320 Mary Davies Swartz, 



The products of hydrolysis were dextro-rotatory and contained 

 sugar fermentable with yeast. A rich yield of mannose-hydrazone 

 was obtained with phenyl-hydrazine acetate, melting on recrystalliza- 

 tion at 188° C. According to Thamm (276), salep extract yields ex- 

 clusively mannose on complete hydrolysis. 



Hydrolyzed for three hours, the reducing power of this mannan was 

 91.6 per cent. 



Determinations of ash, moisture, starch, and mannan were made on 

 the salep obtained in the form of a powder. Starch and mannan were 

 determined as follows: 1 gram of air dry powder was boiled in 250 cc. 

 water, and after cooling to 37.5° C, the starch hydrolyzed with malt 

 diastase, dialyzed sugar-free. The solution was then filtered, con- 

 centrated to small volume, and the mannan precipitated with absolute 

 alcohol. The precipitate was filtered off, dissolved in a little water 

 and reprecipitated, to obtain any sugar retained in the first precipi- 

 tation. The mannan was then dried at 100° C. and weighed. The 

 filtrates were combined, freed from alcohol, hydrolyzed with 2 per 

 cent hydrochloric acid 45 minutes to convert all the maltose to dextrose, 

 and sugar determined by Allihn's method. The results of these analy- 

 ses are shown in the following table: 



Per cent Per cent 



Moisture . 77 Starch 26 . 4 



Ash 8.9 Mannan 19.5 



According to Dragendorf^ the composition of Orchis tubers is as 

 follows : 



Per cent Per cent 



Starch... 27.3 Protein 4.9 



Mucilage 48. 1 Cellulose 2.4 



Sugar 1.2 



Thamm also reports a jdeld of 40^5 per cent mucilage from the 

 salep powder used in his investigations. Hence the powder used in 

 this the present experiment was for some reason very deficient in 

 mannan. 



Its reducing power was as follows: 



TIME OF BOILING. SUGAR AS DEXTROSE. 



Hours. Per cent 



2 74.2 



3 75.8 

 5 75.8 



^Cited in the National Dispensator}^ (1884), also by Thamm (276). 



