10 NEW IXVESTKiATIOXS OX RICKETS AXI> MACROZAMIA. 



tioned later on. The time when the poisonous resin is found in 

 the leaves coincides with the period of flowering and fructifi- 

 cation. The nuts contain a much larger quantity of it than the 

 leaves, and it has heen known long ago that people eating them 

 have been seized with violent vomiting and purging, the 

 symtoms of Gasti'oenteritis, which, in the woi*st cases, was even 

 followed by death. The thick half-subterranean stem contains, 

 like the niits, a large amount of starch besides the poisonous- 

 resin, and it is a very noteworthy fact that the aboriginals have 

 never used for food the starch hoarded in the INIacroaamia 

 stems, whereas they eat everywhere the Hour prepared from the 

 poisonous Colocasia root. 



The poisonous Macrozamia resin must not be confounded 

 w4th the inert gum exuded by the peduncle of Macrozamia cones 

 when freshly cut, which gum also collects in the cavity of the 

 stem when the head of the plant is cut off. The gum has 

 already been analysed by Mv. ]\hxiden. It consists of colourless 

 pearly, tough and hard, tears, and SAvells very much in water, 

 but nothing is dissolved of it, not even if the water is boiled. 

 Diluted caustic potash solution and diluted hydrochloric acid 

 dissolve the gum on boiling. Ferric chloride does not coagulate 

 or gelatinize this solution of metarabin. 



At some times of the year the Macrozamia leaves are alto- 

 gether free from poison. This fact is not astonishing at all, as 

 there are similar instances in this country. Some time ago the 

 author proved that many wattles, like Acacia Cunninghamii and 

 Acacia penninervis, at the period of fructification are highly 

 poisonous owing to a large amount of Saponin contained in the 

 unripe pods and in the leaves, whereas, at other times, the 

 saponin is practically absent, its place being taken up by 

 catechutannic acid. Another instance is given by the amount 

 of alkaloids contained in l^uboisia leaves. This was so small in 

 samples collected and examined by me in July, 1895, that a 

 strong infusion did not give a precipitate with tannin although 

 it was able to produce mydriasis in a cat's eye. 



Another fact in connection with principles obtained from 

 plants has to be mentioned here, the dependence of the plant 

 from the soil on which it n'rows and from the climate under the 



