970 



as early as the following year D. Plks was able to show analyti- 

 cally that the secretions in djaliwood consisted chiefly of calcium- 

 phosphate (analysis 1) '). Abel, who with the same object examined in 

 1862 the concretions in teakwood, ariived at a fairly similar result. 

 (Analysis II) '). 



The experiments of either, however, did not prevent Winkklmann 

 from asserting J 6 years later: "Im Holzpaienchym sieht man kürzere 

 rait oxalsaurem Kalk*) und langere mit Lnft oder Harz angefiillte 

 Zeilen. Kieselsanre ist durch die ganze Holzmasse verbreitet ^). 



We owe the latest analyses of concretions that have come to my 

 knowledge to G. Thoms. The results were very similar to those of 

 his predecessors, so that he felt justified in saying that they were 

 composed of an aqueous calciumphosphate expressed in the formula: 

 2CaH, HH,PO' + Xaq ^). 



I have been induced to make a new experiment by samples of 

 concretions, for which I am indebted to the kindness of Dr. H. C. 

 Prinsen-Geerligs, then of Kagok Tegal. The samples are elongated, 

 more or less angular, to a length of 50 cm. and of ±z 7, to 1 cm. 

 diameter, the weight not exceeding 5 grms"). They evidently originate 

 from hollows that run parallel to the long axis of the stem and 



^) Onderzoek naar de samenstelling eener witte stof, welke zich in het hart, 

 alsmede in de scheuren van sommige djaliboomen afzet, waarom de boomen bij 

 de Inlanders den naam van Djati-Kapor dragen. Nat. Tijdschr. Ned.-lndië, 15, 

 Batavia 1858, p. 345—348 (extract: Examen d'une matière blanche inorganique 

 dans l'inlérieur du tronc de l'arbre djati a Java. Journ. de Bolan. Neérl. 1, 

 Amsterdam-Utrecht 1861, p. 135 — 136. 



2) J. S. Gamble, A Manual of Indian Timbers, 2d ed. London 1902, p 533. 



3) Julius Wiesner (Die RohslofTe des Pflanzenreiches 2, Leipzig 1903. 2te Aufl. 

 p. 1005) was mistaken in presuming that G. A. Blits also has assumed the 

 presence of calciumoxalate. 



*) Fremde Nutzhölzer, Die Natur. Halle a,S. 1878, p. 93. — Carl Sanio was 

 the fust to record something about the anatomical structure of Tectona grandis 

 (Vergleichende Untersuchungen iiber die Elementarorgane des Holzkörpers, Bot. 

 Zeitung 21, Leipzig 1863, p. 110—111), J. W. H. Cordes (De Djati-bosschen op 

 Java, Batavia 1881, p. 22—26, pi. Ill, fig. 1, 2) and G. A. Blits (De anatomische 

 bouw der Oost-Indische Ijzerhoutsoorten en van het Djatihout. Buil. van het 

 Kolon. Museum te Haarlem, 19, Amsterdam 1898,. p. 48—50, pi. VI) gave fuller 

 descriptions. The latter was in a position to see the phosphate secretions as 

 fillings of the vessels. 



•) Beitrag zur Kenntniss des Teakholzes {Tectona grandis). Die Landwirtsch. 

 Yersuchsstationen 23, Berlin 1879, p. 68—69, 416—417). 



6) Similar concretions may appear like fine dust, scattered in the wood as white 

 powdery, circular or irregular particles. On the other hand they may far surpass 

 as to size and circumference any known secretion in the vegetable kingdom. 

 W. J. Spaan has observed concretions of an arm's thickness. (Aanteekeningen over 



