“Find that, whatever issues may be granted for trying this case, the proposal of Mrs Armstrong, and declaration herein referred to, form the basis of the contract in the policy of insurance in question, and import a warranty only to the effect that the declarant was, and has been, according to her own knowledge and reasonable belief, free from any disease or symptom of disease material to the risk, and that they do not import a warranty against any latent and imperceptible disease that only could be discovered by post-mortem examination, or from symptoms disclosing themselves at an after period of time.”