ment this study by microscopic work. Perhaps 
through the aid or some doctor or other scientist 
you may be able now to get a peep into this world 
of the unseen. 
If these les'sons point out dangers of which 
you were before unconscious, they also suggest 
ways of escape from those dangers. You will gain 
some knowledge of the causes of waste and disease 
If this leads you to efforts for the prevention 
and removal of such causes, *the result will be 
those healthful conditions which make the most 
effectual safeguard against the attacks of the 
few micro-organi3ms that are our foes. 
I hope the relations between hygiene and some 
of the daily tasks of housekeeping will gain a 
deeper significance in your mind; and this ele¬ 
mentary study may result not only in pleasure and 
profit to you, but also, through you, in better 
conditions of healthful living for others* 
Sincerely yours. 
Instructor 
