FIELD T-2 

 Columns 58, 59, 60, and 61 



In programming a retrieval of toxicity data from the punched card files, the CBCC invariably 

 makes the initial sort on the basis of taxonomy. In other words, instead of removing from the files all 

 cards coded with "death" in Field T-2 and subsequently sorting for the organisms relevant to the corre- 

 lation study, the cards are removed which have coded on them the organisms desired and from these 

 are sorted the cards coded with "death" in Field T-2. Thus, the coding distinction that the two groups 

 of symbols is intended to make in Field T-2 (11-- vs. 18-- and 17--) has so far proved to have little 

 retrieval value and whatever advantage it may pretend is outweighed by the confusion it has caused 

 coders. 



For these reasons, it is suggested that, for a new coding project, consideration be given to 

 coding "death" caused by the test compound (or secondary compound) by only a single set of symbols 

 (i. e. , death of all vertebrates, invertebrates, and plants), except that lethal effects on pathogenic 

 organisms in the living host (representing a specific disease) should probably continue being coded as 

 one of the ameliorative effects on pathology (i.e. , with the 17-- symbol series) and lethal effects on 

 populations of special taxonomic groups should probably be coded separately, as the 13-- symbol series 

 does for arthropod infestations of living hosts, when the nature of the information collection indicates 

 it would be an advantage. 



5. Symbols 11, 111, and 112 are never used with Symbol 3 of Field T-l to code prevention of 

 death; only Symbol 7, 8, 9, or A of Field T-l may be used with death coded in Field T-2 



Chemical tests on biological systems may involve "death" (considered as a biological state) 

 caused by agents or conditions other than the test compound or secondary compound. In such tests, 

 the test compound or secondary compound may be administered as a preventive to the state of death 

 caused by pathologies which in turn were caused by agents or conditions other than the test compound 

 or secondary compound. 



According to its definition, Symbol 3 of Field T-l can be used to code the test compound's pre- 

 vention of either a naturally occurring process or a pathological symptom coded in Field T-2. HOWEVER, 

 its definition also stipulates that Symbol 3 is never used by the CBCC to code prevention of death 

 (Symbols 11, 111, 112, and 1812). The coding of effects on death due to pathology (e.g., hastening 

 or delaying death) is accomplished only by use of symbols of the 16-- and 17-- series of Field T-2, 

 as explained in Divisions 9 and 13. As a consequence, the restriction is placed on Symbols 11, 111, 

 112, and 1812 that they are used only for coding death caused by the test compound or secondary 

 compound, and only Symbol 7, 8, 9, or A of Field T-l may be used to code this. Symbols 1 and 2 of 

 Field T-l are never used with Symbol 11, 111, 112, or 1812, because the increase or decrease of death 

 in an individual (or in a colony of microorganisms, regarded collectively) is not reasonable; death can 

 only be "produced" (Symbol 7 of Field T-l) in an individual. In a group of individuals (or a group of 

 colonies of microorganisms), increase or decrease of death would describe the test compound's effect 

 on an existing death rate due to a factor other than the test compound; if this other factor is a secondary 

 compound, the test compound's effect on that death rate (incidence) caused by the secondary compound 

 would be coded by Symbols 8, 9, or C instead of Symbols 1 or 2; if the other factor were any other 

 pathology than a secondary compound's effect, the test compound's effect would be coded as preventing 

 death (permitting survival) of a percentage of the group of individuals (or colonies of microorganisms), 

 using Symbol 1754 (or 1711, 172, or 1752) of Field T-2, rather than Symbol 1 1, 111, 112, or 1812. 



6. Symbols 11, 111, and 112; explanation for coding such effects as death as 

 STATES (Field T-2) CAUSED (Field T-l) 



With certain of the Field T-2 items, the use of Field T-l (or at least the use of two fields, T-l 

 and T-2) may appear unnecessary and seem to represent a redundancy. The items particularly con- 

 cerned are a few of those which, by their nature, can be "caused" by the test compound or secondary 

 compound. Thus, such states as death (Symbols 11, 111, 112, and 1812), relief (symbols of the 13-- 

 series and 17-- series), exacerbation (symbols of the 16-- series), irritation (Symbol 1131), dehydration 

 (Symbol 875), and discoloration (Symbol 416), when caused by the test compound could be expressed in 

 English adequately merely by saying that the test compound "kills", "relieves", "exacerbates", "irritates' 

 "dehydrates", or "discolors". 



It will be observed that this is not the case with most Field T-2 states, however. Most of the 

 Field T-2 states can be expressed in English as having been caused by (1) specifically naming the 



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