PKELIMINAKY NOTES ON THE CHEMISTKY 01' THE LATEX OK C'ALOTliOl'IK ritOCEHA 93 



received an inoculation corresponding to O'O c.c. latex of tlio filtrate [ (b) Table Bj 

 from animal charcoal, while a foitrth was inoculated with 0'5 c.c. of the water solution 

 of the alcoholic extract [Table B]. In all cases the animals remained quite well, 

 and showed no symptoms of illness. 



With regard to the feeding experiments, the fresh latex was slowly dropped from a 

 pipette into the mouth of the animal. In the first experiments, doses of 005 c.c. and t'ei'dmg 

 03 c.c. were given, but these produced no effect. Larger doses were then tried, 1 c.c. (2) 

 1-5 c.c. (1) and 2 c.c. (2) being given. The rabbits receiving the 1 c.c. doses showed 

 no symptoms. One of the rabbits receiving the 2 c.c. quantity showed, almost 

 innnediately, paresis of the hind legs and died in 20 minutes. Post mortem examination 

 showed slight congestion of the mucous membrane of the stomach, Init no other 

 pathological change. The stomach contents were tested for the presence of tiie latex, 

 and gave a positive result. 



The other i-abl)it receiving 2 c.c, and the one receiving 1'5 c.c, showed no symptoms 

 during the time they were under observation — viz., six hours — but died during the 

 night. A rabbit receiving 2 c.c. of latex which had been digested in boiling water for 

 half-an-hour also died. Post mortem examination showed no pathological change in 

 the organs ; the contents of the intestines were, however, semi-liquid. The stomach 

 contents were tested for the presence of the latex, with a positive result where the 

 2 c.c. fresh latex had been given, and negative results in the case of the 1'5 c.c. fi'esh 

 latex and 2 c.c. boiled latex. 



A rabbit fed witli 2 c.c. of fresh latex, from which the gutta-percha had been 

 removed by coagulation, remained well. 



So far as can be judged from tlie experiments yet carried out, the fresh latex of 

 0. procera is toxic to rabbits when given by the mouth in doses greater than 1 c.c per 

 kilo body-weight. In smaller doses it produces no toxic symptoms whatever. 



The fact that 2 c.c. of boiled latex proved toxic, while 2 c.c. of latex from which conclusions 

 the gutta-percha had been removed, was non-toxic, indicates that the toxic bodies 

 are in all probability the resins or other bodies associated with the gutta-percha, but 

 further experiments are necessary before any definite conclusions can be arrived at. 



I desire to acknowledge my indebtedness to Captain E. G. Archiijald, K.A.^M.C, and 

 Lieutenant W. E. Marshall, E.A.M.C., for their assistance in the toxicological experiments. 



[Editor's note. — The continuation of the above research by Dr. Thompson was 

 unfortunately prevented by his illness and retirement from these laboratories. The 

 extent to which the colour tests mentioned nuiy be relied ui)on in cases of suspected 

 poisoning remains, therefore, to bu determined. Attention should especially be called 

 to the fact that the production of a violet colour on the addition of sulphuric acid 

 containing a small amount of iron constitutes Hehner's test for formaldehyde in milk 

 and that the colour described above as "strawberry" is yielded by sulphuric acid, formalin 

 and peptone. The last named is a common constituent of stomach contents so that the 

 possibility of error from this source nmst be borne in mind, in the presence of proteids 

 and of vegetable matters it may be found that a reaction sinuilating that of the above 

 confirmatory test might be produced, or again tluit the colour due to these might mask 

 that of the latex. These points are now under investigation. In any case, the 

 reactions described are useful presumptive indications of the presence of ushar latex.] 



