H. 31.

Vaccine Laboratory. It is satisfactory to be able to report that our difficulties with regard to the weakness of the vaccine lymph mentioned in last year's report have been to a great extent overcome, and, as the accompanyingtable shows, the percentage of case-success has risen to 91 per cent. This figure we may hope to see improved in future, as the influence of the alteration in methods which brought about the improvement did not extend to the whole of the past year. The principal cause of failure we found to be a very simple matter —namely, the sudden changes in the temperature to which the lymph was exposed. Lymph taken straight from our ice-chest and submitted to a temperature of 90° Fahr. or so in the postal bags during summer produced very unsatisfactory results. If the change is made gradually, less deterioration takes place. For comparative purposes, some imported lymph of a well-known maker was obtained and distributed throughout the Dominion. The returns from this lymph showed only 58 per cent, of successful eases, thus affording proof that it was more satisfactory to prepare our own lymph for local use.

Return showing Results of Vaccine Lymph for Year 1908-9.

The following matters, apart from laboratory work, occupied my attention during the year : — A report on the question of the suitability of tree-planting camps for consumptives was prepared after visiting the work being done by the Forestry Department in the Rotorua district. Further investigations were made into the question of regulations for the control of carbon-monoxide-producing plants. It was finally decided that, in view of the varying conditions met with, it was advisable that the control should be in the hands of the Inspectors of Machinery, and a series of model regulations was drawn up for their guidance. A special investigation was made into the growth and prevention of moulds in freezing-chambers. Air analysis : The ventilation of the Otira Tunnel works was the subject of a series of observations. An examination was made of the air in the hold of a vessel on which a fire had taken place. During the absence of Dr. Mason, in October, the Head Office was in my charge. During the latter end of February some time was devoted in assisting the police in the recovering of corpses subsequent to the wreck of the " Penguin " at Terawhiti. I have, &c, R. H. Makgill. Dr. J. M. Mason, Chief Health Officer, Wellington. Bacteriologist.

71

i Rem; irks. Series. Number of Tubes issued. Number of Scarify ations to which Lymph was applied. Number of Vesicles obtained. Percentage. ('a.ses done. Percentage. Cases successful. .„ I Chloroformed i Glycerinized . . i Chloroformed i Glycerinized . _ i Chloroformed I Glycerinized ,,, i Chloroformed i Glycerinized , - i Chloroformed i Glycerinized . „ i Chloroformed i Glycerinized . q I Chloroformed i Glycerinized 50 Glycerinized ■ r )l 52 53 54 .)O „ 56 483 264 221 381 468 315 i no (iio 332 30 321 204 30 442 183 786 355 430 210 834 516 483 264 221 381 468 315 i no (iio 332 30 321 204 30 442 183 786 355 430 210 834 516 160 221 172 315 299 309 167 193 232 18 144 65 18 139 286 502 64 115 84 577 21 76 177 156 295 268 296 133 176 221 18 135 50 18 92 183 398 32 115 83 476 16 47-5 80-09 90-7 93-6 89-6 95-8 79-6 911 95-2 100-0 93-7 76-9 100-0 66-1 63-9 79-2 50-0 100-0 98-8 82-4 76-2 58 71 58 106 111 112 48 69 76 6 51 23 6 42 92 163 21 46 31 177 7 37 68 57 104 106 111 41 65 76 6 50 20 6 36 77 143 13 46 31 163 J 6 63-8 95-7 98-2 98-1 95-4 99-1 85-4 94-2 100-0 100-0 98-0 87-0 100-0 85-7 83-6 87-7 61-9 100-0 100-0 92-09 85-7 Total 7,565 7,565 4,101 3,414 83-2 1,374 1,262 91-8