Br JAMES ir. PETRIE. "1-19 



was seen tu <lrag- the liind legs slightly but otherwise it was apparently- ^\-ell. It 

 died two days afterwards. There was no other food available Init the fresh leaves 

 of Heterodendron. 



On the same station, in 1920, when the drought was very severe, and the 

 stock were being- fed almost entirely on this one plant, the animals died at the 

 rate of one or two each day. In June, on Locharino station, a Rosebush was cut 

 m the afternoon for 15 cattle, and towards evening- the whole 1.5 were ill. They 

 were treated for some hours with warm water and salt, and in a few days 1-2 had 

 recovered. In every case the animals showed frothing at the nose and mouth. 



The record from Narrabri district may also be given. The plant is known 

 here as the "Boonery tree," and is much used for feeding- stock in times of 

 drought. It is considered by the stockmen to be a good edible shrub, and the 

 animals are said to be very fond of it. The Stock Inspector informed the writer, 

 however, that frei|uently numbers of sheep died suddenly when first fed on the 

 leaves, more especially if rain fell at the same time. 



On one cattle station in this district, in 1919. a stock-owner lost G cattle. 

 They died suddenly, succumbing without a struggle. On another station in the 

 same locality, a number of cattle died suddenly. They were seen to eat the 

 suckers, or young- growth of the Boonery trees, which had been topped for 

 cattle food during- the previous year. 



Prelimixaet Te.sts. 



In the first samples which were tested it was proved that no poisonous alka- 

 loid or other group of well-known active principles w'as present. However, on 

 allowing the crushed leaves to macerate with water for a few hours, free hydro- 

 cyanic acid -was detected in the solution. The presence of hydrocyanic acid was 

 confirmed by the almost iimnediate change of colour of the sodium picrate test- 

 paper, and by the formation of prussian blue. The powerful reaction obtained 

 by testing- quite a small quantity, even a single leaf, was sufficient to indicate 

 the presence of a considerable amount of some poisonous eyauogeuetic compound. 



In the list of trees whose foliage was used for feeding stock, two only -were 

 found to be cyanogenetic — i.e., to yield hydrocyanic acid when treated in the 

 manner described, — namely, the Rosebush and Wild Orange. In the latter, Cap- 

 paris Mitchell!, we have the first record of a cyanogenetic plant in the family 

 Capparidaceae. 



Heterodendron oleaefolia. — Samples were received from the Stock Inspectors 

 at various times and also from a number of station-owners. They were tested 

 in the following months, during the period 1915 to 1020. 



January, Gulargambone. 

 « February, Narrabri district. 



May, Coonamble district, 

 .lune, Coonamble district. 

 November, Coonamble district. 

 December, Gulargambone. 

 All these sam]iles were very strongly cyanogenetic. 



That the hydrocyanic acid was involved in the constitution of some cyano- 

 genetic glucoside was shown by its behaviour towards enzymes. 



fl) A small quantity of the leaf-powder was placed in two bottles with strips 

 of sodium picrate paper suspended from the corks: (ol to one was added a few 

 drops of chloroform, and (b) the other was left as a control. The result was 

 hvdrocvanic acid evolved from («) onlv. 



