THE ORCHID REVIEW. 233 
The method adopted was that of analysing plants of this Cattleya when 
imported in 1891, and others after six years’ culture, in 1897, at the end of 
the period of degeneration. The results are given in comparative tables, from 
which we see that the latter has less dry material, organic matter, potash, 
lime, magnesia, phosphoric acid, and nitrogen, with an increase in the 
amount of water, sulphuric acid, and two or three other matters, some of 
which were only present as traces in the imported plants. They then 
analysed the flowers and found them to contain very similar elements to 
those which had diminished in the cultivated plants, showing that the 
degeneration is largely attributable to the exhaustion caused by the production 
of flowers, without any means being taken to compensate the plants for the 
loss. The conclusions which they arrive at is that, in order to counteract 
this degeneration, Cattleyas should receive a mixture of suitable manures, 
containing nitrogen, phosphoric acid, potash, lime, and magnesia. 
We may take these indications as conclusive, and the question now for 
us is, as practical men, how may these elements be most successfully 
applied ? 
CHEMICAL COMPOSITION OF CATTLEYA. 
Two papers, prepared by Mr. Smee, were laid before the Scientific 
Committee of the Royal Horticultural Society, on July 13th, by Mr. Veitch, 
to whom they had been addressed as Chairman of the Orchid Committee. 
The first contained some figures connected with the composition of the 
atmosphere ; analyses of old and young pseudobulbs were also given; and 
of the flower, including observations upon the colouring matters of plants. 
Professor A. Church, having given careful consideration to the first of the 
two papers, reserving the second for a future meeting, remarked that Mr. 
Smee had scarcely paid sufficient attention to the more recent analyses of 
the atmosphere and of rain; the amount of CO, in the free air over land 
and sea being now found to be almost absolutely uniform everywhere 
(except where locally contaminated), and less in quantity than three parts in 
10,000, so that no conclusions could be drawn from the data furnished in 
the paper on this point. With regard to the amount of ammonia in the air, 
it is so infinitesimally small in quantity that it can only be estimated by the 
most modern and refined chemical operations, so that he was obliged to 
express some hesitation in accepting Mr. Smee’s statements on this point. 
With regard to Mr. Smee’s analysis of pseudobulbs and of flowers, Prof. 
Church said that they agreed fairly well with average results hitherto 
obtained from terrestrial and epiphytic plants, but he thought that the 
percentage of undermined ash constituents—viz., about one half, was far too 
great, and he questioned the presence of aluminium, observing that though 
