116 Proceedings of Royal Society of Edinburgh. [sess. 
reached a stage of comparative perfection, so that we are now 
certain of sending out from the laboratory vaccine which is pure- 
and sterile, and capable, when used in the doses prescribed, of pro- 
ducing a uniform protective effect in those on whom it is used. 
Unfortunately this new laboratory was not in existence when the 
Indian Plague Commission visited India, and in consequence there 
will be found in their report, recently published, various criticisms 
of the processes then employed which are now no longer applicable,, 
as I hope to show presently. 
Fig. 1 . — Old Government House, Pare! 
A description of the preparation of the prophylactic will serve 
to illustrate the size of the laboratory and the difficulties that had 
to be overcome by Mr Haffkine and his staff in suiting themselves 
to the conditions of Oriental life, and the religious and other pre- 
judices of the natives. 
The plague prophylactic is essentially a culture in broth of the 
plague bacillus, thus differing entirely from the curative serums 
which are produced by the action of the bacillus on a living 
animal. 
The preparation of the culture medium or bouillon is the first 
