286 THE AMERICAN MONTHLY [Sept 



Paste For Labelling on Tin. — ^The tin surface is first 

 coated thinly with shellac after which there is no difficulty 

 in making- labels adhere. If a coating- of shellac is then ap- 

 plied over the label, in which case wliite shellac should be 

 used, the label may be washed. 



To Determine the Genuineness of Ivory. — When put in 

 concentrated sulphuric acid for twelve or fifteen minutes 

 g-enuine animal ivory retains its white color, while veg-eta- 

 ble ivory, from the phytelepas macrocarpra, assumes a 

 pink color, which may be removed by washing- with water. 



How to Make Paper ^A^aterproof.^ — The sheet is coated 

 on both sides with a solution consisting- of one part g-elatin, 

 four parts water, and one part g-lycerin. When dry, the 

 paper is immersed in a 10 per cent solution of formalin. 

 After this treatment the paper is said to become impervi- 

 ous even to steam. 



BACTERIOLOGY. 



A New Stain for the Bacillus Tuberculosis. — In view 

 of the fact that Sudan III has been found a useful stain for 

 fat in histolog-ical and patholog-ical work, Marion Dorset has 

 applied it to the tubercular bacilli with excellent results,as 

 demonstrated by the excellent cuts with which his article 

 is illustrated. The technique is carefully described in N. 

 Y. Medical Journal, Feb. 4, 1899. 



Mosquitoes and Malaria. — In the Annales de ITnstitute 

 Pasteur for February, 1899, Ronal Ross, of the Indian 

 military service of Calcutta, presents the results of a 

 leng-thy series of examinations on this question. He states 

 that the plasmodium may be found in the stomach of the 

 mosquito; that it can g-row there and can develope what 

 have been called spore-threads. These may also be found 

 in the poison sac of the mosquito, and from this may be 

 conveyed to man in the sting-. He thinks he has been able 

 to follow the cycle throug-hout its various stagfes. He has 

 been unable to show, by any yet developed technical pro- 

 cedures, the spore-threads in the poison sac, nor has he 



