AMOUNT OF ALCOHOL REQUIRED. 121 



Ligaments, bones, and cartilages should be placed in 42-55 per 

 cent, for two days, and then kept in 22-30 per cent. 



When the same specimen contains two or more of these kinds of 

 organs, the strength of the alcohol should be adapted to the more 

 perishable, provided these latter are to be fully preserved. 



For injection into the viscera or abdomen, 52-67 per cent. ; for 

 arterial injection, 84-95 per cent., is to be preferred, but any 

 strength above 30 per cent, would be of some service. 



While hardening, specimens should be kept in a cool place. 



287. Fresh Specimens should not be in contact with the sides 

 of the vessel. In order that all parts may be reached by the alco- 

 hol, the specimen should be suspended so as to hang freely, or cot- 

 ton or "excelsior" interposed between the jar and parts which 

 would be in contact with it, or the specimen jar laid upon one side, 

 and shifted daily for a week, so that no part of the specimen is in 

 contact for more than 24 hours. With well-preserved specimens, 

 this precaution need not be observed. 



288. Flexible Specimens. If it is desirable that flexible spe- 

 cimens should harden without contortion, they should be suspended 

 from the cover of the jar, or the jar itself laid upon the side, as sug- 

 gested in 287 ; it is safer to place the jar upon a tray. The mouth 

 end should be slightly raised and very securely closed. 



289. Amount of Alcohol Required. AVith fresh specimens the 

 alcohol should not be less than twice the volume of the specimen. 

 The results are more satisfactory if the ratio is as 4 : 1. The smaller 

 amount may be more safely used with specimens when alcohol has 

 been injected into the arteries ( 286). 



A. Specimens which have been once saturated with alcohol may be stored or placed 

 on exhibition in the minimum quantity required to cover them ; in this way a single jar 

 or can may hold a large number of specimens. But fresh or partly preserved specimens, 

 especially of viscera, should have plenty of space and abundance of alcohol. Neverthe 

 less, experienced collectors are sometimes led to fill a jar with fresh specimens, in the 

 hope, apparently, that the inevitable laws of decay will be overruled in their favor. In 

 most cases, a single well-preserved specimen is of more value to science than ten which 

 have been insufficiently cared for. What is worth preserving at all is worth preserving well. 



B. With museum specimens, and for exhibition, the odor of the alcohol is less impor- 

 tant ; but the clearness and strength are essential. 



C. Old alcohol, whether filtered or not, may be used for storage, and for the pri- 

 mary treatment of some fresh specimens. 



290. Provisional Preparations. It is not always possible or 

 even desirable to make the final preparation of a part upon a fresh 

 specimen, or immediately upon the reception of 'one in alcohol. In 



