Nov. 13,1916 
Vegetable-Ivory Meal 
303 
tested for the presence of lignin, but neither phloroglucinol nor anilin 
sulphate produced any color reaction whatever. As three-fourths of the 
vegetable ivory was found to be nitrogeh-free extract, it was to this 
portion that the most attention was given. 
It has long been known that the greater part of the carbohydrate 
material consists of mannose, or, more accurately speaking, mannan, its 
anhydrid condensation product. 
The isolation of mannose was carried out practically as described by 
Fischer and Hirschberger (7). One hundred gm. of vegetable-ivory meal 
were digested on the water bath with reflux condenser for six hours with 
200 c. c. of 6 per cent hydrochloric acid. The liquid was then filtered 
off, the filtrate and washings neutralized with sodium hydroxid, and 
shaken out several times with carbon black. After filtration, phenyl- 
hydrazin (dissolved in acetic acid) was added at the rate of 0.3 gm. for 
every gram of ivory meal used. The mannose phenylhydrazone sepa¬ 
rated out on standing for 24 hours in the cold as a heavy, fine-grained, 
buff-colored precipitate. This was washed with cold water and dried 
in a vacuum at room temperature. Particles of this impure hydrazone 
when placed in a capillary tube and heated slowly in a sulphuric-acid 
bath melted at 183° C. 
A portion of the precipitate was purified by boiling for a long time with 
a large volume of 95 per cent alcohol, filtering, and again boiling with 
fresh alcohol until at the end of two days an almost snow-white hydrazone 
resulted. This melted at 196° C., demonstrating the existence of man¬ 
nose or its polymer mannan in vegetable ivory. 
To liberate mannose from its phenylhydrazone, a portion of the latter 
was digested with benzaldehyde and alcohol until crystals of benzaldehyde 
hydrazone formed. The mannose containing filtrate from these, after 
clarifying and evaporating to a sirup, was treated with absolute alcohol 
and set aside to crystallize. The mannose crystals obtained had a melting 
point of 132 0 C. 
Pentosans were determined by the hydrochloric-acid distillation 
method and precipitation with phloroglucinol. The average of three 
determinations was 2.43 per cent of the dry matter. 
Repeated attempts to produce mucic acid by oxidation with nitric 
acid proved futile. The exact method for the detection and determi¬ 
nation of galactan was carried out always with negative results. 
Microscopic examination with iodin failed to give the slightest evidence 
of starch, either in the white fleshy part of the nut or in the brown outer 
coating. 
Dextrose (or dextran) was shown to be absent in vegetable ivory by 
its inability to form saccharic acid. As a check on the method used, a 
sample of pure glucose was treated exactly as was the ivory meal. No 
difficulty was experienced in obtaining the saccharic acid from the check. 
