LfiNNEAN SOCEETY OF LONDOX. 95 



though the System of Classification which tliey are all designed to 

 support is ueither in practical use nor perhaps more natural than 

 many other proposed systems. 



Mr. B. Clarke also made many experiments with new vegetable 

 therapeutic agents, and was much interested in advocating the 

 isolation (by police regulations) of patients suffering from in- 

 fectious diseases. 



His simplicity of character, and pure devotion to scientific 

 inquiry, commanded the sympathy of all with whom he came in 

 contact. 



He was elected Fellow of the Society May 6th, 1845. 



Joshua Claeke, elder brother of the foregoing, was born 10th 

 April, 1805, and died at Saffron AValden on 27th February, 1S9L). 

 Although it was never directly acknowledged, it is nevertheless 

 true, that Joshua Clarke was the instigator of Gibson's ' Flora 

 of Essex,' in the preface of which we read, that "... he has 

 studied its botany for more than thirty years." This was written 

 in 1862, and puts on record the attention to Essex botany paid 

 by our late Fellow for so long a time. 

 He was elected 18th January, 1853. 



CossoK, Ernest, was born in 1819, and was the son of a well-to-do 

 father engaged in commercial pursuits, w-ho, seeing that his son 

 had bat little liking for his own calling, allowed him to study 

 medicine, and young Cosson in due time took his degree of M.D. 

 He had hardly reached the age of tvventj^ when he allied him- 

 self with Germain de St. Pierre in a work on certain critical 

 plants growiug in the vicinity of Paris, which came out in 1810, 

 followed two years later by a more general work on the flora of 

 that neighbourhood, Weddell also taking part in this venture. 

 With the same coadjutors he issued in 1813 a catalogue of the 

 vascular plants of the locality, and in the next he brought out 

 his w^ell-known ' Flore descriptive et analytique des environs 

 de Paris,' which reached a third edition in 1876. After a 

 few small contributions to the same subject, he published in 

 1852 his first work on that flora which he was destined to make 

 so peculiarly his own, ' Eapport sur uu voyage botanique en 

 Algerie ; ' an-d thenceforward his efforts were almost wholly 

 confined to the Flora of Northern Africa, either by himself or 

 Avith his helpers, Louis Kralik, and Durieu de Maisonueuve. 

 Altogether he made ten journeys in the northern pavis of Africa, 

 fur the accumulation of immense materials for his intended great 

 work on a general account of the Mediterranean region of 

 Africa. A preliminary volume on some introductory details saw 

 the light in 1881, and the first descriptive volume of the great work 

 in 1883-87 ; but the plan sketched out was on too extensive a scale 

 to permit of the hope of its ever being finished by Cosson; at the 

 rate of publication it would have needed close upon thirty years* 

 labour to complete it. Four fasciculi of plates were issued in 

 1882-90. 



