Agricultural bulletin of the Straits and Federated Malay StatesNew series . uct possessing all the irremedi-able drawbacks which above we discussed at some length. On the plantation at Las Cascadas, Calonyction speciosum isvery common, and I ascertained that decoctions prepared from ithave a strongly acid reaction. Therefore, coagulation with such adecoction is simply the wellknown coagulation of solutions of albu-men with acids. I have not been able to discover at Las CascadasIpomoea bona nox. but I very much doubt the highly alkalinecharacter of its juice which it is almost certain to posses
Agricultural bulletin of the Straits and Federated Malay StatesNew series . uct possessing all the irremedi-able drawbacks which above we discussed at some length. On the plantation at Las Cascadas, Calonyction speciosum isvery common, and I ascertained that decoctions prepared from ithave a strongly acid reaction. Therefore, coagulation with such adecoction is simply the wellknown coagulation of solutions of albu-men with acids. I have not been able to discover at Las CascadasIpomoea bona nox. but I very much doubt the highly alkalinecharacter of its juice which it is almost certain to possess likewise adistinctly acid reaction. The treatment with alum, a process due toH. A. STRAUSS, and purchased from him by the local Government ofthe province of Pernambuco, owes its coagulating action entirely tothe strongly acid reaction of that salt. This process is a bad onefrom every point of view. The removal of the alum solution fromthe coagulated rubber is physical impossibility, and the perniciousaction of an alum solution upon the drying rubber is quite sufficient. The following footnote should be inserted on page 170:— * NOTE—Caionyction speciosum and Ipomoea bona-nox, arc thesame thing.—Ed. 1 i7i to render its continued employment most deplorable. The coagula-tion with soap as practised in the Isthmus of Panama is barbarousin the extreme, and it is not surprising that it yields a product ofvery bad quality indeed. Amongst the above-named process I have not enumerated a pro-cess said to be practised in Mexico, and simply consisting in theboiling of the latex in earthen vessels (jacaras). If this process isactually used, it can certainly not be carried out with the fresh latexfor the simple reason that over and over again I have satisfied my-self that even on very prolonged boiling of the slightly diluted latexfurnished by the tree at Las Cascadas no coagulation can be oV>tained. The cause of this is to be found in the fact that the aqueousvehicle of the latex,
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