320 ANNUAL OF SCIENTIFIC DISCOVERY 



DENTAL PARASITES. 



AT a meeting of the American Academy, December, 1849, a pa- 

 per was read by Dr. H. I. Bowditch, on the animal and vegetable 

 parasites infesting the teeth, with the effects of different agents in 

 causing their removal and destruction. Microscopical examinations 

 had been made of the matter deposited on the teeth and gums of 

 more than forty individuals, selected from all classes of society, in 

 every variety of bodily condition, and in nearly every case animal and 

 vegetable parasites in great numbers had been discovered. Of the 

 animal parasites there were three or four species, and of the vegeta- 

 ble one or two. In fact, the only persons whose mouths were found 

 to be completely free from them cleansed their teeth four times 

 daily, using soap once. One or two of these individuals also passed 

 a thread between the teeth to cleanse them more effectually. In all 

 cases the number of parasites was greater in proportion to the neglect 

 of cleanliness. 



The effect of the application of various agents was also noticed. 

 Tobacco juice and smoke did not impair the vitality of the parasites in 

 the least. The same was also true of the Chlorine Tooth-wash, of pul- 

 verized bark, of soda, ammonia, and various other popular detergents. 

 The application of soap, however, appeared to destroy them instantly. 

 We may hence infer that this is the best and most proper specific for 

 cleansing the teeth. In all cases where it has been tried, it receives un- 

 qualified commendation. It may be also proper to add, that none but 

 the purest white soap, free from all discolorations, should be used. 



BLOOD-SPOTS ON HUMAN FOOD. 



FROM the siege of Tyre, when Alexander was alarmed by the ap- 

 pearance of bloody spots on the soldiers' bread, to the year 1848, 

 when a similar phenomenon was noticed at Berlin, public attention 

 has been at various times attracted by red discolorations in different 

 sorts of food, and the credulous have ascribed them to a miracle, 

 while others have doubted whether their pretended appearance \vas 

 not the effect of an excited imagination. But in 1819, M. Sette ex- 

 amined some of these spots, and discovered that they were formed by 

 myriads of small bodies, which appeared to be microscopic fungi, and 

 he reported that they were so. In 1848, Ehrenberg's attention was 

 attracted to some of these blood-spots in food, and he commenced 

 studying them, and he now believes them to be, not fungi, but ani- 

 malcules. These little beings appear as corpuscles, almost round, of 

 "s'oVo" to ToVir f a l me m length, transparent when separately ex- 

 amined, but in a mass of the color of blood. M. Ehrenberg calculates 

 that in a space of a cubic inch there are from 46,656,000,000,000 

 to 884,836,000,000,000 of these monads. Medical Times. 



THE UNICORN. 



THE London Atlicnccum says that M. Antoine d'Abbadie, writing 

 from Cairo, gives the following account of an animal new to Euro- 



