by the teacher if he has had any training 

 in microscopical technic. If not, they may be bought 

 cheaply, of such dealers in natural history supplies as the 

 Bausch & Lomb Optical Co., Rochester, N. Y.; the Kny- 

 Scheerer Co., 17 Park Place, New York City; Queen & 

 Co., loio Chestnut Street, Philadelphia, Pa., and numerous 

 others. From these dealers also can be bought all of the 

 laboratory suppHes, such as lenses, slides, cover-glasses, 

 dissecting-scalpels, scissors and needles, etc., mentioned in 

 this book. 



