A letter to the learned Caleb Cotesworth ... Containing, a comparison between the mortality of the natural small pox, and that given by inoculation ... To which is subjoined, an account of the success of inoculation in New England; as likewise an extract from several letters concerning a like method of communicating the small pox, that has been used time out of mind in South Wales A letter to the learned Caleb Cotesworth ... Containing, a comparison between the mortality of the natural small pox, and that given by inoculation ... To which is subjoined, an account of the success of inoculation in New England; as likewise an extract from several letters concerning a like method of communicating the small pox, that has been used time out of mind in South Wales