397 



April 8. Mr. James Mc'Nab made a communication " On some 

 anomalous methods of cultivating plants in hot-houses." This com- 

 munication, with several illustrative wood-cuts, appeared in the ' Gar- 

 deners' Chronicle ' for August 14, 1841. The plants experimented 

 on were Ficus elastica, Polypodium am-eum, Acrostichum alcicome, 

 Euphorbia splendens and Bilbergia nudicaulis. The roots were first 

 denuded of the soil ; the plants of Ficus were suspended from the roof 

 in various ways, with their roots entirely exposed ; the Polypodium, 

 Acrostichum and Euphorbia had their roots covered ^\'ith moss, they 

 were then suspended from the roof in an inverted position. All the 

 plants thus treated grew well, and the ferns had a very handsome 

 appearance. 



July 8. Dr. Douglas Maclagan read a notice of the Chemical Con- 

 stitution of the Fruit of a species of Phytelephas, commonly called 

 " Vegetable Ivory." This fruit is the product of a South American 

 plant, and has lately been much used as a substitute for ivory. The 

 seed is triangular, from l^- to 2^ inches long and from 1 to 2 broad; 

 its substance is hard, and closely resembling ivory in its physical cha- 

 racters. The specimen examined, on being cut across, was found to 

 have a cavity in the centre, the walls of which were soft and yielded to 

 the nail. A portion of the white matter, including part of both the soft 

 and hard substance, was analysed by the action of cold and hot water, 

 alcohol, and subsequent incineration. The constituents of the portion 

 examined are then stated, with their several proportions; and the results 

 of a subsequent analysis of the ashes are also given. The notice is 

 concluded with the statement that " from these experiments it ap- 

 peared that there was nothing in the chemical constitution of the ve- 

 getable ivory, which could account for its hardness, which must be 

 due only to a peculiar texture in the woody fibre." — p. 131. 



Art. XCYll.— Varieties. 



222. Note on Primulas. I have no other observation to make on the common yel- 

 low Primulae, than that in the district haunted by me, in canton Appenzell, varying 

 from 3000 to 8000 feet above the sea, not a specimen of P. veris (cowslip), or P. vul- 

 garis (primrose), was to be seen, or, by the most diligent enquiry, had ever been heard 

 of, that I could find. P. elatior (oxlip) was everywhere over the meadows, peeping up 

 among the very earliest, on the first warm patches cleared of snow in February, and 

 continuing to gladden the eye, more or less sparingly, according to the altitude and 

 protection, until all is again covered up with snow in November. P. veris abounded 



