176 



HARDWICKE'S SCIENCE-GOSSIP. 



[Aug. 1, 1870. 



HASAN-i-YUSAF. 



ONE of the obscure substances occasionally and 

 locally employed in India for medicinal pur- 

 poses by the natives is known by the name of 

 " Hasan-i-Yusaf." This is seldom mentioned, and 

 does not appear to be generally known in India 

 itself. Lahore, and probably Kashmir, seem to be 

 almost the only places where it has any reputation ; 

 and for what diseases it is supposed to be a remedy, 

 we have no information. After some ineffectual 

 attempts, we at length succeeded, through the 

 kindness of Dr. J. L. Stewart, in obtaining a 

 sample of this drug by post from Mr. B. Powell, 

 of Lahore. 



The description of this substance given by Honig- 

 berger in his " Thirty-five Years in the East " is 

 very brief. "Hossen Jussif," he writes, "is 

 officinal in Lahore. It is a whitish seed of the 

 smallest size, very likely to be mistaken for unripe 

 poppy-seeds." In reference to this, there is a note 

 in the " Handbook of the Economic Products of 

 the Punjab" (p. 384), to the effect that the 

 " Hasan-i-Yusaf is a minute, siliceous shell of a tri- 

 angular form, found floating on lakes and ponds in 

 the hills of Cashmir, whence it is skimmed off and 

 dried. Erroneously described by Honigberger and 

 others as a seed." A little more explicit infor- 

 mation on the same subject is given in another 

 portion of that work (p. 320). Repeating the name 

 as "Hussan Yusuf," it states :— "This is a very in- 

 teresting specimen of the siliceous frustule of one 

 of the Liatomacece. It is of a pyramidal form, with 



Fig. 1 65. " Hasan-i-Yusaf " from Kashmir. 



a convex base, and on each triangular face is a pro- 

 minent rounded knot. These markings are not 

 affected by acids, and remain after heating to red- 

 ness. When heated in a reduction-tube, it gives off 

 a peculiar smell and combustible gas, showing that 

 it is quite in a fresh state; otherwise it appears 

 somewhat similar to a fossil. 'Hussan Yusuf is 



collected in lakes and ponds in the hills around 

 Srinagar, in Kashmir. It floats on the surface, and 

 is skimmed off and dried " (fig. 165). 



A momentary glance is quite sufficient to convince 

 any one practically acquainted with the Biatomacece 

 that this white granular powder is not composed of 

 diatoms, and has no affinity with the DiatomacecP 

 whatever. It was suggested that it might be 

 foraminiferous, to which there is a greater re- 

 semblance. Fortunately we sent a little to Dr. 

 Henry Carter, E.R.S., who was well acquainted 

 with microscopic objects in India, and foraminifera 

 in particular. This gentleman at once suggested 

 its affinity with the spores of Selaginella, and 

 furnished for comparison those of Selaginella cernua, 

 referring at the same time to the figure at page 436 

 of the " Micrographical Dictionary." The spores of 

 Selaginella are almost identical in size, but more 

 globose, less definitely ribbed, and, although allied 

 are not alike. Keeping in view the place at which 

 this substance is said to be collected, "from the 

 surface of lakes," it occurred to us at once that some 

 species of Isoetes would be the probable source. 

 There being a family relationship between Selagi- 

 nella and Isoetes, it seemed probable that the spores 

 of Isoetes would resemble those of Selaginella and the 

 " Hasan-i-Yusaf." A reference to the figures of the 

 fruit of Isoetes capsularis, in Griffith's "Icones 

 Plantarum Asiaticarum," part 2, plates 116 to 11 S, 

 has confirmed the opinion that the curious sub- 

 stance, instead of being a diatom, consists of the 

 macrospores of a species of Isoetes, allied to, even 

 if not identical with, the Isoetes capsularis of Rox- 

 burgh, or the common European species. Especially 

 should figure 4 of the 116th plate be compared with 

 the "Hasan-i-Yusaf" (fig. 166). It is, moreover, 

 perfectly true that this substance does not appear to 

 be at all influenced by contact with cold nitric acid ; 

 and even when subjected to boiling in acid, very slow 

 and gradual, as well as imperfect, disintegration 

 takes place, unless the spores are first broken up. 

 This fact, however, is by no means fatal to the con- 

 clusion that they are Isoetes spores, in which, if we 



Fig. 166. Spores of Isoetes capsularis from Griffith's "Icones 

 Plantarum." Facsimile from Plate 116. 



mistake not, a similar result will accrue, at least if 

 we may judge from the treatment of Selaginella 

 spores with cold acid. 



Perhaps the strongest evidence of all is that fur- 

 nished by the "Flore d'Algerie," the 36th and 



