[Page 118] Chapter IV Toxio Substances and Methods of 



Eliminating Them 



Seotion 1 TOxic Substances 



The following is a discussion of what we were able to learn concerning the 

 toxio substances in the various poisonous fishes recorded in preceding sections. 



Previously Yasukawa (op. cit.) experimented on the assumption that the 

 poison was bacterial in nature, and reported negative results. 



Matsuo expressed the opinion that it was similar to the poison found in 

 betraodonts * 



In the various experiments with animals reported in Chapter III of this 

 paper, the strength of the poison was not in most cases affected by heating at 

 100 C for 20 minutes. Furthennore, in the experiments with extracts reported 

 below it was clear that the poison persisted in preparations made with absolute 

 iloohol. From these facts it is not difficult to deduce that the poisons in the 

 various species discussed in this paper are chemical in nature. 



Since the chemical analysis of this poison was not the main objective of 

 the present study, the author, as explained below, merely experimented to find a 

 uethod of making extracts of the poison, as necessary in eliminating it, and 

 also to discover methods of transporting material from the field for later study. 



Facilities and supplies for chemical experiments were almost unobtainable 

 In the field, and our preparations were inadequate, consequently, except in a 

 very few cases, we preserved the materials and performed our experiments in 

 Japan. 



[BsLge 119] Seotion 2 Location of the Poison and Changes 



Resulting from Preparation for the Table 



Let us consider the localisation of the poison in the body of the fish. In 

 feeding experiments with animals the author tested each organ, insofar as they 

 could be divided. The muscle tissues, t^o, were tested in various sections and 

 an attempt was made to compare their effect. 



No definite results were obtained from these experiments, that is, we could 

 not detect anything like the limitation of the poison to any particular organ. 

 In Idle case of the blood, ovaries, liver, and so forth, because the materials 

 were given by mouth, the amounts eaten varied, and consequently the effect also 

 varied. Comparing these organs with the mviscle tissue, in most cases the latter 

 was eaten in larger quantities and, contrary to expectation, produced more 

 clearly marked poisoning. It should also be noted that most of the reported 

 cases of accidental poisoning resulted from eating muscle tissues. 



From this it is clear that muscle tissues taken from the fish and prepared 

 for the table in the most ordinary manner vdll contain poison. It may be imagined 

 that such material will still have blood remaining in the capillaries. If the 



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