44 



NATURAL SCIENCE NEWS. 



oft-times tiresome routine work of 

 the school room. But these trips 

 are rarely made and in many cases 

 entirely neglected. In anatomy, 

 dissections should be made on rep- 

 tiles and the smaller mammals; for 

 in addition to observing the expan- 

 sion of the lungs, exemplified as 

 well, in a squirrel, cat or rabbit as 

 in the human cadaver, there is the 

 additional pleasure of comparative 

 study in many parts of the body. 



Not less important are practical 

 demonstrations of the heavens on 

 clear nights by a painstaking in- 

 structor. Although a telescope is 

 a valuable adjunct, it may often 

 be dispensed with when the con- 

 stellations are being studied, for 

 the naked eye is sufficient in defin- 

 ing star-groups. An interested 

 teacher can produce better results 

 by instruction under the star-be- 

 spangled vault; can give a better 

 idea of the course of the moon 

 among the stars, and more lasting 

 impressions as concerns the con- 

 stellations, than is possible from 

 one, no matter how well up in 

 mathematics, who relies on black- 

 board and chalk. Instruction by 

 long rows of figures, often, nay, 

 nearly always, becomes oppressive 

 and distasteful, but a view through 

 a telescope, revealing the satellites 

 of Jupiter cannot fail to have an 

 impression of wonder mingled 

 with awe, which to a thoughtful 

 child or youth tends toward the 

 acquirment of further knowledge. 



One could continue this subject 

 indefinitely. Let us have the 

 sciences in all schools, but as- 

 suredly let us have the elementary 

 branches in science and at the 

 proper time. For if our boys and 

 girls can once get an insight into 

 the work, with the aid of compet- 

 ent teachers, then those who have 

 developed a predilection for the 

 sciences, can and will go on with 

 these pursuits, even if unaided. 



Kalamazoo, Mich. 



Dry Preservation of Anatomical 

 and Other Preparations. 



The preservation of bodies or 

 parts of bodies, without the trouble, 

 expense, etc. , of fluid preservatives 

 has long been the ideal of preserva- 

 tion. In fact the first attempts at 

 preservation of bodies was prob- 

 ably by the "dry process." In 

 ancient times many nations and 

 tribes preserved their dead as 

 mummies. Various processes were 

 used and various results obtained. In 

 America bodies are found which 



were simply dried, e.g: the Alaskan 

 cave mummies. At the other end 

 of the New World, in Peru and 

 Chili, are found bodies which were 

 preserved by drying in the sand, 

 which there contains quite a per- 

 cent of sodium nitrate. These 

 mummies are none of them very 

 life like; being reduced by drying 

 to mere skeletons covered with a 

 yellow parchment-like skin. Also 

 when brought into ordinary climates 

 they show, to most noses, strong 

 evidences of decay. The Egyptian 

 mummies were preserved in various 

 ways and with varying degrees of 

 success; they all resist decay, but 

 they all show a decided shrinkage 

 of the muscles, etc., during pre- 

 paration, and this destroys much 

 of the trueness to life. 



In modern times various process- 

 es of embalmiug are used and most 

 of these try to prevent much of 

 the shrinkage. The underlying 

 principles of modern embalming 

 are thorough permeating of the 

 flesh and viscera by some antisep- 

 tic and hardening agent, and the 

 replacing of the water of the body 

 by some nonvolatile substance. 



The first is generally done by 

 washing out the veins and arteries 

 and then filling them with a solu- 

 tion of some of the various metal- 

 lic salts: notably the chloride and 

 sulphate of zinc, mercuric chloride, 

 arsenious acid, potassium and sod- 

 ium nitrate. Solutions containing 

 one or more of these and other 

 substances are often used. The 

 viscera are also filled with these 

 fluids. Day after day, as these 

 fluids evaporate, glycerine is in- 

 jected into the blood vessels, and 

 the glycerine being nonvolatile pre- 

 serves the plumpness originally 

 caused by the water of the body. 

 Such a process is, however, too 

 tedious and costly for ordinary 

 anatomical and Natural History 

 specimens. 



Articulated skeletons (those with 

 the ligements in place) prepara- 

 tions to show relations of tendons, 

 etc., blood vessels injected with 

 plaster and simular objects may be 

 preserved b}< simply poisoning and 

 allowing to dry. If they are soak- 

 ed in Wickersheimers, fluid, 

 tendons, etc., will retain much 

 of their pliability. 



Formula — Potash alum 100 

 grams, Sodium Chlor. 2og., Salt 

 petre i2g., Carbonate of Potash 60 

 g., White Arsenic 2o-25g. Dissolve 

 by boiling in 3,000 cubic centimet- 

 res of pure water. When cool add 

 1, 500c. c. of Glycerine and 300c. c. 

 of Alcohol. Label Wickersheim- 

 ers Fl. Specimen intended for dis- 



sections only may be kept in this 

 fluid. They become, however, 

 slightly "greasy" to the touch af- 

 ter a time. 



As a whole, however, dry pre- 

 parations of soft parts and whole 

 animals cannot be made which 

 will show a true resemblance to 

 nature because of shrinkage. 



The successful embalming of 

 birds has long been attempted but 

 shrinkage has caused them to be 

 mere caricaturesof living specimens. 

 Dr. Morris Gibbs claims to have 

 found a method by which this is 

 compensated for and good speci- 

 mens obtained. His method will 

 probably be a great boon for those 

 who have never learned the difficult 

 art of Taxidermy. 



There is a process of dry pre- 

 servation used in Europe for the 

 preservation of Brain dissections 

 and of small animals which pre- 

 vents all shrinkage of structure and 

 preserves the histology fairly well. 

 This is known as Giacomini's dry 

 process. 



The tissue is killed and harden- 

 ed in a solution of zinc chloride, 

 Bichromate of Potash 3 per cent, 

 Mullers fluid, 10 per cent Nitric 

 acid, or Alcohol. 



Supposing zinc choride is used. 

 The object is left in this solution 

 until it sinks to the bottom. It is 

 then transfered to commercial al- 

 cohol, ie: 70-95 per cent Ale, for 

 from 10 days to a month. It is 

 then removed to pure glycerine 

 containing 1 per cent carbolic acid, 

 cover the receptacle and leave ob- 

 ject till it sinks below the surface. 

 Then remove it at your earliest 

 convenience and place it on a dish 

 out of the way of dust for a few 

 days till it has thoroughly drained. 

 Then varnish it with a thin solution 

 of India Rubber or with Marine 

 Glue diluted with a little alcohol. 

 Object should be left a month or 

 so in chromic solutions. 



In Nitric acid, 10-12 percent, for 

 10 days. This gives very tough 

 preparations of brains. Objects 

 hardened in chromic solutions or 

 Nitric acid should be thoroughly 

 washed 3 or 4 times in water before 

 placing in alcohol. All dissections 

 should be made before placing in 

 glycerine. 



In general it may be said that 

 objects should be preserved in fluid. 



Dry perservation;, except Taxi- 

 dermy is good only for special 

 cases, and the amateur, unless he 

 has plenty of time and supplies, 

 had better stick to fluid preserva- 

 tion. 



Will C. Hall, 

 Creston, la. 



