ALSTON 285 



1720 was able to begin his botanical lectures in the Garden, 

 followed in November by a course on Materia Medica. These 

 courses he carried on until 1739 when he was given the Uni- 

 versity Chair of Botany and Materia Medica, and the two 

 Botany Schools were thus merged in one. Alston was now 

 colleague of Munro, Rutherford, Sinclair, and other famous men 

 who at this time were increasing the reputation of the University 

 as a Medical School, and he continued to teach Botany and 

 Materia Medica until his death in 1760. 



Alston's teaching was mainly directed to the Materia Medica. 

 His full course of lectures on the subject prepared for publica- 

 tion by himself appeared only as a posthumous work edited by 

 his successor Dr Hope, and they reflect the best knowledge of 

 the time, showing rational scepticism of the efficacy of many 

 simples which experiment had not tested. Essays "On Opium," 

 and " On tin as anthelmintic," and an " Index of Simples ' 

 published by him tell of his pharmacological investigations, to 

 which his correspondence with Fothergill and others is also 

 witness. The subject in this line to which he gave most attention 

 and on which he wrote three dissertations based on experiments 

 is that of Quicklime and Water its efficacy in Calculus and 

 also as an agent for keeping water sweet. From Alston, Stephen 

 Hales, then in touch with the Admiralty upon questions of venti- 

 lation and other matters of sanitation, obtained early suggestions, 

 and a long correspondence followed. 



Alston, who had to earn his livelihood by medical practice, 

 gave much time to the administration of the Botanic Gardens 

 under his charge, and the elaborate lists which he prepared 

 showing the disposition of plants in the Gardens, witness to 

 his interest in their cultivation. His predilection in systematic 

 arrangement was Tournefortian, and on the promulgation by 

 Linnaeus of his "sexual system " in 1736, no writer was more 

 trenchant than Alston in opposition to it, and by this he 

 became widely known. His criticism was directed against it, 

 not as a method of arranging plants by readily recognised 

 characters, but from the standpoint of denial of the existence 

 of sex. By various experiments as well as by argument, 

 Alston endeavoured to disprove the necessity of the stamens 



