amount of fresh tissue correspondinT to a lethal dos© was 0«75 gr. This cannot 

 pronerly be compared with the dried tissues because the species used Tjere differ- 

 ent, but compared with the lethal dose for the aka.^in f Plectropomus tnjncatus j, 

 and allowin,*^ for shrinka^je in dryin**, it apnears that the toxicity is soiaewhat 

 diminished by this method of preservation. 



U* Preservation in formalin 



Two experiments v»ere made with the tissues of fish which had been 

 TJreserved in 10^ formalin for 9 months as taxonomic specimens. The results are 

 shewn 5n the tabids for Preparations Nos, 5 and 8. There Tins a vjide variation 

 in their toxicity, the Inthal lose for one beinrr 1.2 ^r nnd 0.5 "7 for the 

 other. It is not known vihether one of the specimens nas nashed in water while 

 bein^ mreserved, or whether these results arc due to an individunl variation in 

 toxicity. , 

 CPo-^ 12P] 



Preparations Nos. 2 and B rnd Controls Nos. 6 and 7 lere nade by the same 

 alcohol extraction metho'' and afford an oprortunity to note the difference in 

 toxicity as betvieen species. The aka.lin is in the mildly toxic classification 

 and 2. flav5mar^lnatug 1p stront^ly toxic. Anticipating this difference, vje 

 decreased the amount injected for the latter species, and as a consequence mere 

 unable to ascertain the lethal quantity. It is not clear -vhether the fact that 

 the difference in toxic effect between these two species was not more marked 

 was dtie to some difference in the method of preparation or to individual varia- 

 tions in the fish. The materials used for controls v.ere dried barracuda "pur- 

 chased at Atami in Shlzuoka Prefecture and dried lanqpreyC probably okimekura ) 

 obtained at Odawara in Kanagawa Prefecture. By way of comparison with the lethal 

 quantity of 0.26 f^r determined for the aka^lin. that for the barracuda nas 0.7 gr 

 and that for the mekuraunadl was 0,75 ^. It is vjondered whether these differ- 

 ences can be ascribed to the preservation of the toxic substances contained in 

 the fresh tissues. The dried fish from the South Seas had been kept for 9 

 months, vihile the barracuda had been preserved 2 months and the lair^srey for only 

 a few days. Perhaps similar poisons may have developed in the tissues during 

 preseirvation, but the symptoms observed in these experiments very closely re- 

 sembled those seen in experiments with fresh material. 



A comparison of the methods described above indicates that salting and dry- 

 inw and preservation in formalin are satisfactory. It is thouTht that canning; 

 or bottling would perhaps be best if facilities for conplete sterilization were 

 available. It is regrettable that we v/ere unable to experiment ith this 

 method. It »oe8 .ithout sayinT that it would be best to reduce the poison to a 

 chemically pure and stobilized condition. From the author's experience in the 

 field he believes that the next best thIn'T, in areas where chemicals and faci- 

 lities are lackin'^, is to preserve the mrtorials by salting and drying or by the 

 use of formalin. 

 [TQ<r.e 129] 



Section 5 Elimination of the Poison 



As shown In the preceding section, the poison is easily extracted in water 

 or alcohol and it is difficult to detect any traces of it re.-naining in tissues 

 so treated. This method uorks experimentally, but for practical purposes it 

 would spoil the flavor and make it impossible to eat much of the fish. 



The Japanese fishomen of jaipan remove the poison from mildly toxic species 

 onlv such as the dokuhirna.li f C^^ranx melamoyrus ] and the sazanamihafti 



78 



